diff options
Diffstat (limited to 'fs/btrfs/sysfs.c')
| -rw-r--r-- | fs/btrfs/sysfs.c | 966 |
1 files changed, 966 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c new file mode 100644 index 000000000..afec808a7 --- /dev/null +++ b/fs/btrfs/sysfs.c @@ -0,0 +1,966 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2007 Oracle. All rights reserved. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/kobject.h> +#include <linux/bug.h> +#include <linux/debugfs.h> +#include <linux/sched/mm.h> + +#include "ctree.h" +#include "disk-io.h" +#include "transaction.h" +#include "sysfs.h" +#include "volumes.h" + +static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj); +static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj); + +static u64 get_features(struct btrfs_fs_info *fs_info, + enum btrfs_feature_set set) +{ + struct btrfs_super_block *disk_super = fs_info->super_copy; + if (set == FEAT_COMPAT) + return btrfs_super_compat_flags(disk_super); + else if (set == FEAT_COMPAT_RO) + return btrfs_super_compat_ro_flags(disk_super); + else + return btrfs_super_incompat_flags(disk_super); +} + +static void set_features(struct btrfs_fs_info *fs_info, + enum btrfs_feature_set set, u64 features) +{ + struct btrfs_super_block *disk_super = fs_info->super_copy; + if (set == FEAT_COMPAT) + btrfs_set_super_compat_flags(disk_super, features); + else if (set == FEAT_COMPAT_RO) + btrfs_set_super_compat_ro_flags(disk_super, features); + else + btrfs_set_super_incompat_flags(disk_super, features); +} + +static int can_modify_feature(struct btrfs_feature_attr *fa) +{ + int val = 0; + u64 set, clear; + switch (fa->feature_set) { + case FEAT_COMPAT: + set = BTRFS_FEATURE_COMPAT_SAFE_SET; + clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; + break; + case FEAT_COMPAT_RO: + set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; + clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; + break; + case FEAT_INCOMPAT: + set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; + clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; + break; + default: + pr_warn("btrfs: sysfs: unknown feature set %d\n", + fa->feature_set); + return 0; + } + + if (set & fa->feature_bit) + val |= 1; + if (clear & fa->feature_bit) + val |= 2; + + return val; +} + +static ssize_t btrfs_feature_attr_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + int val = 0; + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); + if (fs_info) { + u64 features = get_features(fs_info, fa->feature_set); + if (features & fa->feature_bit) + val = 1; + } else + val = can_modify_feature(fa); + + return snprintf(buf, PAGE_SIZE, "%d\n", val); +} + +static ssize_t btrfs_feature_attr_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t count) +{ + struct btrfs_fs_info *fs_info; + struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a); + u64 features, set, clear; + unsigned long val; + int ret; + + fs_info = to_fs_info(kobj); + if (!fs_info) + return -EPERM; + + if (sb_rdonly(fs_info->sb)) + return -EROFS; + + ret = kstrtoul(skip_spaces(buf), 0, &val); + if (ret) + return ret; + + if (fa->feature_set == FEAT_COMPAT) { + set = BTRFS_FEATURE_COMPAT_SAFE_SET; + clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR; + } else if (fa->feature_set == FEAT_COMPAT_RO) { + set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET; + clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR; + } else { + set = BTRFS_FEATURE_INCOMPAT_SAFE_SET; + clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR; + } + + features = get_features(fs_info, fa->feature_set); + + /* Nothing to do */ + if ((val && (features & fa->feature_bit)) || + (!val && !(features & fa->feature_bit))) + return count; + + if ((val && !(set & fa->feature_bit)) || + (!val && !