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Pull fscrypt updates from Eric Biggers:
"A fix for an issue where CONFIG_FS_ENCRYPTION could be enabled without
some of its dependencies, and a small documentation update"
* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/linux:
fscrypt: mention init_on_free instead of page poisoning
fscrypt: drop obsolete recommendation to enable optimized ChaCha20
Revert "fscrypt: relax Kconfig dependencies for crypto API algorithms"
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Pull fsverity updates from Eric Biggers:
"A fix for an issue where CONFIG_FS_VERITY could be enabled without
some of its dependencies, and a small documentation update"
* tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fsverity/linux:
Revert "fsverity: relax build time dependency on CRYPTO_SHA256"
Documentation: add a usecase for FS_IOC_READ_VERITY_METADATA
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer cleanups from Thomas Gleixner:
"A treewide hrtimer timer cleanup
hrtimers are initialized with hrtimer_init() and a subsequent store to
the callback pointer. This turned out to be suboptimal for the
upcoming Rust integration and is obviously a silly implementation to
begin with.
This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
with hrtimer_setup(T, cb);
The conversion was done with Coccinelle and a few manual fixups.
Once the conversion has completely landed in mainline, hrtimer_init()
will be removed and the hrtimer::function becomes a private member"
* tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
wifi: rt2x00: Switch to use hrtimer_update_function()
io_uring: Use helper function hrtimer_update_function()
serial: xilinx_uartps: Use helper function hrtimer_update_function()
ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup()
RDMA: Switch to use hrtimer_setup()
virtio: mem: Switch to use hrtimer_setup()
drm/vmwgfx: Switch to use hrtimer_setup()
drm/xe/oa: Switch to use hrtimer_setup()
drm/vkms: Switch to use hrtimer_setup()
drm/msm: Switch to use hrtimer_setup()
drm/i915/request: Switch to use hrtimer_setup()
drm/i915/uncore: Switch to use hrtimer_setup()
drm/i915/pmu: Switch to use hrtimer_setup()
drm/i915/perf: Switch to use hrtimer_setup()
drm/i915/gvt: Switch to use hrtimer_setup()
drm/i915/huc: Switch to use hrtimer_setup()
drm/amdgpu: Switch to use hrtimer_setup()
stm class: heartbeat: Switch to use hrtimer_setup()
i2c: Switch to use hrtimer_setup()
iio: Switch to use hrtimer_setup()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core updates from Thomas Gleixner:
- Fix a memory ordering issue in posix-timers
Posix-timer lookup is lockless and reevaluates the timer validity
under the timer lock, but the update which validates the timer is not
protected by the timer lock. That allows the store to be reordered
against the initialization stores, so that the lookup side can
observe a partially initialized timer. That's mostly a theoretical
problem, but incorrect nevertheless.
- Fix a long standing inconsistency of the coarse time getters
The coarse time getters read the base time of the current update
cycle without reading the actual hardware clock. NTP frequency
adjustment can set the base time backwards. The fine grained
interfaces compensate this by reading the clock and applying the new
conversion factor, but the coarse grained time getters use the base
time directly. That allows the user to observe time going backwards.
Cure it by always forwarding base time, when NTP changes the
frequency with an immediate step.
- Rework of posix-timer hashing
The posix-timer hash is not scalable and due to the CRIU timer
restore mechanism prone to massive contention on the global hash
bucket lock.
Replace the global hash lock with a fine grained per bucket locking
scheme to address that.
- Rework the proc/$PID/timers interface.
/proc/$PID/timers is provided for CRIU to be able to restore a timer.
The printout happens with sighand lock held and interrupts disabled.
That's not required as this can be done with RCU protection as well.
- Provide a sane mechanism for CRIU to restore a timer ID
CRIU restores timers by creating and deleting them until the kernel
internal per process ID counter reached the requested ID. That's
horribly slow for sparse timer IDs.
Provide a prctl() which allows CRIU to restore a timer with a given
ID. When enabled the ID pointer is used as input pointer to read the
requested ID from user space. When disabled, the normal allocation
scheme (next ID) is active as before. This is backwards compatible
for both kernel and user space.
- Make hrtimer_update_function() less expensive.
The sanity checks are valuable, but expensive for high frequency
usage in io/uring. Make the debug checks conditional and enable them
only when lockdep is enabled.
- Small updates, cleanups and improvements
* tag 'timers-core-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
selftests/timers: Improve skew_consistency by testing with other clockids
timekeeping: Fix possible inconsistencies in _COARSE clockids
posix-timers: Drop redundant memset() invocation
selftests/timers/posix-timers: Add a test for exact allocation mode
posix-timers: Provide a mechanism to allocate a given timer ID
posix-timers: Dont iterate /proc/$PID/timers with sighand:: Siglock held
posix-timers: Make per process list RCU safe
posix-timers: Avoid false cacheline sharing
posix-timers: Switch to jhash32()
posix-timers: Improve hash table performance
posix-timers: Make signal_struct:: Next_posix_timer_id an atomic_t
posix-timers: Make lock_timer() use guard()
posix-timers: Rework timer removal
posix-timers: Simplify lock/unlock_timer()
posix-timers: Use guards in a few places
posix-timers: Remove SLAB_PANIC from kmem cache
posix-timers: Remove a few paranoid warnings
posix-timers: Cleanup includes
posix-timers: Add cond_resched() to posix_timer_add() search loop
posix-timers: Initialise timer before adding it to the hash table
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Core & fair scheduler changes:
- Cancel the slice protection of the idle entity (Zihan Zhou)
- Reduce the default slice to avoid tasks getting an extra tick
(Zihan Zhou)
- Force propagating min_slice of cfs_rq when {en,de}queue tasks
(Tianchen Ding)
- Refactor can_migrate_task() to elimate looping (I Hsin Cheng)
- Add unlikey branch hints to several system calls (Colin Ian King)
- Optimize current_clr_polling() on certain architectures (Yujun
Dong)
Deadline scheduler: (Juri Lelli)
- Remove redundant dl_clear_root_domain call
- Move dl_rebuild_rd_accounting to cpuset.h
Uclamp:
- Use the uclamp_is_used() helper instead of open-coding it (Xuewen
Yan)
- Optimize sched_uclamp_used static key enabling (Xuewen Yan)
Scheduler topology support: (Juri Lelli)
- Ignore special tasks when rebuilding domains
- Add wrappers for sched_domains_mutex
- Generalize unique visiting of root domains
- Rebuild root domain accounting after every update
- Remove partition_and_rebuild_sched_domains
- Stop exposing partition_sched_domains_locked
RSEQ: (Michael Jeanson)
- Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y
- Fix segfault on registration when rseq_cs is non-zero
- selftests: Add rseq syscall errors test
- selftests: Ensure the rseq ABI TLS is actually 1024 bytes
Membarriers:
- Fix redundant load of membarrier_state (Nysal Jan K.A.)
