linux.git/fs/fat, branch v6.17

Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-08-03T23:23:09+00:00

Pull non-MM updates from Andrew Morton:
 "Significant patch series in this pull request:

   - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
     us closer to being able to remove page->mapping

   - "relayfs: misc changes" (Jason Xing) does some maintenance and
     minor feature addition work in relayfs

   - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
     us from static preallocation of the kdump crashkernel's working
     memory over to dynamic allocation. So the difficulty of a-priori
     estimation of the second kernel's needs is removed and the first
     kernel obtains extra memory

   - "generalize panic_print's dump function to be used by other
     kernel parts" (Feng Tang) implements some consolidation and
     rationalization of the various ways in which a failing kernel
     splats information at the operator

* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
  tools/getdelays: add backward compatibility for taskstats version
  kho: add test for kexec handover
  delaytop: enhance error logging and add PSI feature description
  samples: Kconfig: fix spelling mistake "instancess" -> "instances"
  fat: fix too many log in fat_chain_add()
  scripts/spelling.txt: add notifer||notifier to spelling.txt
  xen/xenbus: fix typo "notifer"
  net: mvneta: fix typo "notifer"
  drm/xe: fix typo "notifer"
  cxl: mce: fix typo "notifer"
  KVM: x86: fix typo "notifer"
  MAINTAINERS: add maintainers for delaytop
  ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
  ucount: fix atomic_long_inc_below() argument type
  kexec: enable CMA based contiguous allocation
  stackdepot: make max number of pools boot-time configurable
  lib/xxhash: remove unused functions
  init/Kconfig: restore CONFIG_BROKEN help text
  lib/raid6: update recov_rvv.c zero page usage
  docs: update docs after introducing delaytop
  ...

fat: fix too many log in fat_chain_add()

2025-08-02T19:01:40+00:00

This log was excessive for a serial console.  So use the ratelimited
version instead.

Link: https://lkml.kernel.org/r/87qzy611d9.fsf@mail.parknet.co.jp
Signed-off-by: OGAWA Hirofumi 
Reported-by: syzbot+fa7ef54f66c189c04b73@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fa7ef54f66c189c04b73
Cc: Namjae Jeon 
Cc: Sungjong Seo 
Signed-off-by: Andrew Morton

Merge tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-07-28T20:43:25+00:00

Pull mmap_prepare updates from Christian Brauner:
 "Last cycle we introduce f_op->mmap_prepare() in c84bf6dd2b83 ("mm:
  introduce new .mmap_prepare() file callback").

  This is preferred to the existing f_op->mmap() hook as it does require
  a VMA to be established yet, thus allowing the mmap logic to invoke
  this hook far, far earlier, prior to inserting a VMA into the virtual
  address space, or performing any other heavy handed operations.

  This allows for much simpler unwinding on error, and for there to be a
  single attempt at merging a VMA rather than having to possibly
  reattempt a merge based on potentially altered VMA state.

  Far more importantly, it prevents inappropriate manipulation of
  incompletely initialised VMA state, which is something that has been
  the cause of bugs and complexity in the past.

  The intent is to gradually deprecate f_op->mmap, and in that vein this
  series coverts the majority of file systems to using f_op->mmap_prepare.

  Prerequisite steps are taken - firstly ensuring all checks for mmap
  capabilities use the file_has_valid_mmap_hooks() helper rather than
  directly checking for f_op->mmap (which is now not a valid check) and
  secondly updating daxdev_mapping_supported() to not require a VMA
  parameter to allow ext4 and xfs to be converted.

  Commit bb666b7c2707 ("mm: add mmap_prepare() compatibility layer for
  nested file systems") handles the nasty edge-case of nested file
  systems like overlayfs, which introduces a compatibility shim to allow
  f_op->mmap_prepare() to be invoked from an f_op->mmap() callback.

  This allows for nested filesystems to continue to function correctly
  with all file systems regardless of which callback is used. Once we
  finally convert all file systems, this shim can be removed.

  As a result, ecryptfs, fuse, and overlayfs remain unaltered so they
  can nest all other file systems.

