hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAQ487 CVE: NA

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When I enabled ext4 debug for fault injection testing, I encountered the following warning:

EXT4-fs error (device sda): ext4_read_inode_bitmap:201: comm fsstress: Cannot read inode bitmap - block_group = 8, inode_bitmap = 1051 WARNING: CPU: 0 PID: 511 at fs/buffer.c:1181 mark_buffer_dirty+0x1b3/0x1d0

The root cause of the issue lies in the improper implementation of ext4's buffer_head read fault injection. The actual completion of buffer_head read and the buffer_head fault injection are not atomic, which can lead to the uptodate flag being cleared on normally used buffer_heads in race conditions.

[CPU0] [CPU1] [CPU2] ext4_read_inode_bitmap ext4_read_bh() <bh read complete> ext4_read_inode_bitmap if (buffer_uptodate(bh)) return bh jbd2_journal_commit_transaction __jbd2_journal_refile_buffer __jbd2_journal_unfile_buffer __jbd2_journal_temp_unlink_buffer ext4_simulate_fail_bh() clear_buffer_uptodate mark_buffer_dirty <report warning> WARN_ON_ONCE(!buffer_uptodate(bh))

The best approach would be to perform fault injection in the IO completion callback function, rather than after IO completion. However, the IO completion callback function cannot get the fault injection code in sb.

Fix it by passing the result of fault injection into the bh read function, we simulate faults within the bh read function itself. This requires adding an extra parameter to the bh read functions that need fault injection.

Fixes: 46f870d690fe ("ext4: simulate various I/O and checksum errors when reading metadata") Signed-off-by: Long Li leo.lilong@huawei.com --- fs/ext4/balloc.c | 4 ++-- fs/ext4/ext4.h | 12 ++---------- fs/ext4/extents.c | 2 +- fs/ext4/ialloc.c | 5 +++-- fs/ext4/indirect.c | 2 +- fs/ext4/inode.c | 4 ++-- fs/ext4/mmp.c | 2 +- fs/ext4/move_extent.c | 2 +- fs/ext4/resize.c | 2 +- fs/ext4/super.c | 23 +++++++++++++++-------- 10 files changed, 29 insertions(+), 29 deletions(-)

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 79b20d6ae39e..396474e9e2bf 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -545,7 +545,8 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group, trace_ext4_read_block_bitmap_load(sb, block_group, ignore_locked); ext4_read_bh_nowait(bh, REQ_META | REQ_PRIO | (ignore_locked ? REQ_RAHEAD : 0), - ext4_end_bitmap_read); + ext4_end_bitmap_read, + ext4_simulate_fail(sb, EXT4_SIM_BBITMAP_EIO)); return bh; verify: err = ext4_validate_block_bitmap(sb, desc, block_group, bh); @@ -569,7 +570,6 @@ int ext4_wait_block_bitmap(struct super_block *sb, ext4_group_t block_group, if (!desc) return -EFSCORRUPTED; wait_on_buffer(bh); - ext4_simulate_fail_bh(sb, bh, EXT4_SIM_BBITMAP_EIO); if (!buffer_uptodate(bh)) { ext4_error_err(sb, EIO, "Cannot read block bitmap - " "block_group = %u, block_bitmap = %llu", diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index a6a2981526ef..3f914d4c6d98 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1866,14 +1866,6 @@ static inline bool ext4_simulate_fail(struct super_block *sb, return false; }

-static inline void ext4_simulate_fail_bh(struct super_block *sb, - struct buffer_head *bh, - unsigned long code) -{ - if (!IS_ERR(bh) && ext4_simulate_fail(sb, code)) - clear_buffer_uptodate(bh); -} - /* * Error number codes for s_{first,last}_error_errno * @@ -3092,9 +3084,9 @@ extern struct buffer_head *ext4_sb_bread(struct super_block *sb, extern struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb, sector_t block); extern void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags, - bh_end_io_t *end_io); + bh_end_io_t *end_io, bool simu_fail); extern int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, - bh_end_io_t *end_io); + bh_end_io_t *end_io, bool simu_fail); extern int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait); extern void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block); extern int ext4_seq_options_show(struct seq_file *seq, void *offset); diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 2f73c0d9e9e9..d618ff9b6b94 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -564,7 +564,7 @@ __read_extent_tree_block(const char *function, unsigned int line,

