diff options
Diffstat (limited to 'fs/btrfs/volumes.c')
| -rw-r--r-- | fs/btrfs/volumes.c | 7855 |
1 files changed, 7855 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c new file mode 100644 index 000000000..eaf5cd043 --- /dev/null +++ b/fs/btrfs/volumes.c @@ -0,0 +1,7855 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2007 Oracle. All rights reserved. + */ + +#include <linux/sched.h> +#include <linux/sched/mm.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/blkdev.h> +#include <linux/ratelimit.h> +#include <linux/kthread.h> +#include <linux/raid/pq.h> +#include <linux/semaphore.h> +#include <linux/uuid.h> +#include <linux/list_sort.h> +#include <linux/namei.h> +#include "misc.h" +#include "ctree.h" +#include "extent_map.h" +#include "disk-io.h" +#include "transaction.h" +#include "print-tree.h" +#include "volumes.h" +#include "raid56.h" +#include "async-thread.h" +#include "check-integrity.h" +#include "rcu-string.h" +#include "dev-replace.h" +#include "sysfs.h" +#include "tree-checker.h" +#include "space-info.h" +#include "block-group.h" +#include "discard.h" + +const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = { + [BTRFS_RAID_RAID10] = { + .sub_stripes = 2, + .dev_stripes = 1, + .devs_max = 0, /* 0 == as many as possible */ + .devs_min = 4, + .tolerated_failures = 1, + .devs_increment = 2, + .ncopies = 2, + .nparity = 0, + .raid_name = "raid10", + .bg_flag = BTRFS_BLOCK_GROUP_RAID10, + .mindev_error = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET, + }, + [BTRFS_RAID_RAID1] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 2, + .devs_min = 2, + .tolerated_failures = 1, + .devs_increment = 2, + .ncopies = 2, + .nparity = 0, + .raid_name = "raid1", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1, + .mindev_error = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET, + }, + [BTRFS_RAID_RAID1C3] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 3, + .devs_min = 3, + .tolerated_failures = 2, + .devs_increment = 3, + .ncopies = 3, + .nparity = 0, + .raid_name = "raid1c3", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1C3, + .mindev_error = BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET, + }, + [BTRFS_RAID_RAID1C4] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 4, + .devs_min = 4, + .tolerated_failures = 3, + .devs_increment = 4, + .ncopies = 4, + .nparity = 0, + .raid_name = "raid1c4", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1C4, + .mindev_error = BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET, + }, + [BTRFS_RAID_DUP] = { + .sub_stripes = 1, + .dev_stripes = 2, + .devs_max = 1, + .devs_min = 1, + .tolerated_failures = 0, + .devs_increment = 1, + .ncopies = 2, + .nparity = 0, + .raid_name = "dup", + .bg_flag = BTRFS_BLOCK_GROUP_DUP, + .mindev_error = 0, + }, + [BTRFS_RAID_RAID0] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 2, + .tolerated_failures = 0, + .devs_increment = 1, + .ncopies = 1, + .nparity = 0, + .raid_name = "raid0", + .bg_flag = BTRFS_BLOCK_GROUP_RAID0, + .mindev_error = 0, + }, + [BTRFS_RAID_SINGLE] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 1, + .devs_min = 1, + .tolerated_failures = 0, + .devs_increment = 1, + .ncopies = 1, + .nparity = 0, + .raid_name = "single", + .bg_flag = 0, + .mindev_error = 0, + }, + [BTRFS_RAID_RAID5] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 2, + .tolerated_failures = 1, + .devs_increment = 1, + .ncopies = 1, + .nparity = 1, + .raid_name = "raid5", + .bg_flag = BTRFS_BLOCK_GROUP_RAID5, + .mindev_error = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET, + }, + [BTRFS_RAID_RAID6] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 3, + .tolerated_failures = 2, + .devs_increment = 1, + .ncopies = 1, + .nparity = 2, + .raid_name = "raid6", + .bg_flag = BTRFS_BLOCK_GROUP_RAID6, + .mindev_error = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET, + }, +}; + +const char *btrfs_bg_type_to_raid_name(u64 flags) +{ + const int index = btrfs_bg_flags_to_raid_index(flags); + + if (index >= BTRFS_NR_RAID_TYPES) + return NULL; + + return btrfs_raid_array[index].raid_name; +} + +/* + * Fill @buf with textual description of @bg_flags, no more than @size_buf + * bytes including terminating null byte. + */ +void btrfs_describe_block_groups(u64 bg_flags, char *buf, u32 size_buf) +{ + int i; + int ret; + char *bp = buf; + u64 flags = bg_flags; + u32 size_bp = size_buf; + + if (!flags) { + strcpy(bp, "NONE"); + return; + } + +#define DESCRIBE_FLAG(flag, desc) \ + do { \ + if (flags & (flag)) { \ + ret = snprintf(bp, size_bp, "%s|", (desc)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + flags &= ~(flag); \ + } \ + } while (0) + + DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_DATA, "data"); + DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_SYSTEM, "system"); + DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_METADATA, "metadata"); + + DESCRIBE_FLAG(BTRFS_AVAIL_ALLOC_BIT_SINGLE, "single"); + for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) + DESCRIBE_FLAG(btrfs_raid_array[i].bg_flag, + btrfs_raid_array[i].raid_name); +#undef DESCRIBE_FLAG + + if (flags) { + ret = snprintf(bp, size_bp, "0x%llx|", flags); + size_bp -= ret; + } + + if (size_bp < size_buf) + buf[size_buf - size_bp - 1] = '\0'; /* remove last | */ + + /* + * The text is trimmed, it's up to the caller to provide sufficiently + * large buffer + */ +out_overflow:; +} + +static int init_first_rw_device(struct btrfs_trans_handle *trans); +static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info); +static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev); +static void btrfs_dev_stat_print_on_load(struct btrfs_device *device); +static int __btrfs_map_block(struct btrfs_fs_info *fs_info, + enum btrfs_map_op op, + u64 logical, u64 *length, + struct btrfs_bio **bbio_ret, + int mirror_num, int need_raid_map); + +/* + * Device locking + * ============== + * + * There are several mutexes that protect manipulation of devices and low-level + * structures like chunks but not block groups, extents or files + * + * uuid_mutex (global lock) + * ------------------------ + * protects the fs_uuids list that tracks all per-fs fs_devices, resulting from + * the SCAN_DEV ioctl registration or from mount either implicitly (the first + * device) or requested by the device= mount option + * + * the mutex can be very coarse and can cover long-running operations + * + * protects: updates to fs_devices counters like missing devices, rw devices, + * seeding, structure cloning, opening/closing devices at mount/umount time + * + * global::fs_devs - add, remove, updates to the global list + * + * does not protect: manipulation of the fs_devices::devices list in general + * but in mount context it could be used to exclude list modifications by eg. + * scan ioctl + * + * btrfs_device::name - renames (write side), read is RCU + * + * fs_devices::device_list_mutex (per-fs, with RCU) + * ------------------------------------------------ + * protects updates to fs_devices::devices, ie. adding and deleting + * + * simple list traversal with read-only actions can be done with RCU protection + * + * may be used to exclude some operations from running concurrently without any + * modifications to the list (see write_all_supers) + * + * Is not required at mount and close times, because our device list is + * protected by the uuid_mutex at that point. + * + * balance_mutex + * ------------- + * protects balance structures (status, state) and context accessed from + * several places (internally, ioctl) + * + * chunk_mutex + * ----------- + * protects chunks, adding or removing during allocation, trim or when a new + * device is added/removed. Additionally it also protects post_commit_list of + * individual devices, since they can be added to the transaction's + * post_commit_list only with chunk_mutex held. + * + * cleaner_mutex + * ------------- + * a big lock that is held by the cleaner thread and prevents running subvolume + * cleaning together with relocation or delayed iputs + * + * + * Lock nesting + * ============ + * + * uuid_mutex + * device_list_mutex + * chunk_mutex + * balance_mutex + * + * + * Exclusive operations + * ==================== + * + * Maintains the exclusivity of the following operations that apply to the + * whole filesystem and cannot run in parallel. + * + * - Balance (*) + * - Device add + * - Device remove + * - Device replace (*) + * - Resize + * + * The device operations (as above) can be in one of the following states: + * + * - Running state + * - Paused state + * - Completed state + * + * Only device operations marked with (*) can go into the Paused state for the + * following reasons: + * + * - ioctl (only Balance can be Paused through ioctl) + * - filesystem remounted as read-only + * - filesystem unmounted and mounted as read-only + * - system power-cycle and filesystem mounted as read-only + * - filesystem or device errors leading to forced read-only + * + * The status of exclusive operation is set and cleared atomically. + * During the course of Paused state, fs_info::exclusive_operation remains set. + * A device operation in Paused or Running state can be canceled or resumed + * either by ioctl (Balance only) or when remounted as read-write. + * The exclusive status is cleared when the device operation is canceled or + * completed. + */ + +DEFINE_MUTEX(uuid_mutex); +static LIST_HEAD(fs_uuids); +struct list_head * __attribute_const__ btrfs_get_fs_uuids(void) +{ + return &fs_uuids; +} + +/* + * alloc_fs_devices - allocate struct btrfs_fs_devices + * @fsid: if not NULL, copy the UUID to fs_devices::fsid + * @metadata_fsid: if not NULL, copy the UUID to fs_devices::metadata_fsid + * + * Return a pointer to a new struct btrfs_fs_devices on success, or ERR_PTR(). + * The returned struct is not linked onto any lists and can be destroyed with + * kfree() right away. + */ +static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid, + const u8 *metadata_fsid) +{ + struct btrfs_fs_devices *fs_devs; + + fs_devs = kzalloc(sizeof(*fs_devs), GFP_KERNEL); + if (!fs_devs) + return ERR_PTR(-ENOMEM); + + mutex_init(&fs_devs->device_list_mutex); + + INIT_LIST_HEAD(&fs_devs->devices); + INIT_LIST_HEAD(&fs_devs->alloc_list); + INIT_LIST_HEAD(&fs_devs->fs_list); + INIT_LIST_HEAD(&fs_devs->seed_list); + if (fsid) + memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE); + + if (metadata_fsid) + memcpy(fs_devs->metadata_uuid, metadata_fsid, BTRFS_FSID_SIZE); + else if (fsid) + memcpy(fs_devs->metadata_uuid, fsid, BTRFS_FSID_SIZE); + + return fs_devs; +} + +void btrfs_free_device(struct btrfs_device *device) +{ + WARN_ON(!list_empty(&device->post_commit_list)); + rcu_string_free(device->name); + extent_io_tree_release(&device->alloc_state); + bio_put(device->flush_bio); + kfree(device); +} + +static void free_fs_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_device *device; + + WARN_ON(fs_devices->opened); + while (!list_empty(&fs_devices->devices)) { + device = list_entry(fs_devices->devices.next, + struct btrfs_device, dev_list); + list_del(&device->dev_list); + btrfs_free_device(device); + } + kfree(fs_devices); +} + +void __exit btrfs_cleanup_fs_uuids(void) +{ + struct btrfs_fs_devices *fs_devices; + + while (!list_empty(&fs_uuids)) { + fs_devices = list_entry(fs_uuids.next, + struct btrfs_fs_devices, fs_list); + list_del(&fs_devices->fs_list); + free_fs_devices(fs_devices); + } +} + +/* + * Returns a pointer to a new btrfs_device on success; ERR_PTR() on error. + * Returned struct is not linked onto any lists and must be destroyed using + * btrfs_free_device. + */ +static struct btrfs_device *__alloc_device(struct btrfs_fs_info *fs_info) +{ + struct btrfs_device *dev; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return ERR_PTR(-ENOMEM); + + /* + * Preallocate a bio that's always going to be used for flushing device + * barriers and matches the device lifespan + */ + dev->flush_bio = bio_alloc_bioset(GFP_KERNEL, 0, NULL); + if (!dev->flush_bio) { + kfree(dev); + return ERR_PTR(-ENOMEM); + } + + INIT_LIST_HEAD(&dev->dev_list); + INIT_LIST_HEAD(&dev->dev_alloc_list); + INIT_LIST_HEAD(&dev->post_commit_list); + + atomic_set(&dev->reada_in_flight, 0); + atomic_set(&dev->dev_stats_ccnt, 0); + btrfs_device_data_ordered_init(dev); + INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM); + INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM); + extent_io_tree_init(fs_info, &dev->alloc_state, + IO_TREE_DEVICE_ALLOC_STATE, NULL); + + return dev; +} + +static noinline struct btrfs_fs_devices *find_fsid( + const u8 *fsid, const u8 *metadata_fsid) +{ + struct btrfs_fs_devices *fs_devices; + + ASSERT(fsid); + + /* Handle non-split brain cases */ + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + if (metadata_fsid) { + if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0 + && memcmp(metadata_fsid, fs_devices->metadata_uuid, + BTRFS_FSID_SIZE) == 0) + return fs_devices; + } else { + if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0) + return fs_devices; + } + } + return NULL; +} + +static struct btrfs_fs_devices *find_fsid_with_metadata_uuid( + struct btrfs_super_block *disk_super) +{ + + struct btrfs_fs_devices *fs_devices; + + /* + * Handle scanned device having completed its fsid change but + * belonging to a fs_devices that was created by first scanning + * a device which didn't have its fsid/metadata_uuid changed + * at all and the CHANGING_FSID_V2 flag set. + */ + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + if (fs_devices->fsid_change && + memcmp(disk_super->metadata_uuid, fs_devices->fsid, + BTRFS_FSID_SIZE) == 0 && + memcmp(fs_devices->fsid, fs_devices->metadata_uuid, + BTRFS_FSID_SIZE) == 0) { + return fs_devices; + } + } + /* + * Handle scanned device having completed its fsid change but + * belonging to a fs_devices that was created by a device that + * has an outdated pair of fsid/metadata_uuid and + * CHANGING_FSID_V2 flag set. + */ + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + if (fs_devices->fsid_change && + memcmp(fs_devices->metadata_uuid, + fs_devices->fsid, BTRFS_FSID_SIZE) != 0 && + memcmp(disk_super->metadata_uuid, fs_devices->metadata_uuid, + BTRFS_FSID_SIZE) == 0) { + return fs_devices; + } + } + + return find_fsid(disk_super->fsid, disk_super->metadata_uuid); +} + + +static int +btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder, + int flush, struct block_device **bdev, + struct btrfs_super_block **disk_super) +{ + int ret; + + *bdev = blkdev_get_by_path(device_path, flags, holder); + + if (IS_ERR(*bdev)) { + ret = PTR_ERR(*bdev); + goto error; + } + + if (flush) + filemap_write_and_wait((*bdev)->bd_inode->i_mapping); + ret = set_blocksize(*bdev, BTRFS_BDEV_BLOCKSIZE); + if (ret) { + blkdev_put(*bdev, flags); + goto error; + } + invalidate_bdev(*bdev); + *disk_super = btrfs_read_dev_super(*bdev); + if (IS_ERR(*disk_super)) { + ret = PTR_ERR(*disk_super); + blkdev_put(*bdev, flags); + goto error; + } + + return 0; + +error: + *bdev = NULL; + return ret; +} + +/* + * Check if the device in the path matches the device in the given struct device. + * + * Returns: + * true If it is the same device. + * false If it is not the same device or on error. + */ +static bool device_matched(const struct btrfs_device *device, const char *path) +{ + char *device_name; + struct block_device *bdev_old; + struct block_device *bdev_new; + + /* + * If we are looking for a device with the matching dev_t, then skip + * device without a name (a missing device). + */ + if (!device->name) + return false; + + device_name = kzalloc(BTRFS_PATH_NAME_MAX, GFP_KERNEL); + if (!device_name) + return false; + + rcu_read_lock(); + scnprintf(device_name, BTRFS_PATH_NAME_MAX, "%s", rcu_str_deref(device->name)); + rcu_read_unlock(); + + bdev_old = lookup_bdev(device_name); + kfree(device_name); + if (IS_ERR(bdev_old)) + return false; + + bdev_new = lookup_bdev(path); + if (IS_ERR(bdev_new)) + return false; + + if (bdev_old == bdev_new) + return true; + + return false; +} + +/* + * Search and remove all stale (devices which are not mounted) devices. + * When both inputs are NULL, it will search and release all stale devices. + * path: Optional. When provided will it release all unmounted devices + * matching this path only. + * skip_dev: Optional. Will skip this device when searching for the stale + * devices. + * Return: 0 for success or if @path is NULL. + * -EBUSY if @path is a mounted device. + * -ENOENT if @path does not match any device in the list. + */ +static int btrfs_free_stale_devices(const char *path, + struct btrfs_device *skip_device) +{ + struct btrfs_fs_devices *fs_devices, *tmp_fs_devices; + struct btrfs_device *device, *tmp_device; + int ret = 0; + + lockdep_assert_held(&uuid_mutex); + + if (path) + ret = -ENOENT; + + list_for_each_entry_safe(fs_devices, tmp_fs_devices, &fs_uuids, fs_list) { + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry_safe(device, tmp_device, + &fs_devices->devices, dev_list) { + if (skip_device && skip_device == device) + continue; + if (path && !device_matched(device, path)) + continue; + if (fs_devices->opened) { + /* for an already deleted device return 0 */ + if (path && ret != 0) + ret = -EBUSY; + break; + } + + /* delete the stale device */ + fs_devices->num_devices--; + list_del(&device->dev_list); + btrfs_free_device(device); + + ret = 0; + } + mutex_unlock(&fs_devices->device_list_mutex); + + if (fs_devices->num_devices == 0) { + btrfs_sysfs_remove_fsid(fs_devices); + list_del(&fs_devices->fs_list); + free_fs_devices(fs_devices); + } + } + + return ret; +} + +/* + * This is only used on mount, and we are protected from competing things + * messing with our fs_devices by the uuid_mutex, thus we do not need the + * fs_devices->device_list_mutex here. + */ +static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices, + struct btrfs_device *device, fmode_t flags, + void *holder) +{ + struct request_queue *q; + struct block_device *bdev; + struct btrfs_super_block *disk_super; + u64 devid; + int ret; + + if (device->bdev) + return -EINVAL; + if (!device->name) + return -EINVAL; + + ret = btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1, + &bdev, &disk_super); + if (ret) + return ret; + + devid = btrfs_stack_device_id(&disk_super->dev_item); + if (devid != device->devid) + goto error_free_page; + + if (memcmp(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE)) + goto error_free_page; + + device->generation = btrfs_super_generation(disk_super); + + if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) { + if (btrfs_super_incompat_flags(disk_super) & + BTRFS_FEATURE_INCOMPAT_METADATA_UUID) { + pr_err( + "BTRFS: Invalid seeding and uuid-changed device detected\n"); + goto error_free_page; + } + + clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + fs_devices->seeding = true; + } else { + if (bdev_read_only(bdev)) + clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + else + set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + } + + q = bdev_get_queue(bdev); + if (!blk_queue_nonrot(q)) + fs_devices->rotating = true; + + device->bdev = bdev; + clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); + device->mode = flags; + + fs_devices->open_devices++; + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) && + device->devid != BTRFS_DEV_REPLACE_DEVID) { + fs_devices->rw_devices++; + list_add_tail(&device->dev_alloc_list, &fs_devices->alloc_list); + } + btrfs_release_disk_super(disk_super); + + return 0; + +error_free_page: + btrfs_release_disk_super(disk_super); + blkdev_put(bdev, flags); + + return -EINVAL; +} + +u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb) +{ + bool has_metadata_uuid = (btrfs_super_incompat_flags(sb) & + BTRFS_FEATURE_INCOMPAT_METADATA_UUID); + + return has_metadata_uuid ? sb->metadata_uuid : sb->fsid; +} + +/* + * Handle scanned device having its CHANGING_FSID_V2 flag set and the fs_devices + * being created with a disk that has already completed its fsid change. Such + * disk can belong to an fs which has its FSID changed or to one which doesn't. + * Handle both cases here. + */ +static struct btrfs_fs_devices *find_fsid_inprogress( + struct btrfs_super_block *disk_super) +{ + struct btrfs_fs_devices *fs_devices; + + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid, + BTRFS_FSID_SIZE) != 0 && + memcmp(fs_devices->metadata_uuid, disk_super->fsid, + BTRFS_FSID_SIZE) == 0 && !fs_devices->fsid_change) { + return fs_devices; + } + } + + return find_fsid(disk_super->fsid, NULL); +} + + +static struct btrfs_fs_devices *find_fsid_changed( + struct btrfs_super_block *disk_super) +{ + struct btrfs_fs_devices *fs_devices; + + /* + * Handles the case where scanned device is part of an fs that had + * multiple successful changes of FSID but curently device didn't + * observe it. Meaning our fsid will be different than theirs. We need + * to handle two subcases : + * 1 - The fs still continues to have different METADATA/FSID uuids. + * 2 - The fs is switched back to its original FSID (METADATA/FSID + * are equal). + */ + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + /* Changed UUIDs */ + if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid, + BTRFS_FSID_SIZE) != 0 && + memcmp(fs_devices->metadata_uuid, disk_super->metadata_uuid, + BTRFS_FSID_SIZE) == 0 && + memcmp(fs_devices->fsid, disk_super->fsid, + BTRFS_FSID_SIZE) != 0) + return fs_devices; + + /* Unchanged UUIDs */ + if (memcmp(fs_devices->metadata_uuid, fs_devices->fsid, + BTRFS_FSID_SIZE) == 0 && + memcmp(fs_devices->fsid, disk_super->metadata_uuid, + BTRFS_FSID_SIZE) == 0) + return fs_devices; + } + + return NULL; +} + +static struct btrfs_fs_devices *find_fsid_reverted_metadata( + struct btrfs_super_block *disk_super) +{ + struct btrfs_fs_devices *fs_devices; + + /* + * Handle the case where the scanned device is part of an fs whose last + * metadata UUID change reverted it to the original FSID. At the same + * time * fs_devices was first created by another constitutent device + * which didn't fully observe the operation. This results in an + * btrfs_fs_devices created with metadata/fsid different AND + * btrfs_fs_devices::fsid_change set AND the metadata_uuid of the + * fs_devices equal to the FSID of the disk. + */ + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + if (memcmp(fs_devices->fsid, fs_devices->metadata_uuid, + BTRFS_FSID_SIZE) != 0 && + memcmp(fs_devices->metadata_uuid, disk_super->fsid, + BTRFS_FSID_SIZE) == 0 && + fs_devices->fsid_change) + return fs_devices; + } + + return NULL; +} +/* + * Add new device to list of registered devices + * + * Returns: + * device pointer which was just added or updated when successful + * error pointer when failed + */ +static noinline struct btrfs_device *device_list_add(const char *path, + struct btrfs_super_block *disk_super, + bool *new_device_added) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *fs_devices = NULL; + struct rcu_string *name; + u64 found_transid = btrfs_super_generation(disk_super); + u64 devid = btrfs_stack_device_id(&disk_super->dev_item); + bool has_metadata_uuid = (btrfs_super_incompat_flags(disk_super) & + BTRFS_FEATURE_INCOMPAT_METADATA_UUID); + bool fsid_change_in_progress = (btrfs_super_flags(disk_super) & + BTRFS_SUPER_FLAG_CHANGING_FSID_V2); + + if (fsid_change_in_progress) { + if (!has_metadata_uuid) + fs_devices = find_fsid_inprogress(disk_super); + else + fs_devices = find_fsid_changed(disk_super); + } else if (has_metadata_uuid) { + fs_devices = find_fsid_with_metadata_uuid(disk_super); + } else { + fs_devices = find_fsid_reverted_metadata(disk_super); + if (!fs_devices) + fs_devices = find_fsid(disk_super->fsid, NULL); + } + + + if (!fs_devices) { + if (has_metadata_uuid) + fs_devices = alloc_fs_devices(disk_super->fsid, + disk_super->metadata_uuid); + else + fs_devices = alloc_fs_devices(disk_super->fsid, NULL); + + if (IS_ERR(fs_devices)) + return ERR_CAST(fs_devices); + + fs_devices->fsid_change = fsid_change_in_progress; + + mutex_lock(&fs_devices->device_list_mutex); + list_add(&fs_devices->fs_list, &fs_uuids); + + device = NULL; + } else { + mutex_lock(&fs_devices->device_list_mutex); + device = btrfs_find_device(fs_devices, devid, + disk_super->dev_item.uuid, NULL, false); + + /* + * If this disk has been pulled into an fs devices created by + * a device which had the CHANGING_FSID_V2 flag then replace the + * metadata_uuid/fsid values of the fs_devices. + */ + if (fs_devices->fsid_change && + found_transid > fs_devices->latest_generation) { + memcpy(fs_devices->fsid, disk_super->fsid, + BTRFS_FSID_SIZE); + + if (has_metadata_uuid) + memcpy(fs_devices->metadata_uuid, + disk_super->metadata_uuid, + BTRFS_FSID_SIZE); + else + memcpy(fs_devices->metadata_uuid, + disk_super->fsid, BTRFS_FSID_SIZE); + + fs_devices->fsid_change = false; + } + } + + if (!device) { + if (fs_devices->opened) { + mutex_unlock(&fs_devices->device_list_mutex); + return ERR_PTR(-EBUSY); + } + + device = btrfs_alloc_device(NULL, &devid, + disk_super->dev_item.uuid); + if (IS_ERR(device)) { + mutex_unlock(&fs_devices->device_list_mutex); + /* we can safely leave the fs_devices entry around */ + return device; + } + + name = rcu_string_strdup(path, GFP_NOFS); + if (!name) { + btrfs_free_device(device); + mutex_unlock(&fs_devices->device_list_mutex); + return ERR_PTR(-ENOMEM); + } + rcu_assign_pointer(device->name, name); + + list_add_rcu(&device->dev_list, &fs_devices->devices); + fs_devices->num_devices++; + + device->fs_devices = fs_devices; + *new_device_added = true; + + if (disk_super->label[0]) + pr_info( + "BTRFS: device label %s devid %llu transid %llu %s scanned by %s (%d)\n", + disk_super->label, devid, found_transid, path, + current->comm, task_pid_nr(current)); + else + pr_info( + "BTRFS: device fsid %pU devid %llu transid %llu %s scanned by %s (%d)\n", + disk_super->fsid, devid, found_transid, path, + current->comm, task_pid_nr(current)); + + } else if (!device->name || strcmp(device->name->str, path)) { + /* + * When FS is already mounted. + * 1. If you are here and if the device->name is NULL that + * means this device was missing at time of FS mount. + * 2. If you are here and if the device->name