Scheduler debugging:
- Introduce and use preempt_model_str() (Sebastian Andrzej Siewior)
- Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar)
Fixes and cleanups:
- Always save/restore x86 TSC sched_clock() on suspend/resume
(Guilherme G. Piccoli)
- Misc fixes and cleanups (Thorsten Blum, Juri Lelli, Sebastian
Andrzej Siewior)"
* tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
cpuidle, sched: Use smp_mb__after_atomic() in current_clr_polling()
sched/debug: Remove CONFIG_SCHED_DEBUG
sched/debug: Remove CONFIG_SCHED_DEBUG from self-test config files
sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation
sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional
sched/debug: Make 'const_debug' tunables unconditional __read_mostly
sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE()
rseq/selftests: Fix namespace collision with rseq UAPI header
include/{topology,cpuset}: Move dl_rebuild_rd_accounting to cpuset.h
sched/topology: Stop exposing partition_sched_domains_locked
cgroup/cpuset: Remove partition_and_rebuild_sched_domains
sched/topology: Remove redundant dl_clear_root_domain call
sched/deadline: Rebuild root domain accounting after every update
sched/deadline: Generalize unique visiting of root domains
sched/topology: Wrappers for sched_domains_mutex
sched/deadline: Ignore special tasks when rebuilding domains
tracing: Use preempt_model_str()
xtensa: Rely on generic printing of preemption model
x86: Rely on generic printing of preemption model
s390: Rely on generic printing of preemption model
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull tiny pstore update from Kees Cook:
- pstore: Change kmsg_bytes storage size to u32
* tag 'pstore-v6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
pstore: Change kmsg_bytes storage size to u32
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull lib kunit selftest move from Kees Cook:
"This is a one-off tree to coordinate the move of selftests out of lib/
and into lib/tests/. A separate tree was used for this to keep the
paths sane with all the work in the same place.
- move lib/ selftests into lib/tests/ (Kees Cook, Gabriela
Bittencourt, Luis Felipe Hernandez, Lukas Bulwahn, Tamir
Duberstein)
- lib/math: Add int_log test suite (Bruno Sobreira França)
- lib/math: Add Kunit test suite for gcd() (Yu-Chun Lin)
- lib/tests/kfifo_kunit.c: add tests for the kfifo structure (Diego
Vieira)
- unicode: refactor selftests into KUnit (Gabriela Bittencourt)
- lib/prime_numbers: convert self-test to KUnit (Tamir Duberstein)
- printf: convert self-test to KUnit (Tamir Duberstein)
- scanf: convert self-test to KUnit (Tamir Duberstein)"
* tag 'move-lib-kunit-v6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (21 commits)
scanf: break kunit into test cases
scanf: convert self-test to KUnit
scanf: remove redundant debug logs
scanf: implicate test line in failure messages
printf: implicate test line in failure messages
printf: break kunit into test cases
printf: convert self-test to KUnit
kunit/fortify: Replace "volatile" with OPTIMIZER_HIDE_VAR()
kunit/fortify: Expand testing of __compiletime_strlen()
kunit/stackinit: Use fill byte different from Clang i386 pattern
kunit/overflow: Fix DEFINE_FLEX tests for counted_by
selftests: remove reference to prime_numbers.sh
MAINTAINERS: adjust entries in FORTIFY_SOURCE and KERNEL HARDENING
lib/prime_numbers: convert self-test to KUnit
lib/math: Add Kunit test suite for gcd()
unicode: kunit: change tests filename and path
unicode: kunit: refactor selftest to kunit tests
lib/tests/kfifo_kunit.c: add tests for the kfifo structure
lib: Move KUnit tests into tests/ subdirectory
lib/math: Add int_log test suite
...
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull execve updates from Kees Cook:
- elf: Define and use note name macros (Akihiko Odaki)
- elf: add remaining SHF_ flag macros (Timur Tabi)
- binfmt: Remove loader from linux_binprm struct (Yonatan Goldschmidt)
- binfmt_elf_fdpic: fix variable set but not used warning (sunliming)
* tag 'execve-v6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
binfmt_elf_fdpic: fix variable set but not used warning
elf: add remaining SHF_ flag macros
binfmt: Remove loader from linux_binprm struct
crash: Remove KEXEC_CORE_NOTE_NAME
s390/crash: Use note name macros
crash: Use note name macros
powerpc/crash: Use note name macros
binfmt_elf: Use note name macros
elf: Define note name macros
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs file handling updates from Christian Brauner:
"This contains performance improvements for struct file's new refcount
mechanism and various other performance work:
- The stock kernel transitioning the file to no refs held penalizes
the caller with an extra atomic to block any increments. For cases
where the file is highly likely to be going away this is easily
avoidable.
Add file_ref_put_close() to better handle the common case where
closing a file descriptor also operates on the last reference and
build fput_close_sync() and fput_close() on top of it. This brings
about 1% performance improvement by eliding one atomic in the
common case.
- Predict no error in close() since the vast majority of the time
system call returns 0.
- Reduce the work done in fdget_pos() by predicting that the file was
found and by explicitly comparing the reference count to one and
ignoring the dead zone"
* tag 'vfs-6.15-rc1.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: reduce work in fdget_pos()
fs: use fput_close() in path_openat()
fs: use fput_close() in filp_close()
fs: use fput_close_sync() in close()
file: add fput and file_ref_put routines optimized for use when closing a fd
fs: predict no error in close()
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs orangefs updates from Christian Brauner:
"This contains the work to remove orangefs_writepage() and partially
convert it to folios.
A few regular bugfixes are included as well"
* tag 'vfs-6.15-rc1.orangefs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
orangefs: Convert orangefs_writepages to contain an array of folios
orangefs: Simplify bvec setup in orangefs_writepages_work()
orangefs: Unify error & success paths in orangefs_writepages_work()
orangefs: Pass mapping to orangefs_writepages_work()
orangefs: Convert orangefs_writepage_locked() to take a folio
orangefs: Remove orangefs_writepage()
orangefs: make open_for_read and open_for_write boolean
orangefs: Move s_kmod_keyword_mask_map to orangefs-debugfs.c
orangefs: Do not truncate file size
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs afs updates from Christian Brauner:
"This contains the work for afs for this cycle:
- Fix an occasional hang that's only really encountered when
rmmod'ing the kafs module
- Remove the "-o autocell" mount option. This is obsolete with the
dynamic root and removing it makes the next patch slightly easier
- Change how the dynamic root mount is constructed. Currently, the
root directory is (de)populated when it is (un)mounted if there are
cells already configured and, further, pairs of automount points
have to be created/removed each time a cell is added/deleted
This is changed so that readdir on the root dir lists all the known
cell automount pairs plus the @cell symlinks and the inodes and
dentries are constructed by lookup on demand. This simplifies the
cell management code
- A few improvements to the afs_volume and afs_server tracepoints
- Pass trace info into the afs_lookup_cell() function to allow the
trace log to indicate the purpose of the lookup
- Remove the 'net' parameter from afs_unuse_cell() as it's
superfluous
- In rxrpc, allow a kernel app (such as kafs) to store a word of
information on rxrpc_peer records
- Use the information stored on the rxrpc_peer record to point to the
afs_server record. This allows the server address lookup to be done
away with
- Simplify the afs_server ref/activity accounting to make each one
self-contained and not garbage collected from the cell management
work item
- Simplify the afs_cell ref/activity accounting to make each one of
these also self-contained and not driven by a central management
work item
The current code was intended to make it such that a single timer
for the namespace and one work item per cell could do all the work
required to maintain these records. This, however, made for some
sequencing problems when cleaning up these records. Further, the
attempt to pass refs along with timers and work items made getting
it right rather tricky when the timer or work item already had a
ref attached and now a ref had to be got rid of"
* tag 'vfs-6.15-rc1.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
afs: Simplify cell record handling
afs: Fix afs_server ref accounting
afs: Use the per-peer app data provided by rxrpc
rxrpc: Allow the app to store private data on peer structs
afs: Drop the net parameter from afs_unuse_cell()
afs: Make afs_lookup_cell() take a trace note
afs: Improve server refcount/active count tracing
afs: Improve afs_volume tracing to display a debug ID
afs: Change dynroot to create contents on demand
afs: Remove the "autocell" mount option
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs ceph updates from Christian Brauner:
"This contains the work to remove access to page->index from ceph
and fixes the test failure observed for ceph with generic/421 by
refactoring ceph_writepages_start()"
* tag 'vfs-6.15-rc1.ceph' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fscrypt: Change fscrypt_encrypt_pagecache_blocks() to take a folio
ceph: Fix error handling in fill_readdir_cache()
fs: Remove page_mkwrite_check_truncate()
ceph: Pass a folio to ceph_allocate_page_array()
ceph: Convert ceph_move_dirty_page_in_page_array() to move_dirty_folio_in_page_array()
ceph: Remove uses of page from ceph_process_folio_batch()
ceph: Convert ceph_check_page_before_write() to use a folio
ceph: Convert writepage_nounlock() to write_folio_nounlock()
ceph: Convert ceph_readdir_cache_control to store a folio
ceph: Convert ceph_find_incompatible() to take a folio
ceph: Use a folio in ceph_page_mkwrite()
ceph: Remove ceph_writepage()
ceph: fix generic/421 test failure
ceph: introduce ceph_submit_write() method
ceph: introduce ceph_process_folio_batch() method
ceph: extend ceph_writeback_ctl for ceph_writepages_start() refactoring
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs pagesize updates from Christian Brauner:
"This enables block sizes greater than the page size for block devices.
