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Diffstat (limited to 'fs/btrfs/check-integrity.c')
| -rw-r--r-- | fs/btrfs/check-integrity.c | 2864 |
1 files changed, 2864 insertions, 0 deletions
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c new file mode 100644 index 000000000..98c6e5fea --- /dev/null +++ b/fs/btrfs/check-integrity.c @@ -0,0 +1,2864 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) STRATO AG 2011. All rights reserved. + */ + +/* + * This module can be used to catch cases when the btrfs kernel + * code executes write requests to the disk that bring the file + * system in an inconsistent state. In such a state, a power-loss + * or kernel panic event would cause that the data on disk is + * lost or at least damaged. + * + * Code is added that examines all block write requests during + * runtime (including writes of the super block). Three rules + * are verified and an error is printed on violation of the + * rules: + * 1. It is not allowed to write a disk block which is + * currently referenced by the super block (either directly + * or indirectly). + * 2. When a super block is written, it is verified that all + * referenced (directly or indirectly) blocks fulfill the + * following requirements: + * 2a. All referenced blocks have either been present when + * the file system was mounted, (i.e., they have been + * referenced by the super block) or they have been + * written since then and the write completion callback + * was called and no write error was indicated and a + * FLUSH request to the device where these blocks are + * located was received and completed. + * 2b. All referenced blocks need to have a generation + * number which is equal to the parent's number. + * + * One issue that was found using this module was that the log + * tree on disk became temporarily corrupted because disk blocks + * that had been in use for the log tree had been freed and + * reused too early, while being referenced by the written super + * block. + * + * The search term in the kernel log that can be used to filter + * on the existence of detected integrity issues is + * "btrfs: attempt". + * + * The integrity check is enabled via mount options. These + * mount options are only supported if the integrity check + * tool is compiled by defining BTRFS_FS_CHECK_INTEGRITY. + * + * Example #1, apply integrity checks to all metadata: + * mount /dev/sdb1 /mnt -o check_int + * + * Example #2, apply integrity checks to all metadata and + * to data extents: + * mount /dev/sdb1 /mnt -o check_int_data + * + * Example #3, apply integrity checks to all metadata and dump + * the tree that the super block references to kernel messages + * each time after a super block was written: + * mount /dev/sdb1 /mnt -o check_int,check_int_print_mask=263 + * + * If the integrity check tool is included and activated in + * the mount options, plenty of kernel memory is used, and + * plenty of additional CPU cycles are spent. Enabling this + * functionality is not intended for normal use. In most + * cases, unless you are a btrfs developer who needs to verify + * the integrity of (super)-block write requests, do not + * enable the config option BTRFS_FS_CHECK_INTEGRITY to + * include and compile the integrity check tool. + * + * Expect millions of lines of information in the kernel log with an + * enabled check_int_print_mask. Therefore set LOG_BUF_SHIFT in the + * kernel config to at least 26 (which is 64MB). Usually the value is + * limited to 21 (which is 2MB) in init/Kconfig. The file needs to be + * changed like this before LOG_BUF_SHIFT can be set to a high value: + * config LOG_BUF_SHIFT + * int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" + * range 12 30 + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/blkdev.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <crypto/hash.h> +#include "ctree.h" +#include "disk-io.h" +#include "transaction.h" +#include "extent_io.h" +#include "volumes.h" +#include "print-tree.h" +#include "locking.h" +#include "check-integrity.h" +#include "rcu-string.h" +#include "compression.h" + +#define BTRFSIC_BLOCK_HASHTABLE_SIZE 0x10000 +#define BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE 0x10000 +#define BTRFSIC_DEV2STATE_HASHTABLE_SIZE 0x100 +#define BTRFSIC_BLOCK_MAGIC_NUMBER 0x14491051 +#define BTRFSIC_BLOCK_LINK_MAGIC_NUMBER 0x11070807 +#define BTRFSIC_DEV2STATE_MAGIC_NUMBER 0x20111530 +#define BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER 20111300 +#define BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL (200 - 6) /* in characters, + * excluding " [...]" */ +#define BTRFSIC_GENERATION_UNKNOWN ((u64)-1) + +/* + * The definition of the bitmask fields for the print_mask. + * They are specified with the mount option check_integrity_print_mask. + */ +#define BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE 0x00000001 +#define BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION 0x00000002 +#define BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE 0x00000004 +#define BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE 0x00000008 +#define BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH 0x00000010 +#define BTRFSIC_PRINT_MASK_END_IO_BIO_BH 0x00000020 +#define BTRFSIC_PRINT_MASK_VERBOSE 0x00000040 +#define BTRFSIC_PRINT_MASK_VERY_VERBOSE 0x00000080 +#define BTRFSIC_PRINT_MASK_INITIAL_TREE 0x00000100 +#define BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES 0x00000200 +#define BTRFSIC_PRINT_MASK_INITIAL_DATABASE 0x00000400 +#define BTRFSIC_PRINT_MASK_NUM_COPIES 0x00000800 +#define BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS 0x00001000 +#define BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE 0x00002000 + +struct btrfsic_dev_state; +struct btrfsic_state; + +struct btrfsic_block { + u32 magic_num; /* only used for debug purposes */ + unsigned int is_metadata:1; /* if it is meta-data, not data-data */ + unsigned int is_superblock:1; /* if it is one of the superblocks */ + unsigned int is_iodone:1; /* if is done by lower subsystem */ + unsigned int iodone_w_error:1; /* error was indicated to endio */ + unsigned int never_written:1; /* block was added because it was + * referenced, not because it was + * written */ + unsigned int mirror_num; /* large enough to hold + * BTRFS_SUPER_MIRROR_MAX */ + struct btrfsic_dev_state *dev_state; + u64 dev_bytenr; /* key, physical byte num on disk */ + u64 logical_bytenr; /* logical byte num on disk */ + u64 generation; + struct btrfs_disk_key disk_key; /* extra info to print in case of + * issues, will not always be correct */ + struct list_head collision_resolving_node; /* list node */ + struct list_head all_blocks_node; /* list node */ + + /* the following two lists contain block_link items */ + struct list_head ref_to_list; /* list */ + struct list_head ref_from_list; /* list */ + struct btrfsic_block *next_in_same_bio; + void *orig_bio_private; + bio_end_io_t *orig_bio_end_io; + blk_opf_t submit_bio_bh_rw; + u64 flush_gen; /* only valid if !never_written */ +}; + +/* + * Elements of this type are allocated dynamically and required because + * each block object can refer to and can be ref from multiple blocks. + * The key to lookup them in the hashtable is the dev_bytenr of + * the block ref to plus the one from the block referred from. + * The fact that they are searchable via a hashtable and that a + * ref_cnt is maintained is not required for the btrfs integrity + * check algorithm itself, it is only used to make the output more + * beautiful in case that an error is detected (an error is defined + * as a write operation to a block while that block is still referenced). + */ +struct btrfsic_block_link { + u32 magic_num; /* only used for debug purposes */ + u32 ref_cnt; + struct list_head node_ref_to; /* list node */ + struct list_head node_ref_from; /* list node */ + struct list_head collision_resolving_node; /* list node */ + struct btrfsic_block *block_ref_to; + struct btrfsic_block *block_ref_from; + u64 parent_generation; +}; + +struct btrfsic_dev_state { + u32 magic_num; /* only used for debug purposes */ + struct block_device *bdev; + struct btrfsic_state *state; + struct list_head collision_resolving_node; /* list node */ + struct btrfsic_block dummy_block_for_bio_bh_flush; + u64 last_flush_gen; +}; + +struct btrfsic_block_hashtable { + struct list_head table[BTRFSIC_BLOCK_HASHTABLE_SIZE]; +}; + +struct btrfsic_block_link_hashtable { + struct list_head table[BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE]; +}; + +struct btrfsic_dev_state_hashtable { + struct list_head table[BTRFSIC_DEV2STATE_HASHTABLE_SIZE]; +}; + +struct btrfsic_block_data_ctx { + u64 start; /* virtual bytenr */ + u64 dev_bytenr; /* physical bytenr on device */ + u32 len; + struct btrfsic_dev_state *dev; + char **datav; + struct page **pagev; + void *mem_to_free; +}; + +/* This structure is used to implement recursion without occupying + * any stack space, refer to btrfsic_process_metablock() */ +struct btrfsic_stack_frame { + u32 magic; + u32 nr; + int error; + int i; + int limit_nesting; + int num_copies; + int mirror_num; + struct btrfsic_block *block; + struct btrfsic_block_data_ctx *block_ctx; + struct btrfsic_block *next_block; + struct btrfsic_block_data_ctx next_block_ctx; + struct btrfs_header *hdr; + struct btrfsic_stack_frame *prev; +}; + +/* Some state per mounted filesystem */ +struct btrfsic_state { + u32 print_mask; + int include_extent_data; + struct list_head all_blocks_list; + struct btrfsic_block_hashtable block_hashtable; + struct btrfsic_block_link_hashtable block_link_hashtable; + struct btrfs_fs_info *fs_info; + u64 max_superblock_generation; + struct btrfsic_block *latest_superblock; + u32 metablock_size; + u32 datablock_size; +}; + +static int btrfsic_process_metablock(struct btrfsic_state *state, + struct btrfsic_block *block, + struct btrfsic_block_data_ctx *block_ctx, + int limit_nesting, int force_iodone_flag); +static void btrfsic_read_from_block_data( + struct btrfsic_block_data_ctx *block_ctx, + void *dst, u32 offset, size_t len); +static int btrfsic_create_link_to_next_block( + struct btrfsic_state *state, + struct btrfsic_block *block, + struct btrfsic_block_data_ctx + *block_ctx, u64 next_bytenr, + int limit_nesting, + struct btrfsic_block_data_ctx *next_block_ctx, + struct btrfsic_block **next_blockp, + int force_iodone_flag, + int *num_copiesp, int *mirror_nump, + struct btrfs_disk_key *disk_key, + u64 parent_generation); +static int btrfsic_handle_extent_data(struct btrfsic_state *state, + struct btrfsic_block *block, + struct btrfsic_block_data_ctx *block_ctx, + u32 item_offset, int