  We additionally do not update resctl - as this requires an update to
  remap_pfn_range() (or an alternative to it) which we defer to a later
  series, equally we do not update cramfs which needs a mixed mapping
  insertion with the same issue, nor do we update procfs, hugetlbfs,
  syfs or kernfs all of which require VMAs for internal state and hooks.
  We shall return to all of these later"

* tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  doc: update porting, vfs documentation to describe mmap_prepare()
  fs: replace mmap hook with .mmap_prepare for simple mappings
  fs: convert most other generic_file_*mmap() users to .mmap_prepare()
  fs: convert simple use of generic_file_*_mmap() to .mmap_prepare()
  mm/filemap: introduce generic_file_*_mmap_prepare() helpers
  fs/xfs: transition from deprecated .mmap hook to .mmap_prepare
  fs/ext4: transition from deprecated .mmap hook to .mmap_prepare
  fs/dax: make it possible to check dev dax support without a VMA
  fs: consistently use can_mmap_file() helper
  mm/nommu: use file_has_valid_mmap_hooks() helper
  mm: rename call_mmap/mmap_prepare to vfs_mmap/mmap_prepare

Merge tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-07-28T18:22:56+00:00

Pull misc VFS updates from Christian Brauner:
 "This contains the usual selections of misc updates for this cycle.

  Features:

   - Add ext4 IOCB_DONTCACHE support

     This refactors the address_space_operations write_begin() and
     write_end() callbacks to take const struct kiocb * as their first
     argument, allowing IOCB flags such as IOCB_DONTCACHE to propagate
     to the filesystem's buffered I/O path.

     Ext4 is updated to implement handling of the IOCB_DONTCACHE flag
     and advertises support via the FOP_DONTCACHE file operation flag.

     Additionally, the i915 driver's shmem write paths are updated to
     bypass the legacy write_begin/write_end interface in favor of
     directly calling write_iter() with a constructed synchronous kiocb.
     Another i915 change replaces a manual write loop with
     kernel_write() during GEM shmem object creation.

  Cleanups:

   - don't duplicate vfs_open() in kernel_file_open()

   - proc_fd_getattr(): don't bother with S_ISDIR() check

   - fs/ecryptfs: replace snprintf with sysfs_emit in show function

   - vfs: Remove unnecessary list_for_each_entry_safe() from
     evict_inodes()

   - filelock: add new locks_wake_up_waiter() helper

   - fs: Remove three arguments from block_write_end()

   - VFS: change old_dir and new_dir in struct renamedata to dentrys

   - netfs: Remove unused declaration netfs_queue_write_request()

  Fixes:

   - eventpoll: Fix semi-unbounded recursion

   - eventpoll: fix sphinx documentation build warning

   - fs/read_write: Fix spelling typo

   - fs: annotate data race between poll_schedule_timeout() and
     pollwake()

   - fs/pipe: set FMODE_NOWAIT in create_pipe_files()

   - docs/vfs: update references to i_mutex to i_rwsem

   - fs/buffer: remove comment about hard sectorsize

   - fs/buffer: remove the min and max limit checks in __getblk_slow()

   - fs/libfs: don't assume blocksize <= PAGE_SIZE in
     generic_check_addressable

   - fs_context: fix parameter name in infofc() macro

   - fs: Prevent file descriptor table allocations exceeding INT_MAX"

* tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits)
  netfs: Remove unused declaration netfs_queue_write_request()
  eventpoll: fix sphinx documentation build warning
  ext4: support uncached buffered I/O
  mm/pagemap: add write_begin_get_folio() helper function
  fs: change write_begin/write_end interface to take struct kiocb *
  drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter
  drm/i915: Use kernel_write() in shmem object create
  eventpoll: Fix semi-unbounded recursion
  vfs: Remove unnecessary list_for_each_entry_safe() from evict_inodes()
  fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable
  fs/buffer: remove the min and max limit checks in __getblk_slow()
  fs: Prevent file descriptor table allocations exceeding INT_MAX
  fs: Remove three arguments from block_write_end()
  fs/ecryptfs: replace snprintf with sysfs_emit in show function
  fs: annotate suspected data race between poll_schedule_timeout() and pollwake()
  docs/vfs: update references to i_mutex to i_rwsem
  fs/buffer: remove comment about hard sectorsize
  fs_context: fix parameter name in infofc() macro
  VFS: change old_dir and new_dir in struct renamedata to dentrys
  proc_fd_getattr(): don't bother with S_ISDIR() check
  ...

fs: change write_begin/write_end interface to take struct kiocb *

2025-07-16T12:48:18+00:00

Change the address_space_operations callbacks write_begin() and
write_end() to take struct kiocb * as the first argument instead of
struct file *.