With this we can start supporting block devices with logical block
sizes larger than 4k.
It also allows to lift the device cache sector size support to 64k.
This allows filesystems which can use larger sector sizes up to 64k to
ensure that the filesystem will not generate writes that are smaller
than the specified sector size"
* tag 'vfs-6.15-rc1.pagesize' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
bdev: add back PAGE_SIZE block size validation for sb_set_blocksize()
bdev: use bdev_io_min() for statx block size
block/bdev: lift block size restrictions to 64k
block/bdev: enable large folio support for large logical block sizes
fs/buffer fs/mpage: remove large folio restriction
fs/mpage: use blocks_per_folio instead of blocks_per_page
fs/mpage: avoid negative shift for large blocksize
fs/buffer: remove batching from async read
fs/buffer: simplify block_read_full_folio() with bh_offset()
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs mount namespace updates from Christian Brauner:
"This expands the ability of anonymous mount namespaces:
- Creating detached mounts from detached mounts
Currently, detached mounts can only be created from attached
mounts. This limitaton prevents various use-cases. For example, the
ability to mount a subdirectory without ever having to make the
whole filesystem visible first.
The current permission modelis:
(1) Check that the caller is privileged over the owning user
namespace of it's current mount namespace.
(2) Check that the caller is located in the mount namespace of the
mount it wants to create a detached copy of.
While it is not strictly necessary to do it this way it is
consistently applied in the new mount api. This model will also be
used when allowing the creation of detached mount from another
detached mount.
The (1) requirement can simply be met by performing the same check
as for the non-detached case, i.e., verify that the caller is
privileged over its current mount namespace.
To meet the (2) requirement it must be possible to infer the origin
mount namespace that the anonymous mount namespace of the detached
mount was created from.
The origin mount namespace of an anonymous mount is the mount
namespace that the mounts that were copied into the anonymous mount
namespace originate from.
In order to check the origin mount namespace of an anonymous mount
namespace the sequence number of the original mount namespace is
recorded in the anonymous mount namespace.
With this in place it is possible to perform an equivalent check
(2') to (2). The origin mount namespace of the anonymous mount
namespace must be the same as the caller's mount namespace. To
establish this the sequence number of the caller's mount namespace
and the origin sequence number of the anonymous mount namespace are
compared.
The caller is always located in a non-anonymous mount namespace
since anonymous mount namespaces cannot be setns()ed into. The
caller's mount namespace will thus always have a valid sequence
number.
The owning namespace of any mount namespace, anonymous or
non-anonymous, can never change. A mount attached to a
non-anonymous mount namespace can never change mount namespace.
If the sequence number of the non-anonymous mount namespace and the
origin sequence number of the anonymous mount namespace match, the
owning namespaces must match as well.
Hence, the capability check on the owning namespace of the caller's
mount namespace ensures that the caller has the ability to copy the
mount tree.
- Allow mount detached mounts on detached mounts
Currently, detached mounts can only be mounted onto attached
mounts. This limitation makes it impossible to assemble a new
private rootfs and move it into place. Instead, a detached tree
must be created, attached, then mounted open and then either moved
or detached again. Lift this restriction.
In order to allow mounting detached mounts onto other detached
mounts the same permission model used for creating detached mounts
from detached mounts can be used (cf. above).
Allowing to mount detached mounts onto detached mounts leaves three
cases to consider:
(1) The source mount is an attached mount and the target mount is
a detached mount. This would be equivalent to moving a mount
between different mount namespaces. A caller could move an
attached mount to a detached mount. The detached mount can now
be freely attached to any mount namespace. This changes the
current delegatioh model significantly for no good reason. So
this will fail.
(2) Anonymous mount namespaces are always attached fully, i.e., it
is not possible to only attach a subtree of an anoymous mount
namespace. This simplifies the implementation and reasoning.
Consequently, if the anonymous mount namespace of the source
detached mount and the target detached mount are the identical
the mount request will fail.
(3) The source mount's anonymous mount namespace is different from
the target mount's anonymous mount namespace.
In this case the source anonymous mount namespace of the
source mount tree must be freed after its mounts have been
moved to the target anonymous mount namespace. The source
anonymous mount namespace must be empty afterwards.
By allowing to mount detached mounts onto detached mounts a caller
may do the following:
fd_tree1 = open_tree(-EBADF, "/mnt", OPEN_TREE_CLONE)
fd_tree2 = open_tree(-EBADF, "/tmp", OPEN_TREE_CLONE)
fd_tree1 and fd_tree2 refer to two different detached mount trees
that belong to two different anonymous mount namespace.
It is important to note that fd_tree1 and fd_tree2 both refer to
the root of their respective anonymous mount namespaces.
By allowing to mount detached mounts onto detached mounts the
caller may now do:
move_mount(fd_tree1, "", fd_tree2, "",
MOVE_MOUNT_F_EMPTY_PATH | MOVE_MOUNT_T_EMPTY_PATH)
This will cause the detached mount referred to by fd_tree1 to be
mounted on top of the detached mount referred to by fd_tree2.
Thus, the detached mount fd_tree1 is moved from its separate
anonymous mount namespace into fd_tree2's anonymous mount
namespace.
It also means that while fd_tree2 continues to refer to the root of
its respective anonymous mount namespace fd_tree1 doesn't anymore.
This has the consequence that only fd_tree2 can be moved to another
anonymous or non-anonymous mount namespace. Moving fd_tree1 will
now fail as fd_tree1 doesn't refer to the root of an anoymous mount
namespace anymore.
Now fd_tree1 and fd_tree2 refer to separate detached mount trees
referring to the same anonymous mount namespace.
This is conceptually fine. The new mount api does allow for this to
happen already via:
mount -t tmpfs tmpfs /mnt
mkdir -p /mnt/A
mount -t tmpfs tmpfs /mnt/A
fd_tree3 = open_tree(-EBADF, "/mnt", OPEN_TREE_CLONE | AT_RECURSIVE)
fd_tree4 = open_tree(-EBADF, "/mnt/A", 0)
Both fd_tree3 and fd_tree4 refer to two different detached mount
trees but both detached mount trees refer to the same anonymous
mount namespace. An as with fd_tree1 and fd_tree2, only fd_tree3
may be moved another mount namespace as fd_tree3 refers to the root
of the anonymous mount namespace just while fd_tree4 doesn't.