is different + * from 'path' that means either + * a. The same device disappeared and reappeared with + * different name. or + * b. The missing-disk-which-was-replaced, has + * reappeared now. + * + * We must allow 1 and 2a above. But 2b would be a spurious + * and unintentional. + * + * Further in case of 1 and 2a above, the disk at 'path' + * would have missed some transaction when it was away and + * in case of 2a the stale bdev has to be updated as well. + * 2b must not be allowed at all time. + */ + + /* + * For now, we do allow update to btrfs_fs_device through the + * btrfs dev scan cli after FS has been mounted. We're still + * tracking a problem where systems fail mount by subvolume id + * when we reject replacement on a mounted FS. + */ + if (!fs_devices->opened && found_transid < device->generation) { + /* + * That is if the FS is _not_ mounted and if you + * are here, that means there is more than one + * disk with same uuid and devid.We keep the one + * with larger generation number or the last-in if + * generation are equal. + */ + mutex_unlock(&fs_devices->device_list_mutex); + return ERR_PTR(-EEXIST); + } + + /* + * We are going to replace the device path for a given devid, + * make sure it's the same device if the device is mounted + */ + if (device->bdev) { + struct block_device *path_bdev; + + path_bdev = lookup_bdev(path); + if (IS_ERR(path_bdev)) { + mutex_unlock(&fs_devices->device_list_mutex); + return ERR_CAST(path_bdev); + } + + if (device->bdev != path_bdev) { + bdput(path_bdev); + mutex_unlock(&fs_devices->device_list_mutex); + /* + * device->fs_info may not be reliable here, so + * pass in a NULL instead. This avoids a + * possible use-after-free when the fs_info and + * fs_info->sb are already torn down. + */ + btrfs_warn_in_rcu(NULL, + "duplicate device %s devid %llu generation %llu scanned by %s (%d)", + path, devid, found_transid, + current->comm, + task_pid_nr(current)); + return ERR_PTR(-EEXIST); + } + bdput(path_bdev); + btrfs_info_in_rcu(device->fs_info, + "devid %llu device path %s changed to %s scanned by %s (%d)", + devid, rcu_str_deref(device->name), + path, current->comm, + task_pid_nr(current)); + } + + name = rcu_string_strdup(path, GFP_NOFS); + if (!name) { + mutex_unlock(&fs_devices->device_list_mutex); + return ERR_PTR(-ENOMEM); + } + rcu_string_free(device->name); + rcu_assign_pointer(device->name, name); + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) { + fs_devices->missing_devices--; + clear_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state); + } + } + + /* + * Unmount does not free the btrfs_device struct but would zero + * generation along with most of the other members. So just update + * it back. We need it to pick the disk with largest generation + * (as above). + */ + if (!fs_devices->opened) { + device->generation = found_transid; + fs_devices->latest_generation = max_t(u64, found_transid, + fs_devices->latest_generation); + } + + fs_devices->total_devices = btrfs_super_num_devices(disk_super); + + mutex_unlock(&fs_devices->device_list_mutex); + return device; +} + +static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig) +{ + struct btrfs_fs_devices *fs_devices; + struct btrfs_device *device; + struct btrfs_device *orig_dev; + int ret = 0; + + lockdep_assert_held(&uuid_mutex); + + fs_devices = alloc_fs_devices(orig->fsid, NULL); + if (IS_ERR(fs_devices)) + return fs_devices; + + fs_devices->total_devices = orig->total_devices; + + list_for_each_entry(orig_dev, &orig->devices, dev_list) { + struct rcu_string *name; + + device = btrfs_alloc_device(NULL, &orig_dev->devid, + orig_dev->uuid); + if (IS_ERR(device)) { + ret = PTR_ERR(device); + goto error; + } + + /* + * This is ok to do without rcu read locked because we hold the + * uuid mutex so nothing we touch in here is going to disappear. + */ + if (orig_dev->name) { + name = rcu_string_strdup(orig_dev->name->str, + GFP_KERNEL); + if (!name) { + btrfs_free_device(device); + ret = -ENOMEM; + goto error; + } + rcu_assign_pointer(device->name, name); + } + + list_add(&device->dev_list, &fs_devices->devices); + device->fs_devices = fs_devices; + fs_devices->num_devices++; + } + return fs_devices; +error: + free_fs_devices(fs_devices); + return ERR_PTR(ret); +} + +static void __btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, + int step, struct btrfs_device **latest_dev) +{ + struct btrfs_device *device, *next; + + /* This is the initialized path, it is safe to release the devices. */ + list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { + if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state)) { + if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, + &device->dev_state) && + !test_bit(BTRFS_DEV_STATE_MISSING, + &device->dev_state) && + (!*latest_dev || + device->generation > (*latest_dev)->generation)) { + *latest_dev = device; + } + continue; + } + + /* + * We have already validated the presence of BTRFS_DEV_REPLACE_DEVID, + * in btrfs_init_dev_replace() so just continue. + */ + if (device->devid == BTRFS_DEV_REPLACE_DEVID) + continue; + + if (device->bdev) { + blkdev_put(device->bdev, device->mode); + device->bdev = NULL; + fs_devices->open_devices--; + } + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + list_del_init(&device->dev_alloc_list); + clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + fs_devices->rw_devices--; + } + list_del_init(&device->dev_list); + fs_devices->num_devices--; + btrfs_free_device(device); + } + +} + +/* + * After we have read the system tree and know devids belonging to this + * filesystem, remove the device which does not belong there. + */ +void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step) +{ + struct btrfs_device *latest_dev = NULL; + struct btrfs_fs_devices *seed_dev; + + mutex_lock(&uuid_mutex); + __btrfs_free_extra_devids(fs_devices, step, &latest_dev); + + list_for_each_entry(seed_dev, &fs_devices->seed_list, seed_list) + __btrfs_free_extra_devids(seed_dev, step, &latest_dev); + + fs_devices->latest_bdev = latest_dev->bdev; + + mutex_unlock(&uuid_mutex); +} + +static void btrfs_close_bdev(struct btrfs_device *device) +{ + if (!device->bdev) + return; + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + sync_blockdev(device->bdev); + invalidate_bdev(device->bdev); + } + + blkdev_put(device->bdev, device->mode); +} + +static void btrfs_close_one_device(struct btrfs_device *device) +{ + struct btrfs_fs_devices *fs_devices = device->fs_devices; + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) && + device->devid != BTRFS_DEV_REPLACE_DEVID) { + list_del_init(&device->dev_alloc_list); + fs_devices->rw_devices--; + } + + if (device->devid == BTRFS_DEV_REPLACE_DEVID) + clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); + + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) { + clear_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state); + fs_devices->missing_devices--; + } + + btrfs_close_bdev(device); + if (device->bdev) { + fs_devices->open_devices--; + device->bdev = NULL; + } + clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + + device->fs_info = NULL; + atomic_set(&device->dev_stats_ccnt, 0); + extent_io_tree_release(&device->alloc_state); + + /* + * Reset the flush error record. We might have a transient flush error + * in this mount, and if so we aborted the current transaction and set + * the fs to an error state, guaranteeing no super blocks can be further + * committed. However that error might be transient and if we unmount the + * filesystem and mount it again, we should allow the mount to succeed + * (btrfs_check_rw_degradable() should not fail) - if after mounting the + * filesystem again we still get flush errors, then we will again abort + * any transaction and set the error state, guaranteeing no commits of + * unsafe super blocks. + */ + device->last_flush_error = 0; + + /* Verify the device is back in a pristine state */ + ASSERT(!test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state)); + ASSERT(!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)); + ASSERT(list_empty(&device->dev_alloc_list)); + ASSERT(list_empty(&device->post_commit_list)); + ASSERT(atomic_read(&device->reada_in_flight) == 0); +} + +static void close_fs_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_device *device, *tmp; + + lockdep_assert_held(&uuid_mutex); + + if (--fs_devices->opened > 0) + return; + + list_for_each_entry_safe(device, tmp, &fs_devices->devices, dev_list) + btrfs_close_one_device(device); + + WARN_ON(fs_devices->open_devices); + WARN_ON(fs_devices->rw_devices); + fs_devices->opened = 0; + fs_devices->seeding = false; + fs_devices->fs_info = NULL; +} + +void btrfs_close_devices(struct btrfs_fs_devices *fs_devices) +{ + LIST_HEAD(list); + struct btrfs_fs_devices *tmp; + + mutex_lock(&uuid_mutex); + close_fs_devices(fs_devices); + if (!fs_devices->opened) { + list_splice_init(&fs_devices->seed_list, &list); + + /* + * If the struct btrfs_fs_devices is not assembled with any + * other device, it can be re-initialized during the next mount + * without the needing device-scan step. Therefore, it can be + * fully freed. + */ + if (fs_devices->num_devices == 1) { + list_del(&fs_devices->fs_list); + free_fs_devices(fs_devices); + } + } + + + list_for_each_entry_safe(fs_devices, tmp, &list, seed_list) { + close_fs_devices(fs_devices); + list_del(&fs_devices->seed_list); + free_fs_devices(fs_devices); + } + mutex_unlock(&uuid_mutex); +} + +static int open_fs_devices(struct btrfs_fs_devices *fs_devices, + fmode_t flags, void *holder) +{ + struct btrfs_device *device; + struct btrfs_device *latest_dev = NULL; + struct btrfs_device *tmp_device; + + flags |= FMODE_EXCL; + + list_for_each_entry_safe(device, tmp_device, &fs_devices->devices, + dev_list) { + int ret; + + ret = btrfs_open_one_device(fs_devices, device, flags, holder); + if (ret == 0 && + (!latest_dev || device->generation > latest_dev->generation)) { + latest_dev = device; + } else if (ret == -ENODATA) { + fs_devices->num_devices--; + list_del(&device->dev_list); + btrfs_free_device(device); + } + } + if (fs_devices->open_devices == 0) + return -EINVAL; + + fs_devices->opened = 1; + fs_devices->latest_bdev = latest_dev->bdev; + fs_devices->total_rw_bytes = 0; + fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_REGULAR; + + return 0; +} + +static int devid_cmp(void *priv, const struct list_head *a, + const struct list_head *b) +{ + struct btrfs_device *dev1, *dev2; + + dev1 = list_entry(a, struct btrfs_device, dev_list); + dev2 = list_entry(b, struct btrfs_device, dev_list); + + if (dev1->devid < dev2->devid) + return -1; + else if (dev1->devid > dev2->devid) + return 1; + return 0; +} + +int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, + fmode_t flags, void *holder) +{ + int ret; + + lockdep_assert_held(&uuid_mutex); + /* + * The device_list_mutex cannot be taken here in case opening the + * underlying device takes further locks like bd_mutex. + * + * We also don't need the lock here as this is called during mount and + * exclusion is provided by uuid_mutex + */ + + if (fs_devices->opened) { + fs_devices->opened++; + ret = 0; + } else { + list_sort(NULL, &fs_devices->devices, devid_cmp); + ret = open_fs_devices(fs_devices, flags, holder); + } + + return ret; +} + +void btrfs_release_disk_super(struct btrfs_super_block *super) +{ + struct page *page = virt_to_page(super); + + put_page(page); +} + +static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev, + u64 bytenr) +{ + struct btrfs_super_block *disk_super; + struct page *page; + void *p; + pgoff_t index; + + /* make sure our super fits in the device */ + if (bytenr + PAGE_SIZE >= i_size_read(bdev->bd_inode)) + return ERR_PTR(-EINVAL); + + /* make sure our super fits in the page */ + if (sizeof(*disk_super) > PAGE_SIZE) + return ERR_PTR(-EINVAL); + + /* make sure our super doesn't straddle pages on disk */ + index = bytenr >> PAGE_SHIFT; + if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_SHIFT != index) + return ERR_PTR(-EINVAL); + + /* pull in the page with our super */ + page = read_cache_page_gfp(bdev->bd_inode->i_mapping, index, GFP_KERNEL); + + if (IS_ERR(page)) + return ERR_CAST(page); + + p = page_address(page); + + /* align our pointer to the offset of the super block */ + disk_super = p + offset_in_page(bytenr); + + if (btrfs_super_bytenr(disk_super) != bytenr || + btrfs_super_magic(disk_super) != BTRFS_MAGIC) { + btrfs_release_disk_super(p); + return ERR_PTR(-EINVAL); + } + + if (disk_super->label[0] && disk_super->label[BTRFS_LABEL_SIZE - 1]) + disk_super->label[BTRFS_LABEL_SIZE - 1] = 0; + + return disk_super; +} + +int btrfs_forget_devices(const char *path) +{ + int ret; + + mutex_lock(&uuid_mutex); + ret = btrfs_free_stale_devices(strlen(path) ? path : NULL, NULL); + mutex_unlock(&uuid_mutex); + + return ret; +} + +/* + * Look for a btrfs signature on a device. This may be called out of the mount path + * and we are not allowed to call set_blocksize during the scan. The superblock + * is read via pagecache + */ +struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags, + void *holder) +{ + struct btrfs_super_block *disk_super; + bool new_device_added = false; + struct btrfs_device *device = NULL; + struct block_device *bdev; + u64 bytenr; + + lockdep_assert_held(&uuid_mutex); + + /* + * we would like to check all the supers, but that would make + * a btrfs mount succeed after a mkfs from a different FS. + * So, we need to add a special mount option to scan for + * later supers, using BTRFS_SUPER_MIRROR_MAX instead + */ + bytenr = btrfs_sb_offset(0); + + /* + * Avoid using flag |= FMODE_EXCL here, as the systemd-udev may + * initiate the device scan which may race with the user's mount + * or mkfs command, resulting in failure. + * Since the device scan is solely for reading purposes, there is + * no need for FMODE_EXCL. Additionally, the devices are read again + * during the mount process. It is ok to get some inconsistent + * values temporarily, as the device paths of the fsid are the only + * required information for assembling the volume. + */ + bdev = blkdev_get_by_path(path, flags, holder); + if (IS_ERR(bdev)) + return ERR_CAST(bdev); + + disk_super = btrfs_read_disk_super(bdev, bytenr); + if (IS_ERR(disk_super)) { + device = ERR_CAST(disk_super); + goto error_bdev_put; + } + + device = device_list_add(path, disk_super, &new_device_added); + if (!IS_ERR(device)) { + if (new_device_added) + btrfs_free_stale_devices(path, device); + } + + btrfs_release_disk_super(disk_super); + +error_bdev_put: + blkdev_put(bdev, flags); + + return device; +} + +/* + * Try to find a chunk that intersects [start, start + len] range and when one + * such is found, record the end of it in *start + */ +static bool contains_pending_extent(struct btrfs_device *device, u64 *start, + u64 len) +{ + u64 physical_start, physical_end; + + lockdep_assert_held(&device->fs_info->chunk_mutex); + + if (!find_first_extent_bit(&device->alloc_state, *start, + &physical_start, &physical_end, + CHUNK_ALLOCATED, NULL)) { + + if (in_range(physical_start, *start, len) || + in_range(*start, physical_start, + physical_end - physical_start)) { + *start = physical_end + 1; + return true; + } + } + return false; +} + +static u64 dev_extent_search_start(struct btrfs_device *device, u64 start) +{ + switch (device->fs_devices->chunk_alloc_policy) { + case BTRFS_CHUNK_ALLOC_REGULAR: + /* + * We don't want to overwrite the superblock on the drive nor + * any area used by the boot loader (grub for example), so we + * make sure to start at an offset of at least 1MB. + */ + return max_t(u64, start, SZ_1M); + default: + BUG(); + } +} + +/** + * dev_extent_hole_check - check if specified hole is suitable for allocation + * @device: the device which we have the hole + * @hole_start: starting position of the hole + * @hole_size: the size of the hole + * @num_bytes: the size of the free space that we need + * + * This function may modify @hole_start and @hole_end to reflect the suitable + * position for allocation. Returns 1 if hole position is updated, 0 otherwise. + */ +static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start, + u64 *hole_size, u64 num_bytes) +{ + bool changed = false; + u64 hole_end = *hole_start + *hole_size; + + /* + * Check before we set max_hole_start, otherwise we could end up + * sending back this offset anyway. + */ + if (contains_pending_extent(device, hole_start, *hole_size)) { + if (hole_end >= *hole_start) + *hole_size = hole_end - *hole_start; + else + *hole_size = 0; + changed = true; + } + + switch (device->fs_devices->chunk_alloc_policy) { + case BTRFS_CHUNK_ALLOC_REGULAR: + /* No extra check */ + break; + default: + BUG(); + } + + return changed; +} + +/* + * find_free_dev_extent_start - find free space in the specified device + * @device: the device which we search the free space in + * @num_bytes: the size of the free space that we need + * @search_start: the position from which to begin the search + * @start: store the start of the free space. + * @len: the size of the free space. that we find, or the size + * of the max free space if we don't find suitable free space + * + * this uses a pretty simple search, the expectation is that it is + * called very infrequently and that a given device has a small number + * of extents + * + * @start is used to store the start of the free space if we find. But if we + * don't find suitable free space, it will be used to store the start position + * of the max free space. + * + * @len is used to store the size of the free space that we find. + * But if we don't find suitable free space, it is used to store the size of + * the max free space. + * + * NOTE: This function will search *commit* root of device tree, and does extra + * check to ensure dev extents are not double allocated. + * This makes the function safe to allocate dev extents but may not report + * correct usable device space, as device extent freed in current transaction + * is not reported as avaiable. + */ +static int find_free_dev_extent_start(struct btrfs_device *device, + u64 num_bytes, u64 search_start, u64 *start, + u64 *len) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + struct btrfs_root *root = fs_info->dev_root; + struct btrfs_key key; + struct btrfs_dev_extent *dev_extent; + struct btrfs_path *path; + u64 hole_size; + u64 max_hole_start; + u64 max_hole_size; + u64 extent_end; + u64 search_end = device->total_bytes; + int ret; + int slot; + struct extent_buffer *l; + + search_start = dev_extent_search_start(device, search_start); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + max_hole_start = search_start; + max_hole_size = 0; + +again: + if (search_start >= search_end || + test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) { + ret = -ENOSPC; + goto out; + } + + path->reada = READA_FORWARD; + path->search_commit_root = 1; + path->skip_locking = 1; + + key.objectid = device->devid; + key.offset = search_start; + key.type = BTRFS_DEV_EXTENT_KEY; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret > 0) { + ret = btrfs_previous_item(root, path, key.objectid, key.type); + if (ret < 0) + goto out; + } + + while (search_start < search_end) { + l = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(l)) { + ret = btrfs_next_leaf(root, path); + if (ret == 0) + continue; + if (ret < 0) + goto out; + + break; + } + btrfs_item_key_to_cpu(l, &key, slot); + + if (key.objectid < device->devid) + goto next; + + if (key.objectid > device->devid) + break; + + if (key.type != BTRFS_DEV_EXTENT_KEY) + goto next; + + if (key.offset > search_end) + break; + + if (key.offset > search_start) { + hole_size = key.offset - search_start; + dev_extent_hole_check(device, &search_start, &hole_size, + num_bytes); + + if (hole_size > max_hole_size) { + max_hole_start = search_start; + max_hole_size = hole_size; + } + + /* + * If this free space is greater than which we need, + * it must be the max free space that we have found + * until now, so max_hole_start must point to the start + * of this free space and the length of this free space + * is stored in max_hole_size. Thus, we return + * max_hole_start and max_hole_size and go back to the + * caller. + */ + if (hole_size >= num_bytes) { + ret = 0; + goto out; + } + } + + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + extent_end = key.offset + btrfs_dev_extent_length(l, + dev_extent); + if (extent_end > search_start) + search_start = extent_end; +next: + path->slots[0]++; + cond_resched(); + } + + /* + * At this point, search_start should be the end of + * allocated dev extents, and when shrinking the device, + * search_end may be smaller than search_start. + */ + if (search_end > search_start) { + hole_size = search_end - search_start; + if (dev_extent_hole_check(device, &search_start, &hole_size, + num_bytes)) { + btrfs_release_path(path); + goto again; + } + + if (hole_size > max_hole_size) { + max_hole_start = search_start; + max_hole_size = hole_size; + } + } + + /* See above. */ + if (max_hole_size < num_bytes) + ret = -ENOSPC; + else + ret = 0; + + ASSERT(max_hole_start + max_hole_size <= search_end); +out: + btrfs_free_path(path); + *start = max_hole_start; + if (len) + *len = max_hole_size; + return ret; +} + +int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes, + u64 *start, u64 *len) +{ + /* FIXME use last free of some kind */ + return find_free_dev_extent_start(device, num_bytes, 0, start, len); +} + +static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans, + struct btrfs_device *device, + u64 start, u64 *dev_extent_len) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + struct btrfs_root *root = fs_info->dev_root; + int ret; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *leaf = NULL; + struct btrfs_dev_extent *extent = NULL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = device->devid; + key.offset = start; + key.type = BTRFS_DEV_EXTENT_KEY; +again: + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret > 0) { + ret = btrfs_previous_item(root, path, key.objectid, + BTRFS_DEV_EXTENT_KEY); + if (ret) + goto out; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_extent); + BUG_ON(found_key.offset > start || found_key.offset + + btrfs_dev_extent_length(leaf, extent) < start); + key = found_key; + btrfs_release_path(path); + goto again; + } else if (ret == 0) { + leaf = path->nodes[0]; + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_extent); + } else { + btrfs_handle_fs_error(fs_info, ret, "Slot search failed"); + goto out; + } + + *dev_extent_len = btrfs_dev_extent_length(leaf, extent); + + ret = btrfs_del_item(trans, root, path); + if (ret) { + btrfs_handle_fs_error(fs_info, ret, + "Failed to remove dev extent item"); + } else { + set_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags); + } +out: + btrfs_free_path(path); + return ret; +} + +static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans, + struct btrfs_device *device, + u64 chunk_offset, u64 start, u64 num_bytes) +{ + int ret; + struct btrfs_path *path; + struct btrfs_fs_info *fs_info = device->fs_info; + struct btrfs_root *root = fs_info->dev_root; + struct btrfs_dev_extent *extent; + struct extent_buffer *leaf; + struct btrfs_key key; + + WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state)); + WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)); + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = device->devid; + key.offset = start; + key.type = BTRFS_DEV_EXTENT_KEY; + ret = btrfs_insert_empty_item(trans, root, path, &key, + sizeof(*extent)); + if (ret) + goto out; + + leaf = path->nodes[0]; + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_extent); + btrfs_set_dev_extent_chunk_tree(leaf, extent, + BTRFS_CHUNK_TREE_OBJECTID); + btrfs_set_dev_extent_chunk_objectid(leaf, extent, + BTRFS_FIRST_CHUNK_TREE_OBJECTID); + btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset); + + btrfs_set_dev_extent_length(leaf, extent, num_bytes); + btrfs_mark_buffer_dirty(leaf); +out: + btrfs_free_path(path); + return ret; +} + +static u64 find_next_chunk(struct btrfs_fs_info *fs_info) +{ + struct extent_map_tree *em_tree; + struct extent_map *em; + struct rb_node *n; + u64 ret = 0; + + em_tree = &fs_info->mapping_tree; + read_lock(&em_tree->lock); + n = rb_last(&em_tree->map.rb_root); + if (n) { + em = rb_entry(n, struct extent_map, rb_node); + ret = em->start + em->len; + } + read_unlock(&em_tree->lock); + + return ret; +} + +static noinline int find_next_devid(struct btrfs_fs_info *fs_info, + u64 *devid_ret) +{ + int ret; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_path *path; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0); + if (ret < 0) + goto error; + + if (ret == 0) { + /* Corruption */ + btrfs_err(fs_info, "corrupted chunk tree devid -1 matched"); + ret = -EUCLEAN; + goto error; + } + + ret = btrfs_previous_item(fs_info->chunk_root, path, + BTRFS_DEV_ITEMS_OBJECTID, + BTRFS_DEV_ITEM_KEY); + if (ret) { + *devid_ret = 1; + } else { + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + *devid_ret = found_key.offset + 1; + } + ret = 0; +error: + btrfs_free_path(path); + return ret; +} + +/* + * the device information is stored in the chunk root + * the btrfs_device struct should be fully filled in + */ +static int btrfs_add_dev_item(struct btrfs_trans_handle *trans, + struct btrfs_device *device) +{ + int ret; + struct btrfs_path *path; + struct btrfs_dev_item *dev_item; + struct extent_buffer *leaf; + struct btrfs_key key; + unsigned long ptr; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = device->devid; + + ret = btrfs_insert_empty_item(trans, trans->fs_info->chunk_root, path, + &key, sizeof(*dev_item)); + if (ret) + goto out; + + leaf = path->nodes[0]; + dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); + + btrfs_set_device_id(leaf, dev_item, device->devid); + btrfs_set_device_generation(leaf, dev_item, 0); + btrfs_set_device_type(leaf, dev_item, device->type); + btrfs_set_device_io_align(leaf, dev_item, device->io_align); + btrfs_set_device_io_width(leaf, dev_item, device->io_width); + btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); + btrfs_set_device_total_bytes(leaf, dev_item, + btrfs_device_get_disk_total_bytes(device)); + btrfs_set_device_bytes_used(leaf, dev_item, + btrfs_device_get_bytes_used(device)); + btrfs_set_device_group(leaf, dev_item, 0); + btrfs_set_device_seek_speed(leaf, dev_item, 0); + btrfs_set_device_bandwidth(leaf, dev_item, 0); + btrfs_set_device_start_offset(leaf, dev_item, 0); + + ptr = btrfs_device_uuid(dev_item); + write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); + ptr = btrfs_device_fsid(dev_item); + write_extent_buffer(leaf, trans->fs_info->fs_devices->metadata_uuid, + ptr, BTRFS_FSID_SIZE); + btrfs_mark_buffer_dirty(leaf); + + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + +/* + * Function to update ctime/mtime for a given device path. + * Mainly used for ctime/mtime based probe like libblkid. + * + * We don't care about errors here, this is just to be kind to userspace. + */ +static void update_dev_time(const char *device_path) +{ + struct path path; + struct timespec64 now; + int ret; + + ret = kern_path(device_path, LOOKUP_FOLLOW, &path); + if (ret) + return; + + now = current_time(d_inode(path.dentry)); + inode_update_time(d_inode(path.dentry), &now, S_MTIME | S_CTIME); + path_put(&path); +} + +static int btrfs_rm_dev_item(struct btrfs_device *device) +{ + struct btrfs_root *root = device->fs_info->chunk_root; + int ret; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_trans_handle *trans; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = device->devid; + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret) { + if (ret > 0) + ret = -ENOENT; + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + goto out; + } + + ret = btrfs_del_item(trans, root, path); + if (ret) { + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + } + +out: + btrfs_free_path(path); + if (!ret) + ret = btrfs_commit_transaction(trans); + return ret; +} + +/* + * Verify that @num_devices satisfies the RAID profile constraints in the whole + * filesystem. It's up to the caller to adjust that number regarding eg. device + * replace. + */ +static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info, + u64 num_devices) +{ + u64 all_avail; + unsigned seq; + int i; + + do { + seq = read_seqbegin(&fs_info->profiles_lock); + + all_avail = fs_info->avail_data_alloc_bits | + fs_info->avail_system_alloc_bits | + fs_info->avail_metadata_alloc_bits; + } while (read_seqretry(&fs_info->profiles_lock, seq)); + + for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { + if (!