443 Commits
Author SHA1 Message Date
Linus Torvalds acf6c670e4 Merge tag 'fuse-update-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse update from Miklos Szeredi:

 - Fix possible hang in virtiofs when cleaning up a DAX inode (Sergio
   Lopez)

 - Fix a warning when using large folio as the source of SPLICE_F_MOVE
   on the fuse device (Bernd)

 - Fix uninitialized value found by KMSAN (Luis Henriques)

 - Fix synchronous INIT hang (Miklos)

 - Fix race between inode initialization and FUSE_NOTIFY_INVAL_INODE
   (Horst)

 - Allow fd to be closed after passing fuse device fd to
   fsconfig(..., "fd", ...) (Miklos)

 - Support FSCONFIG_SET_FD for "fd" option (Miklos)

 - Misc fixes and cleanups

* tag 'fuse-update-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (21 commits)
  fuse: support FSCONFIG_SET_FD for "fd" option
  fuse: clean up device cloning
  fuse: don't require /dev/fuse fd to be kept open during mount
  fuse: add refcount to fuse_dev
  fuse: create fuse_dev on /dev/fuse open instead of mount
  fuse: check connection state on notification
  fuse: fuse_dev_ioctl_clone() should wait for device file to be initialized
  fuse: fix inode initialization race
  fuse: abort on fatal signal during sync init
  fuse: fix uninit-value in fuse_dentry_revalidate()
  fuse: use offset_in_page() for page offset calculations
  fuse: use DIV_ROUND_UP() for page count calculations
  fuse: simplify logic in fuse_notify_store() and fuse_retrieve()
  fuse: validate outarg offset and size in notify store/retrieve
  fuse: Check for large folio with SPLICE_F_MOVE
  fuse: quiet down complaints in fuse_conn_limit_write
  fuse: drop unnecessary argument from fuse_lookup_init()
  fuse: fix premature writetrhough request for large folio
  fuse: refactor duplicate queue teardown operation
  virtiofs: add FUSE protocol validation
  ...
2026-04-15 19:04:21 -07:00
Miklos Szeredi 2339f9cc9f fuse: support FSCONFIG_SET_FD for "fd" option
This is not only cleaner to use in userspace (no need to sprintf the fd to
a string) but also allows userspace to detect that the devfd can be closed
after the fsconfig call.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2026-04-02 20:53:00 +02:00
Miklos Szeredi 4ae404afd9 fuse: clean up device cloning
- fuse_mutex is not needed for device cloning, because fuse_dev_install()
   uses cmpxcg() to set fud->fc, which prevents races between clone/mount
   or clone/clone.  This makes the logic simpler

 - Drop fc->dev_count.  This is only used to check in release if the device
   is the last clone, but checking list_empty(&fc->devices) is equivalent
   after removing the released device from the list.  Removing the fuse_dev
   before calling fuse_abort_conn() is okay, since the processing and io
   lists are now empty for this device.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-04-02 20:52:59 +02:00
Miklos Szeredi d42eb23b2e fuse: don't require /dev/fuse fd to be kept open during mount
With the new mount API the sequence of syscalls would be:

        fs_fd = fsopen("fuse", 0);
	snprintf(opt, sizeof(opt), "%i", devfd);
	fsconfig(fs_fd, FSCONFIG_SET_STRING, "fd", opt, 0);
	/* ... */
	fsconfig(fs_fd, FSCONFIG_CMD_CREATE, 0, 0, 0);

Current mount code just stores the value of devfd in the fs_context and
uses it in during FSCONFIG_CMD_CREATE, which is inelegant.

Instead grab a reference to the underlying fuse_dev, and use that during
the filesystem creation.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-04-02 20:43:25 +02:00
Miklos Szeredi e9bf38500e fuse: add refcount to fuse_dev
This will make it possible to grab the fuse_dev and subsequently release
the file that it came from.

In the above case, fud->fc will be set to FUSE_DEV_FC_DISCONNECTED to
indicate that this is no longer a functional device.