However, there's an important difference between the
fd_tree3/fd_tree4 and the fd_tree1/fd_tree2 example.
Closing fd_tree4 and releasing the respective struct file will have
no further effect on fd_tree3's detached mount tree.
However, closing fd_tree3 will cause the mount tree and the
respective anonymous mount namespace to be destroyed causing the
detached mount tree of fd_tree4 to be invalid for further mounting.
By allowing to mount detached mounts on detached mounts as in the
fd_tree1/fd_tree2 example both struct files will affect each other.
Both fd_tree1 and fd_tree2 refer to struct files that have
FMODE_NEED_UNMOUNT set.
To handle this we use the fact that @fd_tree1 will have a parent
mount once it has been attached to @fd_tree2.
When dissolve_on_fput() is called the mount that has been passed in
will refer to the root of the anonymous mount namespace. If it
doesn't it would mean that mounts are leaked. So before allowing to
mount detached mounts onto detached mounts this would be a bug.
Now that detached mounts can be mounted onto detached mounts it
just means that the mount has been attached to another anonymous
mount namespace and thus dissolve_on_fput() must not unmount the
mount tree or free the anonymous mount namespace as the file
referring to the root of the namespace hasn't been closed yet.
If it had been closed yet it would be obvious because the mount
namespace would be NULL, i.e., the @fd_tree1 would have already
been unmounted. If @fd_tree1 hasn't been unmounted yet and has a
parent mount it is safe to skip any cleanup as closing @fd_tree2
will take care of all cleanup operations.
- Allow mount propagation for detached mount trees
In commit ee2e3f50629f ("mount: fix mounting of detached mounts
onto targets that reside on shared mounts") I fixed a bug where
propagating the source mount tree of an anonymous mount namespace
into a target mount tree of a non-anonymous mount namespace could
be used to trigger an integer overflow in the non-anonymous mount
namespace causing any new mounts to fail.
The cause of this was that the propagation algorithm was unable to
recognize mounts from the source mount tree that were already
propagated into the target mount tree and then reappeared as
propagation targets when walking the destination propagation mount
tree.
When fixing this I disabled mount propagation into anonymous mount
namespaces. Make it possible for anonymous mount namespace to
receive mount propagation events correctly. This is now also a
correctness issue now that we allow mounting detached mount trees
onto detached mount trees.
Mark the source anonymous mount namespace with MNTNS_PROPAGATING
indicating that all mounts belonging to this mount namespace are
currently in the process of being propagated and make the
propagation algorithm discard those if they appear as propagation
targets"
* tag 'vfs-6.15-rc1.mount.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (21 commits)
selftests: test subdirectory mounting
selftests: add test for detached mount tree propagation
fs: namespace: fix uninitialized variable use
mount: handle mount propagation for detached mount trees
fs: allow creating detached mounts from fsmount() file descriptors
selftests: seventh test for mounting detached mounts onto detached mounts
selftests: sixth test for mounting detached mounts onto detached mounts
selftests: fifth test for mounting detached mounts onto detached mounts
selftests: fourth test for mounting detached mounts onto detached mounts
selftests: third test for mounting detached mounts onto detached mounts
selftests: second test for mounting detached mounts onto detached mounts
selftests: first test for mounting detached mounts onto detached mounts
fs: mount detached mounts onto detached mounts
fs: support getname_maybe_null() in move_mount()
selftests: create detached mounts from detached mounts
fs: create detached mounts from detached mounts
fs: add may_copy_tree()
fs: add fastpath for dissolve_on_fput()
fs: add assert for move_mount()
fs: add mnt_ns_empty() helper
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs nsfs updates from Christian Brauner:
"This contains non-urgent fixes for nsfs to validate ioctls before
performing any relevant operations.
We alredy did this for a few other filesystems last cycle"
* tag 'vfs-6.15-rc1.nsfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
selftests/nsfs: add ioctl validation tests
nsfs: validate ioctls
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs sysv removal from Christian Brauner:
"This removes the sysv filesystem. We've discussed this various times.
It's time to try"
* tag 'vfs-6.15-rc1.sysv' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
sysv: Remove the filesystem
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|
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs async dir updates from Christian Brauner:
"This contains cleanups that fell out of the work from async directory
handling:
- Change kern_path_locked() and user_path_locked_at() to never return
a negative dentry. This simplifies the usability of these helpers
in various places
- Drop d_exact_alias() from the remaining place in NFS where it is
still used. This also allows us to drop the d_exact_alias() helper
completely
- Drop an unnecessary call to fh_update() from nfsd_create_locked()
- Change i_op->mkdir() to return a struct dentry
Change vfs_mkdir() to return a dentry provided by the filesystems
which is hashed and positive. This allows us to reduce the number
of cases where the resulting dentry is not positive to very few
cases. The code in these places becomes simpler and easier to
understand.
- Repack DENTRY_* and LOOKUP_* flags"
* tag 'vfs-6.15-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
doc: fix inline emphasis warning
VFS: Change vfs_mkdir() to return the dentry.
nfs: change mkdir inode_operation to return alternate dentry if needed.
fuse: return correct dentry for ->mkdir
ceph: return the correct dentry on mkdir
hostfs: store inode in dentry after mkdir if possible.
Change inode_operations.mkdir to return struct dentry *
nfsd: drop fh_update() from S_IFDIR branch of nfsd_create_locked()
nfs/vfs: discard d_exact_alias()
VFS: add common error checks to lookup_one_qstr_excl()
VFS: change kern_path_locked() and user_path_locked_at() to never return negative dentry
VFS: repack LOOKUP_ bit flags.
VFS: repack DENTRY_ flags.
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs overlayfs updates from Christian Brauner:
"Currently overlayfs uses the mounter's credentials for its
override_creds() calls. That provides a consistent permission model.
This patches allows a caller to instruct overlayfs to use its
credentials instead. The caller must be located in the same user
namespace hierarchy as the user namespace the overlayfs instance will
be mounted in. This provides a consistent and simple security model.
With this it is possible to e.g., mount an overlayfs instance where
the mounter must have CAP_SYS_ADMIN but the credentials used for
override_creds() have dropped CAP_SYS_ADMIN. It also allows the usage
of custom fs{g,u}id different from the callers and other tweaks"
* tag 'vfs-6.15-rc1.overlayfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
selftests/ovl: add third selftest for "override_creds"
selftests/ovl: add second selftest for "override_creds"
selftests/filesystems: add utils.{c,h}
selftests/ovl: add first selftest for "override_creds"
ovl: allow to specify override credentials
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|
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs iomap updates from Christian Brauner:
- Allow the filesystem to submit the writeback bios.
- Allow the filsystem to track completions on a per-bio bases
instead of the entire I/O.
- Change writeback_ops so that ->submit_bio can be done by the
filesystem.
- A new ANON_WRITE flag for writes that don't have a block number
assigned to them at the iomap level leaving the filesystem to do
that work in the submission handler.
- Incremental iterator advance
The folio_batch support for zero range where the filesystem provides
a batch of folios to process that might not be logically continguous
requires more flexibility than the current offset based iteration
currently offers.
Update all iomap operations to advance the iterator within the
operation and thus remove the need to advance from the core iomap
iterator.