(clear & fa->feature_bit))) { + btrfs_info(fs_info, + "%sabling feature %s on mounted fs is not supported.", + val ? "En" : "Dis", fa->kobj_attr.attr.name); + return -EPERM; + } + + btrfs_info(fs_info, "%s %s feature flag", + val ? "Setting" : "Clearing", fa->kobj_attr.attr.name); + + spin_lock(&fs_info->super_lock); + features = get_features(fs_info, fa->feature_set); + if (val) + features |= fa->feature_bit; + else + features &= ~fa->feature_bit; + set_features(fs_info, fa->feature_set, features); + spin_unlock(&fs_info->super_lock); + + /* + * We don't want to do full transaction commit from inside sysfs + */ + btrfs_set_pending(fs_info, COMMIT); + wake_up_process(fs_info->transaction_kthread); + + return count; +} + +static umode_t btrfs_feature_visible(struct kobject *kobj, + struct attribute *attr, int unused) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + umode_t mode = attr->mode; + + if (fs_info) { + struct btrfs_feature_attr *fa; + u64 features; + + fa = attr_to_btrfs_feature_attr(attr); + features = get_features(fs_info, fa->feature_set); + + if (can_modify_feature(fa)) + mode |= S_IWUSR; + else if (!(features & fa->feature_bit)) + mode = 0; + } + + return mode; +} + +BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); +BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); +BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); +BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO); +BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD); +BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA); +BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF); +BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56); +BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA); +BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES); +BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE); + +static struct attribute *btrfs_supported_feature_attrs[] = { + BTRFS_FEAT_ATTR_PTR(mixed_backref), + BTRFS_FEAT_ATTR_PTR(default_subvol), + BTRFS_FEAT_ATTR_PTR(mixed_groups), + BTRFS_FEAT_ATTR_PTR(compress_lzo), + BTRFS_FEAT_ATTR_PTR(compress_zstd), + BTRFS_FEAT_ATTR_PTR(big_metadata), + BTRFS_FEAT_ATTR_PTR(extended_iref), + BTRFS_FEAT_ATTR_PTR(raid56), + BTRFS_FEAT_ATTR_PTR(skinny_metadata), + BTRFS_FEAT_ATTR_PTR(no_holes), + BTRFS_FEAT_ATTR_PTR(free_space_tree), + NULL +}; + +/* + * Features which depend on feature bits and may differ between each fs. + * + * /sys/fs/btrfs/features lists all available features of this kernel while + * /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or + * can be changed online. + */ +static const struct attribute_group btrfs_feature_attr_group = { + .name = "features", + .is_visible = btrfs_feature_visible, + .attrs = btrfs_supported_feature_attrs, +}; + +static ssize_t rmdir_subvol_show(struct kobject *kobj, + struct kobj_attribute *ka, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "0\n"); +} +BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show); + +static struct attribute *btrfs_supported_static_feature_attrs[] = { + BTRFS_ATTR_PTR(static_feature, rmdir_subvol), + NULL +}; + +/* + * Features which only depend on kernel version. + * + * These are listed in /sys/fs/btrfs/features along with + * btrfs_feature_attr_group + */ +static const struct attribute_group btrfs_static_feature_attr_group = { + .name = "features", + .attrs = btrfs_supported_static_feature_attrs, +}; + +static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf) +{ + u64 val; + if (lock) + spin_lock(lock); + val = *value_ptr; + if (lock) + spin_unlock(lock); + return snprintf(buf, PAGE_SIZE, "%llu\n", val); +} + +static ssize_t global_rsv_size_show(struct kobject *kobj, + struct kobj_attribute *ka, char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); + struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; + return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf); +} +BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show); + +static ssize_t global_rsv_reserved_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); + struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; + return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf); +} +BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show); + +#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj) +#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj) + +static ssize_t raid_bytes_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf); +BTRFS_ATTR(raid, total_bytes, raid_bytes_show); +BTRFS_ATTR(raid, used_bytes, raid_bytes_show); + +static