force_iodone_flag); +static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len, + struct btrfsic_block_data_ctx *block_ctx_out, + int mirror_num); +static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx); +static int btrfsic_read_block(struct btrfsic_state *state, + struct btrfsic_block_data_ctx *block_ctx); +static int btrfsic_process_written_superblock( + struct btrfsic_state *state, + struct btrfsic_block *const block, + struct btrfs_super_block *const super_hdr); +static void btrfsic_bio_end_io(struct bio *bp); +static int btrfsic_is_block_ref_by_superblock(const struct btrfsic_state *state, + const struct btrfsic_block *block, + int recursion_level); +static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state, + struct btrfsic_block *const block, + int recursion_level); +static void btrfsic_print_add_link(const struct btrfsic_state *state, + const struct btrfsic_block_link *l); +static void btrfsic_print_rem_link(const struct btrfsic_state *state, + const struct btrfsic_block_link *l); +static char btrfsic_get_block_type(const struct btrfsic_state *state, + const struct btrfsic_block *block); +static void btrfsic_dump_tree(const struct btrfsic_state *state); +static void btrfsic_dump_tree_sub(const struct btrfsic_state *state, + const struct btrfsic_block *block, + int indent_level); +static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add( + struct btrfsic_state *state, + struct btrfsic_block_data_ctx *next_block_ctx, + struct btrfsic_block *next_block, + struct btrfsic_block *from_block, + u64 parent_generation); +static struct btrfsic_block *btrfsic_block_lookup_or_add( + struct btrfsic_state *state, + struct btrfsic_block_data_ctx *block_ctx, + const char *additional_string, + int is_metadata, + int is_iodone, + int never_written, + int mirror_num, + int *was_created); +static int btrfsic_process_superblock_dev_mirror( + struct btrfsic_state *state, + struct btrfsic_dev_state *dev_state, + struct btrfs_device *device, + int superblock_mirror_num, + struct btrfsic_dev_state **selected_dev_state, + struct btrfs_super_block *selected_super); +static struct btrfsic_dev_state *btrfsic_dev_state_lookup(dev_t dev); +static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state, + u64 bytenr, + struct btrfsic_dev_state *dev_state, + u64 dev_bytenr); + +static struct mutex btrfsic_mutex; +static int btrfsic_is_initialized; +static struct btrfsic_dev_state_hashtable btrfsic_dev_state_hashtable; + + +static void btrfsic_block_init(struct btrfsic_block *b) +{ + b->magic_num = BTRFSIC_BLOCK_MAGIC_NUMBER; + b->dev_state = NULL; + b->dev_bytenr = 0; + b->logical_bytenr = 0; + b->generation = BTRFSIC_GENERATION_UNKNOWN; + b->disk_key.objectid = 0; + b->disk_key.type = 0; + b->disk_key.offset = 0; + b->is_metadata = 0; + b->is_superblock = 0; + b->is_iodone = 0; + b->iodone_w_error = 0; + b->never_written = 0; + b->mirror_num = 0; + b->next_in_same_bio = NULL; + b->orig_bio_private = NULL; + b->orig_bio_end_io = NULL; + INIT_LIST_HEAD(&b->collision_resolving_node); + INIT_LIST_HEAD(&b->all_blocks_node); + INIT_LIST_HEAD(&b->ref_to_list); + INIT_LIST_HEAD(&b->ref_from_list); + b->submit_bio_bh_rw = 0; + b->flush_gen = 0; +} + +static struct btrfsic_block *btrfsic_block_alloc(void) +{ + struct btrfsic_block *b; + + b = kzalloc(sizeof(*b), GFP_NOFS); + if (NULL != b) + btrfsic_block_init(b); + + return b; +} + +static void btrfsic_block_free(struct btrfsic_block *b) +{ + BUG_ON(!(NULL == b || BTRFSIC_BLOCK_MAGIC_NUMBER == b->magic_num)); + kfree(b); +} + +static void btrfsic_block_link_init(struct btrfsic_block_link *l) +{ + l->magic_num = BTRFSIC_BLOCK_LINK_MAGIC_NUMBER; + l->ref_cnt = 1; + INIT_LIST_HEAD(&l->node_ref_to); + INIT_LIST_HEAD(&l->node_ref_from); + INIT_LIST_HEAD(&l->collision_resolving_node); + l->block_ref_to = NULL; + l->block_ref_from = NULL; +} + +static struct btrfsic_block_link *btrfsic_block_link_alloc(void) +{ + struct btrfsic_block_link *l; + + l = kzalloc(sizeof(*l), GFP_NOFS); + if (NULL != l) + btrfsic_block_link_init(l); + + return l; +} + +static void btrfsic_block_link_free(struct btrfsic_block_link *l) +{ + BUG_ON(!(NULL == l || BTRFSIC_BLOCK_LINK_MAGIC_NUMBER == l->magic_num)); + kfree(l); +} + +static void btrfsic_dev_state_init(struct btrfsic_dev_state *ds) +{ + ds->magic_num = BTRFSIC_DEV2STATE_MAGIC_NUMBER; + ds->bdev = NULL; + ds->state = NULL; + INIT_LIST_HEAD(&ds->collision_resolving_node); + ds->last_flush_gen = 0; + btrfsic_block_init(&ds->dummy_block_for_bio_bh_flush); + ds->dummy_block_for_bio_bh_flush.is_iodone = 1; + ds->dummy_block_for_bio_bh_flush.dev_state = ds; +} + +static struct btrfsic_dev_state *btrfsic_dev_state_alloc(void) +{ + struct btrfsic_dev_state *ds; + + ds = kzalloc(sizeof(*ds), GFP_NOFS); + if (NULL != ds) + btrfsic_dev_state_init(ds); + + return ds; +} + +static void btrfsic_dev_state_free(struct btrfsic_dev_state *ds) +{ + BUG_ON(!(NULL == ds || + BTRFSIC_DEV2STATE_MAGIC_NUMBER == ds->magic_num)); + kfree(ds); +} + +static void btrfsic_block_hashtable_init(struct btrfsic_block_hashtable *h) +{ + int i; + + for (i = 0; i < BTRFSIC_BLOCK_HASHTABLE_SIZE; i++) + INIT_LIST_HEAD(h->table + i); +} + +static void btrfsic_block_hashtable_add(struct btrfsic_block *b, + struct btrfsic_block_hashtable *h) +{ + const unsigned int hashval = + (((unsigned int)(b->dev_bytenr >> 16)) ^ + ((unsigned int)((uintptr_t)b->dev_state->bdev))) & + (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1); + + list_add(&b->collision_resolving_node, h->table + hashval); +} + +static void btrfsic_block_hashtable_remove(struct btrfsic_block *b) +{ + list_del(&b->collision_resolving_node); +} + +static struct btrfsic_block *btrfsic_block_hashtable_lookup( + struct block_device *bdev, + u64 dev_bytenr, + struct btrfsic_block_hashtable *h) +{ + const unsigned int hashval = + (((unsigned int)(dev_bytenr >> 16)) ^ + ((unsigned int)((uintptr_t)bdev))) & + (BTRFSIC_BLOCK_HASHTABLE_SIZE - 1); + struct btrfsic_block *b; + + list_for_each_entry(b, h->table + hashval, collision_resolving_node) { + if (b->dev_state->bdev == bdev && b->dev_bytenr == dev_bytenr) + return b; + } + + return NULL; +} + +static void btrfsic_block_link_hashtable_init( + struct btrfsic_block_link_hashtable *h) +{ + int i; + + for (i = 0; i < BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE; i++) + INIT_LIST_HEAD(h->table + i); +} + +static void btrfsic_block_link_hashtable_add( + struct btrfsic_block_link *l, + struct btrfsic_block_link_hashtable *h) +{ + const unsigned int hashval = + (((unsigned int)(l->block_ref_to->dev_bytenr >> 16)) ^ + ((unsigned int)(l->block_ref_from->dev_bytenr >> 16)) ^ + ((unsigned int)((uintptr_t)l->block_ref_to->dev_state->bdev)) ^ + ((unsigned int)((uintptr_t)l->block_ref_from->dev_state->bdev))) + & (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1); + + BUG_ON(NULL == l->block_ref_to); + BUG_ON(NULL == l->block_ref_from); + list_add(&l->collision_resolving_node, h->table + hashval); +} + +static void btrfsic_block_link_hashtable_remove(struct btrfsic_block_link *l) +{ + list_del(&l->collision_resolving_node); +} + +static struct btrfsic_block_link *btrfsic_block_link_hashtable_lookup( + struct block_device *bdev_ref_to, + u64 dev_bytenr_ref_to, + struct block_device *bdev_ref_from, + u64 dev_bytenr_ref_from, + struct btrfsic_block_link_hashtable *h) +{ + const unsigned int hashval = + (((unsigned int)(dev_bytenr_ref_to >> 16)) ^ + ((unsigned int)(dev_bytenr_ref_from >> 16)) ^ + ((unsigned int)((uintptr_t)bdev_ref_to)) ^ + ((unsigned int)((uintptr_t)bdev_ref_from))) & + (BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE - 1); + struct btrfsic_block_link *l; + + list_for_each_entry(l, h->table + hashval, collision_resolving_node) { + BUG_ON(NULL == l->block_ref_to); + BUG_ON(NULL == l->block_ref_from); + if (l->block_ref_to->dev_state->bdev == bdev_ref_to && + l->block_ref_to->dev_bytenr == dev_bytenr_ref_to && + l->block_ref_from->dev_state->bdev == bdev_ref_from && + l->block_ref_from->dev_bytenr == dev_bytenr_ref_from) + return l; + } + + return NULL; +} + +static void btrfsic_dev_state_hashtable_init( + struct btrfsic_dev_state_hashtable *h) +{ + int i; + + for (i = 0; i < BTRFSIC_DEV2STATE_HASHTABLE_SIZE; i++) + INIT_LIST_HEAD(h->table + i); +} + +static void btrfsic_dev_state_hashtable_add( + struct btrfsic_dev_state *ds, + struct btrfsic_dev_state_hashtable *h) +{ + const unsigned int hashval = + (((unsigned int)((uintptr_t)ds->bdev->bd_dev)) & + (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1)); + + list_add(&ds->collision_resolving_node, h->table + hashval); +} + +static void btrfsic_dev_state_hashtable_remove(struct btrfsic_dev_state *ds) +{ + list_del(&ds->collision_resolving_node); +} + +static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(dev_t dev, + struct btrfsic_dev_state_hashtable *h) +{ + const unsigned int hashval = + dev & (BTRFSIC_DEV2STATE_HASHTABLE_SIZE - 1); + struct btrfsic_dev_state *ds; + + list_for_each_entry(ds, h->table + hashval, collision_resolving_node) { + if (ds->bdev->bd_dev == dev) + return ds; + } + + return NULL; +} + +static int btrfsic_process_superblock(struct btrfsic_state *state, + struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_super_block *selected_super; + struct list_head *dev_head = &fs_devices->devices; + struct btrfs_device *device; + struct btrfsic_dev_state *selected_dev_state = NULL; + int ret = 0; + int pass; + + selected_super = kzalloc(sizeof(*selected_super), GFP_NOFS); + if (!selected_super) + return -ENOMEM; + + list_for_each_entry(device, dev_head, dev_list) { + int i; + struct btrfsic_dev_state *dev_state; + + if (!device->bdev || !device->name) + continue; + + dev_state = btrfsic_dev_state_lookup(device->bdev->bd_dev); + BUG_ON(NULL == dev_state); + for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { + ret = btrfsic_process_superblock_dev_mirror( + state, dev_state, device, i, + &selected_dev_state, selected_super); + if (0 != ret && 0 == i) { + kfree(selected_super); + return ret; + } + } + } + + if (NULL == state->latest_superblock) { + pr_info("btrfsic: no superblock found!