- Make buffered writes work with RWF_DONTCACHE
If RWF_DONTCACHE is set for a write, mark the folios being written as
uncached. On writeback completion the pages will be dropped.
- Introduce infrastructure for large atomic writes
This will eventually be used by xfs and ext4.
* tag 'vfs-6.15-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (42 commits)
iomap: rework IOMAP atomic flags
iomap: comment on atomic write checks in iomap_dio_bio_iter()
iomap: inline iomap_dio_bio_opflags()
iomap: fix inline data on buffered read
iomap: Lift blocksize restriction on atomic writes
iomap: Support SW-based atomic writes
iomap: Rename IOMAP_ATOMIC -> IOMAP_ATOMIC_HW
xfs: flag as supporting FOP_DONTCACHE
iomap: make buffered writes work with RWF_DONTCACHE
iomap: introduce a full map advance helper
iomap: rename iomap_iter processed field to status
iomap: remove unnecessary advance from iomap_iter()
dax: advance the iomap_iter on pte and pmd faults
dax: advance the iomap_iter on dedupe range
dax: advance the iomap_iter on unshare range
dax: advance the iomap_iter on zero range
dax: push advance down into dax_iomap_iter() for read and write
dax: advance the iomap_iter in the read/write path
iomap: convert misc simple ops to incremental advance
iomap: advance the iter on direct I/O
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs pidfs updates from Christian Brauner:
- Allow retrieving exit information after a process has been reaped
through pidfds via the new PIDFD_INTO_EXIT extension for the
PIDFD_GET_INFO ioctl. Various tools need access to information about
a process/task even after it has already been reaped.
Pidfd polling allows waiting on either task exit or for a task to
have been reaped. The contract for PIDFD_INFO_EXIT is simply that
EPOLLHUP must be observed before exit information can be retrieved,
i.e., exit information is only provided once the task has been reaped
and then can be retrieved as long as the pidfd is open.
- Add PIDFD_SELF_{THREAD,THREAD_GROUP} sentinels allowing userspace to
forgo allocating a file descriptor for their own process. This is
useful in scenarios where users want to act on their own process
through pidfds and is akin to AT_FDCWD.
- Improve premature thread-group leader and subthread exec behavior
when polling on pidfds:
(1) During a multi-threaded exec by a subthread, i.e.,
non-thread-group leader thread, all other threads in the
thread-group including the thread-group leader are killed and the
struct pid of the thread-group leader will be taken over by the
subthread that called exec. IOW, two tasks change their TIDs.
(2) A premature thread-group leader exit means that the thread-group
leader exited before all of the other subthreads in the
thread-group have exited.
Both cases lead to inconsistencies for pidfd polling with
PIDFD_THREAD. Any caller that holds a PIDFD_THREAD pidfd to the
current thread-group leader may or may not see an exit notification
on the file descriptor depending on when poll is performed. If the
poll is performed before the exec of the subthread has concluded an
exit notification is generated for the old thread-group leader. If
the poll is performed after the exec of the subthread has concluded
no exit notification is generated for the old thread-group leader.
The correct behavior is to simply not generate an exit notification
on the struct pid of a subhthread exec because the struct pid is
taken over by the subthread and thus remains alive.
But this is difficult to handle because a thread-group may exit
premature as mentioned in (2). In that case an exit notification is
reliably generated but the subthreads may continue to run for an
indeterminate amount of time and thus also may exec at some point.
After this pull no exit notifications will be generated for a
PIDFD_THREAD pidfd for a thread-group leader until all subthreads
have been reaped. If a subthread should exec before no exit
notification will be generated until that task exits or it creates
subthreads and repeates the cycle.
This means an exit notification indicates the ability for the father
to reap the child.
* tag 'vfs-6.15-rc1.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (25 commits)
selftests/pidfd: third test for multi-threaded exec polling
selftests/pidfd: second test for multi-threaded exec polling
selftests/pidfd: first test for multi-threaded exec polling
pidfs: improve multi-threaded exec and premature thread-group leader exit polling
pidfs: ensure that PIDFS_INFO_EXIT is available
selftests/pidfd: add seventh PIDFD_INFO_EXIT selftest
selftests/pidfd: add sixth PIDFD_INFO_EXIT selftest
selftests/pidfd: add fifth PIDFD_INFO_EXIT selftest
selftests/pidfd: add fourth PIDFD_INFO_EXIT selftest
selftests/pidfd: add third PIDFD_INFO_EXIT selftest
selftests/pidfd: add second PIDFD_INFO_EXIT selftest
selftests/pidfd: add first PIDFD_INFO_EXIT selftest
selftests/pidfd: expand common pidfd header
pidfs/selftests: ensure correct headers for ioctl handling
selftests/pidfd: fix header inclusion
pidfs: allow to retrieve exit information
pidfs: record exit code and cgroupid at exit
pidfs: use private inode slab cache
pidfs: move setting flags into pidfs_alloc_file()
pidfd: rely on automatic cleanup in __pidfd_prepare()
...
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|
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs pipe updates from Christian Brauner:
- Introduce struct file_operations pipeanon_fops
- Don't update {a,c,m}time for anonymous pipes to avoid the performance
costs associated with it
- Change pipe_write() to never add a zero-sized buffer
- Limit the slots in pipe_resize_ring()
- Use pipe_buf() to retrieve the pipe buffer everywhere
- Drop an always true check in anon_pipe_write()
- Cache 2 pages instead of 1
- Avoid spurious calls to prepare_to_wait_event() in ___wait_event()
* tag 'vfs-6.15-rc1.pipe' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs/splice: Use pipe_buf() helper to retrieve pipe buffer
fs/pipe: Use pipe_buf() helper to retrieve pipe buffer
kernel/watch_queue: Use pipe_buf() to retrieve the pipe buffer
fs/pipe: Limit the slots in pipe_resize_ring()
wait: avoid spurious calls to prepare_to_wait_event() in ___wait_event()
pipe: cache 2 pages instead of 1
pipe: drop an always true check in anon_pipe_write()
pipe: change pipe_write() to never add a zero-sized buffer
pipe: don't update {a,c,m}time for anonymous pipes
pipe: introduce struct file_operations pipeanon_fops
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs mount updates from Christian Brauner:
- Mount notifications
The day has come where we finally provide a new api to listen for
mount topology changes outside of /proc/<pid>/mountinfo. A mount
namespace file descriptor can be supplied and registered with
fanotify to listen for mount topology changes.
Currently notifications for mount, umount and moving mounts are
generated. The generated notification record contains the unique
mount id of the mount.
The listmount() and statmount() api can be used to query detailed
information about the mount using the received unique mount id.
This allows userspace to figure out exactly how the mount topology
changed without having to generating diffs of /proc/<pid>/mountinfo
in userspace.
- Support O_PATH file descriptors with FSCONFIG_SET_FD in the new mount
api
- Support detached mounts in overlayfs
Since last cycle we support specifying overlayfs layers via file
descriptors. However, we don't allow detached mounts which means
userspace cannot user file descriptors received via
open_tree(OPEN_TREE_CLONE) and fsmount() directly. They have to
attach them to a mount namespace via move_mount() first.
This is cumbersome and means they have to undo mounts via umount().
Allow them to directly use detached mounts.
- Allow to retrieve idmappings with statmount
Currently it isn't possible to figure out what idmapping has been
attached to an idmapped mount. Add an extension to statmount() which
allows to read the idmapping from the mount.
