linux-stable.git/fs/ext4, branch v6.12.2

ext4: fix FS_IOC_GETFSMAP handling

2024-12-05T13:02:41+00:00

commit 4a622e4d477bb12ad5ed4abbc7ad1365de1fa347 upstream.

The original implementation ext4's FS_IOC_GETFSMAP handling only
worked when the range of queried blocks included at least one free
(unallocated) block range.  This is because how the metadata blocks
were emitted was as a side effect of ext4_mballoc_query_range()
calling ext4_getfsmap_datadev_helper(), and that function was only
called when a free block range was identified.  As a result, this
caused generic/365 to fail.

Fix this by creating a new function ext4_getfsmap_meta_helper() which
gets called so that blocks before the first free block range in a
block group can get properly reported.

Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: supress data-race warnings in ext4_free_inodes_{count,set}()

2024-12-05T13:02:41+00:00

commit 902cc179c931a033cd7f4242353aa2733bf8524c upstream.

find_group_other() and find_group_orlov() read *_lo, *_hi with
ext4_free_inodes_count without additional locking. This can cause
data-race warning, but since the lock is held for most writes and free
inodes value is generally not a problem even if it is incorrect, it is
more appropriate to use READ_ONCE()/WRITE_ONCE() than to add locking.

==================================================================
BUG: KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set

write to 0xffff88810404300e of 2 bytes by task 6254 on cpu 1:
 ext4_free_inodes_set+0x1f/0x80 fs/ext4/super.c:405
 __ext4_new_inode+0x15ca/0x2200 fs/ext4/ialloc.c:1216
 ext4_symlink+0x242/0x5a0 fs/ext4/namei.c:3391
 vfs_symlink+0xca/0x1d0 fs/namei.c:4615
 do_symlinkat+0xe3/0x340 fs/namei.c:4641
 __do_sys_symlinkat fs/namei.c:4657 [inline]
 __se_sys_symlinkat fs/namei.c:4654 [inline]
 __x64_sys_symlinkat+0x5e/0x70 fs/namei.c:4654
 x64_sys_call+0x1dda/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:267
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x54/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

read to 0xffff88810404300e of 2 bytes by task 6257 on cpu 0:
 ext4_free_inodes_count+0x1c/0x80 fs/ext4/super.c:349
 find_group_other fs/ext4/ialloc.c:594 [inline]
 __ext4_new_inode+0x6ec/0x2200 fs/ext4/ialloc.c:1017
 ext4_symlink+0x242/0x5a0 fs/ext4/namei.c:3391
 vfs_symlink+0xca/0x1d0 fs/namei.c:4615
 do_symlinkat+0xe3/0x340 fs/namei.c:4641
 __do_sys_symlinkat fs/namei.c:4657 [inline]
 __se_sys_symlinkat fs/namei.c:4654 [inline]
 __x64_sys_symlinkat+0x5e/0x70 fs/namei.c:4654
 x64_sys_call+0x1dda/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:267
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x54/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Cc: stable@vger.kernel.org
Signed-off-by: Jeongjun Park 
Reviewed-by: Andreas Dilger 
Link: https://patch.msgid.link/20241003125337.47283-1-aha310510@gmail.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: fix race in buffer_head read fault injection

2024-12-05T13:01:15+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 remount errors with 'abort' mount option

2024-12-05T13:01:12+00:00

[ Upstream commit 76486b104168ae59703190566e372badf433314b ]

When we remount filesystem with 'abort' mount option while changing
other mount options as well (as is LTP test doing), we can return error
from the system call after commit d3476f3dad4a ("ext4: don't set
SB_RDONLY after filesystem errors") because the application of mount
option changes detects shutdown filesystem and refuses to do anything.
The behavior of application of other mount options in presence of
'abort' mount option is currently rather arbitary as some mount option
changes are handled before 'abort' and some after it.

Move aborting of the filesystem to the end of remount handling so all
requested changes are properly applied before the filesystem is shutdown
to have a reasonably consistent behavior.