\n"); + kfree(selected_super); + return -1; + } + + for (pass = 0; pass < 3; pass++) { + int num_copies; + int mirror_num; + u64 next_bytenr; + + switch (pass) { + case 0: + next_bytenr = btrfs_super_root(selected_super); + if (state->print_mask & + BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION) + pr_info("root@%llu\n", next_bytenr); + break; + case 1: + next_bytenr = btrfs_super_chunk_root(selected_super); + if (state->print_mask & + BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION) + pr_info("chunk@%llu\n", next_bytenr); + break; + case 2: + next_bytenr = btrfs_super_log_root(selected_super); + if (0 == next_bytenr) + continue; + if (state->print_mask & + BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION) + pr_info("log@%llu\n", next_bytenr); + break; + } + + num_copies = btrfs_num_copies(state->fs_info, next_bytenr, + state->metablock_size); + if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES) + pr_info("num_copies(log_bytenr=%llu) = %d\n", + next_bytenr, num_copies); + + for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) { + struct btrfsic_block *next_block; + struct btrfsic_block_data_ctx tmp_next_block_ctx; + struct btrfsic_block_link *l; + + ret = btrfsic_map_block(state, next_bytenr, + state->metablock_size, + &tmp_next_block_ctx, + mirror_num); + if (ret) { + pr_info("btrfsic: btrfsic_map_block(root @%llu, mirror %d) failed!\n", + next_bytenr, mirror_num); + kfree(selected_super); + return -1; + } + + next_block = btrfsic_block_hashtable_lookup( + tmp_next_block_ctx.dev->bdev, + tmp_next_block_ctx.dev_bytenr, + &state->block_hashtable); + BUG_ON(NULL == next_block); + + l = btrfsic_block_link_hashtable_lookup( + tmp_next_block_ctx.dev->bdev, + tmp_next_block_ctx.dev_bytenr, + state->latest_superblock->dev_state-> + bdev, + state->latest_superblock->dev_bytenr, + &state->block_link_hashtable); + BUG_ON(NULL == l); + + ret = btrfsic_read_block(state, &tmp_next_block_ctx); + if (ret < (int)PAGE_SIZE) { + pr_info("btrfsic: read @logical %llu failed!\n", + tmp_next_block_ctx.start); + btrfsic_release_block_ctx(&tmp_next_block_ctx); + kfree(selected_super); + return -1; + } + + ret = btrfsic_process_metablock(state, + next_block, + &tmp_next_block_ctx, + BTRFS_MAX_LEVEL + 3, 1); + btrfsic_release_block_ctx(&tmp_next_block_ctx); + } + } + + kfree(selected_super); + return ret; +} + +static int btrfsic_process_superblock_dev_mirror( + struct btrfsic_state *state, + struct btrfsic_dev_state *dev_state, + struct btrfs_device *device, + int superblock_mirror_num, + struct btrfsic_dev_state **selected_dev_state, + struct btrfs_super_block *selected_super) +{ + struct btrfs_fs_info *fs_info = state->fs_info; + struct btrfs_super_block *super_tmp; + u64 dev_bytenr; + struct btrfsic_block *superblock_tmp; + int pass; + struct block_device *const superblock_bdev = device->bdev; + struct page *page; + struct address_space *mapping = superblock_bdev->bd_inode->i_mapping; + int ret = 0; + + /* super block bytenr is always the unmapped device bytenr */ + dev_bytenr = btrfs_sb_offset(superblock_mirror_num); + if (dev_bytenr + BTRFS_SUPER_INFO_SIZE > device->commit_total_bytes) + return -1; + + page = read_cache_page_gfp(mapping, dev_bytenr >> PAGE_SHIFT, GFP_NOFS); + if (IS_ERR(page)) + return -1; + + super_tmp = page_address(page); + + if (btrfs_super_bytenr(super_tmp) != dev_bytenr || + btrfs_super_magic(super_tmp) != BTRFS_MAGIC || + memcmp(device->uuid, super_tmp->dev_item.uuid, BTRFS_UUID_SIZE) || + btrfs_super_nodesize(super_tmp) != state->metablock_size || + btrfs_super_sectorsize(super_tmp) != state->datablock_size) { + ret = 0; + goto out; + } + + superblock_tmp = + btrfsic_block_hashtable_lookup(superblock_bdev, + dev_bytenr, + &state->block_hashtable); + if (NULL == superblock_tmp) { + superblock_tmp = btrfsic_block_alloc(); + if (NULL == superblock_tmp) { + ret = -1; + goto out; + } + /* for superblock, only the dev_bytenr makes sense */ + superblock_tmp->dev_bytenr = dev_bytenr; + superblock_tmp->dev_state = dev_state; + superblock_tmp->logical_bytenr = dev_bytenr; + superblock_tmp->generation = btrfs_super_generation(super_tmp); + superblock_tmp->is_metadata = 1; + superblock_tmp->is_superblock = 1; + superblock_tmp->is_iodone = 1; + superblock_tmp->never_written = 0; + superblock_tmp->mirror_num = 1 + superblock_mirror_num; + if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE) + btrfs_info_in_rcu(fs_info, + "new initial S-block (bdev %p, %s) @%llu (%pg/%llu/%d)", + superblock_bdev, + rcu_str_deref(device->name), dev_bytenr, + dev_state->bdev, dev_bytenr, + superblock_mirror_num); + list_add(&superblock_tmp->all_blocks_node, + &state->all_blocks_list); + btrfsic_block_hashtable_add(superblock_tmp, + &state->block_hashtable); + } + + /* select the one with the highest generation field */ + if (btrfs_super_generation(super_tmp) > + state->max_superblock_generation || + 0 == state->max_superblock_generation) { + memcpy(selected_super, super_tmp, sizeof(*selected_super)); + *selected_dev_state = dev_state; + state->max_superblock_generation = + btrfs_super_generation(super_tmp); + state->latest_superblock = superblock_tmp; + } + + for (pass = 0; pass < 3; pass++) { + u64 next_bytenr; + int num_copies; + int mirror_num; + const char *additional_string = NULL; + struct btrfs_disk_key tmp_disk_key; + + tmp_disk_key.type = BTRFS_ROOT_ITEM_KEY; + tmp_disk_key.offset = 0; + switch (pass) { + case 0: + btrfs_set_disk_key_objectid(&tmp_disk_key, + BTRFS_ROOT_TREE_OBJECTID); + additional_string = "initial root "; + next_bytenr = btrfs_super_root(super_tmp); + break; + case 1: + btrfs_set_disk_key_objectid(&tmp_disk_key, + BTRFS_CHUNK_TREE_OBJECTID); + additional_string = "initial chunk "; + next_bytenr = btrfs_super_chunk_root(super_tmp); + break; + case 2: + btrfs_set_disk_key_objectid(&tmp_disk_key, + BTRFS_TREE_LOG_OBJECTID); + additional_string = "initial log "; + next_bytenr = btrfs_super_log_root(super_tmp); + if (0 == next_bytenr) + continue; + break; + } + + num_copies = btrfs_num_copies(fs_info, next_bytenr, + state->metablock_size); + if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES) + pr_info("num_copies(log_bytenr=%llu) = %d\n", + next_bytenr, num_copies); + for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) { + struct btrfsic_block *next_block; + struct btrfsic_block_data_ctx tmp_next_block_ctx; + struct btrfsic_block_link *l; + + if (btrfsic_map_block(state, next_bytenr, + state->metablock_size, + &tmp_next_block_ctx, + mirror_num)) { + pr_info("btrfsic: btrfsic_map_block(bytenr @%llu, mirror %d) failed!\n", + next_bytenr, mirror_num); + ret = -1; + goto out; + } + + next_block = btrfsic_block_lookup_or_add( + state, &tmp_next_block_ctx, + additional_string, 1, 1, 0, + mirror_num, NULL); + if (NULL == next_block) { + btrfsic_release_block_ctx(&tmp_next_block_ctx); + ret = -1; + goto out; + } + + next_block->disk_key = tmp_disk_key; + next_block->generation = BTRFSIC_GENERATION_UNKNOWN; + l = btrfsic_block_link_lookup_or_add( + state, &tmp_next_block_ctx, + next_block, superblock_tmp, + BTRFSIC_GENERATION_UNKNOWN); + btrfsic_release_block_ctx(&tmp_next_block_ctx); + if (NULL == l) { + ret = -1; + goto out; + } + } + } + if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_ALL_TREES) + btrfsic_dump_tree_sub(state, superblock_tmp, 0); + +out: + put_page(page); + return ret; +} + +static struct btrfsic_stack_frame *btrfsic_stack_frame_alloc(void) +{ + struct btrfsic_stack_frame *sf; + + sf = kzalloc(sizeof(*sf), GFP_NOFS); + if (sf) + sf->magic = BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER; + return sf; +} + +static void btrfsic_stack_frame_free(struct btrfsic_stack_frame *sf) +{ + BUG_ON(!(NULL == sf || + BTRFSIC_BLOCK_STACK_FRAME_MAGIC_NUMBER == sf->magic)); + kfree(sf); +} + +static noinline_for_stack int btrfsic_process_metablock( + struct btrfsic_state *state, + struct btrfsic_block *const first_block, + struct btrfsic_block_data_ctx *const first_block_ctx, + int first_limit_nesting, int force_iodone_flag) +{ + struct btrfsic_stack_frame initial_stack_frame = { 0 }; + struct btrfsic_stack_frame *sf; + struct btrfsic_stack_frame *next_stack; + struct btrfs_header *const first_hdr = + (struct btrfs_header *)first_block_ctx->datav[0]; + + BUG_ON(!first_hdr); + sf = &initial_stack_frame; + sf->error = 0; + sf->i = -1; + sf->limit_nesting = first_limit_nesting; + sf->block = first_block; + sf->block_ctx = first_block_ctx; + sf->next_block = NULL; + sf->hdr = first_hdr; + sf->prev = NULL; + +continue_with_new_stack_frame: + sf->block->generation = btrfs_stack_header_generation(sf->hdr); + if (0 == sf->hdr->level) { + struct btrfs_leaf *const leafhdr = + (struct btrfs_leaf *)sf->hdr; + + if (-1 == sf->i) { + sf->nr = btrfs_stack_header_nritems(&leafhdr->header); + + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("leaf %llu items %d generation %llu owner %llu\n", + sf->block_ctx->start, sf->nr, + btrfs_stack_header_generation( + &leafhdr->header), + btrfs_stack_header_owner( + &leafhdr->header)); + } + +continue_with_current_leaf_stack_frame: + if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) { + sf->i++; + sf->num_copies = 0; + } + + if (sf->i < sf->nr) { + struct btrfs_item disk_item; + u32 disk_item_offset = + (uintptr_t)(leafhdr->items + sf->i) - + (uintptr_t)leafhdr; + struct btrfs_disk_key *disk_key; + u8 type; + u32 item_offset; + u32 item_size; + + if (disk_item_offset + sizeof(struct btrfs_item) > + sf->block_ctx->len) { +leaf_item_out_of_bounce_error: + pr_info( + "btrfsic: leaf item out of bounce at logical %llu, dev %pg\n", + sf->block_ctx->start, + sf->block_ctx->dev->bdev); + goto one_stack_frame_backwards; + } + btrfsic_read_from_block_data(sf->block_ctx, + &disk_item, + disk_item_offset, + sizeof(struct btrfs_item)); + item_offset = btrfs_stack_item_offset(&disk_item); + item_size = btrfs_stack_item_size(&disk_item); + disk_key = &disk_item.key; + type = btrfs_disk_key_type(disk_key); + + if (BTRFS_ROOT_ITEM_KEY == type) { + struct btrfs_root_item root_item; + u32 root_item_offset; + u64 next_bytenr; + + root_item_offset = item_offset + + offsetof(struct btrfs_leaf, items); + if (root_item_offset + item_size > + sf->block_ctx->len) + goto leaf_item_out_of_bounce_error; + btrfsic_read_from_block_data( + sf->block_ctx, &root_item, + root_item_offset, + item_size); + next_bytenr = btrfs_root_bytenr(&root_item); + + sf->error = + btrfsic_create_link_to_next_block( + state, + sf->block, + sf->block_ctx, + next_bytenr, + sf->limit_nesting, + &sf->next_block_ctx, + &sf->next_block, + force_iodone_flag, + &sf->num_copies, + &sf->mirror_num, + disk_key, + btrfs_root_generation( + &root_item)); + if (sf->error) + goto one_stack_frame_backwards; + + if (NULL != sf->next_block) { + struct btrfs_header *const next_hdr = + (struct btrfs_header *) + sf->next_block_ctx.datav[0]; + + next_stack = + btrfsic_stack_frame_alloc(); + if (NULL == next_stack) { + sf->error = -1; + btrfsic_release_block_ctx( + &sf-> + next_block_ctx); + goto one_stack_frame_backwards; + } + + next_stack->i = -1; + next_stack->block = sf->next_block; + next_stack->block_ctx = + &sf->next_block_ctx; + next_stack->next_block = NULL; + next_stack->hdr = next_hdr; + next_stack->limit_nesting = + sf->limit_nesting - 1; + next_stack->prev = sf; + sf = next_stack; + goto continue_with_new_stack_frame; + } + } else if (BTRFS_EXTENT_DATA_KEY == type && + state->include_extent_data) { + sf->error = btrfsic_handle_extent_data( + state, + sf->block, + sf->block_ctx, + item_offset, + force_iodone_flag); + if (sf->error) + goto one_stack_frame_backwards; + } + + goto continue_with_current_leaf_stack_frame; + } + } else { + struct btrfs_node *const nodehdr = (struct btrfs_node *)sf->hdr; + + if (-1 == sf->i) { + sf->nr = btrfs_stack_header_nritems(&nodehdr->header); + + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("node %llu level %d items %d generation %llu owner %llu\n", + sf->block_ctx->start, + nodehdr->header.level, sf->nr, + btrfs_stack_header_generation( + &nodehdr->header), + btrfs_stack_header_owner( + &nodehdr->header)); + } + +continue_with_current_node_stack_frame: + if (0 == sf->num_copies || sf->mirror_num > sf->num_copies) { + sf->i++; + sf->num_copies = 0; + } + + if (sf->i < sf->nr) { + struct btrfs_key_ptr key_ptr; + u32 key_ptr_offset; + u64 next_bytenr; + + key_ptr_offset = (uintptr_t)(nodehdr->ptrs + sf->i) - + (uintptr_t)nodehdr; + if (key_ptr_offset + sizeof(struct btrfs_key_ptr) > + sf->block_ctx->len) { + pr_info( + "btrfsic: node item out of bounce at logical %llu, dev %pg\n", + sf->block_ctx->start, + sf->block_ctx->dev->bdev); + goto one_stack_frame_backwards; + } + btrfsic_read_from_block_data( + sf->block_ctx, &key_ptr, key_ptr_offset, + sizeof(struct btrfs_key_ptr)); + next_bytenr = btrfs_stack_key_blockptr(&key_ptr); + + sf->error = btrfsic_create_link_to_next_block( + state, + sf->block, + sf->block_ctx, + next_bytenr, + sf->limit_nesting, + &sf->next_block_ctx, + &sf->next_block, + force_iodone_flag, + &sf->num_copies, + &sf->mirror_num, + &key_ptr.key, + btrfs_stack_key_generation(&key_ptr)); + if (sf->error) + goto one_stack_frame_backwards; + + if (NULL != sf->next_block) { + struct btrfs_header *const next_hdr = + (struct btrfs_header *) + sf->next_block_ctx.datav[0]; + + next_stack = btrfsic_stack_frame_alloc(); + if (NULL == next_stack) { + sf->error = -1; + goto one_stack_frame_backwards; + } + + next_stack->i = -1; + next_stack->block = sf->next_block; + next_stack->block_ctx = &sf->next_block_ctx; + next_stack->next_block = NULL; + next_stack->hdr = next_hdr; + next_stack->limit_nesting = + sf->limit_nesting - 1; + next_stack->prev = sf; + sf = next_stack; + goto continue_with_new_stack_frame; + } + + goto continue_with_current_node_stack_frame; + } + } + +one_stack_frame_backwards: + if (NULL != sf->prev) { + struct btrfsic_stack_frame *const prev = sf->prev; + + /* the one for the initial block is freed in the caller */ + btrfsic_release_block_ctx(sf->block_ctx); + + if (sf->error) { + prev->error = sf->error; + btrfsic_stack_frame_free(sf); + sf = prev; + goto one_stack_frame_backwards; + } + + btrfsic_stack_frame_free(sf); + sf = prev; + goto continue_with_new_stack_frame; + } else { + BUG_ON(&initial_stack_frame != sf); + } + + return sf->error; +} + +static void btrfsic_read_from_block_data( + struct btrfsic_block_data_ctx *block_ctx, + void *dstv, u32 offset, size_t len) +{ + size_t cur; + size_t pgoff; + char *kaddr; + char *dst = (char *)dstv; + size_t start_offset = offset_in_page(block_ctx->start); + unsigned long i = (start_offset + offset) >> PAGE_SHIFT; + + WARN_ON(offset + len > block_ctx->len); + pgoff = offset_in_page(start_offset + offset); + + while (len > 0) { + cur = min(len, ((size_t)PAGE_SIZE - pgoff)); + BUG_ON(i >= DIV_ROUND_UP(block_ctx->len, PAGE_SIZE)); + kaddr = block_ctx->datav[i]; + memcpy(dst, kaddr + pgoff, cur); + + dst += cur; + len -= cur; + pgoff = 0; + i++; + } +} + +static int btrfsic_create_link_to_next_block( + struct btrfsic_state *state, + struct btrfsic_block *block, + struct btrfsic_block_data_ctx *block_ctx, + u64 next_bytenr, + int limit_nesting, + struct btrfsic_block_data_ctx *next_block_ctx, + struct btrfsic_block **next_blockp, + int force_iodone_flag, + int *num_copiesp, int *mirror_nump, + struct btrfs_disk_key *disk_key, + u64 parent_generation) +{ + struct btrfs_fs_info *fs_info = state->fs_info; + struct btrfsic_block *next_block = NULL; + int ret; + struct btrfsic_block_link *l; + int did_alloc_block_link; + int block_was_created; + + *next_blockp = NULL; + if (0 == *num_copiesp) { + *num_copiesp = btrfs_num_copies(fs_info, next_bytenr, + state->metablock_size); + if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES) + pr_info("num_copies(log_bytenr=%llu) = %d\n", + next_bytenr, *num_copiesp); + *mirror_nump = 1; + } + + if (*mirror_nump > *num_copiesp) + return 0; + + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("btrfsic_create_link_to_next_block(mirror_num=%d)\n", + *mirror_nump); + ret = btrfsic_map_block(state, next_bytenr, + state->metablock_size, + next_block_ctx, *mirror_nump); + if (ret) { + pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n", + next_bytenr, *mirror_nump); + btrfsic_release_block_ctx(next_block_ctx); + *next_blockp = NULL; + return -1; + } + + next_block = btrfsic_block_lookup_or_add(state, + next_block_ctx, "referenced ", + 1, force_iodone_flag, + !force_iodone_flag, + *mirror_nump, + &block_was_created); + if (NULL == next_block) { + btrfsic_release_block_ctx(next_block_ctx); + *next_blockp = NULL; + return -1; + } + if (block_was_created) { + l = NULL; + next_block->generation = BTRFSIC_GENERATION_UNKNOWN; + } else { + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) { + if (next_block->logical_bytenr != next_bytenr && + !(!next_block->is_metadata && + 0 == next_block->logical_bytenr)) + pr_info( +"referenced block @%llu (%pg/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu)\n", + next_bytenr, next_block_ctx->dev->bdev, + next_block_ctx->dev_bytenr, *mirror_nump, + btrfsic_get_block_type(state, + next_block), + next_block->logical_bytenr); + else + pr_info( + "referenced block @%llu (%pg/%llu/%d) found in hash table, %c\n", + next_bytenr, next_block_ctx->dev->bdev, + next_block_ctx->dev_bytenr, *mirror_nump, + btrfsic_get_block_type(state, + next_block)); + } + next_block->logical_bytenr = next_bytenr; + + next_block->mirror_num = *mirror_nump; + l = btrfsic_block_link_hashtable_lookup( + next_block_ctx->dev->bdev, + next_block_ctx->dev_bytenr, + block_ctx->dev->bdev, + block_ctx->dev_bytenr, + &state->block_link_hashtable); + } + + next_block->disk_key = *disk_key; + if (NULL == l) { + l = btrfsic_block_link_alloc(); + if (NULL == l) { + btrfsic_release_block_ctx(next_block_ctx); + *next_blockp = NULL; + return -1; + } + + did_alloc_block_link = 1; + l->block_ref_to = next_block; + l->block_ref_from = block; + l->ref_cnt = 1; + l->parent_generation = parent_generation; + + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + btrfsic_print_add_link(state, l); + + list_add(&l->node_ref_to, &block->ref_to_list); + list_add(&l->node_ref_from, &next_block->ref_from_list); + + btrfsic_block_link_hashtable_add(l, + &state->block_link_hashtable); + } else { + did_alloc_block_link = 0; + if (0 == limit_nesting) { + l->ref_cnt++; + l->parent_generation = parent_generation; + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + btrfsic_print_add_link(state, l); + } + } + + if (limit_nesting > 0 && did_alloc_block_link) { + ret = btrfsic_read_block(state, next_block_ctx); + if (ret < (int)next_block_ctx->len) { + pr_info("btrfsic: read block @logical %llu failed!\n", + next_bytenr); + btrfsic_release_block_ctx(next_block_ctx); + *next_blockp = NULL; + return -1; + } + + *next_blockp = next_block; + } else { + *next_blockp = NULL; + } + (*mirror_nump)++; + + return 0; +} + +static int btrfsic_handle_extent_data( + struct btrfsic_state *state, + struct btrfsic_block *block, + struct btrfsic_block_data_ctx *block_ctx, + u32 item_offset, int force_iodone_flag) +{ + struct btrfs_fs_info *fs_info = state->fs_info; + struct btrfs_file_extent_item file_extent_item; + u64 file_extent_item_offset; + u64 next_bytenr; + u64 num_bytes; + u64 generation; + struct btrfsic_block_link *l; + int ret; + + file_extent_item_offset = offsetof(struct btrfs_leaf, items) + + item_offset; + if (file_extent_item_offset + + offsetof(struct btrfs_file_extent_item, disk_num_bytes) > + block_ctx->len) { + pr_info("btrfsic: file item out of bounce at logical %llu, dev %pg\n", + block_ctx->start, block_ctx->dev->bdev); + return -1; + } + + btrfsic_read_from_block_data(block_ctx, &file_extent_item, + file_extent_item_offset, + offsetof(struct btrfs_file_extent_item, disk_num_bytes)); + if (BTRFS_FILE_EXTENT_REG != file_extent_item.type || + btrfs_stack_file_extent_disk_bytenr(&file_extent_item) == 0) { + if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE) + pr_info("extent_data: type %u, disk_bytenr = %llu\n", + file_extent_item.type, + btrfs_stack_file_extent_disk_bytenr( + &file_extent_item)); + return 0; + } + + if (file_extent_item_offset + sizeof(struct btrfs_file_extent_item) > + block_ctx->len) { + pr_info("btrfsic: file item out of bounce at logical %llu, dev %pg\n", + block_ctx->start, block_ctx->dev->bdev); + return -1; + } + btrfsic_read_from_block_data(block_ctx, &file_extent_item, + file_extent_item_offset, + sizeof(struct btrfs_file_extent_item)); + next_bytenr = btrfs_stack_file_extent_disk_bytenr(&file_extent_item); + if (btrfs_stack_file_extent_compression(&file_extent_item) == + BTRFS_COMPRESS_NONE) { + next_bytenr += btrfs_stack_file_extent_offset(&file_extent_item); + num_bytes = btrfs_stack_file_extent_num_bytes(&file_extent_item); + } else { + num_bytes = btrfs_stack_file_extent_disk_num_bytes(&file_extent_item); + } + generation = btrfs_stack_file_extent_generation(&file_extent_item); + + if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE) + pr_info("extent_data: type %u, disk_bytenr = %llu, offset = %llu, num_bytes = %llu\n", + file_extent_item.type, + btrfs_stack_file_extent_disk_bytenr(&file_extent_item), + btrfs_stack_file_extent_offset(&file_extent_item), + num_bytes); + while (num_bytes > 0) { + u32 chunk_len; + int num_copies; + int mirror_num; + + if (num_bytes > state->datablock_size) + chunk_len = state->datablock_size; + else + chunk_len = num_bytes; + + num_copies = btrfs_num_copies(fs_info, next_bytenr, + state->datablock_size); + if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES) + pr_info("num_copies(log_bytenr=%llu) = %d\n", + next_bytenr, num_copies); + for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) { + struct btrfsic_block_data_ctx next_block_ctx; + struct btrfsic_block *next_block; + int block_was_created; + + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("btrfsic_handle_extent_data(mirror_num=%d)\n", + mirror_num); + if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE) + pr_info("\tdisk_bytenr = %llu, num_bytes %u\n", + next_bytenr, chunk_len); + ret = btrfsic_map_block(state, next_bytenr, + chunk_len, &next_block_ctx, + mirror_num); + if (ret) { + pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n", + next_bytenr, mirror_num); + return -1; + } + + next_block = btrfsic_block_lookup_or_add( + state, + &next_block_ctx, + "referenced ", + 0, + force_iodone_flag, + !force_iodone_flag, + mirror_num, + &block_was_created); + if (NULL == next_block) { + btrfsic_release_block_ctx(&next_block_ctx); + return -1; + } + if (!block_was_created) { + if ((state->print_mask & + BTRFSIC_PRINT_MASK_VERBOSE) && + next_block->logical_bytenr != next_bytenr && + !