- Allow creating idmapped mounts from mounts that are already idmapped
So far it isn't possible to allow the creation of idmapped mounts
from already idmapped mounts as this has significant lifetime
implications. Make the creation of idmapped mounts atomic by allow to
pass struct mount_attr together with the open_tree_attr() system call
allowing to solve these issues without complicating VFS lookup in any
way.
The system call has in general the benefit that creating a detached
mount and applying mount attributes to it becomes an atomic operation
for userspace.
- Add a way to query statmount() for supported options
Allow userspace to query which mount information can be retrieved
through statmount().
- Allow superblock owners to force unmount
* tag 'vfs-6.15-rc1.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (21 commits)
umount: Allow superblock owners to force umount
selftests: add tests for mount notification
selinux: add FILE__WATCH_MOUNTNS
samples/vfs: fix printf format string for size_t
fs: allow changing idmappings
fs: add kflags member to struct mount_kattr
fs: add open_tree_attr()
fs: add copy_mount_setattr() helper
fs: add vfs_open_tree() helper
statmount: add a new supported_mask field
samples/vfs: add STATMOUNT_MNT_{G,U}IDMAP
selftests: add tests for using detached mount with overlayfs
samples/vfs: check whether flag was raised
statmount: allow to retrieve idmappings
uidgid: add map_id_range_up()
fs: allow detached mounts in clone_private_mount()
selftests/overlayfs: test specifying layers as O_PATH file descriptors
fs: support O_PATH fds with FSCONFIG_SET_FD
vfs: add notifications for mount attach and detach
fanotify: notify on mount attach and detach
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs eventpoll updates from Christian Brauner:
"This contains a few preparatory changes to eventpoll to allow io_uring
to support epoll"
* tag 'vfs-6.15-rc1.eventpoll' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
eventpoll: add epoll_sendevents() helper
eventpoll: abstract out ep_try_send_events() helper
eventpoll: abstract out parameter sanity checking
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Features:
- Add CONFIG_DEBUG_VFS infrastucture:
- Catch invalid modes in open
- Use the new debug macros in inode_set_cached_link()
- Use debug-only asserts around fd allocation and install
- Place f_ref to 3rd cache line in struct file to resolve false
sharing
Cleanups:
- Start using anon_inode_getfile_fmode() helper in various places
- Don't take f_lock during SEEK_CUR if exclusion is guaranteed by
f_pos_lock
- Add unlikely() to kcmp()
- Remove legacy ->remount_fs method from ecryptfs after port to the
new mount api
- Remove invalidate_inodes() in favour of evict_inodes()
- Simplify ep_busy_loopER by removing unused argument
- Avoid mmap sem relocks when coredumping with many missing pages
- Inline getname()
- Inline new_inode_pseudo() and de-staticize alloc_inode()
- Dodge an atomic in putname if ref == 1
- Consistently deref the files table with rcu_dereference_raw()
- Dedup handling of struct filename init and refcounts bumps
- Use wq_has_sleeper() in end_dir_add()
- Drop the lock trip around I_NEW wake up in evict()
- Load the ->i_sb pointer once in inode_sb_list_{add,del}
- Predict not reaching the limit in alloc_empty_file()
- Tidy up do_sys_openat2() with likely/unlikely
- Call inode_sb_list_add() outside of inode hash lock
- Sort out fd allocation vs dup2 race commentary
- Turn page_offset() into a wrapper around folio_pos()
- Remove locking in exportfs around ->get_parent() call
- try_lookup_one_len() does not need any locks in autofs
- Fix return type of several functions from long to int in open
- Fix return type of several functions from long to int in ioctls
Fixes:
- Fix watch queue accounting mismatch"
* tag 'vfs-6.15-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (30 commits)
fs: sort out fd allocation vs dup2 race commentary, take 2
fs: call inode_sb_list_add() outside of inode hash lock
fs: tidy up do_sys_openat2() with likely/unlikely
fs: predict not reaching the limit in alloc_empty_file()
fs: load the ->i_sb pointer once in inode_sb_list_{add,del}
fs: drop the lock trip around I_NEW wake up in evict()
fs: use wq_has_sleeper() in end_dir_add()
VFS/autofs: try_lookup_one_len() does not need any locks
fs: dedup handling of struct filename init and refcounts bumps
fs: consistently deref the files table with rcu_dereference_raw()
exportfs: remove locking around ->get_parent() call.
fs: use debug-only asserts around fd allocation and install
fs: dodge an atomic in putname if ref == 1
vfs: Remove invalidate_inodes()
ecryptfs: remove NULL remount_fs from super_operations
watch_queue: fix pipe accounting mismatch
fs: place f_ref to 3rd cache line in struct file to resolve false sharing
epoll: simplify ep_busy_loop by removing always 0 argument
fs: Turn page_offset() into a wrapper around folio_pos()
kcmp: improve performance adding an unlikely hint to task comparisons
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs mount API updates from Christian Brauner:
"This converts the remaining pseudo filesystems to the new mount api.
The sysv conversion is a bit gratuitous because we remove sysv in
another pull request. But if we have to revert the removal we at least
will have it converted to the new mount api already"
* tag 'vfs-6.15-rc1.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
sysv: convert sysv to use the new mount api
vfs: remove some unused old mount api code
devtmpfs: replace ->mount with ->get_tree in public instance
vfs: Convert devpts to use the new mount API
pstore: convert to the new mount API
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Pull smb client fix from Steve French:
"smb3 client reconnect fix"
* tag 'v6.14-rc7-smb3-client-fix' of git://git.samba.org/sfrench/cifs-2.6:
smb: client: don't retry IO on failed negprotos with soft mounts
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
"A final set of fixes for this cycle:
VFS:
- Ensure that the stable offset api doesn't return duplicate
directory entries when userspace has to perform the getdents call
multiple times on large directories
afs:
- Prevent invalid pointer dereference during get_link RCU pathwalk
fuse:
- Fix deadlock caused by uninitialized rings when using io_uring with
fuse
- Handle race condition when using io_uring with fuse to prevent NULL
dereference
libnetfs:
- Ensure that invalidate_cache is only called if implemented
- Fix collection of results during pause when collection is
offloaded
- Ensure rolling_buffer_load_from_ra() doesn't clear mark bits
- Make netfs_unbuffered_read() return ssize_t rather than int"
* tag 'vfs-6.14-final.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
libfs: Fix duplicate directory entry in offset_dir_lookup
fuse: fix possible deadlock if rings are never initialized
netfs: Fix netfs_unbuffered_read() to return ssize_t rather than int
netfs: Fix rolling_buffer_load_from_ra() to not clear mark bits
netfs: Call `invalidate_cache` only if implemented
netfs: Fix collection of results during pause when collection offloaded
fuse: fix uring race condition for null dereference of fc
afs: Fix afs_atcell_get_link() to check if ws_cell is unset first
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git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI fixes from Ard Biesheuvel:
"Here's a final batch of EFI fixes for v6.14.
The efivarfs ones are fixes for changes that were made this cycle.
James's fix is somewhat of a band-aid, but it was blessed by the VFS
folks, who are working with James to come up with something better for
the next cycle.
- Avoid physical address 0x0 for random page allocations
- Add correct lockdep annotation when traversing efivarfs on resume
- Avoid NULL mount in kernel_file_open() when traversing efivarfs on
resume"
* tag 'efi-fixes-for-v6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efivarfs: fix NULL dereference on resume
efivarfs: use I_MUTEX_CHILD nested lock to traverse variables on resume
efi/libstub: Avoid physical address 0x0 when doing random allocation
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polling
This is another attempt trying to make pidfd polling for multi-threaded
exec and premature thread-group leader exit consistent.