Fixes: d3476f3dad4a ("ext4: don't set SB_RDONLY after filesystem errors")
Reported-by: Jan Stancek 
Link: https://lore.kernel.org/all/Zvp6L+oFnfASaoHl@t14s
Signed-off-by: Jan Kara 
Tested-by: Jan Stancek 
Link: https://patch.msgid.link/20241004221556.19222-1-jack@suse.cz
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: fix off by one issue in alloc_flex_gd()

2024-10-04T21:36:28+00:00

Wesley reported an issue:

==================================================================
EXT4-fs (dm-5): resizing filesystem from 7168 to 786432 blocks
------------[ cut here ]------------
kernel BUG at fs/ext4/resize.c:324!
CPU: 9 UID: 0 PID: 3576 Comm: resize2fs Not tainted 6.11.0+ #27
RIP: 0010:ext4_resize_fs+0x1212/0x12d0
Call Trace:
 __ext4_ioctl+0x4e0/0x1800
 ext4_ioctl+0x12/0x20
 __x64_sys_ioctl+0x99/0xd0
 x64_sys_call+0x1206/0x20d0
 do_syscall_64+0x72/0x110
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
==================================================================

While reviewing the patch, Honza found that when adjusting resize_bg in
alloc_flex_gd(), it was possible for flex_gd->resize_bg to be bigger than
flexbg_size.

The reproduction of the problem requires the following:

 o_group = flexbg_size * 2 * n;
 o_size = (o_group + 1) * group_size;
 n_group: [o_group + flexbg_size, o_group + flexbg_size * 2)
 o_size = (n_group + 1) * group_size;

Take n=0,flexbg_size=16 as an example:

              last:15
|o---------------|--------------n-|
o_group:0    resize to      n_group:30

The corresponding reproducer is:

img=test.img
rm -f $img
truncate -s 600M $img
mkfs.ext4 -F $img -b 1024 -G 16 8M
dev=`losetup -f --show $img`
mkdir -p /tmp/test
mount $dev /tmp/test
resize2fs $dev 248M

Delete the problematic plus 1 to fix the issue, and add a WARN_ON_ONCE()
to prevent the issue from happening again.

[ Note: another reproucer which this commit fixes is:

  img=test.img
  rm -f $img
  truncate -s 25MiB $img
  mkfs.ext4 -b 4096 -E nodiscard,lazy_itable_init=0,lazy_journal_init=0 $img
  truncate -s 3GiB $img
  dev=`losetup -f --show $img`
  mkdir -p /tmp/test
  mount $dev /tmp/test
  resize2fs $dev 3G
  umount $dev
  losetup -d $dev

  -- TYT ]

Reported-by: Wesley Hershberger 
Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2081231
Reported-by: Stéphane Graber 
Closes: https://lore.kernel.org/all/20240925143325.518508-1-aleksandr.mikhalitsyn@canonical.com/
Tested-by: Alexander Mikhalitsyn 
Tested-by: Eric Sandeen 
Fixes: 665d3e0af4d3 ("ext4: reduce unnecessary memory allocation in alloc_flex_gd()")
Cc: stable@vger.kernel.org
Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://patch.msgid.link/20240927133329.1015041-1-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o

ext4: mark fc as ineligible using an handle in ext4_xattr_set()

2024-10-04T21:36:09+00:00

Calling ext4_fc_mark_ineligible() with a NULL handle is racy and may result
in a fast-commit being done before the filesystem is effectively marked as
ineligible.  This patch moves the call to this function so that an handle
can be used.  If a transaction fails to start, then there's not point in
trying to mark the filesystem as ineligible, and an error will eventually be
returned to user-space.

Suggested-by: Jan Kara 
Signed-off-by: Luis Henriques (SUSE) 
Reviewed-by: Jan Kara 
Link: https://patch.msgid.link/20240923104909.18342-3-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org

ext4: use handle to mark fc as ineligible in __track_dentry_update()

2024-10-04T21:35:54+00:00

Calling ext4_fc_mark_ineligible() with a NULL handle is racy and may result
in a fast-commit being done before the filesystem is effectively marked as
ineligible.  This patch fixes the calls to this function in
__track_dentry_update() by adding an extra parameter to the callback used in
ext4_fc_track_template().

Suggested-by: Jan Kara 
Signed-off-by: Luis Henriques (SUSE) 
Reviewed-by: Jan Kara 
Link: https://patch.msgid.link/20240923104909.18342-2-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org

Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-09-23T16:35:36+00:00

Pull 'struct fd' updates from Al Viro:
 "Just the 'struct fd' layout change, with conversion to accessor
  helpers"

* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  add struct fd constructors, get rid of __to_fd()
  struct fd: representation change
  introduce fd_file(), convert all accessors to it.