(!next_block->is_metadata && + 0 == next_block->logical_bytenr)) { + pr_info( +"referenced block @%llu (%pg/%llu/%d) found in hash table, D, bytenr mismatch (!= stored %llu)\n", + next_bytenr, + next_block_ctx.dev->bdev, + next_block_ctx.dev_bytenr, + mirror_num, + next_block->logical_bytenr); + } + next_block->logical_bytenr = next_bytenr; + next_block->mirror_num = mirror_num; + } + + l = btrfsic_block_link_lookup_or_add(state, + &next_block_ctx, + next_block, block, + generation); + btrfsic_release_block_ctx(&next_block_ctx); + if (NULL == l) + return -1; + } + + next_bytenr += chunk_len; + num_bytes -= chunk_len; + } + + return 0; +} + +static int btrfsic_map_block(struct btrfsic_state *state, u64 bytenr, u32 len, + struct btrfsic_block_data_ctx *block_ctx_out, + int mirror_num) +{ + struct btrfs_fs_info *fs_info = state->fs_info; + int ret; + u64 length; + struct btrfs_io_context *multi = NULL; + struct btrfs_device *device; + + length = len; + ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, + bytenr, &length, &multi, mirror_num); + + if (ret) { + block_ctx_out->start = 0; + block_ctx_out->dev_bytenr = 0; + block_ctx_out->len = 0; + block_ctx_out->dev = NULL; + block_ctx_out->datav = NULL; + block_ctx_out->pagev = NULL; + block_ctx_out->mem_to_free = NULL; + + return ret; + } + + device = multi->stripes[0].dev; + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state) || + !device->bdev || !device->name) + block_ctx_out->dev = NULL; + else + block_ctx_out->dev = btrfsic_dev_state_lookup( + device->bdev->bd_dev); + block_ctx_out->dev_bytenr = multi->stripes[0].physical; + block_ctx_out->start = bytenr; + block_ctx_out->len = len; + block_ctx_out->datav = NULL; + block_ctx_out->pagev = NULL; + block_ctx_out->mem_to_free = NULL; + + kfree(multi); + if (NULL == block_ctx_out->dev) { + ret = -ENXIO; + pr_info("btrfsic: error, cannot lookup dev (#1)!\n"); + } + + return ret; +} + +static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx) +{ + if (block_ctx->mem_to_free) { + unsigned int num_pages; + + BUG_ON(!block_ctx->datav); + BUG_ON(!block_ctx->pagev); + num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >> + PAGE_SHIFT; + /* Pages must be unmapped in reverse order */ + while (num_pages > 0) { + num_pages--; + if (block_ctx->datav[num_pages]) + block_ctx->datav[num_pages] = NULL; + if (block_ctx->pagev[num_pages]) { + __free_page(block_ctx->pagev[num_pages]); + block_ctx->pagev[num_pages] = NULL; + } + } + + kfree(block_ctx->mem_to_free); + block_ctx->mem_to_free = NULL; + block_ctx->pagev = NULL; + block_ctx->datav = NULL; + } +} + +static int btrfsic_read_block(struct btrfsic_state *state, + struct btrfsic_block_data_ctx *block_ctx) +{ + unsigned int num_pages; + unsigned int i; + size_t size; + u64 dev_bytenr; + int ret; + + BUG_ON(block_ctx->datav); + BUG_ON(block_ctx->pagev); + BUG_ON(block_ctx->mem_to_free); + if (!PAGE_ALIGNED(block_ctx->dev_bytenr)) { + pr_info("btrfsic: read_block() with unaligned bytenr %llu\n", + block_ctx->dev_bytenr); + return -1; + } + + num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >> + PAGE_SHIFT; + size = sizeof(*block_ctx->datav) + sizeof(*block_ctx->pagev); + block_ctx->mem_to_free = kcalloc(num_pages, size, GFP_NOFS); + if (!block_ctx->mem_to_free) + return -ENOMEM; + block_ctx->datav = block_ctx->mem_to_free; + block_ctx->pagev = (struct page **)(block_ctx->datav + num_pages); + ret = btrfs_alloc_page_array(num_pages, block_ctx->pagev); + if (ret) + return ret; + + dev_bytenr = block_ctx->dev_bytenr; + for (i = 0; i < num_pages;) { + struct bio *bio; + unsigned int j; + + bio = bio_alloc(block_ctx->dev->bdev, num_pages - i, + REQ_OP_READ, GFP_NOFS); + bio->bi_iter.bi_sector = dev_bytenr >> 9; + + for (j = i; j < num_pages; j++) { + ret = bio_add_page(bio, block_ctx->pagev[j], + PAGE_SIZE, 0); + if (PAGE_SIZE != ret) + break; + } + if (j == i) { + pr_info("btrfsic: error, failed to add a single page!\n"); + return -1; + } + if (submit_bio_wait(bio)) { + pr_info("btrfsic: read error at logical %llu dev %pg!\n", + block_ctx->start, block_ctx->dev->bdev); + bio_put(bio); + return -1; + } + bio_put(bio); + dev_bytenr += (j - i) * PAGE_SIZE; + i = j; + } + for (i = 0; i < num_pages; i++) + block_ctx->datav[i] = page_address(block_ctx->pagev[i]); + + return block_ctx->len; +} + +static void btrfsic_dump_database(struct btrfsic_state *state) +{ + const struct btrfsic_block *b_all; + + BUG_ON(NULL == state); + + pr_info("all_blocks_list:\n"); + list_for_each_entry(b_all, &state->all_blocks_list, all_blocks_node) { + const struct btrfsic_block_link *l; + + pr_info("%c-block @%llu (%pg/%llu/%d)\n", + btrfsic_get_block_type(state, b_all), + b_all->logical_bytenr, b_all->dev_state->bdev, + b_all->dev_bytenr, b_all->mirror_num); + + list_for_each_entry(l, &b_all->ref_to_list, node_ref_to) { + pr_info( + " %c @%llu (%pg/%llu/%d) refers %u* to %c @%llu (%pg/%llu/%d)\n", + btrfsic_get_block_type(state, b_all), + b_all->logical_bytenr, b_all->dev_state->bdev, + b_all->dev_bytenr, b_all->mirror_num, + l->ref_cnt, + btrfsic_get_block_type(state, l->block_ref_to), + l->block_ref_to->logical_bytenr, + l->block_ref_to->dev_state->bdev, + l->block_ref_to->dev_bytenr, + l->block_ref_to->mirror_num); + } + + list_for_each_entry(l, &b_all->ref_from_list, node_ref_from) { + pr_info( + " %c @%llu (%pg/%llu/%d) is ref %u* from %c @%llu (%pg/%llu/%d)\n", + btrfsic_get_block_type(state, b_all), + b_all->logical_bytenr, b_all->dev_state->bdev, + b_all->dev_bytenr, b_all->mirror_num, + l->ref_cnt, + btrfsic_get_block_type(state, l->block_ref_from), + l->block_ref_from->logical_bytenr, + l->block_ref_from->dev_state->bdev, + l->block_ref_from->dev_bytenr, + l->block_ref_from->mirror_num); + } + + pr_info("\n"); + } +} + +/* + * Test whether the disk block contains a tree block (leaf or node) + * (note that this test fails for the super block) + */ +static noinline_for_stack int btrfsic_test_for_metadata( + struct btrfsic_state *state, + char **datav, unsigned int num_pages) +{ + struct btrfs_fs_info *fs_info = state->fs_info; + SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); + struct btrfs_header *h; + u8 csum[BTRFS_CSUM_SIZE]; + unsigned int i; + + if (num_pages * PAGE_SIZE < state->metablock_size) + return 1; /* not metadata */ + num_pages = state->metablock_size >> PAGE_SHIFT; + h = (struct btrfs_header *)datav[0]; + + if (memcmp(h->fsid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE)) + return 1; + + shash->tfm = fs_info->csum_shash; + crypto_shash_init(shash); + + for (i = 0; i < num_pages; i++) { + u8 *data = i ? datav[i] : (datav[i] + BTRFS_CSUM_SIZE); + size_t sublen = i ? PAGE_SIZE : + (PAGE_SIZE - BTRFS_CSUM_SIZE); + + crypto_shash_update(shash, data, sublen); + } + crypto_shash_final(shash, csum); + if (memcmp(csum, h->csum, fs_info->csum_size)) + return 1; + + return 0; /* is metadata */ +} + +static void btrfsic_process_written_block(struct btrfsic_dev_state *dev_state, + u64 dev_bytenr, char **mapped_datav, + unsigned int num_pages, + struct bio *bio, int *bio_is_patched, + blk_opf_t submit_bio_bh_rw) +{ + int is_metadata; + struct btrfsic_block *block; + struct btrfsic_block_data_ctx block_ctx; + int ret; + struct btrfsic_state *state = dev_state->state; + struct block_device *bdev = dev_state->bdev; + unsigned int processed_len; + + if (NULL != bio_is_patched) + *bio_is_patched = 0; + +again: + if (num_pages == 0) + return; + + processed_len = 0; + is_metadata = (0 == btrfsic_test_for_metadata(state, mapped_datav, + num_pages)); + + block = btrfsic_block_hashtable_lookup(bdev, dev_bytenr, + &state->block_hashtable); + if (NULL != block) { + u64 bytenr = 0; + struct btrfsic_block_link *l, *tmp; + + if (block->is_superblock) { + bytenr = btrfs_super_bytenr((struct btrfs_super_block *) + mapped_datav[0]); + if (num_pages * PAGE_SIZE < + BTRFS_SUPER_INFO_SIZE) { + pr_info("btrfsic: cannot work with too short bios!\n"); + return; + } + is_metadata = 1; + BUG_ON(!PAGE_ALIGNED(BTRFS_SUPER_INFO_SIZE)); + processed_len = BTRFS_SUPER_INFO_SIZE; + if (state->print_mask & + BTRFSIC_PRINT_MASK_TREE_BEFORE_SB_WRITE) { + pr_info("[before new superblock is written]:\n"); + btrfsic_dump_tree_sub(state, block, 0); + } + } + if (is_metadata) { + if (!block->is_superblock) { + if (num_pages * PAGE_SIZE < + state->metablock_size) { + pr_info("btrfsic: cannot work with too short bios!\n"); + return; + } + processed_len = state->metablock_size; + bytenr = btrfs_stack_header_bytenr( + (struct btrfs_header *) + mapped_datav[0]); + btrfsic_cmp_log_and_dev_bytenr(state, bytenr, + dev_state, + dev_bytenr); + } + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) { + if (block->logical_bytenr != bytenr && + !(!block->is_metadata && + block->logical_bytenr == 0)) + pr_info( +"written block @%llu (%pg/%llu/%d) found in hash table, %c, bytenr mismatch (!= stored %llu)\n", + bytenr, dev_state->bdev, + dev_bytenr, + block->mirror_num, + btrfsic_get_block_type(state, + block), + block->logical_bytenr); + else + pr_info( + "written block @%llu (%pg/%llu/%d) found in hash table, %c\n", + bytenr, dev_state->bdev, + dev_bytenr, block->mirror_num, + btrfsic_get_block_type(state, + block)); + } + block->logical_bytenr = bytenr; + } else { + if (num_pages * PAGE_SIZE < + state->datablock_size) { + pr_info("btrfsic: cannot work with too short bios!\n"); + return; + } + processed_len = state->datablock_size; + bytenr = block->logical_bytenr; + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info( + "written block @%llu (%pg/%llu/%d) found in hash table, %c\n", + bytenr, dev_state->bdev, dev_bytenr, + block->mirror_num, + btrfsic_get_block_type(state, block)); + } + + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("ref_to_list: %cE, ref_from_list: %cE\n", + list_empty(&block->ref_to_list) ? ' ' : '!', + list_empty(&block->ref_from_list) ? ' ' : '!'); + if (btrfsic_is_block_ref_by_superblock(state, block, 0)) { + pr_info( +"btrfs: attempt to overwrite %c-block @%llu (%pg/%llu/%d), old(gen=%llu, objectid=%llu, type=%d, offset=%llu), new(gen=%llu), which is referenced by most recent superblock (superblockgen=%llu)!