linux.git/fs/ext4/super.c, branch v6.12

ext4: check stripe size compatibility on remount as well

2024-09-04T02:14:17+00:00

We disable stripe size in __ext4_fill_super if it is not a multiple of
the cluster ratio however this check is missed when trying to remount.
This can leave us with cases where stripe < cluster_ratio after
remount:set making EXT4_B2C(sbi->s_stripe) become 0 that can cause some
unforeseen bugs like divide by 0.

Fix that by adding the check in remount path as well.

Reported-by: syzbot+1ad8bac5af24d01e2cbd@syzkaller.appspotmail.com
Tested-by: syzbot+1ad8bac5af24d01e2cbd@syzkaller.appspotmail.com
Reviewed-by: Kemeng Shi 
Reviewed-by: Ritesh Harjani (IBM) 
Fixes: c3defd99d58c ("ext4: treat stripe in block unit")
Signed-off-by: Ojaswin Mujoo 
Link: https://patch.msgid.link/3a493bb503c3598e25dcfbed2936bb2dff3fece7.1725002410.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o

ext4: fix error message when rejecting the default hash

2024-09-04T02:14:16+00:00

Commit 985b67cd8639 ("ext4: filesystems without casefold feature cannot
be mounted with siphash") properly rejects volumes where
s_def_hash_version is set to DX_HASH_SIPHASH, but the check and the
error message should not look into casefold setup - a filesystem should
never have DX_HASH_SIPHASH as the default hash.  Fix it and, since we
are there, move the check to ext4_hash_info_init.

Fixes:985b67cd8639 ("ext4: filesystems without casefold feature cannot
be mounted with siphash")

Signed-off-by: Gabriel Krisman Bertazi 
Link: https://patch.msgid.link/87jzg1en6j.fsf_-_@mailhost.krisman.be
Signed-off-by: Theodore Ts'o

ext4: don't set SB_RDONLY after filesystem errors

2024-08-27T03:53:20+00:00

When the filesystem is mounted with errors=remount-ro, we were setting
SB_RDONLY flag to stop all filesystem modifications. We knew this misses
proper locking (sb->s_umount) and does not go through proper filesystem
remount procedure but it has been the way this worked since early ext2
days and it was good enough for catastrophic situation damage
mitigation. Recently, syzbot has found a way (see link) to trigger
warnings in filesystem freezing because the code got confused by
SB_RDONLY changing under its hands. Since these days we set
EXT4_FLAGS_SHUTDOWN on the superblock which is enough to stop all
filesystem modifications, modifying SB_RDONLY shouldn't be needed. So
stop doing that.

Link: https://lore.kernel.org/all/000000000000b90a8e061e21d12f@google.com
Reported-by: Christian Brauner 
Signed-off-by: Jan Kara 
Reviewed-by: Christian Brauner 
Link: https://patch.msgid.link/20240805201241.27286-1-jack@suse.cz
Signed-off-by: Theodore Ts'o

ext4: fix access to uninitialised lock in fc replay path

2024-08-27T01:21:20+00:00

The following kernel trace can be triggered with fstest generic/629 when
executed against a filesystem with fast-commit feature enabled:

INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 866 Comm: mount Not tainted 6.10.0+ #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014
Call Trace:
 
 dump_stack_lvl+0x66/0x90
 register_lock_class+0x759/0x7d0
 __lock_acquire+0x85/0x2630
 ? __find_get_block+0xb4/0x380
 lock_acquire+0xd1/0x2d0
 ? __ext4_journal_get_write_access+0xd5/0x160
 _raw_spin_lock+0x33/0x40
 ? __ext4_journal_get_write_access+0xd5/0x160
 __ext4_journal_get_write_access+0xd5/0x160
 ext4_reserve_inode_write+0x61/0xb0
 __ext4_mark_inode_dirty+0x79/0x270
 ? ext4_ext_replay_set_iblocks+0x2f8/0x450
 ext4_ext_replay_set_iblocks+0x330/0x450
 ext4_fc_replay+0x14c8/0x1540
 ? jread+0x88/0x2e0
 ? rcu_is_watching+0x11/0x40
 do_one_pass+0x447/0xd00
 jbd2_journal_recover+0x139/0x1b0
 jbd2_journal_load+0x96/0x390
 ext4_load_and_init_journal+0x253/0xd40
 ext4_fill_super+0x2cc6/0x3180
...

In the replay path there's an attempt to lock sbi->s_bdev_wb_lock in
function ext4_check_bdev_write_error().  Unfortunately, at this point this
spinlock has not been initialized yet.  Moving it's initialization to an
earlier point in __ext4_fill_super() fixes this splat.

Signed-off-by: Luis Henriques (SUSE) 
Link: https://patch.msgid.link/20240718094356.7863-1-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org

ext4: fix timer use-after-free on failed mount

2024-08-27T01:20:57+00:00

Syzbot has found an ODEBUG bug in ext4_fill_super

The del_timer_sync function cancels the s_err_report timer,
which reminds about filesystem errors daily. We should
guarantee the timer is no longer active before kfree(sbi).