Merge tag 'ext4_for_linus-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2024-09-21T02:26:45+00:00

Pull ext4 updates from Ted Ts'o:
 "Lots of cleanups and bug fixes this cycle, primarily in the block
  allocation, extent management, fast commit, and journalling"

* tag 'ext4_for_linus-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (93 commits)
  ext4: convert EXT4_B2C(sbi->s_stripe) users to EXT4_NUM_B2C
  ext4: check stripe size compatibility on remount as well
  ext4: fix i_data_sem unlock order in ext4_ind_migrate()
  ext4: remove the special buffer dirty handling in do_journal_get_write_access
  ext4: fix a potential assertion failure due to improperly dirtied buffer
  ext4: hoist ext4_block_write_begin and replace the __block_write_begin
  ext4: persist the new uptodate buffers in ext4_journalled_zero_new_buffers
  ext4: dax: keep orphan list before truncate overflow allocated blocks
  ext4: fix error message when rejecting the default hash
  ext4: save unnecessary indentation in ext4_ext_create_new_leaf()
  ext4: make some fast commit functions reuse extents path
  ext4: refactor ext4_swap_extents() to reuse extents path
  ext4: get rid of ppath in convert_initialized_extent()
  ext4: get rid of ppath in ext4_ext_handle_unwritten_extents()
  ext4: get rid of ppath in ext4_ext_convert_to_initialized()
  ext4: get rid of ppath in ext4_convert_unwritten_extents_endio()
  ext4: get rid of ppath in ext4_split_convert_extents()
  ext4: get rid of ppath in ext4_split_extent()
  ext4: get rid of ppath in ext4_force_split_extent_at()
  ext4: get rid of ppath in ext4_split_extent_at()
  ...

Merge tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-09-16T07:14:02+00:00

Pull vfs file updates from Christian Brauner:
 "This is the work to cleanup and shrink struct file significantly.

  Right now, (focusing on x86) struct file is 232 bytes. After this
  series struct file will be 184 bytes aka 3 cacheline and a spare 8
  bytes for future extensions at the end of the struct.

  With struct file being as ubiquitous as it is this should make a
  difference for file heavy workloads and allow further optimizations in
  the future.

   - struct fown_struct was embedded into struct file letting it take up
     32 bytes in total when really it shouldn't even be embedded in
     struct file in the first place. Instead, actual users of struct
     fown_struct now allocate the struct on demand. This frees up 24
     bytes.

   - Move struct file_ra_state into the union containg the cleanup hooks
     and move f_iocb_flags out of the union. This closes a 4 byte hole
     we created earlier and brings struct file to 192 bytes. Which means
     struct file is 3 cachelines and we managed to shrink it by 40
     bytes.

   - Reorder struct file so that nothing crosses a cacheline.

     I suspect that in the future we will end up reordering some members
     to mitigate false sharing issues or just because someone does
     actually provide really good perf data.

   - Shrinking struct file to 192 bytes is only part of the work.

     Files use a slab that is SLAB_TYPESAFE_BY_RCU and when a kmem cache
     is created with SLAB_TYPESAFE_BY_RCU the free pointer must be
     located outside of the object because the cache doesn't know what
     part of the memory can safely be overwritten as it may be needed to
     prevent object recycling.

     That has the consequence that SLAB_TYPESAFE_BY_RCU may end up
     adding a new cacheline.

     So this also contains work to add a new kmem_cache_create_rcu()
     function that allows the caller to specify an offset where the
     freelist pointer is supposed to be placed. Thus avoiding the
     implicit addition of a fourth cacheline.

   - And finally this removes the f_version member in struct file.

     The f_version member isn't particularly well-defined. It is mainly
     used as a cookie to detect concurrent seeks when iterating
     directories. But it is also abused by some subsystems for
     completely unrelated things.

     It is mostly a directory and filesystem specific thing that doesn't
     really need to live in struct file and with its wonky semantics it
     really lacks a specific function.

     For pipes, f_version is (ab)used to defer poll notifications until
     a write has happened. And struct pipe_inode_info is used by
     multiple struct files in their ->private_data so there's no chance
     of pushing that down into file->private_data without introducing
     another pointer indirection.

     But pipes don't rely on f_pos_lock so this adds a union into struct
     file encompassing f_pos_lock and a pipe specific f_pipe member that
     pipes can use. This union of course can be extended to other file
     types and is similar to what we do in struct inode already"

* tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
  fs: remove f_version
  pipe: use f_pipe
  fs: add f_pipe
  ubifs: store cookie in private data
  ufs: store cookie in private data
  udf: store cookie in private data
  proc: store cookie in private data
  ocfs2: store cookie in private data
  input: remove f_version abuse
  ext4: store cookie in private data
  ext2: store cookie in private data
  affs: store cookie in private data
  fs: add generic_llseek_cookie()
  fs: use must_set_pos()
  fs: add must_set_pos()
  fs: add vfs_setpos_cookie()
  s390: remove unused f_version
  ceph: remove unused f_version
  adi: remove unused f_version
  mm: Removed @freeptr_offset to prevent doc warning
  ...