\n", + btrfsic_get_block_type(state, block), bytenr, + dev_state->bdev, dev_bytenr, block->mirror_num, + block->generation, + btrfs_disk_key_objectid(&block->disk_key), + block->disk_key.type, + btrfs_disk_key_offset(&block->disk_key), + btrfs_stack_header_generation( + (struct btrfs_header *) mapped_datav[0]), + state->max_superblock_generation); + btrfsic_dump_tree(state); + } + + if (!block->is_iodone && !block->never_written) { + pr_info( +"btrfs: attempt to overwrite %c-block @%llu (%pg/%llu/%d), oldgen=%llu, newgen=%llu, which is not yet iodone!\n", + btrfsic_get_block_type(state, block), bytenr, + dev_state->bdev, dev_bytenr, block->mirror_num, + block->generation, + btrfs_stack_header_generation( + (struct btrfs_header *) + mapped_datav[0])); + /* it would not be safe to go on */ + btrfsic_dump_tree(state); + goto continue_loop; + } + + /* + * Clear all references of this block. Do not free + * the block itself even if is not referenced anymore + * because it still carries valuable information + * like whether it was ever written and IO completed. + */ + list_for_each_entry_safe(l, tmp, &block->ref_to_list, + node_ref_to) { + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + btrfsic_print_rem_link(state, l); + l->ref_cnt--; + if (0 == l->ref_cnt) { + list_del(&l->node_ref_to); + list_del(&l->node_ref_from); + btrfsic_block_link_hashtable_remove(l); + btrfsic_block_link_free(l); + } + } + + block_ctx.dev = dev_state; + block_ctx.dev_bytenr = dev_bytenr; + block_ctx.start = bytenr; + block_ctx.len = processed_len; + block_ctx.pagev = NULL; + block_ctx.mem_to_free = NULL; + block_ctx.datav = mapped_datav; + + if (is_metadata || state->include_extent_data) { + block->never_written = 0; + block->iodone_w_error = 0; + if (NULL != bio) { + block->is_iodone = 0; + BUG_ON(NULL == bio_is_patched); + if (!*bio_is_patched) { + block->orig_bio_private = + bio->bi_private; + block->orig_bio_end_io = + bio->bi_end_io; + block->next_in_same_bio = NULL; + bio->bi_private = block; + bio->bi_end_io = btrfsic_bio_end_io; + *bio_is_patched = 1; + } else { + struct btrfsic_block *chained_block = + (struct btrfsic_block *) + bio->bi_private; + + BUG_ON(NULL == chained_block); + block->orig_bio_private = + chained_block->orig_bio_private; + block->orig_bio_end_io = + chained_block->orig_bio_end_io; + block->next_in_same_bio = chained_block; + bio->bi_private = block; + } + } else { + block->is_iodone = 1; + block->orig_bio_private = NULL; + block->orig_bio_end_io = NULL; + block->next_in_same_bio = NULL; + } + } + + block->flush_gen = dev_state->last_flush_gen + 1; + block->submit_bio_bh_rw = submit_bio_bh_rw; + if (is_metadata) { + block->logical_bytenr = bytenr; + block->is_metadata = 1; + if (block->is_superblock) { + BUG_ON(PAGE_SIZE != + BTRFS_SUPER_INFO_SIZE); + ret = btrfsic_process_written_superblock( + state, + block, + (struct btrfs_super_block *) + mapped_datav[0]); + if (state->print_mask & + BTRFSIC_PRINT_MASK_TREE_AFTER_SB_WRITE) { + pr_info("[after new superblock is written]:\n"); + btrfsic_dump_tree_sub(state, block, 0); + } + } else { + block->mirror_num = 0; /* unknown */ + ret = btrfsic_process_metablock( + state, + block, + &block_ctx, + 0, 0); + } + if (ret) + pr_info("btrfsic: btrfsic_process_metablock(root @%llu) failed!\n", + dev_bytenr); + } else { + block->is_metadata = 0; + block->mirror_num = 0; /* unknown */ + block->generation = BTRFSIC_GENERATION_UNKNOWN; + if (!state->include_extent_data + && list_empty(&block->ref_from_list)) { + /* + * disk block is overwritten with extent + * data (not meta data) and we are configured + * to not include extent data: take the + * chance and free the block's memory + */ + btrfsic_block_hashtable_remove(block); + list_del(&block->all_blocks_node); + btrfsic_block_free(block); + } + } + btrfsic_release_block_ctx(&block_ctx); + } else { + /* block has not been found in hash table */ + u64 bytenr; + + if (!is_metadata) { + processed_len = state->datablock_size; + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info( + "written block (%pg/%llu/?) !found in hash table, D\n", + dev_state->bdev, dev_bytenr); + if (!state->include_extent_data) { + /* ignore that written D block */ + goto continue_loop; + } + + /* this is getting ugly for the + * include_extent_data case... */ + bytenr = 0; /* unknown */ + } else { + processed_len = state->metablock_size; + bytenr = btrfs_stack_header_bytenr( + (struct btrfs_header *) + mapped_datav[0]); + btrfsic_cmp_log_and_dev_bytenr(state, bytenr, dev_state, + dev_bytenr); + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info( + "written block @%llu (%pg/%llu/?) !found in hash table, M\n", + bytenr, dev_state->bdev, dev_bytenr); + } + + block_ctx.dev = dev_state; + block_ctx.dev_bytenr = dev_bytenr; + block_ctx.start = bytenr; + block_ctx.len = processed_len; + block_ctx.pagev = NULL; + block_ctx.mem_to_free = NULL; + block_ctx.datav = mapped_datav; + + block = btrfsic_block_alloc(); + if (NULL == block) { + btrfsic_release_block_ctx(&block_ctx); + goto continue_loop; + } + block->dev_state = dev_state; + block->dev_bytenr = dev_bytenr; + block->logical_bytenr = bytenr; + block->is_metadata = is_metadata; + block->never_written = 0; + block->iodone_w_error = 0; + block->mirror_num = 0; /* unknown */ + block->flush_gen = dev_state->last_flush_gen + 1; + block->submit_bio_bh_rw = submit_bio_bh_rw; + if (NULL != bio) { + block->is_iodone = 0; + BUG_ON(NULL == bio_is_patched); + if (!*bio_is_patched) { + block->orig_bio_private = bio->bi_private; + block->orig_bio_end_io = bio->bi_end_io; + block->next_in_same_bio = NULL; + bio->bi_private = block; + bio->bi_end_io = btrfsic_bio_end_io; + *bio_is_patched = 1; + } else { + struct btrfsic_block *chained_block = + (struct btrfsic_block *) + bio->bi_private; + + BUG_ON(NULL == chained_block); + block->orig_bio_private = + chained_block->orig_bio_private; + block->orig_bio_end_io = + chained_block->orig_bio_end_io; + block->next_in_same_bio = chained_block; + bio->bi_private = block; + } + } else { + block->is_iodone = 1; + block->orig_bio_private = NULL; + block->orig_bio_end_io = NULL; + block->next_in_same_bio = NULL; + } + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("new written %c-block @%llu (%pg/%llu/%d)\n", + is_metadata ? 'M' : 'D', + block->logical_bytenr, block->dev_state->bdev, + block->dev_bytenr, block->mirror_num); + list_add(&block->all_blocks_node, &state->all_blocks_list); + btrfsic_block_hashtable_add(block, &state->block_hashtable); + + if (is_metadata) { + ret = btrfsic_process_metablock(state, block, + &block_ctx, 0, 0); + if (ret) + pr_info("btrfsic: process_metablock(root @%llu) failed!\n", + dev_bytenr); + } + btrfsic_release_block_ctx(&block_ctx); + } + +continue_loop: + BUG_ON(!processed_len); + dev_bytenr += processed_len; + mapped_datav += processed_len >> PAGE_SHIFT; + num_pages -= processed_len >> PAGE_SHIFT; + goto again; +} + +static void btrfsic_bio_end_io(struct bio *bp) +{ + struct btrfsic_block *block = bp->bi_private; + int iodone_w_error; + + /* mutex is not held! This is not save if IO is not yet completed + * on umount */ + iodone_w_error = 0; + if (bp->bi_status) + iodone_w_error = 1; + + BUG_ON(NULL == block); + bp->bi_private = block->orig_bio_private; + bp->bi_end_io = block->orig_bio_end_io; + + do { + struct btrfsic_block *next_block; + struct btrfsic_dev_state *const dev_state = block->dev_state; + + if ((dev_state->state->print_mask & + BTRFSIC_PRINT_MASK_END_IO_BIO_BH)) + pr_info("bio_end_io(err=%d) for %c @%llu (%pg/%llu/%d)\n", + bp->bi_status, + btrfsic_get_block_type(dev_state->state, block), + block->logical_bytenr, dev_state->bdev, + block->dev_bytenr, block->mirror_num); + next_block = block->next_in_same_bio; + block->iodone_w_error = iodone_w_error; + if (block->submit_bio_bh_rw & REQ_PREFLUSH) { + dev_state->last_flush_gen++; + if ((dev_state->state->print_mask & + BTRFSIC_PRINT_MASK_END_IO_BIO_BH)) + pr_info("bio_end_io() new %pg flush_gen=%llu\n", + dev_state->bdev, + dev_state->last_flush_gen); + } + if (block->submit_bio_bh_rw & REQ_FUA) + block->flush_gen = 0; /* FUA completed means block is + * on disk */ + block->is_iodone = 1; /* for FLUSH, this releases the block */ + block = next_block; + } while (NULL != block); + + bp->bi_end_io(bp); +} + +static int btrfsic_process_written_superblock( + struct btrfsic_state *state, + struct btrfsic_block *const superblock, + struct btrfs_super_block *const super_hdr) +{ + struct btrfs_fs_info *fs_info = state->fs_info; + int pass; + + superblock->generation = btrfs_super_generation(super_hdr); + if (!(superblock->generation > state->max_superblock_generation || + 0 == state->max_superblock_generation)) { + if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE) + pr_info( + "btrfsic: superblock @%llu (%pg/%llu/%d) with old gen %llu <= %llu\n", + superblock->logical_bytenr, + superblock->dev_state->bdev, + superblock->dev_bytenr, superblock->mirror_num, + btrfs_super_generation(super_hdr), + state->max_superblock_generation); + } else { + if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE) + pr_info( + "btrfsic: got new superblock @%llu (%pg/%llu/%d) with new gen %llu > %llu\n", + superblock->logical_bytenr, + superblock->dev_state->bdev, + superblock->dev_bytenr, superblock->mirror_num, + btrfs_super_generation(super_hdr), + state->max_superblock_generation); + + state->max_superblock_generation = + btrfs_super_generation(super_hdr); + state->latest_superblock = superblock; + } + + for (pass = 0; pass < 3; pass++) { + int ret; + u64 next_bytenr; + struct btrfsic_block *next_block; + struct btrfsic_block_data_ctx tmp_next_block_ctx; + struct btrfsic_block_link *l; + int num_copies; + int mirror_num; + const char *additional_string = NULL; + struct btrfs_disk_key tmp_disk_key = {0}; + + btrfs_set_disk_key_objectid(&tmp_disk_key, + BTRFS_ROOT_ITEM_KEY); + btrfs_set_disk_key_objectid(&tmp_disk_key, 0); + + switch (pass) { + case 0: + btrfs_set_disk_key_objectid(&tmp_disk_key, + BTRFS_ROOT_TREE_OBJECTID); + additional_string = "root "; + next_bytenr = btrfs_super_root(super_hdr); + if (state->print_mask & + BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION) + pr_info("root@%llu\n", next_bytenr); + break; + case 1: + btrfs_set_disk_key_objectid(&tmp_disk_key, + BTRFS_CHUNK_TREE_OBJECTID); + additional_string = "chunk "; + next_bytenr = btrfs_super_chunk_root(super_hdr); + if (state->print_mask & + BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION) + pr_info("chunk@%llu\n", next_bytenr); + break; + case 2: + btrfs_set_disk_key_objectid(&tmp_disk_key, + BTRFS_TREE_LOG_OBJECTID); + additional_string = "log "; + next_bytenr = btrfs_super_log_root(super_hdr); + if (0 == next_bytenr) + continue; + if (state->print_mask & + BTRFSIC_PRINT_MASK_ROOT_CHUNK_LOG_TREE_LOCATION) + pr_info("log@%llu\n", next_bytenr); + break; + } + + num_copies = btrfs_num_copies(fs_info, next_bytenr, + BTRFS_SUPER_INFO_SIZE); + if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES) + pr_info("num_copies(log_bytenr=%llu) = %d\n", + next_bytenr, num_copies); + for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) { + int was_created; + + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("btrfsic_process_written_superblock(mirror_num=%d)\n", mirror_num); + ret = btrfsic_map_block(state, next_bytenr, + BTRFS_SUPER_INFO_SIZE, + &tmp_next_block_ctx, + mirror_num); + if (ret) { + pr_info("btrfsic: btrfsic_map_block(@%llu, mirror=%d) failed!