Update all affected function prototypes, implementations, call sites,
and related documentation across VFS, filesystems, and block layer.

Part of a series refactoring address_space_operations write_begin and
write_end callbacks to use struct kiocb for passing write context and
flags.

Signed-off-by: Taotao Chen 
Link: https://lore.kernel.org/20250716093559.217344-4-chentaotao@didiglobal.com
Signed-off-by: Christian Brauner

fs: fat: Prevent fsfuzzer from dominating the console

2025-07-10T05:57:55+00:00

fsfuzzer may make many invalid access for FAT-fs and generate many kmsg
like "FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)".

For platforms & os that enables hardware serial device whose speed are
slow, this may cause softlockup easily.

So let's ratelimit the error log.

The log as below:
[11916.242560] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.254485] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.266388] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.278287] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.290180] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.302068] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.313962] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.325848] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.337732] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.349619] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.361505] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.373391] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.385272] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.397144] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.409025] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.420909] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.432791] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.444674] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.456558] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.468446] FAT-fs (loop2): error, invalid access to FAT (entry 0x00000ccb)
[11916.480352] watchdog: BUG: soft lockup - CPU#58 stuck for 26s! [cat:2446035]
[11916.480357] Modules linked in: ...
[11916.480503] CPU: 58 PID: 2446035 Comm: cat Kdump: loaded Tainted: ...
[11916.480508] Hardware name: vclusters VSFT5000 B/VSFT5000 B, BIOS ...
[11916.480510] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[11916.480513] pc : console_emit_next_record+0x1b4/0x288
[11916.480524] lr : console_emit_next_record+0x1ac/0x288
[11916.480525] sp : ffff80009bcdae90
[11916.480527] x29: ffff80009bcdaec0 x28: ffff800082513810 x27: 0000000000000001
[11916.480530] x26: 0000000000000001 x25: ffff800081f66000 x24: 0000000000000000
[11916.480533] x23: 0000000000000000 x22: ffff80009bcdaf8f x21: 0000000000000001
[11916.480535] x20: 0000000000000000 x19: ffff800082513810 x18: ffffffffffffffff
[11916.480538] x17: 0000000000000002 x16: 0000000000000001 x15: ffff80009bcdab30
[11916.480541] x14: 0000000000000000 x13: 205d353330363434 x12: 32545b5d36343438
[11916.480543] x11: 652820544146206f x10: 7420737365636361 x9 : ffff800080159a6c
[11916.480546] x8 : 69202c726f727265 x7 : 545b5d3634343836 x6 : 342e36313931315b
[11916.480549] x5 : ffff800082513a01 x4 : ffff80009bcdad31 x3 : 0000000000000000
[11916.480551] x2 : 00000000ffffffff x1 : 0000000001b9b000 x0 : ffff8000836cef00
[11916.480554] Call trace:
[11916.480557]  console_emit_next_record+0x1b4/0x288
[11916.480560]  console_flush_all+0xcc/0x190
[11916.480563]  console_unlock+0x78/0x138
[11916.480565]  vprintk_emit+0x1c4/0x210
[11916.480568]  vprintk_default+0x40/0x58
[11916.480570]  vprintk+0x84/0xc8
[11916.480572]  _printk+0x68/0xa0
[11916.480578]  _fat_msg+0x6c/0xa0 [fat]
[11916.480593]  __fat_fs_error+0xf8/0x118 [fat]
[11916.480601]  fat_ent_read+0x164/0x238 [fat]
[11916.480609]  fat_get_cluster+0x180/0x2c8 [fat]
[11916.480617]  fat_get_mapped_cluster+0xb8/0x170 [fat]

Link: https://lkml.kernel.org/r/20250620020231.9292-1-me@linux.beauty
Signed-off-by: Li Chen 
Acked-by: OGAWA Hirofumi 
Cc: Christian Brauner 
Signed-off-by: Andrew Morton

fs: convert simple use of generic_file_*_mmap() to .mmap_prepare()

2025-06-17T11:47:45+00:00

Since commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file
callback"), the f_op->mmap() hook has been deprecated in favour of
f_op->mmap_prepare().