When filesystem mounting fails, the flow goes to failed_mount3,
where an error occurs when ext4_stop_mmpd is called, causing
a read I/O failure. This triggers the ext4_handle_error function
that ultimately re-arms the timer,
leaving the s_err_report timer active before kfree(sbi) is called.

Fix the issue by canceling the s_err_report timer after calling ext4_stop_mmpd.

Signed-off-by: Xiaxi Shen 
Reported-and-tested-by: syzbot+59e0101c430934bc9a36@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=59e0101c430934bc9a36
Link: https://patch.msgid.link/20240715043336.98097-1-shenxiaxi26@gmail.com
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org

ext4: use seq_putc() in two functions

2024-08-27T01:20:57+00:00

Single characters (line breaks) should be put into a sequence.
Thus use the corresponding function “seq_putc”.

This issue was transformed by using the Coccinelle software.

Signed-off-by: Markus Elfring 
Link: https://patch.msgid.link/076974ab-4da3-4176-89dc-0514e020c276@web.de
Signed-off-by: Theodore Ts'o

ext4: filesystems without casefold feature cannot be mounted with siphash

2024-08-21T01:37:18+00:00

When mounting the ext4 filesystem, if the default hash version is set to
DX_HASH_SIPHASH but the casefold feature is not set, exit the mounting.

Reported-by: syzbot+340581ba9dceb7e06fb3@syzkaller.appspotmail.com
Signed-off-by: Lizhi Xu 
Link: https://patch.msgid.link/20240605012335.44086-1-lizhi.xu@windriver.com
Signed-off-by: Theodore Ts'o

Merge tag 'ext4_for_linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2024-07-19T00:03:42+00:00

Pull ext4 updates from Ted Ts'o:
 "Many cleanups and bug fixes in ext4, especially for the fast commit
  feature.

  Also some performance improvements; in particular, improving IOPS and
  throughput on fast devices running Async Direct I/O by up to 20% by
  optimizing jbd2_transaction_committed()"

* tag 'ext4_for_linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits)
  ext4: make sure the first directory block is not a hole
  ext4: check dot and dotdot of dx_root before making dir indexed
  ext4: sanity check for NULL pointer after ext4_force_shutdown
  jbd2: increase maximum transaction size
  jbd2: drop pointless shrinker batch initialization
  jbd2: avoid infinite transaction commit loop
  jbd2: precompute number of transaction descriptor blocks
  jbd2: make jbd2_journal_get_max_txn_bufs() internal
  jbd2: avoid mount failed when commit block is partial submitted
  ext4: avoid writing unitialized memory to disk in EA inodes
  ext4: don't track ranges in fast_commit if inode has inlined data
  ext4: fix possible tid_t sequence overflows
  ext4: use ext4_update_inode_fsync_trans() helper in inode creation
  ext4: add missing MODULE_DESCRIPTION()
  jbd2: add missing MODULE_DESCRIPTION()
  ext4: use memtostr_pad() for s_volume_name
  jbd2: speed up jbd2_transaction_committed()
  ext4: make ext4_da_map_blocks() buffer_head unaware
  ext4: make ext4_insert_delayed_block() insert multi-blocks
  ext4: factor out a helper to check the cluster allocation state
  ...

Merge tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-07-15T18:31:32+00:00

Pull vfs mount API updates from Christian Brauner:

 - Add a generic helper to parse uid and gid mount options.

   Currently we open-code the same logic in various filesystems which is
   error prone, especially since the verification of uid and gid mount
   options is a sensitive operation in the face of idmappings.

   Add a generic helper and convert all filesystems over to it. Make
   sure that filesystems that are mountable in unprivileged containers
   verify that the specified uid and gid can be represented in the
   owning namespace of the filesystem.

 - Convert hostfs to the new mount api.

* tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fuse: Convert to new uid/gid option parsing helpers
  fuse: verify {g,u}id mount options correctly
  fat: Convert to new uid/gid option parsing helpers
  fat: Convert to new mount api
  fat: move debug into fat_mount_options
  vboxsf: Convert to new uid/gid option parsing helpers
  tracefs: Convert to new uid/gid option parsing helpers
  smb: client: Convert to new uid/gid option parsing helpers
  tmpfs: Convert to new uid/gid option parsing helpers
  ntfs3: Convert to new uid/gid option parsing helpers
  isofs: Convert to new uid/gid option parsing helpers
  hugetlbfs: Convert to new uid/gid option parsing helpers
  ext4: Convert to new uid/gid option parsing helpers
  exfat: Convert to new uid/gid option parsing helpers
  efivarfs: Convert to new uid/gid option parsing helpers
  debugfs: Convert to new uid/gid option parsing helpers
  autofs: Convert to new uid/gid option parsing helpers
  fs_parse: add uid & gid option option parsing helpers
  hostfs: Add const qualifier to host_root in hostfs_fill_super()
  hostfs: convert hostfs to use the new mount API

ext4: Convert to new uid/gid option parsing helpers

2024-07-02T04:21:18+00:00

Convert to new uid/gid option parsing helpers

Signed-off-by: Eric Sandeen 
Link: https://lore.kernel.org/r/a84be40d-5110-4dac-83b1-0ea8e043f0fd@redhat.com
Signed-off-by: Christian Brauner