No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Zhihao Cheng 8eb15ff216 ext4: Fix reusing stale buffer heads from last failed mounting
[ Upstream commit 26fb5290240dc31cae99b8b4dd2af7f46dfcba6b ]

Following process makes ext4 load stale buffer heads from last failed
mounting in a new mounting operation:
mount_bdev
 ext4_fill_super
 | ext4_load_and_init_journal
 |  ext4_load_journal
 |   jbd2_journal_load
 |    load_superblock
 |     journal_get_superblock
 |      set_buffer_verified(bh) // buffer head is verified
 |   jbd2_journal_recover // failed caused by EIO
 | goto failed_mount3a // skip 'sb->s_root' initialization
 deactivate_locked_super
  kill_block_super
   generic_shutdown_super
    if (sb->s_root)
    // false, skip ext4_put_super->invalidate_bdev->
    // invalidate_mapping_pages->mapping_evict_folio->
    // filemap_release_folio->try_to_free_buffers, which
    // cannot drop buffer head.
   blkdev_put
    blkdev_put_whole
     if (atomic_dec_and_test(&bdev->bd_openers))
     // false, systemd-udev happens to open the device. Then
     // blkdev_flush_mapping->kill_bdev->truncate_inode_pages->
     // truncate_inode_folio->truncate_cleanup_folio->
     // folio_invalidate->block_invalidate_folio->
     // filemap_release_folio->try_to_free_buffers will be skipped,
     // dropping buffer head is missed again.

Second mount:
ext4_fill_super
 ext4_load_and_init_journal
  ext4_load_journal
   ext4_get_journal
    jbd2_journal_init_inode
     journal_init_common
      bh = getblk_unmovable
       bh = __find_get_block // Found stale bh in last failed mounting
      journal->j_sb_buffer = bh
   jbd2_journal_load
    load_superblock
     journal_get_superblock
      if (buffer_verified(bh))
      // true, skip journal->j_format_version = 2, value is 0
    jbd2_journal_recover
     do_one_pass
      next_log_block += count_tags(journal, bh)
      // According to journal_tag_bytes(), 'tag_bytes' calculating is
      // affected by jbd2_has_feature_csum3(), jbd2_has_feature_csum3()
      // returns false because 'j->j_format_version >= 2' is not true,
      // then we get wrong next_log_block. The do_one_pass may exit
      // early whenoccuring non JBD2_MAGIC_NUMBER in 'next_log_block'.

The filesystem is corrupted here, journal is partially replayed, and
new journal sequence number actually is already used by last mounting.

The invalidate_bdev() can drop all buffer heads even racing with bare
reading block device(eg. systemd-udev), so we can fix it by invalidating
bdev in error handling path in __ext4_fill_super().

Fetch a reproducer in [Link].

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217171
Fixes: 25ed6e8a54 ("jbd2: enable journal clients to enable v2 checksumming")
Cc: stable@vger.kernel.org # v3.5
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230315013128.3911115-2-chengzhihao1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-11 11:53:44 +02:00
arch x86: fix backwards merge of GDS/SRSO bit 2023-08-08 19:56:37 +02:00
block block/partition: fix signedness issue for Amiga partitions 2023-07-27 08:37:29 +02:00
certs
crypto KEYS: asymmetric: Copy sig and digest in public_key_verify_signature() 2023-06-21 15:44:08 +02:00
Documentation Documentation/x86: Fix backwards on/off logic about YMM support 2023-08-08 19:56:36 +02:00
drivers bcache: Fix __bch_btree_node_alloc to make the failure behavior consistent 2023-08-11 11:53:44 +02:00
fs ext4: Fix reusing stale buffer heads from last failed mounting 2023-08-11 11:53:44 +02:00
include jbd2: fix kernel-doc markups 2023-08-11 11:53:43 +02:00
init x86/mm: Initialize text poking earlier 2023-08-08 19:56:36 +02:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:23:06 +01:00
kernel mm: Move mm_cachep initialization to mm_init() 2023-08-08 19:56:36 +02:00
lib debugobjects: Recheck debug_objects_enabled before reporting 2023-07-27 08:37:41 +02:00
LICENSES
mm mm: make wait_on_page_writeback() wait for multiple pending writebacks 2023-06-28 10:18:42 +02:00
net tcp: annotate data-races around fastopenq.max_qlen 2023-07-27 08:37:45 +02:00
samples samples/bpf: Fix buffer overflow in tcp_basertt 2023-07-27 08:37:07 +02:00
scripts modpost: fix off by one in is_executable_section() 2023-07-27 08:37:18 +02:00
security integrity: Fix possible multiple allocation in integrity_inode_get() 2023-07-27 08:37:25 +02:00
sound ALSA: jack: Fix mutex call in snd_jack_report() 2023-07-27 08:37:24 +02:00
tools x86/bugs: Increase the x86 bugs vector size to two u32s 2023-08-08 19:56:37 +02:00
usr
virt KVM: Destroy target device if coalesced MMIO unregistration fails 2023-03-11 16:44:01 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Remove DECnet support from kernel 2023-06-21 15:44:10 +02:00
Makefile Linux 5.4.252 2023-08-08 19:56:37 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.