When trying to assign an fc to such a disconnected fuse_dev, the fc is set
to the disconnected state.

Use atomic operations xchg() and cmpxchg() to prevent races.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-04-02 20:43:24 +02:00
Miklos Szeredi a8dd5f1b73 fuse: create fuse_dev on /dev/fuse open instead of mount
Allocate struct fuse_dev when opening the device.  This means that unlike
before, ->private_data is always set to a valid pointer.

The use of USE_DEV_SYNC_INIT magic pointer for the private_data is now
replaced with a simple bool sync_init member.

If sync INIT is not set, I/O on the device returns error before mount.
Keep this behavior by checking for the ->fc member.  If fud->fc is set, the
mount has succeeded.  Testing this used READ_ONCE(file->private_data) and
smp_mb() to try and provide the necessary semantics.  Switch this to
smp_store_release() and smp_load_acquire().

Setting fud->fc is protected by fuse_mutex, this is unchanged.

Will need this later so the /dev/fuse open file reference is not held
during FSCONFIG_CMD_CREATE.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2026-04-02 20:43:24 +02:00
Horst BirthelmerandMiklos Szeredi aff12041b4 fuse: fix inode initialization race
Fix a race between fuse_iget() and fuse_reverse_inval_inode() where
invalidation can arrive while an inode is being initialized, causing
the invalidation to be lost.
By keeping the inode state I_NEW as long as the attributes are not valid
the invalidation can wait until the inode is fully initialized.

Suggested-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Horst Birthelmer <hbirthelmer@ddn.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-04-01 12:12:58 +02:00
Miklos Szeredi 204aa22a68 fuse: abort on fatal signal during sync init
When sync init is used and the server exits for some reason (error, crash)
while processing FUSE_INIT, the filesystem creation will hang.  The reason
is that while all other threads will exit, the mounting thread (or process)
will keep the device fd open, which will prevent an abort from happening.

This is a regression from the async mount case, where the mount was done
first, and the FUSE_INIT processing afterwards, in which case there's no
such recursive syscall keeping the fd open.

Fixes: dfb84c3307 ("fuse: allow synchronous FUSE_INIT")
Cc: stable@vger.kernel.org # v6.18
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Bernd Schubert <bernd@bsbernd.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-03-24 15:26:32 +01:00
Joanne KoongandChristian Brauner 76f9377cd2 writeback: don't block sync for filesystems with no data integrity guarantees
Add a SB_I_NO_DATA_INTEGRITY superblock flag for filesystems that cannot
guarantee data persistence on sync (eg fuse). For superblocks with this
flag set, sync kicks off writeback of dirty inodes but does not wait
for the flusher threads to complete the writeback.

This replaces the per-inode AS_NO_DATA_INTEGRITY mapping flag added in
commit f9a49aa302 ("fs/writeback: skip AS_NO_DATA_INTEGRITY mappings
in wait_sb_inodes()"). The flag belongs at the superblock level because
data integrity is a filesystem-wide property, not a per-inode one.
Having this flag at the superblock level also allows us to skip having
to iterate every dirty inode in wait_sb_inodes() only to skip each inode
individually.

Prior to this commit, mappings with no data integrity guarantees skipped
waiting on writeback completion but still waited on the flusher threads
to finish initiating the writeback. Waiting on the flusher threads is
unnecessary. This commit kicks off writeback but does not wait on the
flusher threads. This change properly addresses a recent report [1] for
a suspend-to-RAM hang seen on fuse-overlayfs that was caused by waiting
on the flusher threads to finish:

Workqueue: pm_fs_sync pm_fs_sync_work_fn
Call Trace:
 <TASK>
 __schedule+0x457/0x1720
 schedule+0x27/0xd0
 wb_wait_for_completion+0x97/0xe0
 sync_inodes_sb+0xf8/0x2e0
 __iterate_supers+0xdc/0x160
 ksys_sync+0x43/0xb0
 pm_fs_sync_work_fn+0x17/0xa0
 process_one_work+0x193/0x350
 worker_thread+0x1a1/0x310
 kthread+0xfc/0x240
 ret_from_fork+0x243/0x280
 ret_from_fork_asm+0x1a/0x30
 </TASK>

