linux-stable.git/fs/ext4/ialloc.c, branch linux-6.11.y

ext4: fix race in buffer_head read fault injection

2024-12-05T12:52:48+00:00

[ Upstream commit 2f3d93e210b9c2866c8b3662adae427d5bf511ec ]

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()
  
                 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
                                        
                                        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 
Link: https://patch.msgid.link/20240906091746.510163-1-leo.lilong@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: avoid negative min_clusters in find_group_orlov()

2024-10-04T14:38:00+00:00

[ Upstream commit bb0a12c3439b10d88412fd3102df5b9a6e3cd6dc ]

min_clusters is signed integer and will be converted to unsigned
integer when compared with unsigned number stats.free_clusters.
If min_clusters is negative, it will be converted to a huge unsigned
value in which case all groups may not meet the actual desired free
clusters.
Set negative min_clusters to 0 to avoid unexpected behavior.

Fixes: ac27a0ec112a ("[PATCH] ext4: initial copy of files from ext3")
Signed-off-by: Kemeng Shi 
Link: https://patch.msgid.link/20240820132234.2759926-4-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: avoid potential buffer_head leak in __ext4_new_inode()

2024-10-04T14:38:00+00:00

[ Upstream commit 227d31b9214d1b9513383cf6c7180628d4b3b61f ]

If a group is marked EXT4_GROUP_INFO_IBITMAP_CORRUPT after it's inode
bitmap buffer_head was successfully verified, then __ext4_new_inode()
will get a valid inode_bitmap_bh of a corrupted group from
ext4_read_inode_bitmap() in which case inode_bitmap_bh misses a release.
Hnadle "IS_ERR(inode_bitmap_bh)" and group corruption separately like
how ext4_free_inode() does to avoid buffer_head leak.

Fixes: 9008a58e5dce ("ext4: make the bitmap read routines return real error codes")
Signed-off-by: Kemeng Shi 
Link: https://patch.msgid.link/20240820132234.2759926-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: avoid buffer_head leak in ext4_mark_inode_used()

2024-10-04T14:37:59+00:00

[ Upstream commit 5e5b2a56c57def1b41efd49596621504d7bcc61c ]

Release inode_bitmap_bh from ext4_read_inode_bitmap() in
ext4_mark_inode_used() to avoid buffer_head leak.
By the way, remove unneeded goto for invalid ino when inode_bitmap_bh
is NULL.

Fixes: 8016e29f4362 ("ext4: fast commit recovery path")
Signed-off-by: Kemeng Shi 
Link: https://patch.msgid.link/20240820132234.2759926-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: use ext4_update_inode_fsync_trans() helper in inode creation

2024-07-05T20:48:54+00:00

Call helper function ext4_update_inode_fsync_trans() instead of open
coding it in __ext4_new_inode().  This helper checks both that the handle
is valid *and* that it hasn't been aborted due to some fatal error in the
journalling layer, using is_handle_aborted().

Signed-off-by: Luis Henriques (SUSE) 
Link: https://patch.msgid.link/20240527161447.21434-1-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o

ext4: convert to new timestamp accessors

2023-10-18T11:26:21+00:00

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton 
Link: https://lore.kernel.org/r/20231004185347.80880-33-jlayton@kernel.org
Signed-off-by: Christian Brauner

Merge tag 'ext4_for_linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2023-08-31T22:18:15+00:00

Pull ext4 updates from Ted Ts'o:
 "Many ext4 and jbd2 cleanups and bug fixes:

   - Cleanups in the ext4 remount code when going to and from read-only

   - Cleanups in ext4's multiblock allocator

   - Cleanups in the jbd2 setup/mounting code paths

   - Performance improvements when appending to a delayed allocation file

   - Miscellaneous syzbot and other bug fixes"

* tag 'ext4_for_linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (60 commits)
  ext4: fix slab-use-after-free in ext4_es_insert_extent()
  libfs: remove redundant checks of s_encoding
  ext4: remove redundant checks of s_encoding
  ext4: reject casefold inode flag without casefold feature
  ext4: use LIST_HEAD() to initialize the list_head in mballoc.c
  ext4: do not mark inode dirty every time when appending using delalloc
  ext4: rename s_error_work to s_sb_upd_work
  ext4: add periodic superblock update check
  ext4: drop dio overwrite only flag and associated warning
  ext4: add correct group descriptors and reserved GDT blocks to system zone
  ext4: remove unused function declaration
  ext4: mballoc: avoid garbage value from err
  ext4: use sbi instead of EXT4_SB(sb) in ext4_mb_new_blocks_simple()
  ext4: change the type of blocksize in ext4_mb_init_cache()
  ext4: fix unttached inode after power cut with orphan file feature enabled
  jbd2: correct the end of the journal recovery scan range
  ext4: ext4_get_{dev}_journal return proper error value
  ext4: cleanup ext4_get_dev_journal() and ext4_get_journal()
  jbd2: jbd2_journal_init_{dev,inode} return proper error return value
  jbd2: drop useless error tag in jbd2_journal_wipe()
  ...

ext4: drop read-only check in ext4_init_inode_table()

2023-07-29T22:37:53+00:00

We better should not be initializing inode tables on read-only
filesystem. The following transaction start will warn us and make the
function bail anyway so drop the pointless check.

Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20230616165109.21695-8-jack@suse.cz
Signed-off-by: Theodore Ts'o

ext4: make ext4_forced_shutdown() take struct super_block

2023-07-29T22:37:24+00:00

Currently ext4_forced_shutdown() takes struct ext4_sb_info but most
callers need to get it from struct super_block anyway. So just pass in
struct super_block to save all callers from some boilerplate code. No
functional changes.

Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20230616165109.21695-3-jack@suse.cz
Signed-off-by: Theodore Ts'o

ext4: convert to ctime accessor functions

2023-07-24T08:29:54+00:00

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Signed-off-by: Jeff Layton 
Signed-off-by: Jan Kara 
Message-Id: <20230705190309.579783-40-jlayton@kernel.org>
Signed-off-by: Christian Brauner