(all_avail & btrfs_raid_array[i].bg_flag)) + continue; + + if (num_devices < btrfs_raid_array[i].devs_min) { + int ret = btrfs_raid_array[i].mindev_error; + + if (ret) + return ret; + } + } + + return 0; +} + +static struct btrfs_device * btrfs_find_next_active_device( + struct btrfs_fs_devices *fs_devs, struct btrfs_device *device) +{ + struct btrfs_device *next_device; + + list_for_each_entry(next_device, &fs_devs->devices, dev_list) { + if (next_device != device && + !test_bit(BTRFS_DEV_STATE_MISSING, &next_device->dev_state) + && next_device->bdev) + return next_device; + } + + return NULL; +} + +/* + * Helper function to check if the given device is part of s_bdev / latest_bdev + * and replace it with the provided or the next active device, in the context + * where this function called, there should be always be another device (or + * this_dev) which is active. + */ +void __cold btrfs_assign_next_active_device(struct btrfs_device *device, + struct btrfs_device *next_device) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + + if (!next_device) + next_device = btrfs_find_next_active_device(fs_info->fs_devices, + device); + ASSERT(next_device); + + if (fs_info->sb->s_bdev && + (fs_info->sb->s_bdev == device->bdev)) + fs_info->sb->s_bdev = next_device->bdev; + + if (fs_info->fs_devices->latest_bdev == device->bdev) + fs_info->fs_devices->latest_bdev = next_device->bdev; +} + +/* + * Return btrfs_fs_devices::num_devices excluding the device that's being + * currently replaced. + */ +static u64 btrfs_num_devices(struct btrfs_fs_info *fs_info) +{ + u64 num_devices = fs_info->fs_devices->num_devices; + + down_read(&fs_info->dev_replace.rwsem); + if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) { + ASSERT(num_devices > 1); + num_devices--; + } + up_read(&fs_info->dev_replace.rwsem); + + return num_devices; +} + +void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info, + struct block_device *bdev, + const char *device_path) +{ + struct btrfs_super_block *disk_super; + int copy_num; + + if (!bdev) + return; + + for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX; copy_num++) { + struct page *page; + int ret; + + disk_super = btrfs_read_dev_one_super(bdev, copy_num); + if (IS_ERR(disk_super)) + continue; + + memset(&disk_super->magic, 0, sizeof(disk_super->magic)); + + page = virt_to_page(disk_super); + set_page_dirty(page); + lock_page(page); + /* write_on_page() unlocks the page */ + ret = write_one_page(page); + if (ret) + btrfs_warn(fs_info, + "error clearing superblock number %d (%d)", + copy_num, ret); + btrfs_release_disk_super(disk_super); + + } + + /* Notify udev that device has changed */ + btrfs_kobject_uevent(bdev, KOBJ_CHANGE); + + /* Update ctime/mtime for device path for libblkid */ + update_dev_time(device_path); +} + +int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path, + u64 devid) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *cur_devices; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + u64 num_devices; + int ret = 0; + + /* + * The device list in fs_devices is accessed without locks (neither + * uuid_mutex nor device_list_mutex) as it won't change on a mounted + * filesystem and another device rm cannot run. + */ + num_devices = btrfs_num_devices(fs_info); + + ret = btrfs_check_raid_min_devices(fs_info, num_devices - 1); + if (ret) + goto out; + + device = btrfs_find_device_by_devspec(fs_info, devid, device_path); + + if (IS_ERR(device)) { + if (PTR_ERR(device) == -ENOENT && + device_path && strcmp(device_path, "missing") == 0) + ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND; + else + ret = PTR_ERR(device); + goto out; + } + + if (btrfs_pinned_by_swapfile(fs_info, device)) { + btrfs_warn_in_rcu(fs_info, + "cannot remove device %s (devid %llu) due to active swapfile", + rcu_str_deref(device->name), device->devid); + ret = -ETXTBSY; + goto out; + } + + if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) { + ret = BTRFS_ERROR_DEV_TGT_REPLACE; + goto out; + } + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) && + fs_info->fs_devices->rw_devices == 1) { + ret = BTRFS_ERROR_DEV_ONLY_WRITABLE; + goto out; + } + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + mutex_lock(&fs_info->chunk_mutex); + list_del_init(&device->dev_alloc_list); + device->fs_devices->rw_devices--; + mutex_unlock(&fs_info->chunk_mutex); + } + + ret = btrfs_shrink_device(device, 0); + if (!ret) + btrfs_reada_remove_dev(device); + if (ret) + goto error_undo; + + /* + * TODO: the superblock still includes this device in its num_devices + * counter although write_all_supers() is not locked out. This + * could give a filesystem state which requires a degraded mount. + */ + ret = btrfs_rm_dev_item(device); + if (ret) + goto error_undo; + + clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); + btrfs_scrub_cancel_dev(device); + + /* + * the device list mutex makes sure that we don't change + * the device list while someone else is writing out all + * the device supers. Whoever is writing all supers, should + * lock the device list mutex before getting the number of + * devices in the super block (super_copy). Conversely, + * whoever updates the number of devices in the super block + * (super_copy) should hold the device list mutex. + */ + + /* + * In normal cases the cur_devices == fs_devices. But in case + * of deleting a seed device, the cur_devices should point to + * its own fs_devices listed under the fs_devices->seed. + */ + cur_devices = device->fs_devices; + mutex_lock(&fs_devices->device_list_mutex); + list_del_rcu(&device->dev_list); + + cur_devices->num_devices--; + cur_devices->total_devices--; + /* Update total_devices of the parent fs_devices if it's seed */ + if (cur_devices != fs_devices) + fs_devices->total_devices--; + + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) + cur_devices->missing_devices--; + + btrfs_assign_next_active_device(device, NULL); + + if (device->bdev) { + cur_devices->open_devices--; + /* remove sysfs entry */ + btrfs_sysfs_remove_device(device); + } + + num_devices = btrfs_super_num_devices(fs_info->super_copy) - 1; + btrfs_set_super_num_devices(fs_info->super_copy, num_devices); + mutex_unlock(&fs_devices->device_list_mutex); + + /* + * at this point, the device is zero sized and detached from + * the devices list. All that's left is to zero out the old + * supers and free the device. + */ + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) + btrfs_scratch_superblocks(fs_info, device->bdev, + device->name->str); + + btrfs_close_bdev(device); + synchronize_rcu(); + btrfs_free_device(device); + + if (cur_devices->open_devices == 0) { + list_del_init(&cur_devices->seed_list); + close_fs_devices(cur_devices); + free_fs_devices(cur_devices); + } + +out: + return ret; + +error_undo: + btrfs_reada_undo_remove_dev(device); + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + mutex_lock(&fs_info->chunk_mutex); + list_add(&device->dev_alloc_list, + &fs_devices->alloc_list); + device->fs_devices->rw_devices++; + mutex_unlock(&fs_info->chunk_mutex); + } + goto out; +} + +void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev) +{ + struct btrfs_fs_devices *fs_devices; + + lockdep_assert_held(&srcdev->fs_info->fs_devices->device_list_mutex); + + /* + * in case of fs with no seed, srcdev->fs_devices will point + * to fs_devices of fs_info. However when the dev being replaced is + * a seed dev it will point to the seed's local fs_devices. In short + * srcdev will have its correct fs_devices in both the cases. + */ + fs_devices = srcdev->fs_devices; + + list_del_rcu(&srcdev->dev_list); + list_del(&srcdev->dev_alloc_list); + fs_devices->num_devices--; + if (test_bit(BTRFS_DEV_STATE_MISSING, &srcdev->dev_state)) + fs_devices->missing_devices--; + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &srcdev->dev_state)) + fs_devices->rw_devices--; + + if (srcdev->bdev) + fs_devices->open_devices--; +} + +void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev) +{ + struct btrfs_fs_devices *fs_devices = srcdev->fs_devices; + + mutex_lock(&uuid_mutex); + + btrfs_close_bdev(srcdev); + synchronize_rcu(); + btrfs_free_device(srcdev); + + /* if this is no devs we rather delete the fs_devices */ + if (!fs_devices->num_devices) { + /* + * On a mounted FS, num_devices can't be zero unless it's a + * seed. In case of a seed device being replaced, the replace + * target added to the sprout FS, so there will be no more + * device left under the seed FS. + */ + ASSERT(fs_devices->seeding); + + list_del_init(&fs_devices->seed_list); + close_fs_devices(fs_devices); + free_fs_devices(fs_devices); + } + mutex_unlock(&uuid_mutex); +} + +void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev) +{ + struct btrfs_fs_devices *fs_devices = tgtdev->fs_info->fs_devices; + + mutex_lock(&fs_devices->device_list_mutex); + + btrfs_sysfs_remove_device(tgtdev); + + if (tgtdev->bdev) + fs_devices->open_devices--; + + fs_devices->num_devices--; + + btrfs_assign_next_active_device(tgtdev, NULL); + + list_del_rcu(&tgtdev->dev_list); + + mutex_unlock(&fs_devices->device_list_mutex); + + /* + * The update_dev_time() with in btrfs_scratch_superblocks() + * may lead to a call to btrfs_show_devname() which will try + * to hold device_list_mutex. And here this device + * is already out of device list, so we don't have to hold + * the device_list_mutex lock. + */ + btrfs_scratch_superblocks(tgtdev->fs_info, tgtdev->bdev, + tgtdev->name->str); + + btrfs_close_bdev(tgtdev); + synchronize_rcu(); + btrfs_free_device(tgtdev); +} + +static struct btrfs_device *btrfs_find_device_by_path( + struct btrfs_fs_info *fs_info, const char *device_path) +{ + int ret = 0; + struct btrfs_super_block *disk_super; + u64 devid; + u8 *dev_uuid; + struct block_device *bdev; + struct btrfs_device *device; + + ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ, + fs_info->bdev_holder, 0, &bdev, &disk_super); + if (ret) + return ERR_PTR(ret); + + devid = btrfs_stack_device_id(&disk_super->dev_item); + dev_uuid = disk_super->dev_item.uuid; + if (btrfs_fs_incompat(fs_info, METADATA_UUID)) + device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid, + disk_super->metadata_uuid, true); + else + device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid, + disk_super->fsid, true); + + btrfs_release_disk_super(disk_super); + if (!device) + device = ERR_PTR(-ENOENT); + blkdev_put(bdev, FMODE_READ); + return device; +} + +/* + * Lookup a device given by device id, or the path if the id is 0. + */ +struct btrfs_device *btrfs_find_device_by_devspec( + struct btrfs_fs_info *fs_info, u64 devid, + const char *device_path) +{ + struct btrfs_device *device; + + if (devid) { + device = btrfs_find_device(fs_info->fs_devices, devid, NULL, + NULL, true); + if (!device) + return ERR_PTR(-ENOENT); + return device; + } + + if (!device_path || !device_path[0]) + return ERR_PTR(-EINVAL); + + if (strcmp(device_path, "missing") == 0) { + /* Find first missing device */ + list_for_each_entry(device, &fs_info->fs_devices->devices, + dev_list) { + if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, + &device->dev_state) && !device->bdev) + return device; + } + return ERR_PTR(-ENOENT); + } + + return btrfs_find_device_by_path(fs_info, device_path); +} + +/* + * does all the dirty work required for changing file system's UUID. + */ +static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_fs_devices *old_devices; + struct btrfs_fs_devices *seed_devices; + struct btrfs_super_block *disk_super = fs_info->super_copy; + struct btrfs_device *device; + u64 super_flags; + + lockdep_assert_held(&uuid_mutex); + if (!fs_devices->seeding) + return -EINVAL; + + /* + * Private copy of the seed devices, anchored at + * fs_info->fs_devices->seed_list + */ + seed_devices = alloc_fs_devices(NULL, NULL); + if (IS_ERR(seed_devices)) + return PTR_ERR(seed_devices); + + /* + * It's necessary to retain a copy of the original seed fs_devices in + * fs_uuids so that filesystems which have been seeded can successfully + * reference the seed device from open_seed_devices. This also supports + * multiple fs seed. + */ + old_devices = clone_fs_devices(fs_devices); + if (IS_ERR(old_devices)) { + kfree(seed_devices); + return PTR_ERR(old_devices); + } + + list_add(&old_devices->fs_list, &fs_uuids); + + memcpy(seed_devices, fs_devices, sizeof(*seed_devices)); + seed_devices->opened = 1; + INIT_LIST_HEAD(&seed_devices->devices); + INIT_LIST_HEAD(&seed_devices->alloc_list); + mutex_init(&seed_devices->device_list_mutex); + + mutex_lock(&fs_devices->device_list_mutex); + list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices, + synchronize_rcu); + list_for_each_entry(device, &seed_devices->devices, dev_list) + device->fs_devices = seed_devices; + + fs_devices->seeding = false; + fs_devices->num_devices = 0; + fs_devices->open_devices = 0; + fs_devices->missing_devices = 0; + fs_devices->rotating = false; + list_add(&seed_devices->seed_list, &fs_devices->seed_list); + + generate_random_uuid(fs_devices->fsid); + memcpy(fs_devices->metadata_uuid, fs_devices->fsid, BTRFS_FSID_SIZE); + memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE); + mutex_unlock(&fs_devices->device_list_mutex); + + super_flags = btrfs_super_flags(disk_super) & + ~BTRFS_SUPER_FLAG_SEEDING; + btrfs_set_super_flags(disk_super, super_flags); + + return 0; +} + +/* + * Store the expected generation for seed devices in device items. + */ +static int btrfs_finish_sprout(struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *root = fs_info->chunk_root; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_dev_item *dev_item; + struct btrfs_device *device; + struct btrfs_key key; + u8 fs_uuid[BTRFS_FSID_SIZE]; + u8 dev_uuid[BTRFS_UUID_SIZE]; + u64 devid; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.offset = 0; + key.type = BTRFS_DEV_ITEM_KEY; + + while (1) { + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); + if (ret < 0) + goto error; + + leaf = path->nodes[0]; +next_slot: + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret > 0) + break; + if (ret < 0) + goto error; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + btrfs_release_path(path); + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID || + key.type != BTRFS_DEV_ITEM_KEY) + break; + + dev_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_item); + devid = btrfs_device_id(leaf, dev_item); + read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item), + BTRFS_UUID_SIZE); + read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item), + BTRFS_FSID_SIZE); + device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid, + fs_uuid, true); + BUG_ON(!device); /* Logic error */ + + if (device->fs_devices->seeding) { + btrfs_set_device_generation(leaf, dev_item, + device->generation); + btrfs_mark_buffer_dirty(leaf); + } + + path->slots[0]++; + goto next_slot; + } + ret = 0; +error: + btrfs_free_path(path); + return ret; +} + +int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path) +{ + struct btrfs_root *root = fs_info->dev_root; + struct request_queue *q; + struct btrfs_trans_handle *trans; + struct btrfs_device *device; + struct block_device *bdev; + struct super_block *sb = fs_info->sb; + struct rcu_string *name; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + u64 orig_super_total_bytes; + u64 orig_super_num_devices; + int seeding_dev = 0; + int ret = 0; + bool locked = false; + + if (sb_rdonly(sb) && !fs_devices->seeding) + return -EROFS; + + bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, + fs_info->bdev_holder); + if (IS_ERR(bdev)) + return PTR_ERR(bdev); + + if (fs_devices->seeding) { + seeding_dev = 1; + down_write(&sb->s_umount); + mutex_lock(&uuid_mutex); + locked = true; + } + + sync_blockdev(bdev); + + rcu_read_lock(); + list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { + if (device->bdev == bdev) { + ret = -EEXIST; + rcu_read_unlock(); + goto error; + } + } + rcu_read_unlock(); + + device = btrfs_alloc_device(fs_info, NULL, NULL); + if (IS_ERR(device)) { + /* we can safely leave the fs_devices entry around */ + ret = PTR_ERR(device); + goto error; + } + + name = rcu_string_strdup(device_path, GFP_KERNEL); + if (!name) { + ret = -ENOMEM; + goto error_free_device; + } + rcu_assign_pointer(device->name, name); + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto error_free_device; + } + + q = bdev_get_queue(bdev); + set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + device->generation = trans->transid; + device->io_width = fs_info->sectorsize; + device->io_align = fs_info->sectorsize; + device->sector_size = fs_info->sectorsize; + device->total_bytes = round_down(i_size_read(bdev->bd_inode), + fs_info->sectorsize); + device->disk_total_bytes = device->total_bytes; + device->commit_total_bytes = device->total_bytes; + device->fs_info = fs_info; + device->bdev = bdev; + set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); + clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); + device->mode = FMODE_EXCL; + device->dev_stats_valid = 1; + set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); + + if (seeding_dev) { + sb->s_flags &= ~SB_RDONLY; + ret = btrfs_prepare_sprout(fs_info); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto error_trans; + } + } + + device->fs_devices = fs_devices; + + mutex_lock(&fs_devices->device_list_mutex); + mutex_lock(&fs_info->chunk_mutex); + list_add_rcu(&device->dev_list, &fs_devices->devices); + list_add(&device->dev_alloc_list, &fs_devices->alloc_list); + fs_devices->num_devices++; + fs_devices->open_devices++; + fs_devices->rw_devices++; + fs_devices->total_devices++; + fs_devices->total_rw_bytes += device->total_bytes; + + atomic64_add(device->total_bytes, &fs_info->free_chunk_space); + + if (!blk_queue_nonrot(q)) + fs_devices->rotating = true; + + orig_super_total_bytes = btrfs_super_total_bytes(fs_info->super_copy); + btrfs_set_super_total_bytes(fs_info->super_copy, + round_down(orig_super_total_bytes + device->total_bytes, + fs_info->sectorsize)); + + orig_super_num_devices = btrfs_super_num_devices(fs_info->super_copy); + btrfs_set_super_num_devices(fs_info->super_copy, + orig_super_num_devices + 1); + + /* + * we've got more storage, clear any full flags on the space + * infos + */ + btrfs_clear_space_info_full(fs_info); + + mutex_unlock(&fs_info->chunk_mutex); + + /* Add sysfs device entry */ + btrfs_sysfs_add_device(device); + + mutex_unlock(&fs_devices->device_list_mutex); + + if (seeding_dev) { + mutex_lock(&fs_info->chunk_mutex); + ret = init_first_rw_device(trans); + mutex_unlock(&fs_info->chunk_mutex); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto error_sysfs; + } + } + + ret = btrfs_add_dev_item(trans, device); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto error_sysfs; + } + + if (seeding_dev) { + ret = btrfs_finish_sprout(trans); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto error_sysfs; + } + + /* + * fs_devices now represents the newly sprouted filesystem and + * its fsid has been changed by btrfs_prepare_sprout + */ + btrfs_sysfs_update_sprout_fsid(fs_devices); + } + + ret = btrfs_commit_transaction(trans); + + if (seeding_dev) { + mutex_unlock(&uuid_mutex); + up_write(&sb->s_umount); + locked = false; + + if (ret) /* transaction commit */ + return ret; + + ret = btrfs_relocate_sys_chunks(fs_info); + if (ret < 0) + btrfs_handle_fs_error(fs_info, ret, + "Failed to relocate sys chunks after device initialization. This can be fixed using the \"btrfs balance\" command."); + trans = btrfs_attach_transaction(root); + if (IS_ERR(trans)) { + if (PTR_ERR(trans) == -ENOENT) + return 0; + ret = PTR_ERR(trans); + trans = NULL; + goto error_sysfs; + } + ret = btrfs_commit_transaction(trans); + } + + /* + * Now that we have written a new super block to this device, check all + * other fs_devices list if device_path alienates any other scanned + * device. + * We can ignore the return value as it typically returns -EINVAL and + * only succeeds if the device was an alien. + */ + btrfs_forget_devices(device_path); + + /* Update ctime/mtime for blkid or udev */ + update_dev_time(device_path); + + return ret; + +error_sysfs: + btrfs_sysfs_remove_device(device); + mutex_lock(&fs_info->fs_devices->device_list_mutex); + mutex_lock(&fs_info->chunk_mutex); + list_del_rcu(&device->dev_list); + list_del(&device->dev_alloc_list); + fs_info->fs_devices->num_devices--; + fs_info->fs_devices->open_devices--; + fs_info->fs_devices->rw_devices--; + fs_info->fs_devices->total_devices--; + fs_info->fs_devices->total_rw_bytes -= device->total_bytes; + atomic64_sub(device->total_bytes, &fs_info->free_chunk_space); + btrfs_set_super_total_bytes(fs_info->super_copy, + orig_super_total_bytes); + btrfs_set_super_num_devices(fs_info->super_copy, + orig_super_num_devices); + mutex_unlock(&fs_info->chunk_mutex); + mutex_unlock(&fs_info->fs_devices->device_list_mutex); +error_trans: + if (seeding_dev) + sb->s_flags |= SB_RDONLY; + if (trans) + btrfs_end_transaction(trans); +error_free_device: + btrfs_free_device(device); +error: + blkdev_put(bdev, FMODE_EXCL); + if (locked) { + mutex_unlock(&uuid_mutex); + up_write(&sb->s_umount); + } + return ret; +} + +static noinline int btrfs_update_device(struct btrfs_trans_handle *trans, + struct btrfs_device *device) +{ + int ret; + struct btrfs_path *path; + struct btrfs_root *root = device->fs_info->chunk_root; + struct btrfs_dev_item *dev_item; + struct extent_buffer *leaf; + struct btrfs_key key; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = device->devid; + + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); + if (ret < 0) + goto out; + + if (ret > 0) { + ret = -ENOENT; + goto out; + } + + leaf = path->nodes[0]; + dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); + + btrfs_set_device_id(leaf, dev_item, device->devid); + btrfs_set_device_type(leaf, dev_item, device->type); + btrfs_set_device_io_align(leaf, dev_item, device->io_align); + btrfs_set_device_io_width(leaf, dev_item, device->io_width); + btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); + btrfs_set_device_total_bytes(leaf, dev_item, + btrfs_device_get_disk_total_bytes(device)); + btrfs_set_device_bytes_used(leaf, dev_item, + btrfs_device_get_bytes_used(device)); + btrfs_mark_buffer_dirty(leaf); + +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_grow_device(struct btrfs_trans_handle *trans, + struct btrfs_device *device, u64 new_size) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + struct btrfs_super_block *super_copy = fs_info->super_copy; + u64 old_total; + u64 diff; + + if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) + return -EACCES; + + new_size = round_down(new_size, fs_info->sectorsize); + + mutex_lock(&fs_info->chunk_mutex); + old_total = btrfs_super_total_bytes(super_copy); + diff = round_down(new_size - device->total_bytes, fs_info->sectorsize); + + if (new_size <= device->total_bytes || + test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) { + mutex_unlock(&fs_info->chunk_mutex); + return -EINVAL; + } + + btrfs_set_super_total_bytes(super_copy, + round_down(old_total + diff, fs_info->sectorsize)); + device->fs_devices->total_rw_bytes += diff; + + btrfs_device_set_total_bytes(device, new_size); + btrfs_device_set_disk_total_bytes(device, new_size); + btrfs_clear_space_info_full(device->fs_info); + if (list_empty(&device->post_commit_list)) + list_add_tail(&device->post_commit_list, + &trans->transaction->dev_update_list); + mutex_unlock(&fs_info->chunk_mutex); + + return btrfs_update_device(trans, device); +} + +static int btrfs_free_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *root = fs_info->chunk_root; + int ret; + struct btrfs_path *path; + struct btrfs_key key; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.offset = chunk_offset; + key.type = BTRFS_CHUNK_ITEM_KEY; + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto out; + else if (ret > 0) { /* Logic error or corruption */ + btrfs_handle_fs_error(fs_info, -ENOENT, + "Failed lookup while freeing chunk."); + ret = -ENOENT; + goto out; + } + + ret = btrfs_del_item(trans, root, path); + if (ret < 0) + btrfs_handle_fs_error(fs_info, ret, + "Failed to delete chunk item."); +out: + btrfs_free_path(path); + return ret; +} + +static int btrfs_del_sys_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset) +{ + struct btrfs_super_block *super_copy = fs_info->super_copy; + struct btrfs_disk_key *disk_key; + struct btrfs_chunk *chunk; + u8 *ptr; + int ret = 0; + u32 num_stripes; + u32 array_size; + u32 len = 0; + u32 cur; + struct btrfs_key key; + + mutex_lock(&fs_info->chunk_mutex); + array_size = btrfs_super_sys_array_size(super_copy); + + ptr = super_copy->sys_chunk_array; + cur = 0; + + while (cur < array_size) { + disk_key = (struct btrfs_disk_key *)ptr; + btrfs_disk_key_to_cpu(&key, disk_key); + + len = sizeof(*disk_key); + + if (key.type == BTRFS_CHUNK_ITEM_KEY) { + chunk = (struct btrfs_chunk *)(ptr + len); + num_stripes = btrfs_stack_chunk_num_stripes(chunk); + len += btrfs_chunk_item_size(num_stripes); + } else { + ret = -EIO; + break; + } + if (key.objectid == BTRFS_FIRST_CHUNK_TREE_OBJECTID && + key.offset == chunk_offset) { + memmove(ptr, ptr + len, array_size - (cur + len)); + array_size -= len; + btrfs_set_super_sys_array_size(super_copy, array_size); + } else { + ptr += len; + cur += len; + } + } + mutex_unlock(&fs_info->chunk_mutex); + return ret; +} + +/* + * btrfs_get_chunk_map() - Find the mapping containing the given logical extent. + * @logical: Logical block offset in bytes. + * @length: Length of extent in bytes. + * + * Return: Chunk mapping or ERR_PTR. + */ +struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info, + u64 logical, u64 length) +{ + struct extent_map_tree *em_tree; + struct extent_map *em; + + em_tree = &fs_info->mapping_tree; + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, logical, length); + read_unlock(&em_tree->lock); + + if (!em) { + btrfs_crit(fs_info, + "unable to find chunk map for logical %llu length %llu", + logical, length); + return ERR_PTR(-EINVAL); + } + + if (em->start > logical || em->start + em->len <= logical) { + btrfs_crit(fs_info, + "found a bad chunk map, wanted %llu-%llu, found %llu-%llu", + logical, logical + length, em->start, em->start + em->len); + free_extent_map(em); + return ERR_PTR(-EINVAL); + } + + /* callers are responsible for dropping em's ref. */ + return em; +} + +int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct extent_map *em; + struct map_lookup *map; + u64 dev_extent_len = 0; + int i, ret = 0; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + + em = btrfs_get_chunk_map(fs_info, chunk_offset, 1); + if (IS_ERR(em)) { + /* + * This is a logic error, but we don't want to just rely on the + * user having built with ASSERT enabled, so if ASSERT doesn't + * do anything we still error out. + */ + ASSERT(0); + return PTR_ERR(em); + } + map = em->map_lookup; + mutex_lock(&fs_info->chunk_mutex); + check_system_chunk(trans, map->type); + mutex_unlock(&fs_info->chunk_mutex); + + /* + * Take the device list mutex to prevent races with the final phase of + * a device replace operation that replaces the device object associated + * with map stripes (dev-replace.c:btrfs_dev_replace_finishing()). + */ + mutex_lock(&fs_devices->device_list_mutex); + for (i = 0; i < map->num_stripes; i++) { + struct btrfs_device *device = map->stripes[i].dev; + ret = btrfs_free_dev_extent(trans, device, + map->stripes[i].physical, + &dev_extent_len); + if (ret) { + mutex_unlock(&fs_devices->device_list_mutex); + btrfs_abort_transaction(trans, ret); + goto out; + } + + if (device->bytes_used > 0) { + mutex_lock(&fs_info->chunk_mutex); + btrfs_device_set_bytes_used(device, + device->bytes_used - dev_extent_len); + atomic64_add(dev_extent_len, &fs_info->free_chunk_space); + btrfs_clear_space_info_full(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + } + + ret = btrfs_update_device(trans, device); + if (ret) { + mutex_unlock(&fs_devices->device_list_mutex); + btrfs_abort_transaction(trans, ret); + goto out; + } + } + mutex_unlock(&fs_devices->device_list_mutex); + + ret = btrfs_free_chunk(trans, chunk_offset); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out; + } + + trace_btrfs_chunk_free(fs_info, map, chunk_offset, em->len); + + if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) { + ret = btrfs_del_sys_chunk(fs_info, chunk_offset); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out; + } + } + + ret = btrfs_remove_block_group(trans, chunk_offset, em); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out; + } + +out: + /* once for us */ + free_extent_map(em); + return ret; +} + +static int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset) +{ + struct btrfs_root *root = fs_info->chunk_root; + struct btrfs_trans_handle *trans; + struct btrfs_block_group *block_group; + int ret; + + /* + * Prevent races with automatic removal of unused block groups. + * After we relocate and before we remove the chunk with offset + * chunk_offset, automatic removal of the block group can kick in, + * resulting in a failure when calling btrfs_remove_chunk() below. + * + * Make sure to acquire this mutex before doing a tree search (dev + * or chunk trees) to find chunks. Otherwise the cleaner kthread might + * call btrfs_remove_chunk() (through btrfs_delete_unused_bgs()) after + * we release the path used to search the chunk/dev tree and before + * the current task acquires this mutex and calls us. + */ + lockdep_assert_held(&fs_info->delete_unused_bgs_mutex); + + /* step one, relocate all the extents inside this chunk */ + btrfs_scrub_pause(fs_info); + ret = btrfs_relocate_block_group(fs_info, chunk_offset); + btrfs_scrub_continue(fs_info); + if (ret) + return ret; + + block_group = btrfs_lookup_block_group(fs_info, chunk_offset); + if (!block_group) + return -ENOENT; + btrfs_discard_cancel_work(&fs_info->discard_ctl, block_group); + btrfs_put_block_group(block_group); + + trans = btrfs_start_trans_remove_block_group(root->fs_info, + chunk_offset); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + btrfs_handle_fs_error(root->fs_info, ret, NULL); + return ret; + } + + /* + * step two, delete the device extents and the + * chunk tree entries + */ + ret = btrfs_remove_chunk(trans, chunk_offset); + btrfs_end_transaction(trans); + return ret; +} + +static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *chunk_root = fs_info->chunk_root; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_chunk *chunk; + struct btrfs_key key; + struct btrfs_key found_key; + u64 chunk_type; + bool retried = false; + int failed = 0; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + +again: + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.offset = (u64)-1; + key.type = BTRFS_CHUNK_ITEM_KEY; + + while (1) { + mutex_lock(&fs_info->delete_unused_bgs_mutex); + ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); + if (ret < 0) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + goto error; + } + BUG_ON(ret == 0); /* Corruption */ + + ret = btrfs_previous_item(chunk_root, path, key.objectid, + key.type); + if (ret) + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + if (ret < 0) + goto error; + if (ret > 0) + break; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + chunk = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_chunk); + chunk_type = btrfs_chunk_type(leaf, chunk); + btrfs_release_path(path); + + if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) { + ret = btrfs_relocate_chunk(fs_info, found_key.offset); + if (ret == -ENOSPC) + failed++; + else + BUG_ON(ret); + } + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + + if (found_key.offset == 0) + break; + key.offset = found_key.offset - 1; + } + ret = 0; + if (failed && !retried) { + failed = 0; + retried = true; + goto again; + } else if (WARN_ON(failed && retried)) { + ret = -ENOSPC; + } +error: + btrfs_free_path(path); + return ret; +} + +/* + * return 1 : allocate a data chunk successfully, + * return <0: errors during allocating a data chunk, + * return 0 : no need to allocate a data chunk. + */ +static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info, + u64 chunk_offset) +{ + struct btrfs_block_group *cache; + u64 bytes_used; + u64 chunk_type; + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + ASSERT(cache); + chunk_type = cache->flags; + btrfs_put_block_group(cache); + + if (!(chunk_type & BTRFS_BLOCK_GROUP_DATA)) + return 0; + + spin_lock(&fs_info->data_sinfo->lock); + bytes_used = fs_info->data_sinfo->bytes_used; + spin_unlock(&fs_info->data_sinfo->lock); + + if (!bytes_used) { + struct btrfs_trans_handle *trans; + int ret; + + trans = btrfs_join_transaction(fs_info->tree_root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_force_chunk_alloc(trans, BTRFS_BLOCK_GROUP_DATA); + btrfs_end_transaction(trans); + if (ret < 0) + return ret; + return 1; + } + + return 0; +} + +static int insert_balance_item(struct btrfs_fs_info *fs_info, + struct btrfs_balance_control *bctl) +{ + struct btrfs_root *root = fs_info->tree_root; + struct btrfs_trans_handle *trans; + struct btrfs_balance_item *item; + struct btrfs_disk_balance_args disk_bargs; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key key; + int ret, err; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + + key.objectid = BTRFS_BALANCE_OBJECTID; + key.type = BTRFS_TEMPORARY_ITEM_KEY; + key.offset = 0; + + ret = btrfs_insert_empty_item(trans, root, path, &key, + sizeof(*item)); + if (ret) + goto out; + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item); + + memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item)); + + btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data); + btrfs_set_balance_data(leaf, item, &disk_bargs); + btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta); + btrfs_set_balance_meta(leaf, item, &disk_bargs); + btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys); + btrfs_set_balance_sys(leaf, item, &disk_bargs); + + btrfs_set_balance_flags(leaf, item, bctl->flags); + + btrfs_mark_buffer_dirty(leaf); +out: + btrfs_free_path(path); + err = btrfs_commit_transaction(trans); + if (err && !ret) + ret = err; + return ret; +} + +static int del_balance_item(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root = fs_info->tree_root; + struct btrfs_trans_handle *trans; + struct btrfs_path *path; + struct btrfs_key key; + int ret, err; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_start_transaction_fallback_global_rsv(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + + key.objectid = BTRFS_BALANCE_OBJECTID; + key.type = BTRFS_TEMPORARY_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto out; + if (ret > 0) { + ret = -ENOENT; + goto out; + } + + ret = btrfs_del_item(trans, root, path); +out: + btrfs_free_path(path); + err = btrfs_commit_transaction(trans); + if (err && !ret) + ret = err; + return ret; +} + +/* + * This is a heuristic used to reduce the number of chunks balanced on + * resume after balance was interrupted. + */ +static void update_balance_args(struct btrfs_balance_control *bctl) +{ + /* + * Turn on soft mode for chunk types that were being converted. + */ + if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) + bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT; + if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) + bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT; + if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) + bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT; + + /* + * Turn on usage filter if is not already used. The idea is + * that chunks that we have already balanced should be + * reasonably full. Don't do it for chunks that are being + * converted - that will keep us from relocating unconverted + * (albeit full) chunks. + */ + if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) && + !(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) && + !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) { + bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE; + bctl->data.usage = 90; + } + if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) && + !(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) && + !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) { + bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE; + bctl->sys.usage = 90; + } + if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) && + !(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) && + !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) { + bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE; + bctl->meta.usage = 90; + } +} + +/* + * Clear the balance status in fs_info and delete the balance item from disk. + */ +static void reset_balance_state(struct btrfs_fs_info *fs_info) +{ + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + int ret; + + BUG_ON(!fs_info->balance_ctl); + + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl = NULL; + spin_unlock(&fs_info->balance_lock); + + kfree(bctl); + ret = del_balance_item(fs_info); + if (ret) + btrfs_handle_fs_error(fs_info, ret, NULL); +} + +/* + * Balance filters. Return 1 if chunk should be filtered out + * (should not be balanced). + */ +static int chunk_profiles_filter(u64 chunk_type, + struct btrfs_balance_args *bargs) +{ + chunk_type = chunk_to_extended(chunk_type) & + BTRFS_EXTENDED_PROFILE_MASK; + + if (bargs->profiles & chunk_type) + return 0; + + return 1; +} + +static int chunk_usage_range_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset, + struct btrfs_balance_args *bargs) +{ + struct btrfs_block_group *cache; + u64 chunk_used; + u64 user_thresh_min; + u64 user_thresh_max; + int ret = 1; + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + chunk_used = cache->used; + + if (bargs->usage_min == 0) + user_thresh_min = 0; + else + user_thresh_min = div_factor_fine(cache->length, + bargs->usage_min); + + if (bargs->usage_max == 0) + user_thresh_max = 1; + else if (bargs->usage_max > 100) + user_thresh_max = cache->length; + else + user_thresh_max = div_factor_fine(cache->length, + bargs->usage_max); + + if (user_thresh_min <= chunk_used && chunk_used < user_thresh_max) + ret = 0; + + btrfs_put_block_group(cache); + return ret; +} + +static int chunk_usage_filter(struct btrfs_fs_info *fs_info, + u64 chunk_offset, struct btrfs_balance_args *bargs) +{ + struct btrfs_block_group *cache; + u64 chunk_used, user_thresh; + int ret = 1; + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + chunk_used = cache->used; + + if (bargs->usage_min == 0) + user_thresh = 1; + else if (bargs->usage > 100) + user_thresh = cache->length; + else + user_thresh = div_factor_fine(cache->length, bargs->usage); + + if (chunk_used < user_thresh) + ret = 0; + + btrfs_put_block_group(cache); + return ret; +} + +static int chunk_devid_filter(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + struct btrfs_balance_args *bargs) +{ + struct btrfs_stripe *stripe; + int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + int i; + + for (i = 0; i < num_stripes; i++) { + stripe = btrfs_stripe_nr(chunk, i); + if (btrfs_stripe_devid(leaf, stripe) == bargs->devid) + return 0; + } + + return 1; +} + +static u64 calc_data_stripes(u64 type, int num_stripes) +{ + const int index = btrfs_bg_flags_to_raid_index(type); + const int ncopies = btrfs_raid_array[index].ncopies; + const int nparity = btrfs_raid_array[index].nparity; + + if (nparity) + return num_stripes - nparity; + else + return num_stripes / ncopies; +} + +/* [pstart, pend) */ +static int chunk_drange_filter(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + struct btrfs_balance_args *bargs) +{ + struct btrfs_stripe *stripe; + int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + u64 stripe_offset; + u64 stripe_length; + u64 type; + int factor; + int i; + + if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID)) + return 0; + + type = btrfs_chunk_type(leaf, chunk); + factor = calc_data_stripes(type, num_stripes); + + for (i = 0; i < num_stripes; i++) { + stripe = btrfs_stripe_nr(chunk, i); + if (btrfs_stripe_devid(leaf, stripe) != bargs->devid) + continue; + + stripe_offset = btrfs_stripe_offset(leaf, stripe); + stripe_length = btrfs_chunk_length(leaf, chunk); + stripe_length = div_u64(stripe_length, factor); + + if (stripe_offset < bargs->pend && + stripe_offset + stripe_length > bargs->pstart) + return 0; + } + + return 1; +} + +/* [vstart, vend) */ +static int chunk_vrange_filter(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + u64 chunk_offset, + struct btrfs_balance_args *bargs) +{ + if (chunk_offset < bargs->vend && + chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart) + /* at least part of the chunk is inside this vrange */ + return 0; + + return 1; +} + +static int chunk_stripes_range_filter(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + struct btrfs_balance_args *bargs) +{ + int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + + if (bargs->stripes_min <= num_stripes + && num_stripes <= bargs->stripes_max) + return 0; + + return 1; +} + +static int chunk_soft_convert_filter(u64 chunk_type, + struct btrfs_balance_args *bargs) +{ + if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT)) + return 0; + + chunk_type = chunk_to_extended(chunk_type) & + BTRFS_EXTENDED_PROFILE_MASK; + + if (bargs->target == chunk_type) + return 1; + + return 0; +} + +static int should_balance_chunk(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, u64 chunk_offset) +{ + struct btrfs_fs_info *fs_info = leaf->fs_info; + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + struct btrfs_balance_args *bargs = NULL; + u64 chunk_type = btrfs_chunk_type(leaf, chunk); + + /* type filter */ + if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) & + (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) { + return 0; + } + + if (chunk_type & BTRFS_BLOCK_GROUP_DATA) + bargs = &bctl->data; + else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) + bargs = &bctl->sys; + else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA) + bargs = &bctl->meta; + + /* profiles filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) && + chunk_profiles_filter(chunk_type, bargs)) { + return 0; + } + + /* usage filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) && + chunk_usage_filter(fs_info, chunk_offset, bargs)) { + return 0; + } else if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) && + chunk_usage_range_filter(fs_info, chunk_offset, bargs)) { + return 0; + } + + /* devid filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) && + chunk_devid_filter(leaf, chunk, bargs)) { + return 0; + } + + /* drange filter, makes sense only with devid filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) && + chunk_drange_filter(leaf, chunk, bargs)) { + return 0; + } + + /* vrange filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) && + chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) { + return 0; + } + + /* stripes filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE) && + chunk_stripes_range_filter(leaf, chunk, bargs)) { + return 0; + } + + /* soft profile changing mode */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) && + chunk_soft_convert_filter(chunk_type, bargs)) { + return 0; + } + + /* + * limited by count, must be the last filter + */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT)) { + if (bargs->limit == 0) + return 0; + else + bargs->limit--; + } else if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)) { + /* + * Same logic as the 'limit' filter; the minimum cannot be + * determined here because we do not have the global information + * about the count of all chunks that satisfy the filters. + */ + if (bargs->limit_max == 0) + return 0; + else + bargs->limit_max--; + } + + return 1; +} + +static int __btrfs_balance(struct btrfs_fs_info *fs_info) +{ + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + struct btrfs_root *chunk_root = fs_info->chunk_root; + u64 chunk_type; + struct btrfs_chunk *chunk; + struct btrfs_path *path = NULL; + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *leaf; + int slot; + int ret; + int enospc_errors = 0; + bool counting = true; + /* The single value limit and min/max limits use the same bytes in the */ + u64 limit_data = bctl->data.limit; + u64 limit_meta = bctl->meta.limit; + u64 limit_sys = bctl->sys.limit; + u32 count_data = 0; + u32 count_meta = 0; + u32 count_sys = 0; + int chunk_reserved = 0; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto error; + } + + /* zero out stat counters */ + spin_lock(&fs_info->balance_lock); + memset(&bctl->stat, 0, sizeof(bctl->stat)); + spin_unlock(&fs_info->balance_lock); +again: + if (!counting) { + /* + * The single value limit and min/max limits use the same bytes + * in the + */ + bctl->data.limit = limit_data; + bctl->meta.limit = limit_meta; + bctl->sys.limit = limit_sys; + } + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.offset = (u64)-1; + key.type = BTRFS_CHUNK_ITEM_KEY; + + while (1) { + if ((!counting && atomic_read(&fs_info->balance_pause_req)) || + atomic_read(&fs_info->balance_cancel_req)) { + ret = -ECANCELED; + goto error; + } + + mutex_lock(&fs_info->delete_unused_bgs_mutex); + ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); + if (ret < 0) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + goto error; + } + + /* + * this shouldn't happen, it means the last relocate + * failed + */ + if (ret == 0) + BUG(); /* FIXME break ? */ + + ret = btrfs_previous_item(chunk_root, path, 0, + BTRFS_CHUNK_ITEM_KEY); + if (ret) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + ret = 0; + break; + } + + leaf = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + if (found_key.objectid != key.objectid) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + break; + } + + chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); + chunk_type = btrfs_chunk_type(leaf, chunk); + + if (!counting) { + spin_lock(&fs_info->balance_lock); + bctl->stat.considered++; + spin_unlock(&fs_info->balance_lock); + } + + ret = should_balance_chunk(leaf, chunk, found_key.offset); + + btrfs_release_path(path); + if (!ret) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + goto loop; + } + + if (counting) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + spin_lock(&fs_info->balance_lock); + bctl->stat.expected++; + spin_unlock(&fs_info->balance_lock); + + if (chunk_type & BTRFS_BLOCK_GROUP_DATA) + count_data++; + else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) + count_sys++; + else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA) + count_meta++; + + goto loop; + } + + /* + * Apply limit_min filter, no need to check if the LIMITS + * filter is used, limit_min is 0 by default + */ + if (((chunk_type & BTRFS_BLOCK_GROUP_DATA) && + count_data < bctl->data.limit_min) + || ((chunk_type & BTRFS_BLOCK_GROUP_METADATA) && + count_meta < bctl->meta.limit_min) + || ((chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) && + count_sys < bctl->sys.limit_min)) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + goto loop; + } + + if (!chunk_reserved) { + /* + * We may be relocating the only data chunk we have, + * which could potentially end up with losing data's + * raid profile, so lets allocate an empty one in + * advance. + */ + ret = btrfs_may_alloc_data_chunk(fs_info, + found_key.offset); + if (ret < 0) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + goto error; + } else if (ret == 1) { + chunk_reserved = 1; + } + } + + ret = btrfs_relocate_chunk(fs_info, found_key.offset); + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + if (ret == -ENOSPC) { + enospc_errors++; + } else if (ret == -ETXTBSY) { + btrfs_info(fs_info, + "skipping relocation of block group %llu due to active swapfile", + found_key.offset); + ret = 0; + } else if (ret) { + goto error; + } else { + spin_lock(&fs_info->balance_lock); + bctl->stat.completed++; + spin_unlock(&fs_info->balance_lock); + } +loop: + if (found_key.offset == 0) + break; + key.offset = found_key.offset - 1; + } + + if (counting) { + btrfs_release_path(path); + counting = false; + goto again; + } +error: + btrfs_free_path(path); + if (enospc_errors) { + btrfs_info(fs_info, "%d enospc errors during balance", + enospc_errors); + if (!ret) + ret = -ENOSPC; + } + + return ret; +} + +/** + * alloc_profile_is_valid - see if a given profile is valid and reduced + * @flags: profile to validate + * @extended: if true @flags is treated as an extended profile + */ +static int alloc_profile_is_valid(u64 flags, int extended) +{ + u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK : + BTRFS_BLOCK_GROUP_PROFILE_MASK); + + flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK; + + /* 1) check that all other bits are zeroed */ + if (flags & ~mask) + return 0; + + /* 2) see if profile is reduced */ + if (flags == 0) + return !extended; /* "0" is valid for usual profiles */ + + return has_single_bit_set(flags); +} + +static inline int balance_need_close(struct btrfs_fs_info *fs_info) +{ + /* cancel requested || normal exit path */ + return atomic_read(&fs_info->balance_cancel_req) || + (atomic_read(&fs_info->balance_pause_req) == 0 && + atomic_read(&fs_info->balance_cancel_req) == 0); +} + +/* + * Validate target profile against allowed profiles and return true if it's OK. + * Otherwise print the error message and return false. + */ +static inline int validate_convert_profile(struct btrfs_fs_info *fs_info, + const struct btrfs_balance_args *bargs, + u64 allowed, const char *type) +{ + if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT)) + return true; + + /* Profile is valid and does not have bits outside of the allowed set */ + if (alloc_profile_is_valid(bargs->target, 1) && + (bargs->target & ~allowed) == 0) + return true; + + btrfs_err(fs_info, "balance: invalid convert %s profile %s", + type, btrfs_bg_type_to_raid_name(bargs->target)); + return false; +} + +/* + * Fill @buf with textual description of balance filter flags @bargs, up to + * @size_buf including the terminating null. The output may be trimmed if it + * does not fit into the provided buffer. + */ +static void describe_balance_args(struct btrfs_balance_args *bargs, char *buf, + u32 size_buf) +{ + int ret; + u32 size_bp = size_buf; + char *bp = buf; + u64 flags = bargs->flags; + char tmp_buf[128] = {'\0'}; + + if (!flags) + return; + +#define CHECK_APPEND_NOARG(a) \ + do { \ + ret = snprintf(bp, size_bp, (a)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + } while (0) + +#define CHECK_APPEND_1ARG(a, v1) \ + do { \ + ret = snprintf(bp, size_bp, (a), (v1)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + } while (0) + +#define CHECK_APPEND_2ARG(a, v1, v2) \ + do { \ + ret = snprintf(bp, size_bp, (a), (v1), (v2)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + } while (0) + + if (flags & BTRFS_BALANCE_ARGS_CONVERT) + CHECK_APPEND_1ARG("convert=%s,", + btrfs_bg_type_to_raid_name(bargs->target)); + + if (flags & BTRFS_BALANCE_ARGS_SOFT) + CHECK_APPEND_NOARG("soft,"); + + if (flags & BTRFS_BALANCE_ARGS_PROFILES) { + btrfs_describe_block_groups(bargs->profiles, tmp_buf, + sizeof(tmp_buf)); + CHECK_APPEND_1ARG("profiles=%s,", tmp_buf); + } + + if (flags & BTRFS_BALANCE_ARGS_USAGE) + CHECK_APPEND_1ARG("usage=%llu,", bargs->usage); + + if (flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) + CHECK_APPEND_2ARG("usage=%u..