On fuse this is problematic because there are paths that may cause the
flusher thread to block (eg if systemd freezes the user session cgroups
first, which freezes the fuse daemon, before invoking the kernel
suspend. The kernel suspend triggers ->write_node() which on fuse issues
a synchronous setattr request, which cannot be processed since the
daemon is frozen. Or if the daemon is buggy and cannot properly complete
writeback, initiating writeback on a dirty folio already under writeback
leads to writeback_get_folio() -> folio_prepare_writeback() ->
unconditional wait on writeback to finish, which will cause a hang).
This commit restores fuse to its prior behavior before tmp folios were
removed, where sync was essentially a no-op.

[1] https://lore.kernel.org/linux-fsdevel/CAJnrk1a-asuvfrbKXbEwwDSctvemF+6zfhdnuzO65Pt8HsFSRw@mail.gmail.com/T/#m632c4648e9cafc4239299887109ebd880ac6c5c1

Fixes: 0c58a97f91 ("fuse: remove tmp folio for writebacks and internal rb tree")
Reported-by: John <therealgraysky@proton.me>
Cc: stable@vger.kernel.org
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Link: https://patch.msgid.link/20260320005145.2483161-2-joannelkoong@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-20 14:18:56 +01:00
Linus Torvalds bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook 69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Linus Torvalds 4b6b432128 Merge tag 'fuse-update-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:

 - Add mechanism for cleaning out unused, stale dentries; controlled via
   a module option (Luis Henriques)

 - Fix various bugs

 - Cleanups

* tag 'fuse-update-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: Uninitialized variable in fuse_epoch_work()
  fuse: fix io-uring list corruption for terminated non-committed requests
  fuse: signal that a fuse inode should exhibit local fs behaviors
  fuse: Always flush the page cache before FOPEN_DIRECT_IO write
  fuse: Invalidate the page cache after FOPEN_DIRECT_IO write
  fuse: rename 'namelen' to 'namesize'
  fuse: use strscpy instead of strcpy
  fuse: refactor fuse_conn_put() to remove negative logic.
  fuse: new work queue to invalidate dentries from old epochs
  fuse: new work queue to periodically invalidate expired dentries
  dcache: export shrink_dentry_list() and add new helper d_dispose_if_unused()
  fuse: add WARN_ON and comment for RCU revalidate
  fuse: Fix whitespace for fuse_uring_args_to_ring() comment
  fuse: missing copy_finish in fuse-over-io-uring argument copies
  fuse: fix readahead reclaim deadlock
2025-12-05 15:25:13 -08:00
Linus Torvalds 9368f0f941 Merge tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs inode updates from Christian Brauner:
 "Features:

   - Hide inode->i_state behind accessors. Open-coded accesses prevent
     asserting they are done correctly. One obvious aspect is locking,
     but significantly more can be checked. For example it can be
     detected when the code is clearing flags which are already missing,
     or is setting flags when it is illegal (e.g., I_FREEING when
     ->i_count > 0)

   - Provide accessors for ->i_state, converts all filesystems using
     coccinelle and manual conversions (btrfs, ceph, smb, f2fs, gfs2,
     overlayfs, nilfs2, xfs), and makes plain ->i_state access fail to
     compile

   - Rework I_NEW handling to operate without fences, simplifying the
     code after the accessor infrastructure is in place

  Cleanups:

   - Move wait_on_inode() from writeback.h to fs.h

   - Spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
     for clarity

   - Cosmetic fixes to LRU handling

   - Push list presence check into inode_io_list_del()

   - Touch up predicts in __d_lookup_rcu()

   - ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage

   - Assert on ->i_count in iput_final()