We have provided generic .mmap_prepare() equivalents, so update all file
systems that specify these directly in their file_operations structures.

This updates 9p, adfs, affs, bfs, fat, hfs, hfsplus, hostfs, hpfs, jffs2,
jfs, minix, omfs, ramfs and ufs file systems directly.

It updates generic_ro_fops which impacts qnx4, cramfs, befs, squashfs,
frebxfs, qnx6, efs, romfs, erofs and isofs file systems.

There are remaining file systems which use generic hooks in a less direct
way which we address in a subsequent commit.

Signed-off-by: Lorenzo Stoakes 
Link: https://lore.kernel.org/c7dc90e44a9e75e750939ea369290d6e441a18e6.1750099179.git.lorenzo.stoakes@oracle.com
Reviewed-by: Jan Kara 
Reviewed-by: Viacheslav Dubeyko 
Signed-off-by: Christian Brauner

new helper: set_default_d_op()

2025-06-11T02:21:16+00:00

... to be used instead of manually assigning to ->s_d_op.
All in-tree filesystem converted (and field itself is renamed,
so any out-of-tree ones in need of conversion will be caught
by compiler).

Reviewed-by: Christian Brauner 
Signed-off-by: Al Viro

Change inode_operations.mkdir to return struct dentry *

2025-02-27T19:00:17+00:00

Some filesystems, such as NFS, cifs, ceph, and fuse, do not have
complete control of sequencing on the actual filesystem (e.g.  on a
different server) and may find that the inode created for a mkdir
request already exists in the icache and dcache by the time the mkdir
request returns.  For example, if the filesystem is mounted twice the
directory could be visible on the other mount before it is on the
original mount, and a pair of name_to_handle_at(), open_by_handle_at()
calls could instantiate the directory inode with an IS_ROOT() dentry
before the first mkdir returns.

This means that the dentry passed to ->mkdir() may not be the one that
is associated with the inode after the ->mkdir() completes.  Some
callers need to interact with the inode after the ->mkdir completes and
they currently need to perform a lookup in the (rare) case that the
dentry is no longer hashed.

This lookup-after-mkdir requires that the directory remains locked to
avoid races.  Planned future patches to lock the dentry rather than the
directory will mean that this lookup cannot be performed atomically with
the mkdir.

To remove this barrier, this patch changes ->mkdir to return the
resulting dentry if it is different from the one passed in.
Possible returns are:
  NULL - the directory was created and no other dentry was used
  ERR_PTR() - an error occurred
  non-NULL - this other dentry was spliced in

This patch only changes file-systems to return "ERR_PTR(err)" instead of
"err" or equivalent transformations.  Subsequent patches will make
further changes to some file-systems to return a correct dentry.

Not all filesystems reliably result in a positive hashed dentry:

- NFS, cifs, hostfs will sometimes need to perform a lookup of
  the name to get inode information.  Races could result in this
  returning something different. Note that this lookup is
  non-atomic which is what we are trying to avoid.  Placing the
  lookup in filesystem code means it only happens when the filesystem
  has no other option.
- kernfs and tracefs leave the dentry negative and the ->revalidate
  operation ensures that lookup will be called to correctly populate
  the dentry.  This could be fixed but I don't think it is important
  to any of the users of vfs_mkdir() which look at the dentry.

The recommendation to use
    d_drop();d_splice_alias()
is ugly but fits with current practice.  A planned future patch will
change this.

Reviewed-by: Jeff Layton 
Reviewed-by: Jan Kara 
Signed-off-by: NeilBrown 
Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de
Signed-off-by: Christian Brauner

vfat_revalidate{,_ci}(): use stable parent inode passed by caller

2025-01-28T00:25:24+00:00

Reviewed-by: Jeff Layton 
Signed-off-by: Al Viro