\n", + next_bytenr, mirror_num); + return -1; + } + + next_block = btrfsic_block_lookup_or_add( + state, + &tmp_next_block_ctx, + additional_string, + 1, 0, 1, + mirror_num, + &was_created); + if (NULL == next_block) { + btrfsic_release_block_ctx(&tmp_next_block_ctx); + return -1; + } + + next_block->disk_key = tmp_disk_key; + if (was_created) + next_block->generation = + BTRFSIC_GENERATION_UNKNOWN; + l = btrfsic_block_link_lookup_or_add( + state, + &tmp_next_block_ctx, + next_block, + superblock, + BTRFSIC_GENERATION_UNKNOWN); + btrfsic_release_block_ctx(&tmp_next_block_ctx); + if (NULL == l) + return -1; + } + } + + if (WARN_ON(-1 == btrfsic_check_all_ref_blocks(state, superblock, 0))) + btrfsic_dump_tree(state); + + return 0; +} + +static int btrfsic_check_all_ref_blocks(struct btrfsic_state *state, + struct btrfsic_block *const block, + int recursion_level) +{ + const struct btrfsic_block_link *l; + int ret = 0; + + if (recursion_level >= 3 + BTRFS_MAX_LEVEL) { + /* + * Note that this situation can happen and does not + * indicate an error in regular cases. It happens + * when disk blocks are freed and later reused. + * The check-integrity module is not aware of any + * block free operations, it just recognizes block + * write operations. Therefore it keeps the linkage + * information for a block until a block is + * rewritten. This can temporarily cause incorrect + * and even circular linkage information. This + * causes no harm unless such blocks are referenced + * by the most recent super block. + */ + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("btrfsic: abort cyclic linkage (case 1).\n"); + + return ret; + } + + /* + * This algorithm is recursive because the amount of used stack + * space is very small and the max recursion depth is limited. + */ + list_for_each_entry(l, &block->ref_to_list, node_ref_to) { + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info( + "rl=%d, %c @%llu (%pg/%llu/%d) %u* refers to %c @%llu (%pg/%llu/%d)\n", + recursion_level, + btrfsic_get_block_type(state, block), + block->logical_bytenr, block->dev_state->bdev, + block->dev_bytenr, block->mirror_num, + l->ref_cnt, + btrfsic_get_block_type(state, l->block_ref_to), + l->block_ref_to->logical_bytenr, + l->block_ref_to->dev_state->bdev, + l->block_ref_to->dev_bytenr, + l->block_ref_to->mirror_num); + if (l->block_ref_to->never_written) { + pr_info( +"btrfs: attempt to write superblock which references block %c @%llu (%pg/%llu/%d) which is never written!\n", + btrfsic_get_block_type(state, l->block_ref_to), + l->block_ref_to->logical_bytenr, + l->block_ref_to->dev_state->bdev, + l->block_ref_to->dev_bytenr, + l->block_ref_to->mirror_num); + ret = -1; + } else if (!l->block_ref_to->is_iodone) { + pr_info( +"btrfs: attempt to write superblock which references block %c @%llu (%pg/%llu/%d) which is not yet iodone!\n", + btrfsic_get_block_type(state, l->block_ref_to), + l->block_ref_to->logical_bytenr, + l->block_ref_to->dev_state->bdev, + l->block_ref_to->dev_bytenr, + l->block_ref_to->mirror_num); + ret = -1; + } else if (l->block_ref_to->iodone_w_error) { + pr_info( +"btrfs: attempt to write superblock which references block %c @%llu (%pg/%llu/%d) which has write error!\n", + btrfsic_get_block_type(state, l->block_ref_to), + l->block_ref_to->logical_bytenr, + l->block_ref_to->dev_state->bdev, + l->block_ref_to->dev_bytenr, + l->block_ref_to->mirror_num); + ret = -1; + } else if (l->parent_generation != + l->block_ref_to->generation && + BTRFSIC_GENERATION_UNKNOWN != + l->parent_generation && + BTRFSIC_GENERATION_UNKNOWN != + l->block_ref_to->generation) { + pr_info( +"btrfs: attempt to write superblock which references block %c @%llu (%pg/%llu/%d) with generation %llu != parent generation %llu!\n", + btrfsic_get_block_type(state, l->block_ref_to), + l->block_ref_to->logical_bytenr, + l->block_ref_to->dev_state->bdev, + l->block_ref_to->dev_bytenr, + l->block_ref_to->mirror_num, + l->block_ref_to->generation, + l->parent_generation); + ret = -1; + } else if (l->block_ref_to->flush_gen > + l->block_ref_to->dev_state->last_flush_gen) { + pr_info( +"btrfs: attempt to write superblock which references block %c @%llu (%pg/%llu/%d) which is not flushed out of disk's write cache (block flush_gen=%llu, dev->flush_gen=%llu)!\n", + btrfsic_get_block_type(state, l->block_ref_to), + l->block_ref_to->logical_bytenr, + l->block_ref_to->dev_state->bdev, + l->block_ref_to->dev_bytenr, + l->block_ref_to->mirror_num, block->flush_gen, + l->block_ref_to->dev_state->last_flush_gen); + ret = -1; + } else if (-1 == btrfsic_check_all_ref_blocks(state, + l->block_ref_to, + recursion_level + + 1)) { + ret = -1; + } + } + + return ret; +} + +static int btrfsic_is_block_ref_by_superblock( + const struct btrfsic_state *state, + const struct btrfsic_block *block, + int recursion_level) +{ + const struct btrfsic_block_link *l; + + if (recursion_level >= 3 + BTRFS_MAX_LEVEL) { + /* refer to comment at "abort cyclic linkage (case 1)" */ + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("btrfsic: abort cyclic linkage (case 2).\n"); + + return 0; + } + + /* + * This algorithm is recursive because the amount of used stack space + * is very small and the max recursion depth is limited. + */ + list_for_each_entry(l, &block->ref_from_list, node_ref_from) { + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info( + "rl=%d, %c @%llu (%pg/%llu/%d) is ref %u* from %c @%llu (%pg/%llu/%d)\n", + recursion_level, + btrfsic_get_block_type(state, block), + block->logical_bytenr, block->dev_state->bdev, + block->dev_bytenr, block->mirror_num, + l->ref_cnt, + btrfsic_get_block_type(state, l->block_ref_from), + l->block_ref_from->logical_bytenr, + l->block_ref_from->dev_state->bdev, + l->block_ref_from->dev_bytenr, + l->block_ref_from->mirror_num); + if (l->block_ref_from->is_superblock && + state->latest_superblock->dev_bytenr == + l->block_ref_from->dev_bytenr && + state->latest_superblock->dev_state->bdev == + l->block_ref_from->dev_state->bdev) + return 1; + else if (btrfsic_is_block_ref_by_superblock(state, + l->block_ref_from, + recursion_level + + 1)) + return 1; + } + + return 0; +} + +static void btrfsic_print_add_link(const struct btrfsic_state *state, + const struct btrfsic_block_link *l) +{ + pr_info("add %u* link from %c @%llu (%pg/%llu/%d) to %c @%llu (%pg/%llu/%d)\n", + l->ref_cnt, + btrfsic_get_block_type(state, l->block_ref_from), + l->block_ref_from->logical_bytenr, + l->block_ref_from->dev_state->bdev, + l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num, + btrfsic_get_block_type(state, l->block_ref_to), + l->block_ref_to->logical_bytenr, + l->block_ref_to->dev_state->bdev, l->block_ref_to->dev_bytenr, + l->block_ref_to->mirror_num); +} + +static void btrfsic_print_rem_link(const struct btrfsic_state *state, + const struct btrfsic_block_link *l) +{ + pr_info("rem %u* link from %c @%llu (%pg/%llu/%d) to %c @%llu (%pg/%llu/%d)\n", + l->ref_cnt, + btrfsic_get_block_type(state, l->block_ref_from), + l->block_ref_from->logical_bytenr, + l->block_ref_from->dev_state->bdev, + l->block_ref_from->dev_bytenr, l->block_ref_from->mirror_num, + btrfsic_get_block_type(state, l->block_ref_to), + l->block_ref_to->logical_bytenr, + l->block_ref_to->dev_state->bdev, l->block_ref_to->dev_bytenr, + l->block_ref_to->mirror_num); +} + +static char btrfsic_get_block_type(const struct btrfsic_state *state, + const struct btrfsic_block *block) +{ + if (block->is_superblock && + state->latest_superblock->dev_bytenr == block->dev_bytenr && + state->latest_superblock->dev_state->bdev == block->dev_state->bdev) + return 'S'; + else if (block->is_superblock) + return 's'; + else if (block->is_metadata) + return 'M'; + else + return 'D'; +} + +static void btrfsic_dump_tree(const struct btrfsic_state *state) +{ + btrfsic_dump_tree_sub(state, state->latest_superblock, 0); +} + +static void btrfsic_dump_tree_sub(const struct btrfsic_state *state, + const struct btrfsic_block *block, + int indent_level) +{ + const struct btrfsic_block_link *l; + int indent_add; + static char buf[80]; + int cursor_position; + + /* + * Should better fill an on-stack buffer with a complete line and + * dump it at once when it is time to print a newline character. + */ + + /* + * This algorithm is recursive because the amount of used stack space + * is very small and the max recursion depth is limited. + */ + indent_add = sprintf(buf, "%c-%llu(%pg/%llu/%u)", + btrfsic_get_block_type(state, block), + block->logical_bytenr, block->dev_state->bdev, + block->dev_bytenr, block->mirror_num); + if (indent_level + indent_add > BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) { + printk("[...]\n"); + return; + } + printk(buf); + indent_level += indent_add; + if (list_empty(&block->ref_to_list)) { + printk("\n"); + return; + } + if (block->mirror_num > 1 && + !(state->print_mask & BTRFSIC_PRINT_MASK_TREE_WITH_ALL_MIRRORS)) { + printk(" [...]\n"); + return; + } + + cursor_position = indent_level; + list_for_each_entry(l, &block->ref_to_list, node_ref_to) { + while (cursor_position < indent_level) { + printk(" "); + cursor_position++; + } + if (l->ref_cnt > 1) + indent_add = sprintf(buf, " %d*--> ", l->ref_cnt); + else + indent_add = sprintf(buf, " --> "); + if (indent_level + indent_add > + BTRFSIC_TREE_DUMP_MAX_INDENT_LEVEL) { + printk("[...]