   - Assert ->i_lock held in __iget()

  Fixes:

   - Add missing fences to I_NEW handling"

* tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (22 commits)
  dcache: touch up predicts in __d_lookup_rcu()
  fs: push list presence check into inode_io_list_del()
  fs: cosmetic fixes to lru handling
  fs: rework I_NEW handling to operate without fences
  fs: make plain ->i_state access fail to compile
  xfs: use the new ->i_state accessors
  nilfs2: use the new ->i_state accessors
  overlayfs: use the new ->i_state accessors
  gfs2: use the new ->i_state accessors
  f2fs: use the new ->i_state accessors
  smb: use the new ->i_state accessors
  ceph: use the new ->i_state accessors
  btrfs: use the new ->i_state accessors
  Manual conversion to use ->i_state accessors of all places not covered by coccinelle
  Coccinelle-based conversion to use ->i_state accessors
  fs: provide accessors for ->i_state
  fs: spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
  fs: move wait_on_inode() from writeback.h to fs.h
  fs: add missing fences to I_NEW handling
  ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage
  ...
2025-12-01 09:02:34 -08:00
Luis HenriquesandMiklos Szeredi b4909ae8d4 fuse: refactor fuse_conn_put() to remove negative logic.
There is no functional change with this patch.  It simply refactors
function fuse_conn_put() to not use negative logic, which makes it more
easier to read.

Signed-off-by: Luis Henriques <luis@igalia.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-11-12 11:45:03 +01:00
Luis HenriquesandMiklos Szeredi 64becd224f fuse: new work queue to invalidate dentries from old epochs
With the infrastructure introduced to periodically invalidate expired
dentries, it is now possible to add an extra work queue to invalidate
dentries when an epoch is incremented.  This work queue will only be
triggered when the 'inval_wq' parameter is set.

Signed-off-by: Luis Henriques <luis@igalia.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-11-12 11:45:03 +01:00
Luis HenriquesandMiklos Szeredi ab84ad5973 fuse: new work queue to periodically invalidate expired dentries
This patch adds the necessary infrastructure to keep track of all dentries
created for FUSE file systems.  A set of rbtrees, protected by hashed
locks, will be used to keep all these dentries sorted by expiry time.

A new module parameter 'inval_wq' is also added.  When set, it will start
a work queue which will periodically invalidate expired dentries.  The
value of this new parameter is the period, in seconds, for this work
queue.  Once this parameter is set, every new dentry will be added to one
of the rbtrees.

When the work queue is executed, it will check all the rbtrees and will
invalidate those dentries that have timed-out.

The work queue period can not be smaller than 5 seconds, but can be
disabled by setting 'inval_wq' to zero (which is the default).

Signed-off-by: Luis Henriques <luis@igalia.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-11-12 11:45:03 +01:00
Joanne KoongandChristian Brauner 93570c652b fuse: remove fc->blkbits workaround for partial writes
Now that fuse is integrated with iomap for read/readahead, we can remove
the workaround that was added in commit bd24d2108e ("fuse: fix fuseblk
i_blkbits for iomap partial writes"), which was previously needed to
avoid a race condition where an iomap partial write may be overwritten
by a read if blocksize < PAGE_SIZE. Now that fuse does iomap
read/readahead, this is protected against since there is granular
uptodate tracking of blocks, which means this workaround can be removed.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Tested-by: syzbot@syzkaller.appspotmail.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-05 12:57:24 +01:00
Mateusz GuzikandChristian Brauner b4dbfd8653 Coccinelle-based conversion to use ->i_state accessors
All places were patched by coccinelle with the default expecting that
->i_lock is held, afterwards entries got fixed up by hand to use
unlocked variants as needed.