%u,", + bargs->usage_min, bargs->usage_max); + + if (flags & BTRFS_BALANCE_ARGS_DEVID) + CHECK_APPEND_1ARG("devid=%llu,", bargs->devid); + + if (flags & BTRFS_BALANCE_ARGS_DRANGE) + CHECK_APPEND_2ARG("drange=%llu..%llu,", + bargs->pstart, bargs->pend); + + if (flags & BTRFS_BALANCE_ARGS_VRANGE) + CHECK_APPEND_2ARG("vrange=%llu..%llu,", + bargs->vstart, bargs->vend); + + if (flags & BTRFS_BALANCE_ARGS_LIMIT) + CHECK_APPEND_1ARG("limit=%llu,", bargs->limit); + + if (flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE) + CHECK_APPEND_2ARG("limit=%u..%u,", + bargs->limit_min, bargs->limit_max); + + if (flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE) + CHECK_APPEND_2ARG("stripes=%u..%u,", + bargs->stripes_min, bargs->stripes_max); + +#undef CHECK_APPEND_2ARG +#undef CHECK_APPEND_1ARG +#undef CHECK_APPEND_NOARG + +out_overflow: + + if (size_bp < size_buf) + buf[size_buf - size_bp - 1] = '\0'; /* remove last , */ + else + buf[0] = '\0'; +} + +static void describe_balance_start_or_resume(struct btrfs_fs_info *fs_info) +{ + u32 size_buf = 1024; + char tmp_buf[192] = {'\0'}; + char *buf; + char *bp; + u32 size_bp = size_buf; + int ret; + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + + buf = kzalloc(size_buf, GFP_KERNEL); + if (!buf) + return; + + bp = buf; + +#define CHECK_APPEND_1ARG(a, v1) \ + do { \ + ret = snprintf(bp, size_bp, (a), (v1)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + } while (0) + + if (bctl->flags & BTRFS_BALANCE_FORCE) + CHECK_APPEND_1ARG("%s", "-f "); + + if (bctl->flags & BTRFS_BALANCE_DATA) { + describe_balance_args(&bctl->data, tmp_buf, sizeof(tmp_buf)); + CHECK_APPEND_1ARG("-d%s ", tmp_buf); + } + + if (bctl->flags & BTRFS_BALANCE_METADATA) { + describe_balance_args(&bctl->meta, tmp_buf, sizeof(tmp_buf)); + CHECK_APPEND_1ARG("-m%s ", tmp_buf); + } + + if (bctl->flags & BTRFS_BALANCE_SYSTEM) { + describe_balance_args(&bctl->sys, tmp_buf, sizeof(tmp_buf)); + CHECK_APPEND_1ARG("-s%s ", tmp_buf); + } + +#undef CHECK_APPEND_1ARG + +out_overflow: + + if (size_bp < size_buf) + buf[size_buf - size_bp - 1] = '\0'; /* remove last " " */ + btrfs_info(fs_info, "balance: %s %s", + (bctl->flags & BTRFS_BALANCE_RESUME) ? + "resume" : "start", buf); + + kfree(buf); +} + +/* + * Should be called with balance mutexe held + */ +int btrfs_balance(struct btrfs_fs_info *fs_info, + struct btrfs_balance_control *bctl, + struct btrfs_ioctl_balance_args *bargs) +{ + u64 meta_target, data_target; + u64 allowed; + int mixed = 0; + int ret; + u64 num_devices; + unsigned seq; + bool reducing_redundancy; + int i; + + if (btrfs_fs_closing(fs_info) || + atomic_read(&fs_info->balance_pause_req) || + btrfs_should_cancel_balance(fs_info)) { + ret = -EINVAL; + goto out; + } + + allowed = btrfs_super_incompat_flags(fs_info->super_copy); + if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) + mixed = 1; + + /* + * In case of mixed groups both data and meta should be picked, + * and identical options should be given for both of them. + */ + allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA; + if (mixed && (bctl->flags & allowed)) { + if (!(bctl->flags & BTRFS_BALANCE_DATA) || + !(bctl->flags & BTRFS_BALANCE_METADATA) || + memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) { + btrfs_err(fs_info, + "balance: mixed groups data and metadata options must be the same"); + ret = -EINVAL; + goto out; + } + } + + /* + * rw_devices will not change at the moment, device add/delete/replace + * are exclusive + */ + num_devices = fs_info->fs_devices->rw_devices; + + /* + * SINGLE profile on-disk has no profile bit, but in-memory we have a + * special bit for it, to make it easier to distinguish. Thus we need + * to set it manually, or balance would refuse the profile. + */ + allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE; + for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++) + if (num_devices >= btrfs_raid_array[i].devs_min) + allowed |= btrfs_raid_array[i].bg_flag; + + if (!validate_convert_profile(fs_info, &bctl->data, allowed, "data") || + !validate_convert_profile(fs_info, &bctl->meta, allowed, "metadata") || + !validate_convert_profile(fs_info, &bctl->sys, allowed, "system")) { + ret = -EINVAL; + goto out; + } + + /* + * Allow to reduce metadata or system integrity only if force set for + * profiles with redundancy (copies, parity) + */ + allowed = 0; + for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++) { + if (btrfs_raid_array[i].ncopies >= 2 || + btrfs_raid_array[i].tolerated_failures >= 1) + allowed |= btrfs_raid_array[i].bg_flag; + } + do { + seq = read_seqbegin(&fs_info->profiles_lock); + + if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (fs_info->avail_system_alloc_bits & allowed) && + !(bctl->sys.target & allowed)) || + ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (fs_info->avail_metadata_alloc_bits & allowed) && + !(bctl->meta.target & allowed))) + reducing_redundancy = true; + else + reducing_redundancy = false; + + /* if we're not converting, the target field is uninitialized */ + meta_target = (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) ? + bctl->meta.target : fs_info->avail_metadata_alloc_bits; + data_target = (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) ? + bctl->data.target : fs_info->avail_data_alloc_bits; + } while (read_seqretry(&fs_info->profiles_lock, seq)); + + if (reducing_redundancy) { + if (bctl->flags & BTRFS_BALANCE_FORCE) { + btrfs_info(fs_info, + "balance: force reducing metadata redundancy"); + } else { + btrfs_err(fs_info, + "balance: reduces metadata redundancy, use --force if you want this"); + ret = -EINVAL; + goto out; + } + } + + if (btrfs_get_num_tolerated_disk_barrier_failures(meta_target) < + btrfs_get_num_tolerated_disk_barrier_failures(data_target)) { + btrfs_warn(fs_info, + "balance: metadata profile %s has lower redundancy than data profile %s", + btrfs_bg_type_to_raid_name(meta_target), + btrfs_bg_type_to_raid_name(data_target)); + } + + if (fs_info->send_in_progress) { + btrfs_warn_rl(fs_info, +"cannot run balance while send operations are in progress (%d in progress)", + fs_info->send_in_progress); + ret = -EAGAIN; + goto out; + } + + ret = insert_balance_item(fs_info, bctl); + if (ret && ret != -EEXIST) + goto out; + + if (!(bctl->flags & BTRFS_BALANCE_RESUME)) { + BUG_ON(ret == -EEXIST); + BUG_ON(fs_info->balance_ctl); + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl = bctl; + spin_unlock(&fs_info->balance_lock); + } else { + BUG_ON(ret != -EEXIST); + spin_lock(&fs_info->balance_lock); + update_balance_args(bctl); + spin_unlock(&fs_info->balance_lock); + } + + ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + set_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags); + describe_balance_start_or_resume(fs_info); + mutex_unlock(&fs_info->balance_mutex); + + ret = __btrfs_balance(fs_info); + + mutex_lock(&fs_info->balance_mutex); + if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req)) + btrfs_info(fs_info, "balance: paused"); + /* + * Balance can be canceled by: + * + * - Regular cancel request + * Then ret == -ECANCELED and balance_cancel_req > 0 + * + * - Fatal signal to "btrfs" process + * Either the signal caught by wait_reserve_ticket() and callers + * got -EINTR, or caught by btrfs_should_cancel_balance() and + * got -ECANCELED. + * Either way, in this case balance_cancel_req = 0, and + * ret == -EINTR or ret == -ECANCELED. + * + * So here we only check the return value to catch canceled balance. + */ + else if (ret == -ECANCELED || ret == -EINTR) + btrfs_info(fs_info, "balance: canceled"); + else + btrfs_info(fs_info, "balance: ended with status: %d", ret); + + clear_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags); + + if (bargs) { + memset(bargs, 0, sizeof(*bargs)); + btrfs_update_ioctl_balance_args(fs_info, bargs); + } + + if ((ret && ret != -ECANCELED && ret != -ENOSPC) || + balance_need_close(fs_info)) { + reset_balance_state(fs_info); + btrfs_exclop_finish(fs_info); + } + + wake_up(&fs_info->balance_wait_q); + + return ret; +out: + if (bctl->flags & BTRFS_BALANCE_RESUME) + reset_balance_state(fs_info); + else + kfree(bctl); + btrfs_exclop_finish(fs_info); + + return ret; +} + +static int balance_kthread(void *data) +{ + struct btrfs_fs_info *fs_info = data; + int ret = 0; + + sb_start_write(fs_info->sb); + mutex_lock(&fs_info->balance_mutex); + if (fs_info->balance_ctl) + ret = btrfs_balance(fs_info, fs_info->balance_ctl, NULL); + mutex_unlock(&fs_info->balance_mutex); + sb_end_write(fs_info->sb); + + return ret; +} + +int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info) +{ + struct task_struct *tsk; + + mutex_lock(&fs_info->balance_mutex); + if (!fs_info->balance_ctl) { + mutex_unlock(&fs_info->balance_mutex); + return 0; + } + mutex_unlock(&fs_info->balance_mutex); + + if (btrfs_test_opt(fs_info, SKIP_BALANCE)) { + btrfs_info(fs_info, "balance: resume skipped"); + return 0; + } + + /* + * A ro->rw remount sequence should continue with the paused balance + * regardless of who pauses it, system or the user as of now, so set + * the resume flag. + */ + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl->flags |= BTRFS_BALANCE_RESUME; + spin_unlock(&fs_info->balance_lock); + + tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance"); + return PTR_ERR_OR_ZERO(tsk); +} + +int btrfs_recover_balance(struct btrfs_fs_info *fs_info) +{ + struct btrfs_balance_control *bctl; + struct btrfs_balance_item *item; + struct btrfs_disk_balance_args disk_bargs; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key key; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_BALANCE_OBJECTID; + key.type = BTRFS_TEMPORARY_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret > 0) { /* ret = -ENOENT; */ + ret = 0; + goto out; + } + + bctl = kzalloc(sizeof(*bctl), GFP_NOFS); + if (!bctl) { + ret = -ENOMEM; + goto out; + } + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item); + + bctl->flags = btrfs_balance_flags(leaf, item); + bctl->flags |= BTRFS_BALANCE_RESUME; + + btrfs_balance_data(leaf, item, &disk_bargs); + btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs); + btrfs_balance_meta(leaf, item, &disk_bargs); + btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs); + btrfs_balance_sys(leaf, item, &disk_bargs); + btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs); + + /* + * This should never happen, as the paused balance state is recovered + * during mount without any chance of other exclusive ops to collide. + * + * This gives the exclusive op status to balance and keeps in paused + * state until user intervention (cancel or umount). If the ownership + * cannot be assigned, show a message but do not fail. The balance + * is in a paused state and must have fs_info::balance_ctl properly + * set up. + */ + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) + btrfs_warn(fs_info, + "balance: cannot set exclusive op status, resume manually"); + + btrfs_release_path(path); + + mutex_lock(&fs_info->balance_mutex); + BUG_ON(fs_info->balance_ctl); + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl = bctl; + spin_unlock(&fs_info->balance_lock); + mutex_unlock(&fs_info->balance_mutex); +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_pause_balance(struct btrfs_fs_info *fs_info) +{ + int ret = 0; + + mutex_lock(&fs_info->balance_mutex); + if (!fs_info->balance_ctl) { + mutex_unlock(&fs_info->balance_mutex); + return -ENOTCONN; + } + + if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) { + atomic_inc(&fs_info->balance_pause_req); + mutex_unlock(&fs_info->balance_mutex); + + wait_event(fs_info->balance_wait_q, + !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + + mutex_lock(&fs_info->balance_mutex); + /* we are good with balance_ctl ripped off from under us */ + BUG_ON(test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + atomic_dec(&fs_info->balance_pause_req); + } else { + ret = -ENOTCONN; + } + + mutex_unlock(&fs_info->balance_mutex); + return ret; +} + +int btrfs_cancel_balance(struct btrfs_fs_info *fs_info) +{ + mutex_lock(&fs_info->balance_mutex); + if (!fs_info->balance_ctl) { + mutex_unlock(&fs_info->balance_mutex); + return -ENOTCONN; + } + + /* + * A paused balance with the item stored on disk can be resumed at + * mount time if the mount is read-write. Otherwise it's still paused + * and we must not allow cancelling as it deletes the item. + */ + if (sb_rdonly(fs_info->sb)) { + mutex_unlock(&fs_info->balance_mutex); + return -EROFS; + } + + atomic_inc(&fs_info->balance_cancel_req); + /* + * if we are running just wait and return, balance item is + * deleted in btrfs_balance in this case + */ + if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) { + mutex_unlock(&fs_info->balance_mutex); + wait_event(fs_info->balance_wait_q, + !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + mutex_lock(&fs_info->balance_mutex); + } else { + mutex_unlock(&fs_info->balance_mutex); + /* + * Lock released to allow other waiters to continue, we'll + * reexamine the status again. + */ + mutex_lock(&fs_info->balance_mutex); + + if (fs_info->balance_ctl) { + reset_balance_state(fs_info); + btrfs_exclop_finish(fs_info); + btrfs_info(fs_info, "balance: canceled"); + } + } + + ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + atomic_dec(&fs_info->balance_cancel_req); + mutex_unlock(&fs_info->balance_mutex); + return 0; +} + +int btrfs_uuid_scan_kthread(void *data) +{ + struct btrfs_fs_info *fs_info = data; + struct btrfs_root *root = fs_info->tree_root; + struct btrfs_key key; + struct btrfs_path *path = NULL; + int ret = 0; + struct extent_buffer *eb; + int slot; + struct btrfs_root_item root_item; + u32 item_size; + struct btrfs_trans_handle *trans = NULL; + bool closing = false; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + key.objectid = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = 0; + + while (1) { + if (btrfs_fs_closing(fs_info)) { + closing = true; + break; + } + ret = btrfs_search_forward(root, &key, path, + BTRFS_OLDEST_GENERATION); + if (ret) { + if (ret > 0) + ret = 0; + break; + } + + if (key.type != BTRFS_ROOT_ITEM_KEY || + (key.objectid < BTRFS_FIRST_FREE_OBJECTID && + key.objectid != BTRFS_FS_TREE_OBJECTID) || + key.objectid > BTRFS_LAST_FREE_OBJECTID) + goto skip; + + eb = path->nodes[0]; + slot = path->slots[0]; + item_size = btrfs_item_size_nr(eb, slot); + if (item_size < sizeof(root_item)) + goto skip; + + read_extent_buffer(eb, &root_item, + btrfs_item_ptr_offset(eb, slot), + (int)sizeof(root_item)); + if (btrfs_root_refs(&root_item) == 0) + goto skip; + + if (!btrfs_is_empty_uuid(root_item.uuid) || + !btrfs_is_empty_uuid(root_item.received_uuid)) { + if (trans) + goto update_tree; + + btrfs_release_path(path); + /* + * 1 - subvol uuid item + * 1 - received_subvol uuid item + */ + trans = btrfs_start_transaction(fs_info->uuid_root, 2); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + continue; + } else { + goto skip; + } +update_tree: + btrfs_release_path(path); + if (!btrfs_is_empty_uuid(root_item.uuid)) { + ret = btrfs_uuid_tree_add(trans, root_item.uuid, + BTRFS_UUID_KEY_SUBVOL, + key.objectid); + if (ret < 0) { + btrfs_warn(fs_info, "uuid_tree_add failed %d", + ret); + break; + } + } + + if (!btrfs_is_empty_uuid(root_item.received_uuid)) { + ret = btrfs_uuid_tree_add(trans, + root_item.received_uuid, + BTRFS_UUID_KEY_RECEIVED_SUBVOL, + key.objectid); + if (ret < 0) { + btrfs_warn(fs_info, "uuid_tree_add failed %d", + ret); + break; + } + } + +skip: + btrfs_release_path(path); + if (trans) { + ret = btrfs_end_transaction(trans); + trans = NULL; + if (ret) + break; + } + + if (key.offset < (u64)-1) { + key.offset++; + } else if (key.type < BTRFS_ROOT_ITEM_KEY) { + key.offset = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + } else if (key.objectid < (u64)-1) { + key.offset = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + key.objectid++; + } else { + break; + } + cond_resched(); + } + +out: + btrfs_free_path(path); + if (trans && !IS_ERR(trans)) + btrfs_end_transaction(trans); + if (ret) + btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret); + else if (!closing) + set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags); + up(&fs_info->uuid_tree_rescan_sem); + return 0; +} + +int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_root *uuid_root; + struct task_struct *task; + int ret; + + /* + * 1 - root node + * 1 - root item + */ + trans = btrfs_start_transaction(tree_root, 2); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + uuid_root = btrfs_create_tree(trans, BTRFS_UUID_TREE_OBJECTID); + if (IS_ERR(uuid_root)) { + ret = PTR_ERR(uuid_root); + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + return ret; + } + + fs_info->uuid_root = uuid_root; + + ret = btrfs_commit_transaction(trans); + if (ret) + return ret; + + down(&fs_info->uuid_tree_rescan_sem); + task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid"); + if (IS_ERR(task)) { + /* fs_info->update_uuid_tree_gen remains 0 in all error case */ + btrfs_warn(fs_info, "failed to start uuid_scan task"); + up(&fs_info->uuid_tree_rescan_sem); + return PTR_ERR(task); + } + + return 0; +} + +/* + * shrinking a device means finding all of the device extents past + * the new size, and then following the back refs to the chunks. + * The chunk relocation code actually frees the device extent + */ +int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + struct btrfs_root *root = fs_info->dev_root; + struct btrfs_trans_handle *trans; + struct btrfs_dev_extent *dev_extent = NULL; + struct btrfs_path *path; + u64 length; + u64 chunk_offset; + int ret; + int slot; + int failed = 0; + bool retried = false; + struct extent_buffer *l; + struct btrfs_key key; + struct btrfs_super_block *super_copy = fs_info->super_copy; + u64 old_total = btrfs_super_total_bytes(super_copy); + u64 old_size = btrfs_device_get_total_bytes(device); + u64 diff; + u64 start; + + new_size = round_down(new_size, fs_info->sectorsize); + start = new_size; + diff = round_down(old_size - new_size, fs_info->sectorsize); + + if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) + return -EINVAL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = READA_BACK; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + + mutex_lock(&fs_info->chunk_mutex); + + btrfs_device_set_total_bytes(device, new_size); + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + device->fs_devices->total_rw_bytes -= diff; + atomic64_sub(diff, &fs_info->free_chunk_space); + } + + /* + * Once the device's size has been set to the new size, ensure all + * in-memory chunks are synced to disk so that the loop below sees them + * and relocates them accordingly. + */ + if (contains_pending_extent(device, &start, diff)) { + mutex_unlock(&fs_info->chunk_mutex); + ret = btrfs_commit_transaction(trans); + if (ret) + goto done; + } else { + mutex_unlock(&fs_info->chunk_mutex); + btrfs_end_transaction(trans); + } + +again: + key.objectid = device->devid; + key.offset = (u64)-1; + key.type = BTRFS_DEV_EXTENT_KEY; + + do { + mutex_lock(&fs_info->delete_unused_bgs_mutex); + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + goto done; + } + + ret = btrfs_previous_item(root, path, 0, key.type); + if (ret) + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + if (ret < 0) + goto done; + if (ret) { + ret = 0; + btrfs_release_path(path); + break; + } + + l = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(l, &key, path->slots[0]); + + if (key.objectid != device->devid) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + btrfs_release_path(path); + break; + } + + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + length = btrfs_dev_extent_length(l, dev_extent); + + if (key.offset + length <= new_size) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + btrfs_release_path(path); + break; + } + + chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); + btrfs_release_path(path); + + /* + * We may be relocating the only data chunk we have, + * which could potentially end up with losing data's + * raid profile, so lets allocate an empty one in + * advance. + */ + ret = btrfs_may_alloc_data_chunk(fs_info, chunk_offset); + if (ret < 0) { + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + goto done; + } + + ret = btrfs_relocate_chunk(fs_info, chunk_offset); + mutex_unlock(&fs_info->delete_unused_bgs_mutex); + if (ret == -ENOSPC) { + failed++; + } else if (ret) { + if (ret == -ETXTBSY) { + btrfs_warn(fs_info, + "could not shrink block group %llu due to active swapfile", + chunk_offset); + } + goto done; + } + } while (key.offset-- > 0); + + if (failed && !retried) { + failed = 0; + retried = true; + goto again; + } else if (failed && retried) { + ret = -ENOSPC; + goto done; + } + + /* Shrinking succeeded, else we would be at "done". */ + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto done; + } + + mutex_lock(&fs_info->chunk_mutex); + /* Clear all state bits beyond the shrunk device size */ + clear_extent_bits(&device->alloc_state, new_size, (u64)-1, + CHUNK_STATE_MASK); + + btrfs_device_set_disk_total_bytes(device, new_size); + if (list_empty(&device->post_commit_list)) + list_add_tail(&device->post_commit_list, + &trans->transaction->dev_update_list); + + WARN_ON(diff > old_total); + btrfs_set_super_total_bytes(super_copy, + round_down(old_total - diff, fs_info->sectorsize)); + mutex_unlock(&fs_info->chunk_mutex); + + /* Now btrfs_update_device() will change the on-disk size. */ + ret = btrfs_update_device(trans, device); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + } else { + ret = btrfs_commit_transaction(trans); + } +done: + btrfs_free_path(path); + if (ret) { + mutex_lock(&fs_info->chunk_mutex); + btrfs_device_set_total_bytes(device, old_size); + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) + device->fs_devices->total_rw_bytes += diff; + atomic64_add(diff, &fs_info->free_chunk_space); + mutex_unlock(&fs_info->chunk_mutex); + } + return ret; +} + +static int btrfs_add_system_chunk(struct btrfs_fs_info *fs_info, + struct btrfs_key *key, + struct btrfs_chunk *chunk, int item_size) +{ + struct btrfs_super_block *super_copy = fs_info->super_copy; + struct btrfs_disk_key disk_key; + u32 array_size; + u8 *ptr; + + mutex_lock(&fs_info->chunk_mutex); + array_size = btrfs_super_sys_array_size(super_copy); + if (array_size + item_size + sizeof(disk_key) + > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) { + mutex_unlock(&fs_info->chunk_mutex); + return -EFBIG; + } + + ptr = super_copy->sys_chunk_array + array_size; + btrfs_cpu_key_to_disk(&disk_key, key); + memcpy(ptr, &disk_key, sizeof(disk_key)); + ptr += sizeof(disk_key); + memcpy(ptr, chunk, item_size); + item_size += sizeof(disk_key); + btrfs_set_super_sys_array_size(super_copy, array_size + item_size); + mutex_unlock(&fs_info->chunk_mutex); + + return 0; +} + +/* + * sort the devices in descending order by max_avail, total_avail + */ +static int btrfs_cmp_device_info(const void *a, const void *b) +{ + const struct btrfs_device_info *di_a = a; + const struct btrfs_device_info *di_b = b; + + if (di_a->max_avail > di_b->max_avail) + return -1; + if (di_a->max_avail < di_b->max_avail) + return 1; + if (di_a->total_avail > di_b->total_avail) + return -1; + if (di_a->total_avail < di_b->total_avail) + return 1; + return 0; +} + +static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type) +{ + if (!(type & BTRFS_BLOCK_GROUP_RAID56_MASK)) + return; + + btrfs_set_fs_incompat(info, RAID56); +} + +static void check_raid1c34_incompat_flag(struct btrfs_fs_info *info, u64 type) +{ + if (!