ssize_t raid_bytes_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) + +{ + struct btrfs_space_info *sinfo = to_space_info(kobj->parent); + struct btrfs_block_group_cache *block_group; + int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags); + u64 val = 0; + + down_read(&sinfo->groups_sem); + list_for_each_entry(block_group, &sinfo->block_groups[index], list) { + if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes)) + val += block_group->key.offset; + else + val += btrfs_block_group_used(&block_group->item); + } + up_read(&sinfo->groups_sem); + return snprintf(buf, PAGE_SIZE, "%llu\n", val); +} + +static struct attribute *raid_attributes[] = { + BTRFS_ATTR_PTR(raid, total_bytes), + BTRFS_ATTR_PTR(raid, used_bytes), + NULL +}; + +static void release_raid_kobj(struct kobject *kobj) +{ + kfree(to_raid_kobj(kobj)); +} + +struct kobj_type btrfs_raid_ktype = { + .sysfs_ops = &kobj_sysfs_ops, + .release = release_raid_kobj, + .default_attrs = raid_attributes, +}; + +#define SPACE_INFO_ATTR(field) \ +static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \ + struct kobj_attribute *a, \ + char *buf) \ +{ \ + struct btrfs_space_info *sinfo = to_space_info(kobj); \ + return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \ +} \ +BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field) + +static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + struct btrfs_space_info *sinfo = to_space_info(kobj); + s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned); + return snprintf(buf, PAGE_SIZE, "%lld\n", val); +} + +SPACE_INFO_ATTR(flags); +SPACE_INFO_ATTR(total_bytes); +SPACE_INFO_ATTR(bytes_used); +SPACE_INFO_ATTR(bytes_pinned); +SPACE_INFO_ATTR(bytes_reserved); +SPACE_INFO_ATTR(bytes_may_use); +SPACE_INFO_ATTR(bytes_readonly); +SPACE_INFO_ATTR(disk_used); +SPACE_INFO_ATTR(disk_total); +BTRFS_ATTR(space_info, total_bytes_pinned, + btrfs_space_info_show_total_bytes_pinned); + +static struct attribute *space_info_attrs[] = { + BTRFS_ATTR_PTR(space_info, flags), + BTRFS_ATTR_PTR(space_info, total_bytes), + BTRFS_ATTR_PTR(space_info, bytes_used), + BTRFS_ATTR_PTR(space_info, bytes_pinned), + BTRFS_ATTR_PTR(space_info, bytes_reserved), + BTRFS_ATTR_PTR(space_info, bytes_may_use), + BTRFS_ATTR_PTR(space_info, bytes_readonly), + BTRFS_ATTR_PTR(space_info, disk_used), + BTRFS_ATTR_PTR(space_info, disk_total), + BTRFS_ATTR_PTR(space_info, total_bytes_pinned), + NULL, +}; + +static void space_info_release(struct kobject *kobj) +{ + struct btrfs_space_info *sinfo = to_space_info(kobj); + percpu_counter_destroy(&sinfo->total_bytes_pinned); + kfree(sinfo); +} + +struct kobj_type space_info_ktype = { + .sysfs_ops = &kobj_sysfs_ops, + .release = space_info_release, + .default_attrs = space_info_attrs, +}; + +static const struct attribute *allocation_attrs[] = { + BTRFS_ATTR_PTR(allocation, global_rsv_reserved), + BTRFS_ATTR_PTR(allocation, global_rsv_size), + NULL, +}; + +static ssize_t btrfs_label_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + char *label = fs_info->super_copy->label; + ssize_t ret; + + spin_lock(&fs_info->super_lock); + ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label); + spin_unlock(&fs_info->super_lock); + + return ret; +} + +static ssize_t btrfs_label_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + size_t p_len; + + if (!fs_info) + return -EPERM; + + if (sb_rdonly(fs_info->sb)) + return -EROFS; + + /* + * p_len is the len until the first occurrence of either + * '\n' or '\0' + */ + p_len = strcspn(buf, "\n"); + + if (p_len >= BTRFS_LABEL_SIZE) + return -EINVAL; + + spin_lock(&fs_info->super_lock); + memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE); + memcpy(fs_info->super_copy->label, buf, p_len); + spin_unlock(&fs_info->super_lock); + + /* + * We don't want to do full transaction commit from inside sysfs + */ + btrfs_set_pending(fs_info, COMMIT); + wake_up_process(fs_info->transaction_kthread); + + return len; +} +BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store); + +static ssize_t btrfs_nodesize_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + + return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize); +} + +BTRFS_ATTR(, nodesize, btrfs_nodesize_show); + +static ssize_t btrfs_sectorsize_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + + return snprintf(buf, PAGE_SIZE, "%u\n", + fs_info->super_copy->sectorsize); +} + +BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show); + +static ssize_t btrfs_clone_alignment_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + + return snprintf(buf, PAGE_SIZE, "%u\n", + fs_info->super_copy->sectorsize); +} + +BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show); + +static ssize_t quota_override_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + int quota_override; + + quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); + return snprintf(buf, PAGE_SIZE, "%d\n", quota_override); +} + +static ssize_t quota_override_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + unsigned long knob; + int err; + + if (!fs_info) + return -EPERM; + + if (!capable(CAP_SYS_RESOURCE)) + return -EPERM; + + err = kstrtoul(buf, 10, &knob); + if (err) + return err; + if (knob > 1) + return -EINVAL; + + if (knob) + set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); + else + clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags); + + return len; +} + +BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store); + +static const struct attribute *btrfs_attrs[] = { + BTRFS_ATTR_PTR(, label), + BTRFS_ATTR_PTR(, nodesize), + BTRFS_ATTR_PTR(, sectorsize), + BTRFS_ATTR_PTR(, clone_alignment), + BTRFS_ATTR_PTR(, quota_override), + NULL, +}; + +static void btrfs_release_fsid_kobj(struct kobject *kobj) +{ + struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj); + + memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject)); + complete(&fs_devs->kobj_unregister); +} + +static struct kobj_type btrfs_ktype = { + .sysfs_ops = &kobj_sysfs_ops, + .release = btrfs_release_fsid_kobj, +}; + +static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj) +{ + if (kobj->ktype != &btrfs_ktype) + return NULL; + return container_of(kobj, struct btrfs_fs_devices, fsid_kobj); +} + +static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj) +{ + if (kobj->ktype != &btrfs_ktype) + return NULL; + return to_fs_devs(kobj)->fs_info; +} + +#define NUM_FEATURE_BITS 64 +#define BTRFS_FEATURE_NAME_MAX 13 +static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX]; +static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS]; + +static const u64 supported_feature_masks[FEAT_MAX] = { + [FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP, + [FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP, + [FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP, +}; + +static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add) +{ + int set; + + for (set = 0; set < FEAT_MAX; set++) { + int i; + struct attribute *attrs[2]; + struct attribute_group agroup = { + .name = "features", + .attrs = attrs, + }; + u64 features = get_features(fs_info, set); + features &= ~supported_feature_masks[set]; + + if (!features) + continue; + + attrs[1] = NULL; + for (i = 0; i < NUM_FEATURE_BITS; i++) { + struct btrfs_feature_attr *fa; + + if (!(features & (1ULL << i))) + continue; + + fa = &btrfs_feature_attrs[set][i]; + attrs[0] = &fa->kobj_attr.attr; + if (add) { + int ret; + ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj, + &agroup); + if (ret) + return ret; + } else + sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj, + &agroup); + } + + } + return 0; +} + +static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) +{ + if (fs_devs->device_dir_kobj) { + kobject_del(fs_devs->device_dir_kobj); + kobject_put(fs_devs->device_dir_kobj); + fs_devs->device_dir_kobj = NULL; + } + + if (fs_devs->fsid_kobj.state_initialized) { + kobject_del(&fs_devs->fsid_kobj); + kobject_put(&fs_devs->fsid_kobj); + wait_for_completion(&fs_devs->kobj_unregister); + } +} + +/* when fs_devs is NULL it will remove all fsid kobject */ +void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs) +{ + struct list_head *fs_uuids = btrfs_get_fs_uuids(); + + if (fs_devs) { + __btrfs_sysfs_remove_fsid(fs_devs); + return; + } + + list_for_each_entry(fs_devs, fs_uuids, fs_list) { + __btrfs_sysfs_remove_fsid(fs_devs); + } +} + +void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info) +{ + btrfs_reset_fs_info_ptr(fs_info); + + if (fs_info->space_info_kobj) { + sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs); + kobject_del(fs_info->space_info_kobj); + kobject_put(fs_info->space_info_kobj); + } + addrm_unknown_feature_attrs(fs_info, false); + sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group); + sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs); + btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL); +} + +const char * const btrfs_feature_set_names[FEAT_MAX] = { + [FEAT_COMPAT] = "compat", + [FEAT_COMPAT_RO] = "compat_ro", + [FEAT_INCOMPAT] = "incompat", +}; + +char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags) +{ + size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */ + int len = 0; + int i; + char *str; + + str = kmalloc(bufsize, GFP_KERNEL); + if (!str) + return str; + + for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { + const char *name; + + if (!(flags & (1ULL << i))) + continue; + + name = btrfs_feature_attrs[set][i].kobj_attr.attr.name; + len += snprintf(str + len, bufsize - len, "%s%s", + len ? "," : "", name); + } + + return str; +} + +static void init_feature_attrs(void) +{ + struct btrfs_feature_attr *fa; + int set, i; + + BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) != + ARRAY_SIZE(btrfs_feature_attrs)); + BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) != + ARRAY_SIZE(btrfs_feature_attrs[0])); + + memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs)); + memset(btrfs_unknown_feature_names, 0, + sizeof(btrfs_unknown_feature_names)); + + for (i = 0; btrfs_supported_feature_attrs[i]; i++) { + struct btrfs_feature_attr *sfa; + struct attribute *a = btrfs_supported_feature_attrs[i]; + int bit; + sfa = attr_to_btrfs_feature_attr(a); + bit = ilog2(sfa->feature_bit); + fa = &btrfs_feature_attrs[sfa->feature_set][bit]; + + fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name; + } + + for (set = 0; set < FEAT_MAX; set++) { + for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) { + char *name = btrfs_unknown_feature_names[set][i]; + fa = &btrfs_feature_attrs[set][i]; + + if (fa->kobj_attr.attr.name) + continue; + + snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u", + btrfs_feature_set_names[set], i); + + fa->kobj_attr.attr.name = name; + fa->kobj_attr.attr.mode = S_IRUGO; + fa->feature_set = set; + fa->feature_bit = 1ULL << i; + } + } +} + +/* when one_device is NULL, it removes all device links */ + +int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices, + struct btrfs_device *one_device) +{ + struct hd_struct *disk; + struct kobject *disk_kobj; + + if (!fs_devices->device_dir_kobj) + return -EINVAL; + + if (one_device && one_device->bdev) { + disk = one_device->bdev->bd_part; + disk_kobj = &part_to_dev(disk)->kobj; + + sysfs_remove_link(fs_devices->device_dir_kobj, + disk_kobj->name); + } + + if (one_device) + return 0; + + list_for_each_entry(one_device, + &fs_devices->devices, dev_list) { + if (!one_device->bdev) + continue; + disk = one_device->bdev->bd_part; + disk_kobj = &part_to_dev(disk)->kobj; + + sysfs_remove_link(fs_devices->device_dir_kobj, + disk_kobj->name); + } + + return 0; +} + +int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs) +{ + if (!fs_devs->device_dir_kobj) + fs_devs->device_dir_kobj = kobject_create_and_add("devices", + &fs_devs->fsid_kobj); + + if (!fs_devs->device_dir_kobj) + return -ENOMEM; + + return 0; +} + +int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices, + struct btrfs_device *one_device) +{ + int error = 0; + struct btrfs_device *dev; + unsigned int nofs_flag; + + nofs_flag = memalloc_nofs_save(); + list_for_each_entry(dev, &fs_devices->devices, dev_list) { + struct hd_struct *disk; + struct kobject *disk_kobj; + + if (!dev->bdev) + continue; + + if (one_device && one_device != dev) + continue; + + disk = dev->bdev->bd_part; + disk_kobj = &part_to_dev(disk)->kobj; + + error = sysfs_create_link(fs_devices->device_dir_kobj, + disk_kobj, disk_kobj->name); + if (error) + break; + } + memalloc_nofs_restore(nofs_flag); + + return error; +} + +/* /sys/fs/btrfs/ entry */ +static struct kset *btrfs_kset; + +/* /sys/kernel/debug/btrfs */ +static struct dentry *btrfs_debugfs_root_dentry; + +/* Debugging tunables and exported data */ +u64 btrfs_debugfs_test; + +/* + * Can be called by the device discovery thread. + * And parent can be specified for seed device + */ +int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs, + struct kobject *parent) +{ + int error; + + init_completion(&fs_devs->kobj_unregister); + fs_devs->fsid_kobj.kset = btrfs_kset; + error = kobject_init_and_add(&fs_devs->fsid_kobj, + &btrfs_ktype, parent, "%pU", fs_devs->fsid); + if (error) { + kobject_put(&fs_devs->fsid_kobj); + return error; + } + + return 0; +} + +int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info) +{ + int error; + struct btrfs_fs_devices *fs_devs = fs_info->fs_devices; + struct kobject *fsid_kobj = &fs_devs->fsid_kobj; + + btrfs_set_fs_info_ptr(fs_info); + + error = btrfs_sysfs_add_device_link(fs_devs, NULL); + if (error) + return error; + + error = sysfs_create_files(fsid_kobj, btrfs_attrs); + if (error) { + btrfs_sysfs_rm_device_link(fs_devs, NULL); + return error; + } + + error = sysfs_create_group(fsid_kobj, + &btrfs_feature_attr_group); + if (error) + goto failure; + + error = addrm_unknown_feature_attrs(fs_info, true); + if (error) + goto failure; + + fs_info->space_info_kobj = kobject_create_and_add("allocation", + fsid_kobj); + if (!fs_info->space_info_kobj) { + error = -ENOMEM; + goto failure; + } + + error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs); + if (error) + goto failure; + + return 0; +failure: + btrfs_sysfs_remove_mounted(fs_info); + return error; +} + + +/* + * Change per-fs features in /sys/fs/btrfs/UUID/features to match current + * values in superblock. Call after any changes to incompat/compat_ro flags + */ +void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info, + u64 bit, enum btrfs_feature_set set) +{ + struct btrfs_fs_devices *fs_devs; + struct kobject *fsid_kobj; + u64 features; + int ret; + + if (!fs_info) + return; + + features = get_features(fs_info, set); + ASSERT(bit & supported_feature_masks[set]); + + fs_devs = fs_info->fs_devices; + fsid_kobj = &fs_devs->fsid_kobj; + + if (!fsid_kobj->state_initialized) + return; + + /* + * FIXME: this is too heavy to update just one value, ideally we'd like + * to use sysfs_update_group but some refactoring is needed first. + */ + sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group); + ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group); +} + +static int btrfs_init_debugfs(void) +{ +#ifdef CONFIG_DEBUG_FS + btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL); + if (!btrfs_debugfs_root_dentry) + return -ENOMEM; + + /* + * Example code, how to export data through debugfs. + * + * file: /sys/kernel/debug/btrfs/test + * contents of: btrfs_debugfs_test + */ +#ifdef CONFIG_BTRFS_DEBUG + debugfs_create_u64("test", S_IRUGO | S_IWUSR, btrfs_debugfs_root_dentry, + &btrfs_debugfs_test); +#endif + +#endif + return 0; +} + +int __init btrfs_init_sysfs(void) +{ + int ret; + + btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); + if (!btrfs_kset) + return -ENOMEM; + + ret = btrfs_init_debugfs(); + if (ret) + goto out1; + + init_feature_attrs(); + ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); + if (ret) + goto out2; + ret = sysfs_merge_group(&btrfs_kset->kobj, + &btrfs_static_feature_attr_group); + if (ret) + goto out_remove_group; + + return 0; + +out_remove_group: + sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); +out2: + debugfs_remove_recursive(btrfs_debugfs_root_dentry); +out1: + kset_unregister(btrfs_kset); + + return ret; +} + +void __cold btrfs_exit_sysfs(void) +{ + sysfs_unmerge_group(&btrfs_kset->kobj, + &btrfs_static_feature_attr_group); + sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); + kset_unregister(btrfs_kset); + debugfs_remove_recursive(btrfs_debugfs_root_dentry); +} + |