The script:
@@
expression inode, flags;
@@

- inode->i_state & flags
+ inode_state_read(inode) & flags

@@
expression inode, flags;
@@

- inode->i_state &= ~flags
+ inode_state_clear(inode, flags)

@@
expression inode, flag1, flag2;
@@

- inode->i_state &= ~flag1 & ~flag2
+ inode_state_clear(inode, flag1 | flag2)

@@
expression inode, flags;
@@

- inode->i_state |= flags
+ inode_state_set(inode, flags)

@@
expression inode, flags;
@@

- inode->i_state = flags
+ inode_state_assign(inode, flags)

@@
expression inode, flags;
@@

- flags = inode->i_state
+ flags = inode_state_read(inode)

@@
expression inode, flags;
@@

- READ_ONCE(inode->i_state) & flags
+ inode_state_read(inode) & flags

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-10-20 20:22:26 +02:00
Linus Torvalds 6238729bfc Merge tag 'fuse-update-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:

 - Extend copy_file_range interface to be fully 64bit capable (Miklos)

 - Add selftest for fusectl (Chen Linxuan)

 - Move fuse docs into a separate directory (Bagas Sanjaya)

 - Allow fuse to enter freezable state in some cases (Sergey
   Senozhatsky)

 - Clean up writeback accounting after removing tmp page copies (Joanne)

 - Optimize virtiofs request handling (Li RongQing)

 - Add synchronous FUSE_INIT support (Miklos)

 - Allow server to request prune of unused inodes (Miklos)

 - Fix deadlock with AIO/sync release (Darrick)

 - Add some prep patches for block/iomap support (Darrick)

 - Misc fixes and cleanups

* tag 'fuse-update-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (26 commits)
  fuse: move CREATE_TRACE_POINTS to a separate file
  fuse: move the backing file idr and code into a new source file
  fuse: enable FUSE_SYNCFS for all fuseblk servers
  fuse: capture the unique id of fuse commands being sent
  fuse: fix livelock in synchronous file put from fuseblk workers
  mm: fix lockdep issues in writeback handling
  fuse: add prune notification
  fuse: remove redundant calls to fuse_copy_finish() in fuse_notify()
  fuse: fix possibly missing fuse_copy_finish() call in fuse_notify()
  fuse: remove FUSE_NOTIFY_CODE_MAX from <uapi/linux/fuse.h>
  fuse: remove fuse_readpages_end() null mapping check
  fuse: fix references to fuse.rst -> fuse/fuse.rst
  fuse: allow synchronous FUSE_INIT
  fuse: zero initialize inode private data
  fuse: remove unused 'inode' parameter in fuse_passthrough_open
  virtio_fs: fix the hash table using in virtio_fs_enqueue_req()
  mm: remove BDI_CAP_WRITEBACK_ACCT
  fuse: use default writeback accounting
  virtio_fs: Remove redundant spinlock in virtio_fs_request_complete()
  fuse: remove unneeded offset assignment when filling write pages
  ...
2025-10-03 12:48:18 -07:00
Linus Torvalds b786405685 Merge tag 'vfs-6.18-rc1.workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs workqueue updates from Christian Brauner:
 "This contains various workqueue changes affecting the filesystem
  layer.

  Currently if a user enqueue a work item using schedule_delayed_work()
  the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
  WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies
  to schedule_work() that is using system_wq and queue_work(), that
  makes use again of WORK_CPU_UNBOUND.

  This replaces the use of system_wq and system_unbound_wq. system_wq is
  a per-CPU workqueue which isn't very obvious from the name and
  system_unbound_wq is to be used when locality is not required.

  So this renames system_wq to system_percpu_wq, and system_unbound_wq
  to system_dfl_wq.

  This also adds a new WQ_PERCPU flag to allow the fs subsystem users to
  explicitly request the use of per-CPU behavior. Both WQ_UNBOUND and
  WQ_PERCPU flags coexist for one release cycle to allow callers to
  transition their calls. WQ_UNBOUND will be removed in a next release
  cycle"

* tag 'vfs-6.18-rc1.workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fs: WQ_PERCPU added to alloc_workqueue users
  fs: replace use of system_wq with system_percpu_wq
  fs: replace use of system_unbound_wq with system_dfl_wq
2025-09-29 10:27:17 -07:00
Linus Torvalds b7ce6fa90f Merge tag 'vfs-6.18-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
 "This contains the usual selections of misc updates for this cycle.