A quick recap of these two cases:
(1) During a multi-threaded exec by a subthread, i.e., non-thread-group
leader thread, all other threads in the thread-group including the
thread-group leader are killed and the struct pid of the
thread-group leader will be taken over by the subthread that called
exec. IOW, two tasks change their TIDs.
(2) A premature thread-group leader exit means that the thread-group
leader exited before all of the other subthreads in the thread-group
have exited.
Both cases lead to inconsistencies for pidfd polling with PIDFD_THREAD.
Any caller that holds a PIDFD_THREAD pidfd to the current thread-group
leader may or may not see an exit notification on the file descriptor
depending on when poll is performed. If the poll is performed before the
exec of the subthread has concluded an exit notification is generated
for the old thread-group leader. If the poll is performed after the exec
of the subthread has concluded no exit notification is generated for the
old thread-group leader.
The correct behavior would be to simply not generate an exit
notification on the struct pid of a subhthread exec because the struct
pid is taken over by the subthread and thus remains alive.
But this is difficult to handle because a thread-group may exit
prematurely as mentioned in (2). In that case an exit notification is
reliably generated but the subthreads may continue to run for an
indeterminate amount of time and thus also may exec at some point.
So far there was no way to distinguish between (1) and (2) internally.
This tiny series tries to address this problem by discarding
PIDFD_THREAD notification on premature thread-group leader exit.
If that works correctly then no exit notifications are generated for a
PIDFD_THREAD pidfd for a thread-group leader until all subthreads have
been reaped. If a subthread should exec aftewards no exit notification
will be generated until that task exits or it creates subthreads and
repeates the cycle.
Co-Developed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20250320-work-pidfs-thread_group-v4-1-da678ce805bf@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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fd_install() has a questionable comment above it.
While it correctly points out a possible race against dup2(), it states:
> We need to detect this and fput() the struct file we are about to
> overwrite in this case.
>
> It should never happen - if we allow dup2() do it, _really_ bad things
> will follow.
I have difficulty parsing the above. The first sentence would suggest
fd_install() tries to detect and recover from the race (it does not),
the next one claims the race needs to be dealt with (it is, by dup2()).
Given that fd_install() does not suffer the burden, this patch removes
the above and instead expands on the race in dup2() commentary.
While here tidy up the docs around fd_install().
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250320102637.1924183-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Flag IOMAP_ATOMIC_SW is not really required. The idea of having this flag
is that the FS ->iomap_begin callback could check if this flag is set to
decide whether to do a SW (FS-based) atomic write. But the FS can set
which ->iomap_begin callback it wants when deciding to do a FS-based
atomic write.
Furthermore, it was thought that IOMAP_ATOMIC_HW is not a proper name, as
the block driver can use SW-methods to emulate an atomic write. So change
back to IOMAP_ATOMIC.
The ->iomap_begin callback needs though to indicate to iomap core that
REQ_ATOMIC needs to be set, so add IOMAP_F_ATOMIC_BIO for that.
These changes were suggested by Christoph Hellwig and Dave Chinner.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20250320120250.4087011-4-john.g.garry@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Help explain the code.
Also clarify the comment for bio size check.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20250320120250.4087011-3-john.g.garry@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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It is neater to build blk_opf_t fully in one place, so inline
iomap_dio_bio_opflags() in iomap_dio_bio_iter().
Also tidy up the logic in dealing with IOMAP_DIO_CALLER_COMP, in generally
separate the logic in dealing with flags associated with reads and writes.
Originally-from: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20250320120250.4087011-2-john.g.garry@oracle.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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There is an issue in the kernel:
In tmpfs, when using the "ls" command to list the contents
of a directory with a large number of files, glibc performs
the getdents call in multiple rounds. If a concurrent unlink
occurs between these getdents calls, it may lead to duplicate
directory entries in the ls output. One possible reproduction
scenario is as follows:
Create 1026 files and execute ls and rm concurrently:
for i in {1..1026}; do
echo "This is file $i" > /tmp/dir/file$i
done
ls /tmp/dir rm /tmp/dir/file4
->getdents(file1026-file5)
->unlink(file4)
->getdents(file5,file3,file2,file1)
It is expected that the second getdents call to return file3
through file1, but instead it returns an extra file5.
The root cause of this problem is in the offset_dir_lookup
function. It uses mas_find to determine the starting position
for the current getdents call. Since mas_find locates the first
position that is greater than or equal to mas->index, when file4
is deleted, it ends up returning file5.
It can be fixed by replacing mas_find with mas_find_rev, which
finds the first position that is less than or equal to mas->index.
Fixes: b9b588f22a0c ("libfs: Use d_children list to iterate simple_offset directories")
Signed-off-by: Yongjian Sun <sunyongjian1@huawei.com>
Link: https://lore.kernel.org/r/20250320034417.555810-1-sunyongjian@huaweicloud.com
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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As both locks are highly contended during significant inode churn,
holding the inode hash lock while waiting for the sb list lock
exacerbates the problem.
Why moving it out is safe: the inode at hand still has I_NEW set and
anyone who finds it through legitimate means waits for the bit to clear,
by which time inode_sb_list_add() is guaranteed to have finished.
This significantly drops hash lock contention for me when stating 20
separate trees in parallel, each with 1000 directories * 1000 files.
However, no speed up was observed as contention increased on the other
locks, notably dentry LRU.
Even so, removal of the lock ordering will help making this faster
later.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250320004643.1903287-1-mjguzik@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Otherwise gcc 13 generates conditional forward jumps (aka branch
mispredict by default) for build_open_flags() being succesfull.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250320092331.1921700-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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1. predict the file was found
2. explicitly compare the ref to "one", ignoring the dead zone
The latter arguably improves the behavior to begin with. Suppose the
count turned bad -- the previously used ref routine is going to check
for it and return 0, indicating the count does not necessitate taking
->f_pos_lock. But there very well may be several users.
i.e. not paying for special-casing the dead zone improves semantics.
While here spell out each condition in a dedicated if statement. This
has no effect on generated code.
Sizes are as follows (in bytes; gcc 13, x86-64):
stock: 321
likely(): 298
likely()+ref: 280
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250319215801.1870660-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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All the big Linux distros enable CONFIG_SCHED_DEBUG, because
the various features it provides help not just with kernel
development, but with system administration and user-space
software development as well.
Reflect this reality and enable this functionality
unconditionally.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250317104257.3496611-4-mingo@kernel.org
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When we currently create a pidfd we check that the task hasn't been
reaped right before we create the pidfd. But it is of course possible
that by the time we return the pidfd to userspace the task has already
been reaped since we don't check again after having created a dentry for
it.
This was fine until now because that race was meaningless. But now that
we provide PIDFD_INFO_EXIT it is a problem because it is possible that
the kernel returns a reaped pidfd and it depends on the race whether
PIDFD_INFO_EXIT information is available. This depends on if the task
gets reaped before or after a dentry has been attached to struct pid.
Make this consistent and only returned pidfds for reaped tasks if
PIDFD_INFO_EXIT information is available. This is done by performing
another check whether the task has been reaped right after we attached a
dentry to struct pid.
Since pidfs_exit() is called before struct pid's task linkage is removed
the case where the task got reaped but a dentry was already attached to
struct pid and exit information was recorded and published can be
handled correctly. In that case we do return a pidfd for a reaped task
like we would've before.