(type & (BTRFS_BLOCK_GROUP_RAID1C3 | BTRFS_BLOCK_GROUP_RAID1C4))) + return; + + btrfs_set_fs_incompat(info, RAID1C34); +} + +/* + * Structure used internally for __btrfs_alloc_chunk() function. + * Wraps needed parameters. + */ +struct alloc_chunk_ctl { + u64 start; + u64 type; + /* Total number of stripes to allocate */ + int num_stripes; + /* sub_stripes info for map */ + int sub_stripes; + /* Stripes per device */ + int dev_stripes; + /* Maximum number of devices to use */ + int devs_max; + /* Minimum number of devices to use */ + int devs_min; + /* ndevs has to be a multiple of this */ + int devs_increment; + /* Number of copies */ + int ncopies; + /* Number of stripes worth of bytes to store parity information */ + int nparity; + u64 max_stripe_size; + u64 max_chunk_size; + u64 dev_extent_min; + u64 stripe_size; + u64 chunk_size; + int ndevs; +}; + +static void init_alloc_chunk_ctl_policy_regular( + struct btrfs_fs_devices *fs_devices, + struct alloc_chunk_ctl *ctl) +{ + u64 type = ctl->type; + + if (type & BTRFS_BLOCK_GROUP_DATA) { + ctl->max_stripe_size = SZ_1G; + ctl->max_chunk_size = BTRFS_MAX_DATA_CHUNK_SIZE; + } else if (type & BTRFS_BLOCK_GROUP_METADATA) { + /* For larger filesystems, use larger metadata chunks */ + if (fs_devices->total_rw_bytes > 50ULL * SZ_1G) + ctl->max_stripe_size = SZ_1G; + else + ctl->max_stripe_size = SZ_256M; + ctl->max_chunk_size = ctl->max_stripe_size; + } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) { + ctl->max_stripe_size = SZ_32M; + ctl->max_chunk_size = 2 * ctl->max_stripe_size; + ctl->devs_max = min_t(int, ctl->devs_max, + BTRFS_MAX_DEVS_SYS_CHUNK); + } else { + BUG(); + } + + /* We don't want a chunk larger than 10% of writable space */ + ctl->max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1), + ctl->max_chunk_size); + ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes; +} + +static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices, + struct alloc_chunk_ctl *ctl) +{ + int index = btrfs_bg_flags_to_raid_index(ctl->type); + + ctl->sub_stripes = btrfs_raid_array[index].sub_stripes; + ctl->dev_stripes = btrfs_raid_array[index].dev_stripes; + ctl->devs_max = btrfs_raid_array[index].devs_max; + if (!ctl->devs_max) + ctl->devs_max = BTRFS_MAX_DEVS(fs_devices->fs_info); + ctl->devs_min = btrfs_raid_array[index].devs_min; + ctl->devs_increment = btrfs_raid_array[index].devs_increment; + ctl->ncopies = btrfs_raid_array[index].ncopies; + ctl->nparity = btrfs_raid_array[index].nparity; + ctl->ndevs = 0; + + switch (fs_devices->chunk_alloc_policy) { + case BTRFS_CHUNK_ALLOC_REGULAR: + init_alloc_chunk_ctl_policy_regular(fs_devices, ctl); + break; + default: + BUG(); + } +} + +static int gather_device_info(struct btrfs_fs_devices *fs_devices, + struct alloc_chunk_ctl *ctl, + struct btrfs_device_info *devices_info) +{ + struct btrfs_fs_info *info = fs_devices->fs_info; + struct btrfs_device *device; + u64 total_avail; + u64 dev_extent_want = ctl->max_stripe_size * ctl->dev_stripes; + int ret; + int ndevs = 0; + u64 max_avail; + u64 dev_offset; + + /* + * in the first pass through the devices list, we gather information + * about the available holes on each device. + */ + list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { + if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + WARN(1, KERN_ERR + "BTRFS: read-only device in alloc_list\n"); + continue; + } + + if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, + &device->dev_state) || + test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) + continue; + + if (device->total_bytes > device->bytes_used) + total_avail = device->total_bytes - device->bytes_used; + else + total_avail = 0; + + /* If there is no space on this device, skip it. */ + if (total_avail < ctl->dev_extent_min) + continue; + + ret = find_free_dev_extent(device, dev_extent_want, &dev_offset, + &max_avail); + if (ret && ret != -ENOSPC) + return ret; + + if (ret == 0) + max_avail = dev_extent_want; + + if (max_avail < ctl->dev_extent_min) { + if (btrfs_test_opt(info, ENOSPC_DEBUG)) + btrfs_debug(info, + "%s: devid %llu has no free space, have=%llu want=%llu", + __func__, device->devid, max_avail, + ctl->dev_extent_min); + continue; + } + + if (ndevs == fs_devices->rw_devices) { + WARN(1, "%s: found more than %llu devices\n", + __func__, fs_devices->rw_devices); + break; + } + devices_info[ndevs].dev_offset = dev_offset; + devices_info[ndevs].max_avail = max_avail; + devices_info[ndevs].total_avail = total_avail; + devices_info[ndevs].dev = device; + ++ndevs; + } + ctl->ndevs = ndevs; + + /* + * now sort the devices by hole size / available space + */ + sort(devices_info, ndevs, sizeof(struct btrfs_device_info), + btrfs_cmp_device_info, NULL); + + return 0; +} + +static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl, + struct btrfs_device_info *devices_info) +{ + /* Number of stripes that count for block group size */ + int data_stripes; + + /* + * The primary goal is to maximize the number of stripes, so use as + * many devices as possible, even if the stripes are not maximum sized. + * + * The DUP profile stores more than one stripe per device, the + * max_avail is the total size so we have to adjust. + */ + ctl->stripe_size = div_u64(devices_info[ctl->ndevs - 1].max_avail, + ctl->dev_stripes); + ctl->num_stripes = ctl->ndevs * ctl->dev_stripes; + + /* This will have to be fixed for RAID1 and RAID10 over more drives */ + data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies; + + /* + * Use the number of data stripes to figure out how big this chunk is + * really going to be in terms of logical address space, and compare + * that answer with the max chunk size. If it's higher, we try to + * reduce stripe_size. + */ + if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) { + /* + * Reduce stripe_size, round it up to a 16MB boundary again and + * then use it, unless it ends up being even bigger than the + * previous value we had already. + */ + ctl->stripe_size = min(round_up(div_u64(ctl->max_chunk_size, + data_stripes), SZ_16M), + ctl->stripe_size); + } + + /* Align to BTRFS_STRIPE_LEN */ + ctl->stripe_size = round_down(ctl->stripe_size, BTRFS_STRIPE_LEN); + ctl->chunk_size = ctl->stripe_size * data_stripes; + + return 0; +} + +static int decide_stripe_size(struct btrfs_fs_devices *fs_devices, + struct alloc_chunk_ctl *ctl, + struct btrfs_device_info *devices_info) +{ + struct btrfs_fs_info *info = fs_devices->fs_info; + + /* + * Round down to number of usable stripes, devs_increment can be any + * number so we can't use round_down() that requires power of 2, while + * rounddown is safe. + */ + ctl->ndevs = rounddown(ctl->ndevs, ctl->devs_increment); + + if (ctl->ndevs < ctl->devs_min) { + if (btrfs_test_opt(info, ENOSPC_DEBUG)) { + btrfs_debug(info, + "%s: not enough devices with free space: have=%d minimum required=%d", + __func__, ctl->ndevs, ctl->devs_min); + } + return -ENOSPC; + } + + ctl->ndevs = min(ctl->ndevs, ctl->devs_max); + + switch (fs_devices->chunk_alloc_policy) { + case BTRFS_CHUNK_ALLOC_REGULAR: + return decide_stripe_size_regular(ctl, devices_info); + default: + BUG(); + } +} + +static int create_chunk(struct btrfs_trans_handle *trans, + struct alloc_chunk_ctl *ctl, + struct btrfs_device_info *devices_info) +{ + struct btrfs_fs_info *info = trans->fs_info; + struct map_lookup *map = NULL; + struct extent_map_tree *em_tree; + struct extent_map *em; + u64 start = ctl->start; + u64 type = ctl->type; + int ret; + int i; + int j; + + map = kmalloc(map_lookup_size(ctl->num_stripes), GFP_NOFS); + if (!map) + return -ENOMEM; + map->num_stripes = ctl->num_stripes; + + for (i = 0; i < ctl->ndevs; ++i) { + for (j = 0; j < ctl->dev_stripes; ++j) { + int s = i * ctl->dev_stripes + j; + map->stripes[s].dev = devices_info[i].dev; + map->stripes[s].physical = devices_info[i].dev_offset + + j * ctl->stripe_size; + } + } + map->stripe_len = BTRFS_STRIPE_LEN; + map->io_align = BTRFS_STRIPE_LEN; + map->io_width = BTRFS_STRIPE_LEN; + map->type = type; + map->sub_stripes = ctl->sub_stripes; + + trace_btrfs_chunk_alloc(info, map, start, ctl->chunk_size); + + em = alloc_extent_map(); + if (!em) { + kfree(map); + return -ENOMEM; + } + set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags); + em->map_lookup = map; + em->start = start; + em->len = ctl->chunk_size; + em->block_start = 0; + em->block_len = em->len; + em->orig_block_len = ctl->stripe_size; + + em_tree = &info->mapping_tree; + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em, 0); + if (ret) { + write_unlock(&em_tree->lock); + free_extent_map(em); + return ret; + } + write_unlock(&em_tree->lock); + + ret = btrfs_make_block_group(trans, 0, type, start, ctl->chunk_size); + if (ret) + goto error_del_extent; + + for (i = 0; i < map->num_stripes; i++) { + struct btrfs_device *dev = map->stripes[i].dev; + + btrfs_device_set_bytes_used(dev, + dev->bytes_used + ctl->stripe_size); + if (list_empty(&dev->post_commit_list)) + list_add_tail(&dev->post_commit_list, + &trans->transaction->dev_update_list); + } + + atomic64_sub(ctl->stripe_size * map->num_stripes, + &info->free_chunk_space); + + free_extent_map(em); + check_raid56_incompat_flag(info, type); + check_raid1c34_incompat_flag(info, type); + + return 0; + +error_del_extent: + write_lock(&em_tree->lock); + remove_extent_mapping(em_tree, em); + write_unlock(&em_tree->lock); + + /* One for our allocation */ + free_extent_map(em); + /* One for the tree reference */ + free_extent_map(em); + + return ret; +} + +int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type) +{ + struct btrfs_fs_info *info = trans->fs_info; + struct btrfs_fs_devices *fs_devices = info->fs_devices; + struct btrfs_device_info *devices_info = NULL; + struct alloc_chunk_ctl ctl; + int ret; + + lockdep_assert_held(&info->chunk_mutex); + + if (!alloc_profile_is_valid(type, 0)) { + ASSERT(0); + return -EINVAL; + } + + if (list_empty(&fs_devices->alloc_list)) { + if (btrfs_test_opt(info, ENOSPC_DEBUG)) + btrfs_debug(info, "%s: no writable device", __func__); + return -ENOSPC; + } + + if (!(type & BTRFS_BLOCK_GROUP_TYPE_MASK)) { + btrfs_err(info, "invalid chunk type 0x%llx requested", type); + ASSERT(0); + return -EINVAL; + } + + ctl.start = find_next_chunk(info); + ctl.type = type; + init_alloc_chunk_ctl(fs_devices, &ctl); + + devices_info = kcalloc(fs_devices->rw_devices, sizeof(*devices_info), + GFP_NOFS); + if (!devices_info) + return -ENOMEM; + + ret = gather_device_info(fs_devices, &ctl, devices_info); + if (ret < 0) + goto out; + + ret = decide_stripe_size(fs_devices, &ctl, devices_info); + if (ret < 0) + goto out; + + ret = create_chunk(trans, &ctl, devices_info); + +out: + kfree(devices_info); + return ret; +} + +/* + * Chunk allocation falls into two parts. The first part does work + * that makes the new allocated chunk usable, but does not do any operation + * that modifies the chunk tree. The second part does the work that + * requires modifying the chunk tree. This division is important for the + * bootstrap process of adding storage to a seed btrfs. + */ +int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans, + u64 chunk_offset, u64 chunk_size) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *extent_root = fs_info->extent_root; + struct btrfs_root *chunk_root = fs_info->chunk_root; + struct btrfs_key key; + struct btrfs_device *device; + struct btrfs_chunk *chunk; + struct btrfs_stripe *stripe; + struct extent_map *em; + struct map_lookup *map; + size_t item_size; + u64 dev_offset; + u64 stripe_size; + int i = 0; + int ret = 0; + + em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size); + if (IS_ERR(em)) + return PTR_ERR(em); + + map = em->map_lookup; + item_size = btrfs_chunk_item_size(map->num_stripes); + stripe_size = em->orig_block_len; + + chunk = kzalloc(item_size, GFP_NOFS); + if (!chunk) { + ret = -ENOMEM; + goto out; + } + + /* + * Take the device list mutex to prevent races with the final phase of + * a device replace operation that replaces the device object associated + * with the map's stripes, because the device object's id can change + * at any time during that final phase of the device replace operation + * (dev-replace.c:btrfs_dev_replace_finishing()). + */ + mutex_lock(&fs_info->fs_devices->device_list_mutex); + for (i = 0; i < map->num_stripes; i++) { + device = map->stripes[i].dev; + dev_offset = map->stripes[i].physical; + + ret = btrfs_update_device(trans, device); + if (ret) + break; + ret = btrfs_alloc_dev_extent(trans, device, chunk_offset, + dev_offset, stripe_size); + if (ret) + break; + } + if (ret) { + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + goto out; + } + + stripe = &chunk->stripe; + for (i = 0; i < map->num_stripes; i++) { + device = map->stripes[i].dev; + dev_offset = map->stripes[i].physical; + + btrfs_set_stack_stripe_devid(stripe, device->devid); + btrfs_set_stack_stripe_offset(stripe, dev_offset); + memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE); + stripe++; + } + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + + btrfs_set_stack_chunk_length(chunk, chunk_size); + btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid); + btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len); + btrfs_set_stack_chunk_type(chunk, map->type); + btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes); + btrfs_set_stack_chunk_io_align(chunk, map->stripe_len); + btrfs_set_stack_chunk_io_width(chunk, map->stripe_len); + btrfs_set_stack_chunk_sector_size(chunk, fs_info->sectorsize); + btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes); + + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.type = BTRFS_CHUNK_ITEM_KEY; + key.offset = chunk_offset; + + ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size); + if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) { + /* + * TODO: Cleanup of inserted chunk root in case of + * failure. + */ + ret = btrfs_add_system_chunk(fs_info, &key, chunk, item_size); + } + +out: + kfree(chunk); + free_extent_map(em); + return ret; +} + +static noinline int init_first_rw_device(struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + u64 alloc_profile; + int ret; + + alloc_profile = btrfs_metadata_alloc_profile(fs_info); + ret = btrfs_alloc_chunk(trans, alloc_profile); + if (ret) + return ret; + + alloc_profile = btrfs_system_alloc_profile(fs_info); + ret = btrfs_alloc_chunk(trans, alloc_profile); + return ret; +} + +static inline int btrfs_chunk_max_errors(struct map_lookup *map) +{ + const int index = btrfs_bg_flags_to_raid_index(map->type); + + return btrfs_raid_array[index].tolerated_failures; +} + +int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset) +{ + struct extent_map *em; + struct map_lookup *map; + int readonly = 0; + int miss_ndevs = 0; + int i; + + em = btrfs_get_chunk_map(fs_info, chunk_offset, 1); + if (IS_ERR(em)) + return 1; + + map = em->map_lookup; + for (i = 0; i < map->num_stripes; i++) { + if (test_bit(BTRFS_DEV_STATE_MISSING, + &map->stripes[i].dev->dev_state)) { + miss_ndevs++; + continue; + } + if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, + &map->stripes[i].dev->dev_state)) { + readonly = 1; + goto end; + } + } + + /* + * If the number of missing devices is larger than max errors, + * we can not write the data into that chunk successfully, so + * set it readonly. + */ + if (miss_ndevs > btrfs_chunk_max_errors(map)) + readonly = 1; +end: + free_extent_map(em); + return readonly; +} + +void btrfs_mapping_tree_free(struct extent_map_tree *tree) +{ + struct extent_map *em; + + while (1) { + write_lock(&tree->lock); + em = lookup_extent_mapping(tree, 0, (u64)-1); + if (em) + remove_extent_mapping(tree, em); + write_unlock(&tree->lock); + if (!em) + break; + /* once for us */ + free_extent_map(em); + /* once for the tree */ + free_extent_map(em); + } +} + +int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) +{ + struct extent_map *em; + struct map_lookup *map; + int ret; + + em = btrfs_get_chunk_map(fs_info, logical, len); + if (IS_ERR(em)) + /* + * We could return errors for these cases, but that could get + * ugly and we'd probably do the same thing which is just not do + * anything else and exit, so return 1 so the callers don't try + * to use other copies. + */ + return 1; + + map = em->map_lookup; + if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1_MASK)) + ret = map->num_stripes; + else if (map->type & BTRFS_BLOCK_GROUP_RAID10) + ret = map->sub_stripes; + else if (map->type & BTRFS_BLOCK_GROUP_RAID5) + ret = 2; + else if (map->type & BTRFS_BLOCK_GROUP_RAID6) + /* + * There could be two corrupted data stripes, we need + * to loop retry in order to rebuild the correct data. + * + * Fail a stripe at a time on every retry except the + * stripe under reconstruction. + */ + ret = map->num_stripes; + else + ret = 1; + free_extent_map(em); + + down_read(&fs_info->dev_replace.rwsem); + if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace) && + fs_info->dev_replace.tgtdev) + ret++; + up_read(&fs_info->dev_replace.rwsem); + + return ret; +} + +unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info, + u64 logical) +{ + struct extent_map *em; + struct map_lookup *map; + unsigned long len = fs_info->sectorsize; + + em = btrfs_get_chunk_map(fs_info, logical, len); + + if (!WARN_ON(IS_ERR(em))) { + map = em->map_lookup; + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) + len = map->stripe_len * nr_data_stripes(map); + free_extent_map(em); + } + return len; +} + +int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info, u64 logical, u64 len) +{ + struct extent_map *em; + struct map_lookup *map; + int ret = 0; + + em = btrfs_get_chunk_map(fs_info, logical, len); + + if(!WARN_ON(IS_ERR(em))) { + map = em->map_lookup; + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) + ret = 1; + free_extent_map(em); + } + return ret; +} + +static int find_live_mirror(struct btrfs_fs_info *fs_info, + struct map_lookup *map, int first, + int dev_replace_is_ongoing) +{ + int i; + int num_stripes; + int preferred_mirror; + int tolerance; + struct btrfs_device *srcdev; + + ASSERT((map->type & + (BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID10))); + + if (map->type & BTRFS_BLOCK_GROUP_RAID10) + num_stripes = map->sub_stripes; + else + num_stripes = map->num_stripes; + + preferred_mirror = first + current->pid % num_stripes; + + if (dev_replace_is_ongoing && + fs_info->dev_replace.cont_reading_from_srcdev_mode == + BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID) + srcdev = fs_info->dev_replace.srcdev; + else + srcdev = NULL; + + /* + * try to avoid the drive that is the source drive for a + * dev-replace procedure, only choose it if no other non-missing + * mirror is available + */ + for (tolerance = 0; tolerance < 2; tolerance++) { + if (map->stripes[preferred_mirror].dev->bdev && + (tolerance || map->stripes[preferred_mirror].dev != srcdev)) + return preferred_mirror; + for (i = first; i < first + num_stripes; i++) { + if (map->stripes[i].dev->bdev && + (tolerance || map->stripes[i].dev != srcdev)) + return i; + } + } + + /* we couldn't find one that doesn't fail. Just return something + * and the io error handling code will clean up eventually + */ + return preferred_mirror; +} + +/* Bubble-sort the stripe set to put the parity/syndrome stripes last */ +static void sort_parity_stripes(struct btrfs_bio *bbio, int num_stripes) +{ + int i; + int again = 1; + + while (again) { + again = 0; + for (i = 0; i < num_stripes - 1; i++) { + /* Swap if parity is on a smaller index */ + if (bbio->raid_map[i] > bbio->raid_map[i + 1]) { + swap(bbio->stripes[i], bbio->stripes[i + 1]); + swap(bbio->raid_map[i], bbio->raid_map[i + 1]); + again = 1; + } + } + } +} + +static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes) +{ + struct btrfs_bio *bbio = kzalloc( + /* the size of the btrfs_bio */ + sizeof(struct btrfs_bio) + + /* plus the variable array for the stripes */ + sizeof(struct btrfs_bio_stripe) * (total_stripes) + + /* plus the variable array for the tgt dev */ + sizeof(int) * (real_stripes) + + /* + * plus the raid_map, which includes both the tgt dev + * and the stripes + */ + sizeof(u64) * (total_stripes), + GFP_NOFS|__GFP_NOFAIL); + + atomic_set(&bbio->error, 0); + refcount_set(&bbio->refs, 1); + + bbio->tgtdev_map = (int *)(bbio->stripes + total_stripes); + bbio->raid_map = (u64 *)(bbio->tgtdev_map + real_stripes); + + return bbio; +} + +void btrfs_get_bbio(struct btrfs_bio *bbio) +{ + WARN_ON(!refcount_read(&bbio->refs)); + refcount_inc(&bbio->refs); +} + +void btrfs_put_bbio(struct btrfs_bio *bbio) +{ + if (!bbio) + return; + if (refcount_dec_and_test(&bbio->refs)) + kfree(bbio); +} + +/* can REQ_OP_DISCARD be sent with other REQ like REQ_OP_WRITE? */ +/* + * Please note that, discard won't be sent to target device of device + * replace. + */ +static int __btrfs_map_block_for_discard(struct btrfs_fs_info *fs_info, + u64 logical, u64 *length_ret, + struct btrfs_bio **bbio_ret) +{ + struct extent_map *em; + struct map_lookup *map; + struct btrfs_bio *bbio; + u64 length = *length_ret; + u64 offset; + u64 stripe_nr; + u64 stripe_nr_end; + u64 stripe_end_offset; + u64 stripe_cnt; + u64 stripe_len; + u64 stripe_offset; + u64 num_stripes; + u32 stripe_index; + u32 factor = 0; + u32 sub_stripes = 0; + u64 stripes_per_dev = 0; + u32 remaining_stripes = 0; + u32 last_stripe = 0; + int ret = 0; + int i; + + /* discard always return a bbio */ + ASSERT(bbio_ret); + + em = btrfs_get_chunk_map(fs_info, logical, length); + if (IS_ERR(em)) + return PTR_ERR(em); + + map = em->map_lookup; + /* we don't discard raid56 yet */ + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { + ret = -EOPNOTSUPP; + goto out; + } + + offset = logical - em->start; + length = min_t(u64, em->start + em->len - logical, length); + *length_ret = length; + + stripe_len = map->stripe_len; + /* + * stripe_nr counts the total number of stripes we have to stride + * to get to this block + */ + stripe_nr = div64_u64(offset, stripe_len); + + /* stripe_offset is the offset of this block in its stripe */ + stripe_offset = offset - stripe_nr * stripe_len; + + stripe_nr_end = round_up(offset + length, map->stripe_len); + stripe_nr_end = div64_u64(stripe_nr_end, map->stripe_len); + stripe_cnt = stripe_nr_end - stripe_nr; + stripe_end_offset = stripe_nr_end * map->stripe_len - + (offset + length); + /* + * after this, stripe_nr is the number of stripes on this + * device we have to walk to find the data, and stripe_index is + * the number of our device in the stripe array + */ + num_stripes = 1; + stripe_index = 0; + if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)) { + if (map->type & BTRFS_BLOCK_GROUP_RAID0) + sub_stripes = 1; + else + sub_stripes = map->sub_stripes; + + factor = map->num_stripes / sub_stripes; + num_stripes = min_t(u64, map->num_stripes, + sub_stripes * stripe_cnt); + stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index); + stripe_index *= sub_stripes; + stripes_per_dev = div_u64_rem(stripe_cnt, factor, + &remaining_stripes); + div_u64_rem(stripe_nr_end - 1, factor, &last_stripe); + last_stripe *= sub_stripes; + } else if (map->type & (BTRFS_BLOCK_GROUP_RAID1_MASK | + BTRFS_BLOCK_GROUP_DUP)) { + num_stripes = map->num_stripes; + } else { + stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, + &stripe_index); + } + + bbio = alloc_btrfs_bio(num_stripes, 0); + if (!bbio) { + ret = -ENOMEM; + goto out; + } + + for (i = 0; i < num_stripes; i++) { + bbio->stripes[i].physical = + map->stripes[stripe_index].physical + + stripe_offset + stripe_nr * map->stripe_len; + bbio->stripes[i].dev = map->stripes[stripe_index].dev; + + if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)) { + bbio->stripes[i].length = stripes_per_dev * + map->stripe_len; + + if (i / sub_stripes < remaining_stripes) + bbio->stripes[i].length += + map->stripe_len; + + /* + * Special for the first stripe and + * the last stripe: + * + * |-------|...