  Features:

   - Add "initramfs_options" parameter to set initramfs mount options.
     This allows to add specific mount options to the rootfs to e.g.,
     limit the memory size

   - Add RWF_NOSIGNAL flag for pwritev2()

     Add RWF_NOSIGNAL flag for pwritev2. This flag prevents the SIGPIPE
     signal from being raised when writing on disconnected pipes or
     sockets. The flag is handled directly by the pipe filesystem and
     converted to the existing MSG_NOSIGNAL flag for sockets

   - Allow to pass pid namespace as procfs mount option

     Ever since the introduction of pid namespaces, procfs has had very
     implicit behaviour surrounding them (the pidns used by a procfs
     mount is auto-selected based on the mounting process's active
     pidns, and the pidns itself is basically hidden once the mount has
     been constructed)

     This implicit behaviour has historically meant that userspace was
     required to do some special dances in order to configure the pidns
     of a procfs mount as desired. Examples include:

     * In order to bypass the mnt_too_revealing() check, Kubernetes
       creates a procfs mount from an empty pidns so that user
       namespaced containers can be nested (without this, the nested
       containers would fail to mount procfs)

       But this requires forking off a helper process because you cannot
       just one-shot this using mount(2)

     * Container runtimes in general need to fork into a container
       before configuring its mounts, which can lead to security issues
       in the case of shared-pidns containers (a privileged process in
       the pidns can interact with your container runtime process)

       While SUID_DUMP_DISABLE and user namespaces make this less of an
       issue, the strict need for this due to a minor uAPI wart is kind
       of unfortunate

       Things would be much easier if there was a way for userspace to
       just specify the pidns they want. So this pull request contains
       changes to implement a new "pidns" argument which can be set
       using fsconfig(2):

           fsconfig(procfd, FSCONFIG_SET_FD, "pidns", NULL, nsfd);
           fsconfig(procfd, FSCONFIG_SET_STRING, "pidns", "/proc/self/ns/pid", 0);

       or classic mount(2) / mount(8):

           // mount -t proc -o pidns=/proc/self/ns/pid proc /tmp/proc
           mount("proc", "/tmp/proc", "proc", MS_..., "pidns=/proc/self/ns/pid");

  Cleanups:

   - Remove the last references to EXPORT_OP_ASYNC_LOCK

   - Make file_remove_privs_flags() static

   - Remove redundant __GFP_NOWARN when GFP_NOWAIT is used

   - Use try_cmpxchg() in start_dir_add()

   - Use try_cmpxchg() in sb_init_done_wq()

   - Replace offsetof() with struct_size() in ioctl_file_dedupe_range()

   - Remove vfs_ioctl() export

   - Replace rwlock() with spinlock in epoll code as rwlock causes
     priority inversion on preempt rt kernels

   - Make ns_entries in fs/proc/namespaces const

   - Use a switch() statement() in init_special_inode() just like we do
     in may_open()

   - Use struct_size() in dir_add() in the initramfs code

   - Use str_plural() in rd_load_image()

   - Replace strcpy() with strscpy() in find_link()

   - Rename generic_delete_inode() to inode_just_drop() and
     generic_drop_inode() to inode_generic_drop()

   - Remove unused arguments from fcntl_{g,s}et_rw_hint()

  Fixes:

   - Document @name parameter for name_contains_dotdot() helper

   - Fix spelling mistake

   - Always return zero from replace_fd() instead of the file descriptor
     number

   - Limit the size for copy_file_range() in compat mode to prevent a
     signed overflow

   - Fix debugfs mount options not being applied

   - Verify the inode mode when loading it from disk in minixfs

   - Verify the inode mode when loading it from disk in cramfs

   - Don't trigger automounts with RESOLVE_NO_XDEV

     If openat2() was called with RESOLVE_NO_XDEV it didn't traverse
     through automounts, but could still trigger them