\n"); + cursor_position = 0; + continue; + } + + printk(buf); + + btrfsic_dump_tree_sub(state, l->block_ref_to, + indent_level + indent_add); + cursor_position = 0; + } +} + +static struct btrfsic_block_link *btrfsic_block_link_lookup_or_add( + struct btrfsic_state *state, + struct btrfsic_block_data_ctx *next_block_ctx, + struct btrfsic_block *next_block, + struct btrfsic_block *from_block, + u64 parent_generation) +{ + struct btrfsic_block_link *l; + + l = btrfsic_block_link_hashtable_lookup(next_block_ctx->dev->bdev, + next_block_ctx->dev_bytenr, + from_block->dev_state->bdev, + from_block->dev_bytenr, + &state->block_link_hashtable); + if (NULL == l) { + l = btrfsic_block_link_alloc(); + if (!l) + return NULL; + + l->block_ref_to = next_block; + l->block_ref_from = from_block; + l->ref_cnt = 1; + l->parent_generation = parent_generation; + + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + btrfsic_print_add_link(state, l); + + list_add(&l->node_ref_to, &from_block->ref_to_list); + list_add(&l->node_ref_from, &next_block->ref_from_list); + + btrfsic_block_link_hashtable_add(l, + &state->block_link_hashtable); + } else { + l->ref_cnt++; + l->parent_generation = parent_generation; + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + btrfsic_print_add_link(state, l); + } + + return l; +} + +static struct btrfsic_block *btrfsic_block_lookup_or_add( + struct btrfsic_state *state, + struct btrfsic_block_data_ctx *block_ctx, + const char *additional_string, + int is_metadata, + int is_iodone, + int never_written, + int mirror_num, + int *was_created) +{ + struct btrfsic_block *block; + + block = btrfsic_block_hashtable_lookup(block_ctx->dev->bdev, + block_ctx->dev_bytenr, + &state->block_hashtable); + if (NULL == block) { + struct btrfsic_dev_state *dev_state; + + block = btrfsic_block_alloc(); + if (!block) + return NULL; + + dev_state = btrfsic_dev_state_lookup(block_ctx->dev->bdev->bd_dev); + if (NULL == dev_state) { + pr_info("btrfsic: error, lookup dev_state failed!\n"); + btrfsic_block_free(block); + return NULL; + } + block->dev_state = dev_state; + block->dev_bytenr = block_ctx->dev_bytenr; + block->logical_bytenr = block_ctx->start; + block->is_metadata = is_metadata; + block->is_iodone = is_iodone; + block->never_written = never_written; + block->mirror_num = mirror_num; + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + pr_info("New %s%c-block @%llu (%pg/%llu/%d)\n", + additional_string, + btrfsic_get_block_type(state, block), + block->logical_bytenr, dev_state->bdev, + block->dev_bytenr, mirror_num); + list_add(&block->all_blocks_node, &state->all_blocks_list); + btrfsic_block_hashtable_add(block, &state->block_hashtable); + if (NULL != was_created) + *was_created = 1; + } else { + if (NULL != was_created) + *was_created = 0; + } + + return block; +} + +static void btrfsic_cmp_log_and_dev_bytenr(struct btrfsic_state *state, + u64 bytenr, + struct btrfsic_dev_state *dev_state, + u64 dev_bytenr) +{ + struct btrfs_fs_info *fs_info = state->fs_info; + struct btrfsic_block_data_ctx block_ctx; + int num_copies; + int mirror_num; + int match = 0; + int ret; + + num_copies = btrfs_num_copies(fs_info, bytenr, state->metablock_size); + + for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) { + ret = btrfsic_map_block(state, bytenr, state->metablock_size, + &block_ctx, mirror_num); + if (ret) { + pr_info("btrfsic: btrfsic_map_block(logical @%llu, mirror %d) failed!\n", + bytenr, mirror_num); + continue; + } + + if (dev_state->bdev == block_ctx.dev->bdev && + dev_bytenr == block_ctx.dev_bytenr) { + match++; + btrfsic_release_block_ctx(&block_ctx); + break; + } + btrfsic_release_block_ctx(&block_ctx); + } + + if (WARN_ON(!match)) { + pr_info( +"btrfs: attempt to write M-block which contains logical bytenr that doesn't map to dev+physical bytenr of submit_bio, buffer->log_bytenr=%llu, submit_bio(bdev=%pg, phys_bytenr=%llu)!\n", + bytenr, dev_state->bdev, dev_bytenr); + for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) { + ret = btrfsic_map_block(state, bytenr, + state->metablock_size, + &block_ctx, mirror_num); + if (ret) + continue; + + pr_info("read logical bytenr @%llu maps to (%pg/%llu/%d)\n", + bytenr, block_ctx.dev->bdev, + block_ctx.dev_bytenr, mirror_num); + } + } +} + +static struct btrfsic_dev_state *btrfsic_dev_state_lookup(dev_t dev) +{ + return btrfsic_dev_state_hashtable_lookup(dev, + &btrfsic_dev_state_hashtable); +} + +static void btrfsic_check_write_bio(struct bio *bio, struct btrfsic_dev_state *dev_state) +{ + unsigned int segs = bio_segments(bio); + u64 dev_bytenr = 512 * bio->bi_iter.bi_sector; + u64 cur_bytenr = dev_bytenr; + struct bvec_iter iter; + struct bio_vec bvec; + char **mapped_datav; + int bio_is_patched = 0; + int i = 0; + + if (dev_state->state->print_mask & BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH) + pr_info( +"submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n", + bio_op(bio), bio->bi_opf, segs, + bio->bi_iter.bi_sector, dev_bytenr, bio->bi_bdev); + + mapped_datav = kmalloc_array(segs, sizeof(*mapped_datav), GFP_NOFS); + if (!mapped_datav) + return; + + bio_for_each_segment(bvec, bio, iter) { + BUG_ON(bvec.bv_len != PAGE_SIZE); + mapped_datav[i] = page_address(bvec.bv_page); + i++; + + if (dev_state->state->print_mask & + BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE) + pr_info("#%u: bytenr=%llu, len=%u, offset=%u\n", + i, cur_bytenr, bvec.bv_len, bvec.bv_offset); + cur_bytenr += bvec.bv_len; + } + + btrfsic_process_written_block(dev_state, dev_bytenr, mapped_datav, segs, + bio, &bio_is_patched, bio->bi_opf); + kfree(mapped_datav); +} + +static void btrfsic_check_flush_bio(struct bio *bio, struct btrfsic_dev_state *dev_state) +{ + if (dev_state->state->print_mask & BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH) + pr_info("submit_bio(rw=%d,0x%x FLUSH, bdev=%p)\n", + bio_op(bio), bio->bi_opf, bio->bi_bdev); + + if (dev_state->dummy_block_for_bio_bh_flush.is_iodone) { + struct btrfsic_block *const block = + &dev_state->dummy_block_for_bio_bh_flush; + + block->is_iodone = 0; + block->never_written = 0; + block->iodone_w_error = 0; + block->flush_gen = dev_state->last_flush_gen + 1; + block->submit_bio_bh_rw = bio->bi_opf; + block->orig_bio_private = bio->bi_private; + block->orig_bio_end_io = bio->bi_end_io; + block->next_in_same_bio = NULL; + bio->bi_private = block; + bio->bi_end_io = btrfsic_bio_end_io; + } else if ((dev_state->state->print_mask & + (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH | + BTRFSIC_PRINT_MASK_VERBOSE))) { + pr_info( +"btrfsic_submit_bio(%pg) with FLUSH but dummy block already in use (ignored)!\n", + dev_state->bdev); + } +} + +void btrfsic_check_bio(struct bio *bio) +{ + struct btrfsic_dev_state *dev_state; + + if (!btrfsic_is_initialized) + return; + + /* + * We can be called before btrfsic_mount, so there might not be a + * dev_state. + */ + dev_state = btrfsic_dev_state_lookup(bio->bi_bdev->bd_dev); + mutex_lock(&btrfsic_mutex); + if (dev_state) { + if (bio_op(bio) == REQ_OP_WRITE && bio_has_data(bio)) + btrfsic_check_write_bio(bio, dev_state); + else if (bio->bi_opf & REQ_PREFLUSH) + btrfsic_check_flush_bio(bio, dev_state); + } + mutex_unlock(&btrfsic_mutex); +} + +int btrfsic_mount(struct btrfs_fs_info *fs_info, + struct btrfs_fs_devices *fs_devices, + int including_extent_data, u32 print_mask) +{ + int ret; + struct btrfsic_state *state; + struct list_head *dev_head = &fs_devices->devices; + struct btrfs_device *device; + + if (!PAGE_ALIGNED(fs_info->nodesize)) { + pr_info("btrfsic: cannot handle nodesize %d not being a multiple of PAGE_SIZE %ld!\n", + fs_info->nodesize, PAGE_SIZE); + return -1; + } + if (!PAGE_ALIGNED(fs_info->sectorsize)) { + pr_info("btrfsic: cannot handle sectorsize %d not being a multiple of PAGE_SIZE %ld!\n", + fs_info->sectorsize, PAGE_SIZE); + return -1; + } + state = kvzalloc(sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + + if (!btrfsic_is_initialized) { + mutex_init(&btrfsic_mutex); + btrfsic_dev_state_hashtable_init(&btrfsic_dev_state_hashtable); + btrfsic_is_initialized = 1; + } + mutex_lock(&btrfsic_mutex); + state->fs_info = fs_info; + state->print_mask = print_mask; + state->include_extent_data = including_extent_data; + state->metablock_size = fs_info->nodesize; + state->datablock_size = fs_info->sectorsize; + INIT_LIST_HEAD(&state->all_blocks_list); + btrfsic_block_hashtable_init(&state->block_hashtable); + btrfsic_block_link_hashtable_init(&state->block_link_hashtable); + state->max_superblock_generation = 0; + state->latest_superblock = NULL; + + list_for_each_entry(device, dev_head, dev_list) { + struct btrfsic_dev_state *ds; + + if (!device->bdev || !device->name) + continue; + + ds = btrfsic_dev_state_alloc(); + if (NULL == ds) { + mutex_unlock(&btrfsic_mutex); + return -ENOMEM; + } + ds->bdev = device->bdev; + ds->state = state; + btrfsic_dev_state_hashtable_add(ds, + &btrfsic_dev_state_hashtable); + } + + ret = btrfsic_process_superblock(state, fs_devices); + if (0 != ret) { + mutex_unlock(&btrfsic_mutex); + btrfsic_unmount(fs_devices); + return ret; + } + + if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_DATABASE) + btrfsic_dump_database(state); + if (state->print_mask & BTRFSIC_PRINT_MASK_INITIAL_TREE) + btrfsic_dump_tree(state); + + mutex_unlock(&btrfsic_mutex); + return 0; +} + +void btrfsic_unmount(struct btrfs_fs_devices *fs_devices) +{ + struct btrfsic_block *b_all, *tmp_all; + struct btrfsic_state *state; + struct list_head *dev_head = &fs_devices->devices; + struct btrfs_device *device; + + if (!btrfsic_is_initialized) + return; + + mutex_lock(&btrfsic_mutex); + + state = NULL; + list_for_each_entry(device, dev_head, dev_list) { + struct btrfsic_dev_state *ds; + + if (!device->bdev || !device->name) + continue; + + ds = btrfsic_dev_state_hashtable_lookup( + device->bdev->bd_dev, + &btrfsic_dev_state_hashtable); + if (NULL != ds) { + state = ds->state; + btrfsic_dev_state_hashtable_remove(ds); + btrfsic_dev_state_free(ds); + } + } + + if (NULL == state) { + pr_info("btrfsic: error, cannot find state information on umount!\n"); + mutex_unlock(&btrfsic_mutex); + return; + } + + /* + * Don't care about keeping the lists' state up to date, + * just free all memory that was allocated dynamically. + * Free the blocks and the block_links. + */ + list_for_each_entry_safe(b_all, tmp_all, &state->all_blocks_list, + all_blocks_node) { + struct btrfsic_block_link *l, *tmp; + + list_for_each_entry_safe(l, tmp, &b_all->ref_to_list, + node_ref_to) { + if (state->print_mask & BTRFSIC_PRINT_MASK_VERBOSE) + btrfsic_print_rem_link(state, l); + + l->ref_cnt--; + if (0 == l->ref_cnt) + btrfsic_block_link_free(l); + } + + if (b_all->is_iodone || b_all->never_written) + btrfsic_block_free(b_all); + else + pr_info( +"btrfs: attempt to free %c-block @%llu (%pg/%llu/%d) on umount which is not yet iodone!\n", + btrfsic_get_block_type(state, b_all), + b_all->logical_bytenr, b_all->dev_state->bdev, + b_all->dev_bytenr, b_all->mirror_num); + } + + mutex_unlock(&btrfsic_mutex); + + kvfree(state); +} |