|-------| + * |----------| + * off end_off + */ + if (i < sub_stripes) + bbio->stripes[i].length -= + stripe_offset; + + if (stripe_index >= last_stripe && + stripe_index <= (last_stripe + + sub_stripes - 1)) + bbio->stripes[i].length -= + stripe_end_offset; + + if (i == sub_stripes - 1) + stripe_offset = 0; + } else { + bbio->stripes[i].length = length; + } + + stripe_index++; + if (stripe_index == map->num_stripes) { + stripe_index = 0; + stripe_nr++; + } + } + + *bbio_ret = bbio; + bbio->map_type = map->type; + bbio->num_stripes = num_stripes; +out: + free_extent_map(em); + return ret; +} + +/* + * In dev-replace case, for repair case (that's the only case where the mirror + * is selected explicitly when calling btrfs_map_block), blocks left of the + * left cursor can also be read from the target drive. + * + * For REQ_GET_READ_MIRRORS, the target drive is added as the last one to the + * array of stripes. + * For READ, it also needs to be supported using the same mirror number. + * + * If the requested block is not left of the left cursor, EIO is returned. This + * can happen because btrfs_num_copies() returns one more in the dev-replace + * case. + */ +static int get_extra_mirror_from_replace(struct btrfs_fs_info *fs_info, + u64 logical, u64 length, + u64 srcdev_devid, int *mirror_num, + u64 *physical) +{ + struct btrfs_bio *bbio = NULL; + int num_stripes; + int index_srcdev = 0; + int found = 0; + u64 physical_of_found = 0; + int i; + int ret = 0; + + ret = __btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS, + logical, &length, &bbio, 0, 0); + if (ret) { + ASSERT(bbio == NULL); + return ret; + } + + num_stripes = bbio->num_stripes; + if (*mirror_num > num_stripes) { + /* + * BTRFS_MAP_GET_READ_MIRRORS does not contain this mirror, + * that means that the requested area is not left of the left + * cursor + */ + btrfs_put_bbio(bbio); + return -EIO; + } + + /* + * process the rest of the function using the mirror_num of the source + * drive. Therefore look it up first. At the end, patch the device + * pointer to the one of the target drive. + */ + for (i = 0; i < num_stripes; i++) { + if (bbio->stripes[i].dev->devid != srcdev_devid) + continue; + + /* + * In case of DUP, in order to keep it simple, only add the + * mirror with the lowest physical address + */ + if (found && + physical_of_found <= bbio->stripes[i].physical) + continue; + + index_srcdev = i; + found = 1; + physical_of_found = bbio->stripes[i].physical; + } + + btrfs_put_bbio(bbio); + + ASSERT(found); + if (!found) + return -EIO; + + *mirror_num = index_srcdev + 1; + *physical = physical_of_found; + return ret; +} + +static void handle_ops_on_dev_replace(enum btrfs_map_op op, + struct btrfs_bio **bbio_ret, + struct btrfs_dev_replace *dev_replace, + int *num_stripes_ret, int *max_errors_ret) +{ + struct btrfs_bio *bbio = *bbio_ret; + u64 srcdev_devid = dev_replace->srcdev->devid; + int tgtdev_indexes = 0; + int num_stripes = *num_stripes_ret; + int max_errors = *max_errors_ret; + int i; + + if (op == BTRFS_MAP_WRITE) { + int index_where_to_add; + + /* + * duplicate the write operations while the dev replace + * procedure is running. Since the copying of the old disk to + * the new disk takes place at run time while the filesystem is + * mounted writable, the regular write operations to the old + * disk have to be duplicated to go to the new disk as well. + * + * Note that device->missing is handled by the caller, and that + * the write to the old disk is already set up in the stripes + * array. + */ + index_where_to_add = num_stripes; + for (i = 0; i < num_stripes; i++) { + if (bbio->stripes[i].dev->devid == srcdev_devid) { + /* write to new disk, too */ + struct btrfs_bio_stripe *new = + bbio->stripes + index_where_to_add; + struct btrfs_bio_stripe *old = + bbio->stripes + i; + + new->physical = old->physical; + new->length = old->length; + new->dev = dev_replace->tgtdev; + bbio->tgtdev_map[i] = index_where_to_add; + index_where_to_add++; + max_errors++; + tgtdev_indexes++; + } + } + num_stripes = index_where_to_add; + } else if (op == BTRFS_MAP_GET_READ_MIRRORS) { + int index_srcdev = 0; + int found = 0; + u64 physical_of_found = 0; + + /* + * During the dev-replace procedure, the target drive can also + * be used to read data in case it is needed to repair a corrupt + * block elsewhere. This is possible if the requested area is + * left of the left cursor. In this area, the target drive is a + * full copy of the source drive. + */ + for (i = 0; i < num_stripes; i++) { + if (bbio->stripes[i].dev->devid == srcdev_devid) { + /* + * In case of DUP, in order to keep it simple, + * only add the mirror with the lowest physical + * address + */ + if (found && + physical_of_found <= + bbio->stripes[i].physical) + continue; + index_srcdev = i; + found = 1; + physical_of_found = bbio->stripes[i].physical; + } + } + if (found) { + struct btrfs_bio_stripe *tgtdev_stripe = + bbio->stripes + num_stripes; + + tgtdev_stripe->physical = physical_of_found; + tgtdev_stripe->length = + bbio->stripes[index_srcdev].length; + tgtdev_stripe->dev = dev_replace->tgtdev; + bbio->tgtdev_map[index_srcdev] = num_stripes; + + tgtdev_indexes++; + num_stripes++; + } + } + + *num_stripes_ret = num_stripes; + *max_errors_ret = max_errors; + bbio->num_tgtdevs = tgtdev_indexes; + *bbio_ret = bbio; +} + +static bool need_full_stripe(enum btrfs_map_op op) +{ + return (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS); +} + +/* + * btrfs_get_io_geometry - calculates the geomery of a particular (address, len) + * tuple. This information is used to calculate how big a + * particular bio can get before it straddles a stripe. + * + * @fs_info - the filesystem + * @logical - address that we want to figure out the geometry of + * @len - the length of IO we are going to perform, starting at @logical + * @op - type of operation - write or read + * @io_geom - pointer used to return values + * + * Returns < 0 in case a chunk for the given logical address cannot be found, + * usually shouldn't happen unless @logical is corrupted, 0 otherwise. + */ +int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, + u64 logical, u64 len, struct btrfs_io_geometry *io_geom) +{ + struct extent_map *em; + struct map_lookup *map; + u64 offset; + u64 stripe_offset; + u64 stripe_nr; + u64 stripe_len; + u64 raid56_full_stripe_start = (u64)-1; + int data_stripes; + int ret = 0; + + ASSERT(op != BTRFS_MAP_DISCARD); + + em = btrfs_get_chunk_map(fs_info, logical, len); + if (IS_ERR(em)) + return PTR_ERR(em); + + map = em->map_lookup; + /* Offset of this logical address in the chunk */ + offset = logical - em->start; + /* Len of a stripe in a chunk */ + stripe_len = map->stripe_len; + /* Stripe wher this block falls in */ + stripe_nr = div64_u64(offset, stripe_len); + /* Offset of stripe in the chunk */ + stripe_offset = stripe_nr * stripe_len; + if (offset < stripe_offset) { + btrfs_crit(fs_info, +"stripe math has gone wrong, stripe_offset=%llu offset=%llu start=%llu logical=%llu stripe_len=%llu", + stripe_offset, offset, em->start, logical, stripe_len); + ret = -EINVAL; + goto out; + } + + /* stripe_offset is the offset of this block in its stripe */ + stripe_offset = offset - stripe_offset; + data_stripes = nr_data_stripes(map); + + if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) { + u64 max_len = stripe_len - stripe_offset; + + /* + * In case of raid56, we need to know the stripe aligned start + */ + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { + unsigned long full_stripe_len = stripe_len * data_stripes; + raid56_full_stripe_start = offset; + + /* + * Allow a write of a full stripe, but make sure we + * don't allow straddling of stripes + */ + raid56_full_stripe_start = div64_u64(raid56_full_stripe_start, + full_stripe_len); + raid56_full_stripe_start *= full_stripe_len; + + /* + * For writes to RAID[56], allow a full stripeset across + * all disks. For other RAID types and for RAID[56] + * reads, just allow a single stripe (on a single disk). + */ + if (op == BTRFS_MAP_WRITE) { + max_len = stripe_len * data_stripes - + (offset - raid56_full_stripe_start); + } + } + len = min_t(u64, em->len - offset, max_len); + } else { + len = em->len - offset; + } + + io_geom->len = len; + io_geom->offset = offset; + io_geom->stripe_len = stripe_len; + io_geom->stripe_nr = stripe_nr; + io_geom->stripe_offset = stripe_offset; + io_geom->raid56_stripe_offset = raid56_full_stripe_start; + +out: + /* once for us */ + free_extent_map(em); + return ret; +} + +static int __btrfs_map_block(struct btrfs_fs_info *fs_info, + enum btrfs_map_op op, + u64 logical, u64 *length, + struct btrfs_bio **bbio_ret, + int mirror_num, int need_raid_map) +{ + struct extent_map *em; + struct map_lookup *map; + u64 stripe_offset; + u64 stripe_nr; + u64 stripe_len; + u32 stripe_index; + int data_stripes; + int i; + int ret = 0; + int num_stripes; + int max_errors = 0; + int tgtdev_indexes = 0; + struct btrfs_bio *bbio = NULL; + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + int dev_replace_is_ongoing = 0; + int num_alloc_stripes; + int patch_the_first_stripe_for_dev_replace = 0; + u64 physical_to_patch_in_first_stripe = 0; + u64 raid56_full_stripe_start = (u64)-1; + struct btrfs_io_geometry geom; + + ASSERT(bbio_ret); + ASSERT(op != BTRFS_MAP_DISCARD); + + ret = btrfs_get_io_geometry(fs_info, op, logical, *length, &geom); + if (ret < 0) + return ret; + + em = btrfs_get_chunk_map(fs_info, logical, *length); + ASSERT(!IS_ERR(em)); + map = em->map_lookup; + + *length = geom.len; + stripe_len = geom.stripe_len; + stripe_nr = geom.stripe_nr; + stripe_offset = geom.stripe_offset; + raid56_full_stripe_start = geom.raid56_stripe_offset; + data_stripes = nr_data_stripes(map); + + down_read(&dev_replace->rwsem); + dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace); + /* + * Hold the semaphore for read during the whole operation, write is + * requested at commit time but must wait. + */ + if (!dev_replace_is_ongoing) + up_read(&dev_replace->rwsem); + + if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 && + !need_full_stripe(op) && dev_replace->tgtdev != NULL) { + ret = get_extra_mirror_from_replace(fs_info, logical, *length, + dev_replace->srcdev->devid, + &mirror_num, + &physical_to_patch_in_first_stripe); + if (ret) + goto out; + else + patch_the_first_stripe_for_dev_replace = 1; + } else if (mirror_num > map->num_stripes) { + mirror_num = 0; + } + + num_stripes = 1; + stripe_index = 0; + if (map->type & BTRFS_BLOCK_GROUP_RAID0) { + stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, + &stripe_index); + if (!need_full_stripe(op)) + mirror_num = 1; + } else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) { + if (need_full_stripe(op)) + num_stripes = map->num_stripes; + else if (mirror_num) + stripe_index = mirror_num - 1; + else { + stripe_index = find_live_mirror(fs_info, map, 0, + dev_replace_is_ongoing); + mirror_num = stripe_index + 1; + } + + } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { + if (need_full_stripe(op)) { + num_stripes = map->num_stripes; + } else if (mirror_num) { + stripe_index = mirror_num - 1; + } else { + mirror_num = 1; + } + + } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { + u32 factor = map->num_stripes / map->sub_stripes; + + stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index); + stripe_index *= map->sub_stripes; + + if (need_full_stripe(op)) + num_stripes = map->sub_stripes; + else if (mirror_num) + stripe_index += mirror_num - 1; + else { + int old_stripe_index = stripe_index; + stripe_index = find_live_mirror(fs_info, map, + stripe_index, + dev_replace_is_ongoing); + mirror_num = stripe_index - old_stripe_index + 1; + } + + } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { + if (need_raid_map && (need_full_stripe(op) || mirror_num > 1)) { + /* push stripe_nr back to the start of the full stripe */ + stripe_nr = div64_u64(raid56_full_stripe_start, + stripe_len * data_stripes); + + /* RAID[56] write or recovery. Return all stripes */ + num_stripes = map->num_stripes; + max_errors = nr_parity_stripes(map); + + *length = map->stripe_len; + stripe_index = 0; + stripe_offset = 0; + } else { + /* + * Mirror #0 or #1 means the original data block. + * Mirror #2 is RAID5 parity block. + * Mirror #3 is RAID6 Q block. + */ + stripe_nr = div_u64_rem(stripe_nr, + data_stripes, &stripe_index); + if (mirror_num > 1) + stripe_index = data_stripes + mirror_num - 2; + + /* We distribute the parity blocks across stripes */ + div_u64_rem(stripe_nr + stripe_index, map->num_stripes, + &stripe_index); + if (!need_full_stripe(op) && mirror_num <= 1) + mirror_num = 1; + } + } else { + /* + * after this, stripe_nr is the number of stripes on this + * device we have to walk to find the data, and stripe_index is + * the number of our device in the stripe array + */ + stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, + &stripe_index); + mirror_num = stripe_index + 1; + } + if (stripe_index >= map->num_stripes) { + btrfs_crit(fs_info, + "stripe index math went horribly wrong, got stripe_index=%u, num_stripes=%u", + stripe_index, map->num_stripes); + ret = -EINVAL; + goto out; + } + + num_alloc_stripes = num_stripes; + if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL) { + if (op == BTRFS_MAP_WRITE) + num_alloc_stripes <<= 1; + if (op == BTRFS_MAP_GET_READ_MIRRORS) + num_alloc_stripes++; + tgtdev_indexes = num_stripes; + } + + bbio = alloc_btrfs_bio(num_alloc_stripes, tgtdev_indexes); + if (!bbio) { + ret = -ENOMEM; + goto out; + } + + for (i = 0; i < num_stripes; i++) { + bbio->stripes[i].physical = map->stripes[stripe_index].physical + + stripe_offset + stripe_nr * map->stripe_len; + bbio->stripes[i].dev = map->stripes[stripe_index].dev; + stripe_index++; + } + + /* build raid_map */ + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK && need_raid_map && + (need_full_stripe(op) || mirror_num > 1)) { + u64 tmp; + unsigned rot; + + /* Work out the disk rotation on this stripe-set */ + div_u64_rem(stripe_nr, num_stripes, &rot); + + /* Fill in the logical address of each stripe */ + tmp = stripe_nr * data_stripes; + for (i = 0; i < data_stripes; i++) + bbio->raid_map[(i+rot) % num_stripes] = + em->start + (tmp + i) * map->stripe_len; + + bbio->raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE; + if (map->type & BTRFS_BLOCK_GROUP_RAID6) + bbio->raid_map[(i+rot+1) % num_stripes] = + RAID6_Q_STRIPE; + + sort_parity_stripes(bbio, num_stripes); + } + + if (need_full_stripe(op)) + max_errors = btrfs_chunk_max_errors(map); + + if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL && + need_full_stripe(op)) { + handle_ops_on_dev_replace(op, &bbio, dev_replace, &num_stripes, + &max_errors); + } + + *bbio_ret = bbio; + bbio->map_type = map->type; + bbio->num_stripes = num_stripes; + bbio->max_errors = max_errors; + bbio->mirror_num = mirror_num; + + /* + * this is the case that REQ_READ && dev_replace_is_ongoing && + * mirror_num == num_stripes + 1 && dev_replace target drive is + * available as a mirror + */ + if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) { + WARN_ON(num_stripes > 1); + bbio->stripes[0].dev = dev_replace->tgtdev; + bbio->stripes[0].physical = physical_to_patch_in_first_stripe; + bbio->mirror_num = map->num_stripes + 1; + } +out: + if (dev_replace_is_ongoing) { + lockdep_assert_held(&dev_replace->rwsem); + /* Unlock and let waiting writers proceed */ + up_read(&dev_replace->rwsem); + } + free_extent_map(em); + return ret; +} + +int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, + u64 logical, u64 *length, + struct btrfs_bio **bbio_ret, int mirror_num) +{ + if (op == BTRFS_MAP_DISCARD) + return __btrfs_map_block_for_discard(fs_info, logical, + length, bbio_ret); + + return __btrfs_map_block(fs_info, op, logical, length, bbio_ret, + mirror_num, 0); +} + +/* For Scrub/replace */ +int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, + u64 logical, u64 *length, + struct btrfs_bio **bbio_ret) +{ + return __btrfs_map_block(fs_info, op, logical, length, bbio_ret, 0, 1); +} + +static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio) +{ + bio->bi_private = bbio->private; + bio->bi_end_io = bbio->end_io; + bio_endio(bio); + + btrfs_put_bbio(bbio); +} + +static void btrfs_end_bio(struct bio *bio) +{ + struct btrfs_bio *bbio = bio->bi_private; + int is_orig_bio = 0; + + if (bio->bi_status) { + atomic_inc(&bbio->error); + if (bio->bi_status == BLK_STS_IOERR || + bio->bi_status == BLK_STS_TARGET) { + struct btrfs_device *dev = btrfs_io_bio(bio)->device; + + ASSERT(dev->bdev); + if (bio_op(bio) == REQ_OP_WRITE) + btrfs_dev_stat_inc_and_print(dev, + BTRFS_DEV_STAT_WRITE_ERRS); + else if (!(bio->bi_opf & REQ_RAHEAD)) + btrfs_dev_stat_inc_and_print(dev, + BTRFS_DEV_STAT_READ_ERRS); + if (bio->bi_opf & REQ_PREFLUSH) + btrfs_dev_stat_inc_and_print(dev, + BTRFS_DEV_STAT_FLUSH_ERRS); + } + } + + if (bio == bbio->orig_bio) + is_orig_bio = 1; + + btrfs_bio_counter_dec(bbio->fs_info); + + if (atomic_dec_and_test(&bbio->stripes_pending)) { + if (!is_orig_bio) { + bio_put(bio); + bio = bbio->orig_bio; + } + + btrfs_io_bio(bio)->mirror_num = bbio->mirror_num; + /* only send an error to the higher layers if it is + * beyond the tolerance of the btrfs bio + */ + if (atomic_read(&bbio->error) > bbio->max_errors) { + bio->bi_status = BLK_STS_IOERR; + } else { + /* + * this bio is actually up to date, we didn't + * go over the max number of errors + */ + bio->bi_status = BLK_STS_OK; + } + + btrfs_end_bbio(bbio, bio); + } else if (!is_orig_bio) { + bio_put(bio); + } +} + +static void submit_stripe_bio(struct btrfs_bio *bbio, struct bio *bio, + u64 physical, struct btrfs_device *dev) +{ + struct btrfs_fs_info *fs_info = bbio->fs_info; + + bio->bi_private = bbio; + btrfs_io_bio(bio)->device = dev; + bio->bi_end_io = btrfs_end_bio; + bio->bi_iter.bi_sector = physical >> 9; + btrfs_debug_in_rcu(fs_info, + "btrfs_map_bio: rw %d 0x%x, sector=%llu, dev=%lu (%s id %llu), size=%u", + bio_op(bio), bio->bi_opf, (u64)bio->bi_iter.bi_sector, + (unsigned long)dev->bdev->bd_dev, rcu_str_deref(dev->name), + dev->devid, bio->bi_iter.bi_size); + bio_set_dev(bio, dev->bdev); + + btrfs_bio_counter_inc_noblocked(fs_info); + + btrfsic_submit_bio(bio); +} + +static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical) +{ + atomic_inc(&bbio->error); + if (atomic_dec_and_test(&bbio->stripes_pending)) { + /* Should be the original bio. */ + WARN_ON(bio != bbio->orig_bio); + + btrfs_io_bio(bio)->mirror_num = bbio->mirror_num; + bio->bi_iter.bi_sector = logical >> 9; + if (atomic_read(&bbio->error) > bbio->max_errors) + bio->bi_status = BLK_STS_IOERR; + else + bio->bi_status = BLK_STS_OK; + btrfs_end_bbio(bbio, bio); + } +} + +blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, + int mirror_num) +{ + struct btrfs_device *dev; + struct bio *first_bio = bio; + u64 logical = (u64)bio->bi_iter.bi_sector << 9; + u64 length = 0; + u64 map_length; + int ret; + int dev_nr; + int total_devs; + struct btrfs_bio *bbio = NULL; + + length = bio->bi_iter.bi_size; + map_length = length; + + btrfs_bio_counter_inc_blocked(fs_info); + ret = __btrfs_map_block(fs_info, btrfs_op(bio), logical, + &map_length, &bbio, mirror_num, 1); + if (ret) { + btrfs_bio_counter_dec(fs_info); + return errno_to_blk_status(ret); + } + + total_devs = bbio->num_stripes; + bbio->orig_bio = first_bio; + bbio->private = first_bio->bi_private; + bbio->end_io = first_bio->bi_end_io; + bbio->fs_info = fs_info; + atomic_set(&bbio->stripes_pending, bbio->num_stripes); + + if ((bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) && + ((bio_op(bio) == REQ_OP_WRITE) || (mirror_num > 1))) { + /* In this case, map_length has been set to the length of + a single stripe; not the whole write */ + if (bio_op(bio) == REQ_OP_WRITE) { + ret = raid56_parity_write(fs_info, bio, bbio, + map_length); + } else { + ret = raid56_parity_recover(fs_info, bio, bbio, + map_length, mirror_num, 1); + } + + btrfs_bio_counter_dec(fs_info); + return errno_to_blk_status(ret); + } + + if (map_length < length) { + btrfs_crit(fs_info, + "mapping failed logical %llu bio len %llu len %llu", + logical, length, map_length); + BUG(); + } + + for (dev_nr = 0; dev_nr < total_devs; dev_nr++) { + dev = bbio->stripes[dev_nr].dev; + if (!dev || !dev->bdev || test_bit(BTRFS_DEV_STATE_MISSING, + &dev->dev_state) || + (bio_op(first_bio) == REQ_OP_WRITE && + !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) { + bbio_error(bbio, first_bio, logical); + continue; + } + + if (dev_nr < total_devs - 1) + bio = btrfs_bio_clone(first_bio); + else + bio = first_bio; + + submit_stripe_bio(bbio, bio, bbio->stripes[dev_nr].physical, dev); + } + btrfs_bio_counter_dec(fs_info); + return BLK_STS_OK; +} + +/* + * Find a device specified by @devid or @uuid in the list of @fs_devices, or + * return NULL. + * + * If devid and uuid are both specified, the match must be exact, otherwise + * only devid is used. + * + * If @seed is true, traverse through the seed devices. + */ +struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices, + u64 devid, u8 *uuid, u8 *fsid, + bool seed) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *seed_devs; + + if (!fsid || !memcmp(fs_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE)) { + list_for_each_entry(device, &fs_devices->devices, dev_list) { + if (device->devid == devid && + (!uuid || memcmp(device->uuid, uuid, + BTRFS_UUID_SIZE) == 0)) + return device; + } + } + + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) { + if (!fsid || + !memcmp(seed_devs->metadata_uuid, fsid, BTRFS_FSID_SIZE)) { + list_for_each_entry(device, &seed_devs->devices, + dev_list) { + if (device->devid == devid && + (!uuid || memcmp(device->uuid, uuid, + BTRFS_UUID_SIZE) == 0)) + return device; + } + } + } + + return NULL; +} + +static struct btrfs_device *add_missing_dev(struct btrfs_fs_devices *fs_devices, + u64 devid, u8 *dev_uuid) +{ + struct btrfs_device *device; + unsigned int nofs_flag; + + /* + * We call this under the chunk_mutex, so we want to use NOFS for this + * allocation, however we don't want to change btrfs_alloc_device() to + * always do NOFS because we use it in a lot of other GFP_KERNEL safe + * places. + */ + nofs_flag = memalloc_nofs_save(); + device = btrfs_alloc_device(NULL, &devid, dev_uuid); + memalloc_nofs_restore(nofs_flag); + if (IS_ERR(device)) + return device; + + list_add(&device->dev_list, &fs_devices->devices); + device->fs_devices = fs_devices; + fs_devices->num_devices++; + + set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state); + fs_devices->missing_devices++; + + return device; +} + +/** + * btrfs_alloc_device - allocate struct btrfs_device + * @fs_info: used only for generating a new devid, can be NULL if + * devid is provided (i.e. @devid != NULL). + * @devid: a pointer to devid for this device. If NULL a new devid + * is generated. + * @uuid: a pointer to UUID for this device. If NULL a new UUID + * is generated. + * + * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR() + * on error. Returned struct is not linked onto any lists and must be + * destroyed with btrfs_free_device. + */ +struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info, + const u64 *devid, + const u8 *uuid) +{ + struct btrfs_device *dev; + u64 tmp; + + if (WARN_ON(!devid && !fs_info)) + return ERR_PTR(-EINVAL); + + dev = __alloc_device(fs_info); + if (IS_ERR(dev)) + return dev; + + if (devid) + tmp = *devid; + else { + int ret; + + ret = find_next_devid(fs_info, &tmp); + if (ret) { + btrfs_free_device(dev); + return ERR_PTR(ret); + } + } + dev->devid = tmp; + + if (uuid) + memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE); + else + generate_random_uuid(dev->uuid); + + return dev; +} + +static void btrfs_report_missing_device(struct btrfs_fs_info *fs_info, + u64 devid, u8 *uuid, bool error) +{ + if (error) + btrfs_err_rl(fs_info, "devid %llu uuid %pU is missing", + devid, uuid); + else + btrfs_warn_rl(fs_info, "devid %llu uuid %pU is missing", + devid, uuid); +} + +static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes) +{ + int index = btrfs_bg_flags_to_raid_index(type); + int ncopies = btrfs_raid_array[index].ncopies; + const int nparity = btrfs_raid_array[index].nparity; + int data_stripes; + + if (nparity) + data_stripes = num_stripes - nparity; + else + data_stripes = num_stripes / ncopies; + + return div_u64(chunk_len, data_stripes); +} + +static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf, + struct btrfs_chunk *chunk) +{ + struct btrfs_fs_info *fs_info = leaf->fs_info; + struct extent_map_tree *map_tree = &fs_info->mapping_tree; + struct map_lookup *map; + struct extent_map *em; + u64 logical; + u64 length; + u64 devid; + u8 uuid[BTRFS_UUID_SIZE]; + int num_stripes; + int ret; + int i; + + logical = key->offset; + length = btrfs_chunk_length(leaf, chunk); + num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + + /* + * Only need to verify chunk item if we're reading from sys chunk array, + * as chunk item in tree block is already verified by tree-checker. + */ + if (leaf->start == BTRFS_SUPER_INFO_OFFSET) { + ret = btrfs_check_chunk_valid(leaf, chunk, logical); + if (ret) + return ret; + } + + read_lock(&map_tree->lock); + em = lookup_extent_mapping(map_tree, logical, 1); + read_unlock(&map_tree->lock); + + /* already mapped? */ + if (em && em->start <= logical && em->start + em->len > logical) { + free_extent_map(em); + return 0; + } else if (em) { + free_extent_map(em); + } + + em = alloc_extent_map(); + if (!em) + return -ENOMEM; + map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS); + if (!map) { + free_extent_map(em); + return -ENOMEM; + } + + set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags); + em->map_lookup = map; + em->start = logical; + em->len = length; + em->orig_start = 0; + em->block_start = 0; + em->block_len = em->len; + + map->num_stripes = num_stripes; + map->io_width = btrfs_chunk_io_width(leaf, chunk); + map->io_align = btrfs_chunk_io_align(leaf, chunk); + map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk); + map->type = btrfs_chunk_type(leaf, chunk); + map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk); + map->verified_stripes = 0; + em->orig_block_len = calc_stripe_length(map->type, em->len, + map->num_stripes); + for (i = 0; i < num_stripes; i++) { + map->stripes[i].physical = + btrfs_stripe_offset_nr(leaf, chunk, i); + devid = btrfs_stripe_devid_nr(leaf, chunk, i); + read_extent_buffer(leaf, uuid, (unsigned long) + btrfs_stripe_dev_uuid_nr(chunk, i), + BTRFS_UUID_SIZE); + map->stripes[i].dev = btrfs_find_device(fs_info->fs_devices, + devid, uuid, NULL, true); + if (!map->stripes[i].dev && + !btrfs_test_opt(fs_info, DEGRADED)) { + free_extent_map(em); + btrfs_report_missing_device(fs_info, devid, uuid, true); + return -ENOENT; + } + if (!map->stripes[i].dev) { + map->stripes[i].dev = + add_missing_dev(fs_info->fs_devices, devid, + uuid); + if (IS_ERR(map->stripes[i].dev)) { + free_extent_map(em); + btrfs_err(fs_info, + "failed to init missing dev %llu: %ld", + devid, PTR_ERR(map->stripes[i].dev)); + return PTR_ERR(map->stripes[i].dev); + } + btrfs_report_missing_device(fs_info, devid, uuid, false); + } + set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, + &(map->stripes[i].dev->dev_state)); + + } + + write_lock(&map_tree->lock); + ret = add_extent_mapping(map_tree, em, 0); + write_unlock(&map_tree->lock); + if (ret < 0) { + btrfs_err(fs_info, + "failed to add chunk map, start=%llu len=%llu: %d", + em->start, em->len, ret); + } + free_extent_map(em); + + return ret; +} + +static void fill_device_from_item(struct extent_buffer *leaf, + struct btrfs_dev_item *dev_item, + struct btrfs_device *device) +{ + unsigned long ptr; + + device->devid = btrfs_device_id(leaf, dev_item); + device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item); + device->total_bytes = device->disk_total_bytes; + device->commit_total_bytes = device->disk_total_bytes; + device->bytes_used = btrfs_device_bytes_used(leaf, dev_item); + device->commit_bytes_used = device->bytes_used; + device->type = btrfs_device_type(leaf, dev_item); + device->io_align = btrfs_device_io_align(leaf, dev_item); + device->io_width = btrfs_device_io_width(leaf, dev_item); + device->sector_size = btrfs_device_sector_size(leaf, dev_item); + WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID); + clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); + + ptr = btrfs_device_uuid(dev_item); + read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); +} + +static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info, + u8 *fsid) +{ + struct btrfs_fs_devices *fs_devices; + int ret; + + lockdep_assert_held(&uuid_mutex); + ASSERT(fsid); + + /* This will match only for multi-device seed fs */ + list_for_each_entry(fs_devices, &fs_info->fs_devices->seed_list, seed_list) + if (!memcmp(fs_devices->fsid, fsid, BTRFS_FSID_SIZE)) + return fs_devices; + + + fs_devices = find_fsid(fsid, NULL); + if (!fs_devices) { + if (!btrfs_test_opt(fs_info, DEGRADED)) + return ERR_PTR(-ENOENT); + + fs_devices = alloc_fs_devices(fsid, NULL); + if (IS_ERR(fs_devices)) + return fs_devices; + + fs_devices->seeding = true; + fs_devices->opened = 1; + return fs_devices; + } + + /* + * Upon first call for a seed fs fsid, just create a private copy of the + * respective fs_devices and anchor it at fs_info->fs_devices->seed_list + */ + fs_devices = clone_fs_devices(fs_devices); + if (IS_ERR(fs_devices)) + return fs_devices; + + ret = open_fs_devices(fs_devices, FMODE_READ, fs_info->bdev_holder); + if (ret) { + free_fs_devices(fs_devices); + return ERR_PTR(ret); + } + + if (!fs_devices->seeding) { + close_fs_devices(fs_devices); + free_fs_devices(fs_devices); + return ERR_PTR(-EINVAL); + } + + list_add(&fs_devices->seed_list, &fs_info->fs_devices->seed_list); + + return fs_devices; +} + +static int read_one_dev(struct extent_buffer *leaf, + struct btrfs_dev_item *dev_item) +{ + struct btrfs_fs_info *fs_info = leaf->fs_info; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_device *device; + u64 devid; + int ret; + u8 fs_uuid[BTRFS_FSID_SIZE]; + u8 dev_uuid[BTRFS_UUID_SIZE]; + + devid = btrfs_device_id(leaf, dev_item); + read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item), + BTRFS_UUID_SIZE); + read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item), + BTRFS_FSID_SIZE); + + if (memcmp(fs_uuid, fs_devices->metadata_uuid, BTRFS_FSID_SIZE)) { + fs_devices = open_seed_devices(fs_info, fs_uuid); + if (IS_ERR(fs_devices)) + return PTR_ERR(fs_devices); + } + + device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid, + fs_uuid, true); + if (!device) { + if (!btrfs_test_opt(fs_info, DEGRADED)) { + btrfs_report_missing_device(fs_info, devid, + dev_uuid, true); + return -ENOENT; + } + + device = add_missing_dev(fs_devices, devid, dev_uuid); + if (IS_ERR(device)) { + btrfs_err(fs_info, + "failed to add missing dev %llu: %ld", + devid, PTR_ERR(device)); + return PTR_ERR(device); + } + btrfs_report_missing_device(fs_info, devid, dev_uuid, false); + } else { + if (!device->bdev) { + if (!btrfs_test_opt(fs_info, DEGRADED)) { + btrfs_report_missing_device(fs_info, + devid, dev_uuid, true); + return -ENOENT; + } + btrfs_report_missing_device(fs_info, devid, + dev_uuid, false); + } + + if (!device->bdev && + !test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) { + /* + * this happens when a device that was properly setup + * in the device info lists suddenly goes bad. + * device->bdev is NULL, and so we have to set + * device->missing to one here + */ + device->fs_devices->missing_devices++; + set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state); + } + + /* Move the device to its own fs_devices */ + if (device->fs_devices != fs_devices) { + ASSERT(test_bit(BTRFS_DEV_STATE_MISSING, + &device->dev_state)); + + list_move(&device->dev_list, &fs_devices->devices); + device->fs_devices->num_devices--; + fs_devices->num_devices++; + + device->fs_devices->missing_devices--; + fs_devices->missing_devices++; + + device->fs_devices = fs_devices; + } + } + + if (device->fs_devices != fs_info->fs_devices) { + BUG_ON(test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)); + if (device->generation != + btrfs_device_generation(leaf, dev_item)) + return -EINVAL; + } + + fill_device_from_item(leaf, dev_item, device); + set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) && + !