if (!bh_uptodate_or_lock(bh)) { trace_ext4_ext_load_extent(inode, pblk, _RET_IP_); - err = ext4_read_bh(bh, 0, NULL); + err = ext4_read_bh(bh, 0, NULL, false); if (err < 0) goto errout; } diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index a72c7167c33f..ea0fe973aca0 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -194,8 +194,9 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) * submit the buffer_head for reading */ trace_ext4_load_inode_bitmap(sb, block_group); - ext4_read_bh(bh, REQ_META | REQ_PRIO, ext4_end_bitmap_read); - ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO); + ext4_read_bh(bh, REQ_META | REQ_PRIO, + ext4_end_bitmap_read, + ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_EIO)); if (!buffer_uptodate(bh)) { put_bh(bh); ext4_error_err(sb, EIO, "Cannot read inode bitmap - " diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index a9f3716119d3..f2c495b745f1 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -170,7 +170,7 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth, }

if (!bh_uptodate_or_lock(bh)) { - if (ext4_read_bh(bh, 0, NULL) < 0) { + if (ext4_read_bh(bh, 0, NULL, false) < 0) { put_bh(bh); goto failure; } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index ef5dfb994f0e..c0b2c6720a66 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5083,10 +5083,10 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino, * Read the block from disk. */ trace_ext4_load_inode(sb, ino); - ext4_read_bh_nowait(bh, REQ_META | REQ_PRIO, NULL); + ext4_read_bh_nowait(bh, REQ_META | REQ_PRIO, NULL, + ext4_simulate_fail(sb, EXT4_SIM_INODE_EIO)); blk_finish_plug(&plug); wait_on_buffer(bh); - ext4_simulate_fail_bh(sb, bh, EXT4_SIM_INODE_EIO); if (!buffer_uptodate(bh)) { if (ret_block) *ret_block = block; diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index bd946d0c71b7..d64c04ed061a 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -94,7 +94,7 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh, }

lock_buffer(*bh); - ret = ext4_read_bh(*bh, REQ_META | REQ_PRIO, NULL); + ret = ext4_read_bh(*bh, REQ_META | REQ_PRIO, NULL, false); if (ret) goto warn_exit;

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index afd7869cae9a..2b6288c2df43 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -221,7 +221,7 @@ mext_page_mkuptodate(struct folio *folio, unsigned from, unsigned to) for (i = 0; i < nr; i++) { bh = arr[i]; if (!bh_uptodate_or_lock(bh)) { - err = ext4_read_bh(bh, 0, NULL); + err = ext4_read_bh(bh, 0, NULL, false); if (err) return err; } diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 5f105171df7b..b34007541e08 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1301,7 +1301,7 @@ static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block) if (unlikely(!bh)) return NULL; if (!bh_uptodate_or_lock(bh)) { - if (ext4_read_bh(bh, 0, NULL) < 0) { + if (ext4_read_bh(bh, 0, NULL, false) < 0) { brelse(bh); return NULL; } diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 9f3c7855095d..78a4324178db 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -185,8 +185,14 @@ MODULE_ALIAS("ext3");

static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, - bh_end_io_t *end_io) + bh_end_io_t *end_io, bool simu_fail) { + if (simu_fail) { + clear_buffer_uptodate(bh); + unlock_buffer(bh); + return; + } + /* * buffer's verified bit is no longer valid after reading from * disk again due to write out error, clear it to make sure we @@ -200,7 +206,7 @@ static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, }

void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags, - bh_end_io_t *end_io) + bh_end_io_t *end_io, bool simu_fail) { BUG_ON(!buffer_locked(bh));

@@ -208,10 +214,11 @@ void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags, unlock_buffer(bh); return; } - __ext4_read_bh(bh, op_flags, end_io); + __ext4_read_bh(bh, op_flags, end_io, simu_fail); }

-int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io) +int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, + bh_end_io_t *end_io, bool simu_fail) { BUG_ON(!buffer_locked(bh));

@@ -220,7 +227,7 @@ int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io return 0; }

- __ext4_read_bh(bh, op_flags, end_io); + __ext4_read_bh(bh, op_flags, end_io, simu_fail);

wait_on_buffer(bh); if (buffer_uptodate(bh)) @@ -232,10 +239,10 @@ int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait) { lock_buffer(bh); if (!wait) { - ext4_read_bh_nowait(bh, op_flags, NULL); + ext4_read_bh_nowait(bh, op_flags, NULL, false); return 0; } - return ext4_read_bh(bh, op_flags, NULL); + return ext4_read_bh(bh, op_flags, NULL, false); }

/* @@ -283,7 +290,7 @@ void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)

if (likely(bh)) { if (trylock_buffer(bh)) - ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL); + ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL, false); brelse(bh); } }