   - Add FL_RECLAIM flag to show_fl_flags() macro so it appears in
     tracepoints

   - Fix unused variable warning in rd_load_image() on s390

   - Make INITRAMFS_PRESERVE_MTIME depend on BLK_DEV_INITRD

   - Use ns_capable_noaudit() when determining net sysctl permissions

   - Don't call path_put() under namespace semaphore in listmount() and
     statmount()"

* tag 'vfs-6.18-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits)
  fcntl: trim arguments
  listmount: don't call path_put() under namespace semaphore
  statmount: don't call path_put() under namespace semaphore
  pid: use ns_capable_noaudit() when determining net sysctl permissions
  fs: rename generic_delete_inode() and generic_drop_inode()
  init: INITRAMFS_PRESERVE_MTIME should depend on BLK_DEV_INITRD
  initramfs: Replace strcpy() with strscpy() in find_link()
  initrd: Use str_plural() in rd_load_image()
  initramfs: Use struct_size() helper to improve dir_add()
  initrd: Fix unused variable warning in rd_load_image() on s390
  fs: use the switch statement in init_special_inode()
  fs/proc/namespaces: make ns_entries const
  filelock: add FL_RECLAIM to show_fl_flags() macro
  eventpoll: Replace rwlock with spinlock
  selftests/proc: add tests for new pidns APIs
  procfs: add "pidns" mount option
  pidns: move is-ancestor logic to helper
  openat2: don't trigger automounts with RESOLVE_NO_XDEV
  namei: move cross-device check to __traverse_mounts
  namei: remove LOOKUP_NO_XDEV check from handle_mounts
  ...
2025-09-29 09:03:07 -07:00
Darrick J. WongandMiklos Szeredi d3906d8f3c fuse: enable FUSE_SYNCFS for all fuseblk servers
Turn on syncfs for all fuseblk servers so that the ones in the know can
flush cached intermediate data and logs to disk.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-09-23 12:45:25 +02:00
Marco CrivellariandChristian Brauner 4ef64db060 fs: replace use of system_wq with system_percpu_wq
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.

This lack of consistentcy cannot be addressed without refactoring the API.

system_wq is a per-CPU worqueue, yet nothing in its name tells about that
CPU affinity constraint, which is very often not required by users.
Make it clear by adding a system_percpu_wq to all the fs subsystem.

The old wq will be kept for a few release cylces.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/20250916082906.77439-3-marco.crivellari@suse.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-19 16:15:07 +02:00
Mateusz GuzikandChristian Brauner f99b391778 fs: rename generic_delete_inode() and generic_drop_inode()
generic_delete_inode() is rather misleading for what the routine is
doing. inode_just_drop() should be much clearer.

The new naming is inconsistent with generic_drop_inode(), so rename that
one as well with inode_ as the suffix.

No functional changes.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-15 16:09:42 +02:00
Miklos Szeredi 3f29d59e92 fuse: add prune notification
Some fuse servers need to prune their caches, which can only be done if the
kernel's own dentry/inode caches are pruned first to avoid dangling
references.

Add FUSE_NOTIFY_PRUNE, which takes an array of node ID's to try and get rid
of.  Inodes with active references are skipped.

A similar functionality is already provided by FUSE_NOTIFY_INVAL_ENTRY with
the FUSE_EXPIRE_ONLY flag.  Differences in the interface are

FUSE_NOTIFY_INVAL_ENTRY:

  - can only prune one dentry

  - dentry is determined by parent ID and name

  - if inode has multiple aliases (cached hard links), then they would have
    to be invalidated individually to be able to get rid of the inode

FUSE_NOTIFY_PRUNE:

  - can prune multiple inodes

  - inodes determined by their node ID

  - aliases are taken care of automatically

Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2025-09-05 09:11:28 +02:00