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) { + device->fs_devices->total_rw_bytes += device->total_bytes; + atomic64_add(device->total_bytes - device->bytes_used, + &fs_info->free_chunk_space); + } + ret = 0; + return ret; +} + +int btrfs_read_sys_array(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root = fs_info->tree_root; + struct btrfs_super_block *super_copy = fs_info->super_copy; + struct extent_buffer *sb; + struct btrfs_disk_key *disk_key; + struct btrfs_chunk *chunk; + u8 *array_ptr; + unsigned long sb_array_offset; + int ret = 0; + u32 num_stripes; + u32 array_size; + u32 len = 0; + u32 cur_offset; + u64 type; + struct btrfs_key key; + + ASSERT(BTRFS_SUPER_INFO_SIZE <= fs_info->nodesize); + /* + * This will create extent buffer of nodesize, superblock size is + * fixed to BTRFS_SUPER_INFO_SIZE. If nodesize > sb size, this will + * overallocate but we can keep it as-is, only the first page is used. + */ + sb = btrfs_find_create_tree_block(fs_info, BTRFS_SUPER_INFO_OFFSET); + if (IS_ERR(sb)) + return PTR_ERR(sb); + set_extent_buffer_uptodate(sb); + btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0); + /* + * The sb extent buffer is artificial and just used to read the system array. + * set_extent_buffer_uptodate() call does not properly mark all it's + * pages up-to-date when the page is larger: extent does not cover the + * whole page and consequently check_page_uptodate does not find all + * the page's extents up-to-date (the hole beyond sb), + * write_extent_buffer then triggers a WARN_ON. + * + * Regular short extents go through mark_extent_buffer_dirty/writeback cycle, + * but sb spans only this function. Add an explicit SetPageUptodate call + * to silence the warning eg. on PowerPC 64. + */ + if (PAGE_SIZE > BTRFS_SUPER_INFO_SIZE) + SetPageUptodate(sb->pages[0]); + + write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE); + array_size = btrfs_super_sys_array_size(super_copy); + + array_ptr = super_copy->sys_chunk_array; + sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array); + cur_offset = 0; + + while (cur_offset < array_size) { + disk_key = (struct btrfs_disk_key *)array_ptr; + len = sizeof(*disk_key); + if (cur_offset + len > array_size) + goto out_short_read; + + btrfs_disk_key_to_cpu(&key, disk_key); + + array_ptr += len; + sb_array_offset += len; + cur_offset += len; + + if (key.type != BTRFS_CHUNK_ITEM_KEY) { + btrfs_err(fs_info, + "unexpected item type %u in sys_array at offset %u", + (u32)key.type, cur_offset); + ret = -EIO; + break; + } + + chunk = (struct btrfs_chunk *)sb_array_offset; + /* + * At least one btrfs_chunk with one stripe must be present, + * exact stripe count check comes afterwards + */ + len = btrfs_chunk_item_size(1); + if (cur_offset + len > array_size) + goto out_short_read; + + num_stripes = btrfs_chunk_num_stripes(sb, chunk); + if (!num_stripes) { + btrfs_err(fs_info, + "invalid number of stripes %u in sys_array at offset %u", + num_stripes, cur_offset); + ret = -EIO; + break; + } + + type = btrfs_chunk_type(sb, chunk); + if ((type & BTRFS_BLOCK_GROUP_SYSTEM) == 0) { + btrfs_err(fs_info, + "invalid chunk type %llu in sys_array at offset %u", + type, cur_offset); + ret = -EIO; + break; + } + + len = btrfs_chunk_item_size(num_stripes); + if (cur_offset + len > array_size) + goto out_short_read; + + ret = read_one_chunk(&key, sb, chunk); + if (ret) + break; + + array_ptr += len; + sb_array_offset += len; + cur_offset += len; + } + clear_extent_buffer_uptodate(sb); + free_extent_buffer_stale(sb); + return ret; + +out_short_read: + btrfs_err(fs_info, "sys_array too short to read %u bytes at offset %u", + len, cur_offset); + clear_extent_buffer_uptodate(sb); + free_extent_buffer_stale(sb); + return -EIO; +} + +/* + * Check if all chunks in the fs are OK for read-write degraded mount + * + * If the @failing_dev is specified, it's accounted as missing. + * + * Return true if all chunks meet the minimal RW mount requirements. + * Return false if any chunk doesn't meet the minimal RW mount requirements. + */ +bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info, + struct btrfs_device *failing_dev) +{ + struct extent_map_tree *map_tree = &fs_info->mapping_tree; + struct extent_map *em; + u64 next_start = 0; + bool ret = true; + + read_lock(&map_tree->lock); + em = lookup_extent_mapping(map_tree, 0, (u64)-1); + read_unlock(&map_tree->lock); + /* No chunk at all? Return false anyway */ + if (!em) { + ret = false; + goto out; + } + while (em) { + struct map_lookup *map; + int missing = 0; + int max_tolerated; + int i; + + map = em->map_lookup; + max_tolerated = + btrfs_get_num_tolerated_disk_barrier_failures( + map->type); + for (i = 0; i < map->num_stripes; i++) { + struct btrfs_device *dev = map->stripes[i].dev; + + if (!dev || !dev->bdev || + test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) || + dev->last_flush_error) + missing++; + else if (failing_dev && failing_dev == dev) + missing++; + } + if (missing > max_tolerated) { + if (!failing_dev) + btrfs_warn(fs_info, + "chunk %llu missing %d devices, max tolerance is %d for writable mount", + em->start, missing, max_tolerated); + free_extent_map(em); + ret = false; + goto out; + } + next_start = extent_map_end(em); + free_extent_map(em); + + read_lock(&map_tree->lock); + em = lookup_extent_mapping(map_tree, next_start, + (u64)(-1) - next_start); + read_unlock(&map_tree->lock); + } +out: + return ret; +} + +static void readahead_tree_node_children(struct extent_buffer *node) +{ + int i; + const int nr_items = btrfs_header_nritems(node); + + for (i = 0; i < nr_items; i++) { + u64 start; + + start = btrfs_node_blockptr(node, i); + readahead_tree_block(node->fs_info, start); + } +} + +int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root = fs_info->chunk_root; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key key; + struct btrfs_key found_key; + int ret; + int slot; + u64 total_dev = 0; + u64 last_ra_node = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* + * uuid_mutex is needed only if we are mounting a sprout FS + * otherwise we don't need it. + */ + mutex_lock(&uuid_mutex); + + /* + * It is possible for mount and umount to race in such a way that + * we execute this code path, but open_fs_devices failed to clear + * total_rw_bytes. We certainly want it cleared before reading the + * device items, so clear it here. + */ + fs_info->fs_devices->total_rw_bytes = 0; + + /* + * Read all device items, and then all the chunk items. All + * device items are found before any chunk item (their object id + * is smaller than the lowest possible object id for a chunk + * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID). + */ + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.offset = 0; + key.type = 0; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto error; + while (1) { + struct extent_buffer *node; + + leaf = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret == 0) + continue; + if (ret < 0) + goto error; + break; + } + /* + * The nodes on level 1 are not locked but we don't need to do + * that during mount time as nothing else can access the tree + */ + node = path->nodes[1]; + if (node) { + if (last_ra_node != node->start) { + readahead_tree_node_children(node); + last_ra_node = node->start; + } + } + btrfs_item_key_to_cpu(leaf, &found_key, slot); + if (found_key.type == BTRFS_DEV_ITEM_KEY) { + struct btrfs_dev_item *dev_item; + dev_item = btrfs_item_ptr(leaf, slot, + struct btrfs_dev_item); + ret = read_one_dev(leaf, dev_item); + if (ret) + goto error; + total_dev++; + } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) { + struct btrfs_chunk *chunk; + chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); + mutex_lock(&fs_info->chunk_mutex); + ret = read_one_chunk(&found_key, leaf, chunk); + mutex_unlock(&fs_info->chunk_mutex); + if (ret) + goto error; + } + path->slots[0]++; + } + + /* + * After loading chunk tree, we've got all device information, + * do another round of validation checks. + */ + if (total_dev != fs_info->fs_devices->total_devices) { + btrfs_warn(fs_info, +"super block num_devices %llu mismatch with DEV_ITEM count %llu, will be repaired on next transaction commit", + btrfs_super_num_devices(fs_info->super_copy), + total_dev); + fs_info->fs_devices->total_devices = total_dev; + btrfs_set_super_num_devices(fs_info->super_copy, total_dev); + } + if (btrfs_super_total_bytes(fs_info->super_copy) < + fs_info->fs_devices->total_rw_bytes) { + btrfs_err(fs_info, + "super_total_bytes %llu mismatch with fs_devices total_rw_bytes %llu", + btrfs_super_total_bytes(fs_info->super_copy), + fs_info->fs_devices->total_rw_bytes); + ret = -EINVAL; + goto error; + } + ret = 0; +error: + mutex_unlock(&uuid_mutex); + + btrfs_free_path(path); + return ret; +} + +void btrfs_init_devices_late(struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs; + struct btrfs_device *device; + + fs_devices->fs_info = fs_info; + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry(device, &fs_devices->devices, dev_list) + device->fs_info = fs_info; + + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) { + list_for_each_entry(device, &seed_devs->devices, dev_list) + device->fs_info = fs_info; + + seed_devs->fs_info = fs_info; + } + mutex_unlock(&fs_devices->device_list_mutex); +} + +static u64 btrfs_dev_stats_value(const struct extent_buffer *eb, + const struct btrfs_dev_stats_item *ptr, + int index) +{ + u64 val; + + read_extent_buffer(eb, &val, + offsetof(struct btrfs_dev_stats_item, values) + + ((unsigned long)ptr) + (index * sizeof(u64)), + sizeof(val)); + return val; +} + +static void btrfs_set_dev_stats_value(struct extent_buffer *eb, + struct btrfs_dev_stats_item *ptr, + int index, u64 val) +{ + write_extent_buffer(eb, &val, + offsetof(struct btrfs_dev_stats_item, values) + + ((unsigned long)ptr) + (index * sizeof(u64)), + sizeof(val)); +} + +static int btrfs_device_init_dev_stats(struct btrfs_device *device, + struct btrfs_path *path) +{ + struct btrfs_dev_stats_item *ptr; + struct extent_buffer *eb; + struct btrfs_key key; + int item_size; + int i, ret, slot; + + key.objectid = BTRFS_DEV_STATS_OBJECTID; + key.type = BTRFS_PERSISTENT_ITEM_KEY; + key.offset = device->devid; + ret = btrfs_search_slot(NULL, device->fs_info->dev_root, &key, path, 0, 0); + if (ret) { + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) + btrfs_dev_stat_set(device, i, 0); + device->dev_stats_valid = 1; + btrfs_release_path(path); + return ret < 0 ? ret : 0; + } + slot = path->slots[0]; + eb = path->nodes[0]; + item_size = btrfs_item_size_nr(eb, slot); + + ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_stats_item); + + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) { + if (item_size >= (1 + i) * sizeof(__le64)) + btrfs_dev_stat_set(device, i, + btrfs_dev_stats_value(eb, ptr, i)); + else + btrfs_dev_stat_set(device, i, 0); + } + + device->dev_stats_valid = 1; + btrfs_dev_stat_print_on_load(device); + btrfs_release_path(path); + + return 0; +} + +int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs; + struct btrfs_device *device; + struct btrfs_path *path = NULL; + int ret = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry(device, &fs_devices->devices, dev_list) { + ret = btrfs_device_init_dev_stats(device, path); + if (ret) + goto out; + } + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) { + list_for_each_entry(device, &seed_devs->devices, dev_list) { + ret = btrfs_device_init_dev_stats(device, path); + if (ret) + goto out; + } + } +out: + mutex_unlock(&fs_devices->device_list_mutex); + + btrfs_free_path(path); + return ret; +} + +static int update_dev_stat_item(struct btrfs_trans_handle *trans, + struct btrfs_device *device) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *dev_root = fs_info->dev_root; + struct btrfs_path *path; + struct btrfs_key key; + struct extent_buffer *eb; + struct btrfs_dev_stats_item *ptr; + int ret; + int i; + + key.objectid = BTRFS_DEV_STATS_OBJECTID; + key.type = BTRFS_PERSISTENT_ITEM_KEY; + key.offset = device->devid; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); + if (ret < 0) { + btrfs_warn_in_rcu(fs_info, + "error %d while searching for dev_stats item for device %s", + ret, rcu_str_deref(device->name)); + goto out; + } + + if (ret == 0 && + btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { + /* need to delete old one and insert a new one */ + ret = btrfs_del_item(trans, dev_root, path); + if (ret != 0) { + btrfs_warn_in_rcu(fs_info, + "delete too small dev_stats item for device %s failed %d", + rcu_str_deref(device->name), ret); + goto out; + } + ret = 1; + } + + if (ret == 1) { + /* need to insert a new item */ + btrfs_release_path(path); + ret = btrfs_insert_empty_item(trans, dev_root, path, + &key, sizeof(*ptr)); + if (ret < 0) { + btrfs_warn_in_rcu(fs_info, + "insert dev_stats item for device %s failed %d", + rcu_str_deref(device->name), ret); + goto out; + } + } + + eb = path->nodes[0]; + ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item); + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) + btrfs_set_dev_stats_value(eb, ptr, i, + btrfs_dev_stat_read(device, i)); + btrfs_mark_buffer_dirty(eb); + +out: + btrfs_free_path(path); + return ret; +} + +/* + * called from commit_transaction. Writes all changed device stats to disk. + */ +int btrfs_run_dev_stats(struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_device *device; + int stats_cnt; + int ret = 0; + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry(device, &fs_devices->devices, dev_list) { + stats_cnt = atomic_read(&device->dev_stats_ccnt); + if (!device->dev_stats_valid || stats_cnt == 0) + continue; + + + /* + * There is a LOAD-LOAD control dependency between the value of + * dev_stats_ccnt and updating the on-disk values which requires + * reading the in-memory counters. Such control dependencies + * require explicit read memory barriers. + * + * This memory barriers pairs with smp_mb__before_atomic in + * btrfs_dev_stat_inc/btrfs_dev_stat_set and with the full + * barrier implied by atomic_xchg in + * btrfs_dev_stats_read_and_reset + */ + smp_rmb(); + + ret = update_dev_stat_item(trans, device); + if (!ret) + atomic_sub(stats_cnt, &device->dev_stats_ccnt); + } + mutex_unlock(&fs_devices->device_list_mutex); + + return ret; +} + +void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index) +{ + btrfs_dev_stat_inc(dev, index); + btrfs_dev_stat_print_on_error(dev); +} + +static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev) +{ + if (!dev->dev_stats_valid) + return; + btrfs_err_rl_in_rcu(dev->fs_info, + "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u", + rcu_str_deref(dev->name), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS)); +} + +static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev) +{ + int i; + + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) + if (btrfs_dev_stat_read(dev, i) != 0) + break; + if (i == BTRFS_DEV_STAT_VALUES_MAX) + return; /* all values == 0, suppress message */ + + btrfs_info_in_rcu(dev->fs_info, + "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u", + rcu_str_deref(dev->name), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS)); +} + +int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info, + struct btrfs_ioctl_get_dev_stats *stats) +{ + struct btrfs_device *dev; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + int i; + + mutex_lock(&fs_devices->device_list_mutex); + dev = btrfs_find_device(fs_info->fs_devices, stats->devid, NULL, NULL, + true); + mutex_unlock(&fs_devices->device_list_mutex); + + if (!dev) { + btrfs_warn(fs_info, "get dev_stats failed, device not found"); + return -ENODEV; + } else if (!dev->dev_stats_valid) { + btrfs_warn(fs_info, "get dev_stats failed, not yet valid"); + return -ENODEV; + } else if (stats->flags & BTRFS_DEV_STATS_RESET) { + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) { + if (stats->nr_items > i) + stats->values[i] = + btrfs_dev_stat_read_and_reset(dev, i); + else + btrfs_dev_stat_set(dev, i, 0); + } + btrfs_info(fs_info, "device stats zeroed by %s (%d)", + current->comm, task_pid_nr(current)); + } else { + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) + if (stats->nr_items > i) + stats->values[i] = btrfs_dev_stat_read(dev, i); + } + if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX) + stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX; + return 0; +} + +/* + * Update the size and bytes used for each device where it changed. This is + * delayed since we would otherwise get errors while writing out the + * superblocks. + * + * Must be invoked during transaction commit. + */ +void btrfs_commit_device_sizes(struct btrfs_transaction *trans) +{ + struct btrfs_device *curr, *next; + + ASSERT(trans->state == TRANS_STATE_COMMIT_DOING); + + if (list_empty(&trans->dev_update_list)) + return; + + /* + * We don't need the device_list_mutex here. This list is owned by the + * transaction and the transaction must complete before the device is + * released. + */ + mutex_lock(&trans->fs_info->chunk_mutex); + list_for_each_entry_safe(curr, next, &trans->dev_update_list, + post_commit_list) { + list_del_init(&curr->post_commit_list); + curr->commit_total_bytes = curr->disk_total_bytes; + curr->commit_bytes_used = curr->bytes_used; + } + mutex_unlock(&trans->fs_info->chunk_mutex); +} + +/* + * Multiplicity factor for simple profiles: DUP, RAID1-like and RAID10. + */ +int btrfs_bg_type_to_factor(u64 flags) +{ + const int index = btrfs_bg_flags_to_raid_index(flags); + + return btrfs_raid_array[index].ncopies; +} + + + +static int verify_one_dev_extent(struct btrfs_fs_info *fs_info, + u64 chunk_offset, u64 devid, + u64 physical_offset, u64 physical_len) +{ + struct extent_map_tree *em_tree = &fs_info->mapping_tree; + struct extent_map *em; + struct map_lookup *map; + struct btrfs_device *dev; + u64 stripe_len; + bool found = false; + int ret = 0; + int i; + + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, chunk_offset, 1); + read_unlock(&em_tree->lock); + + if (!em) { + btrfs_err(fs_info, +"dev extent physical offset %llu on devid %llu doesn't have corresponding chunk", + physical_offset, devid); + ret = -EUCLEAN; + goto out; + } + + map = em->map_lookup; + stripe_len = calc_stripe_length(map->type, em->len, map->num_stripes); + if (physical_len != stripe_len) { + btrfs_err(fs_info, +"dev extent physical offset %llu on devid %llu length doesn't match chunk %llu, have %llu expect %llu", + physical_offset, devid, em->start, physical_len, + stripe_len); + ret = -EUCLEAN; + goto out; + } + + for (i = 0; i < map->num_stripes; i++) { + if (map->stripes[i].dev->devid == devid && + map->stripes[i].physical == physical_offset) { + found = true; + if (map->verified_stripes >= map->num_stripes) { + btrfs_err(fs_info, + "too many dev extents for chunk %llu found", + em->start); + ret = -EUCLEAN; + goto out; + } + map->verified_stripes++; + break; + } + } + if (!found) { + btrfs_err(fs_info, + "dev extent physical offset %llu devid %llu has no corresponding chunk", + physical_offset, devid); + ret = -EUCLEAN; + } + + /* Make sure no dev extent is beyond device bondary */ + dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true); + if (!dev) { + btrfs_err(fs_info, "failed to find devid %llu", devid); + ret = -EUCLEAN; + goto out; + } + + /* It's possible this device is a dummy for seed device */ + if (dev->disk_total_bytes == 0) { + struct btrfs_fs_devices *devs; + + devs = list_first_entry(&fs_info->fs_devices->seed_list, + struct btrfs_fs_devices, seed_list); + dev = btrfs_find_device(devs, devid, NULL, NULL, false); + if (!dev) { + btrfs_err(fs_info, "failed to find seed devid %llu", + devid); + ret = -EUCLEAN; + goto out; + } + } + + if (physical_offset + physical_len > dev->disk_total_bytes) { + btrfs_err(fs_info, +"dev extent devid %llu physical offset %llu len %llu is beyond device boundary %llu", + devid, physical_offset, physical_len, + dev->disk_total_bytes); + ret = -EUCLEAN; + goto out; + } +out: + free_extent_map(em); + return ret; +} + +static int verify_chunk_dev_extent_mapping(struct btrfs_fs_info *fs_info) +{ + struct extent_map_tree *em_tree = &fs_info->mapping_tree; + struct extent_map *em; + struct rb_node *node; + int ret = 0; + + read_lock(&em_tree->lock); + for (node = rb_first_cached(&em_tree->map); node; node = rb_next(node)) { + em = rb_entry(node, struct extent_map, rb_node); + if (em->map_lookup->num_stripes != + em->map_lookup->verified_stripes) { + btrfs_err(fs_info, + "chunk %llu has missing dev extent, have %d expect %d", + em->start, em->map_lookup->verified_stripes, + em->map_lookup->num_stripes); + ret = -EUCLEAN; + goto out; + } + } +out: + read_unlock(&em_tree->lock); + return ret; +} + +/* + * Ensure that all dev extents are mapped to correct chunk, otherwise + * later chunk allocation/free would cause unexpected behavior. + * + * NOTE: This will iterate through the whole device tree, which should be of + * the same size level as the chunk tree. This slightly increases mount time. + */ +int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info) +{ + struct btrfs_path *path; + struct btrfs_root *root = fs_info->dev_root; + struct btrfs_key key; + u64 prev_devid = 0; + u64 prev_dev_ext_end = 0; + int ret = 0; + + key.objectid = 1; + key.type = BTRFS_DEV_EXTENT_KEY; + key.offset = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = READA_FORWARD; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_item(root, path); + if (ret < 0) + goto out; + /* No dev extents at all? Not good */ + if (ret > 0) { + ret = -EUCLEAN; + goto out; + } + } + while (1) { + struct extent_buffer *leaf = path->nodes[0]; + struct btrfs_dev_extent *dext; + int slot = path->slots[0]; + u64 chunk_offset; + u64 physical_offset; + u64 physical_len; + u64 devid; + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.type != BTRFS_DEV_EXTENT_KEY) + break; + devid = key.objectid; + physical_offset = key.offset; + + dext = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent); + chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dext); + physical_len = btrfs_dev_extent_length(leaf, dext); + + /* Check if this dev extent overlaps with the previous one */ + if (devid == prev_devid && physical_offset < prev_dev_ext_end) { + btrfs_err(fs_info, +"dev extent devid %llu physical offset %llu overlap with previous dev extent end %llu", + devid, physical_offset, prev_dev_ext_end); + ret = -EUCLEAN; + goto out; + } + + ret = verify_one_dev_extent(fs_info, chunk_offset, devid, + physical_offset, physical_len); + if (ret < 0) + goto out; + prev_devid = devid; + prev_dev_ext_end = physical_offset + physical_len; + + ret = btrfs_next_item(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + } + + /* Ensure all chunks have corresponding dev extents */ + ret = verify_chunk_dev_extent_mapping(fs_info); +out: + btrfs_free_path(path); + return ret; +} + +/* + * Check whether the given block group or device is pinned by any inode being + * used as a swapfile. + */ +bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr) +{ + struct btrfs_swapfile_pin *sp; + struct rb_node *node; + + spin_lock(&fs_info->swapfile_pins_lock); + node = fs_info->swapfile_pins.rb_node; + while (node) { + sp = rb_entry(node, struct btrfs_swapfile_pin, node); + if (ptr < sp->ptr) + node = node->rb_left; + else if (ptr > sp->ptr) + node = node->rb_right; + else + break; + } + spin_unlock(&fs_info->swapfile_pins_lock); + return node != NULL; +} |