Link: https://lore.kernel.org/r/20250316-kabel-fehden-66bdb6a83436@brauner
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Eliminates a jump over a call to capable() in the common case.
By default the limit is not even set, in which case the check can't even
fail to begin with. It remains unset at least on Debian and Ubuntu.
For this cases this can probably become a static branch instead.
In the meantime tidy it up.
I note the check separate from the bump makes the entire thing racy.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250319124923.1838719-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Previously, iomap_readpage_iter() returning 0 would break out of the
loops of iomap_readahead_iter(), which is what iomap_read_inline_data()
relies on.
However, commit d9dc477ff6a2 ("iomap: advance the iter directly on
buffered read") changes this behavior without calling
iomap_iter_advance(), which causes EROFS to get stuck in
iomap_readpage_iter().
It seems iomap_iter_advance() cannot be called in
iomap_read_inline_data() because of the iomap_write_begin() path, so
handle this in iomap_readpage_iter() instead.
Reported-and-tested-by: Bo Liu <liubo03@inspur.com>
Fixes: d9dc477ff6a2 ("iomap: advance the iter directly on buffered read")
Cc: Brian Foster <bfoster@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250319085125.4039368-1-hsiangkao@linux.alibaba.com
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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When mounting a user-space filesystem using io_uring, the initialization
of the rings is done separately in the server side. If for some reason
(e.g. a server bug) this step is not performed it will be impossible to
unmount the filesystem if there are already requests waiting.
This issue is easily reproduced with the libfuse passthrough_ll example,
if the queue depth is set to '0' and a request is queued before trying to
unmount the filesystem. When trying to force the unmount, fuse_abort_conn()
will try to wake up all tasks waiting in fc->blocked_waitq, but because the
rings were never initialized, fuse_uring_ready() will never return 'true'.
Fixes: 3393ff964e0f ("fuse: block request allocation until io-uring init is complete")
Signed-off-by: Luis Henriques <luis@igalia.com>
Link: https://lore.kernel.org/r/20250306111218.13734-1-luis@igalia.com
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Bernd Schubert <bschubert@ddn.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Fix netfs_unbuffered_read() to return an ssize_t rather than an int as
netfs_wait_for_read() returns ssize_t and this gets implicitly truncated.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20250314164201.1993231-5-dhowells@redhat.com
Acked-by: "Paulo Alcantara (Red Hat)" <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Viacheslav Dubeyko <slava@dubeyko.com>
cc: Alex Markuze <amarkuze@redhat.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: ceph-devel@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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rolling_buffer_load_from_ra() looms large in the perf report because it
loops around doing an atomic clear for each of the three mark bits per
folio. However, this is both inefficient (it would be better to build a
mask and atomically AND them out) and unnecessary as they shouldn't be set.
Fix this by removing the loop.
Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20250314164201.1993231-4-dhowells@redhat.com
Acked-by: "Paulo Alcantara (Red Hat)" <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: netfs@lists.linux.dev
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Many filesystems such as NFS and Ceph do not implement the
`invalidate_cache` method. On those filesystems, if writing to the
cache (`NETFS_WRITE_TO_CACHE`) fails for some reason, the kernel
crashes like this:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 0 P4D 0
Oops: Oops: 0010 [#1] SMP PTI
CPU: 9 UID: 0 PID: 3380 Comm: kworker/u193:11 Not tainted 6.13.3-cm4all1-hp #437
Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 10/17/2018
Workqueue: events_unbound netfs_write_collection_worker
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffff9b86e2ca7dc0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 7fffffffffffffff
RDX: 0000000000000001 RSI: ffff89259d576a18 RDI: ffff89259d576900
RBP: ffff89259d5769b0 R08: ffff9b86e2ca7d28 R09: 0000000000000002
R10: ffff89258ceaca80 R11: 0000000000000001 R12: 0000000000000020
R13: ffff893d158b9338 R14: ffff89259d576900 R15: ffff89259d5769b0
FS: 0000000000000000(0000) GS:ffff893c9fa40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000054442e003 CR4: 00000000001706f0
Call Trace:
<TASK>
? __die+0x1f/0x60
? page_fault_oops+0x15c/0x460
? try_to_wake_up+0x2d2/0x530
? exc_page_fault+0x5e/0x100
? asm_exc_page_fault+0x22/0x30
netfs_write_collection_worker+0xe9f/0x12b0
? xs_poll_check_readable+0x3f/0x80
? xs_stream_data_receive_workfn+0x8d/0x110
process_one_work+0x134/0x2d0
worker_thread+0x299/0x3a0
? __pfx_worker_thread+0x10/0x10
kthread+0xba/0xe0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x30/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Modules linked in:
CR2: 0000000000000000
This patch adds the missing `NULL` check.
Fixes: 0e0f2dfe880f ("netfs: Dispatch write requests to process a writeback slice")
Fixes: 288ace2f57c9 ("netfs: New writeback implementation")
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20250314164201.1993231-3-dhowells@redhat.com
Acked-by: "Paulo Alcantara (Red Hat)" <pc@manguebit.com>
cc: netfs@lists.linux.dev
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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A netfs read request can run in one of two modes: for synchronous reads
writes, the app thread does the collection of results and for asynchronous
reads, this is offloaded to a worker thread. This is controlled by the
NETFS_RREQ_OFFLOAD_COLLECTION flag.
Now, if a subrequest incurs an error, the NETFS_RREQ_PAUSE flag is set to
stop the issuing loop temporarily from issuing more subrequests until a
retry is successful or the request is abandoned.
When the issuing loop sees NETFS_RREQ_PAUSE, it jumps to
netfs_wait_for_pause() which will wait for the PAUSE flag to be cleared -
and whilst it is waiting, it will call out to the collector as more results
acrue... But this is the wrong thing to do if OFFLOAD_COLLECTION is set as
we can then end up with both the app thread and the work item collecting
results simultaneously.
This manifests itself occasionally when running the generic/323 xfstest
against multichannel cifs as an oops that's a bit random but frequently
involving io_submit() (the test does lots of simultaneous async DIO reads).
Fix this by only doing the collection in netfs_wait_for_pause() if the
NETFS_RREQ_OFFLOAD_COLLECTION is not set.
Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item")
Reported-by: Steve French <stfrench@microsoft.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20250314164201.1993231-2-dhowells@redhat.com
Acked-by: "Paulo Alcantara (Red Hat)" <pc@manguebit.com>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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While this may sound like a pedantic clean up, it does in fact impact
code generation -- the patched add routine is slightly smaller.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250319004635.1820589-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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There is a race condition leading to a kernel crash from a null
dereference when attemping to access fc->lock in
fuse_uring_create_queue(). fc may be NULL in the case where another
thread is creating the uring in fuse_uring_create() and has set
fc->ring but has not yet set ring->fc when fuse_uring_create_queue()
reads ring->fc. There is another race condition as well where in
fuse_uring_register(), ring->nr_queues may still be 0 and not yet set
to the new value when we compare qid against it.
This fix sets fc->ring only after ring->fc and ring->nr_queues have been
set, which guarantees now that ring->fc is a proper pointer when any
queues are created and ring->nr_queues reflects the right number of
queues if ring is not NULL. We must use smp_store_release() and
smp_load_acquire() semantics to ensure the ordering will remain correct
where fc->ring is assigned only after ring->fc and ring->nr_queues have
been assigned.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Link: https://lore.kernel.org/r/20250318003028.3330599-1-joannelkoong@gmail.com
Fixes: 24fe962c86f5 ("fuse: {io-uring} Handle SQEs - register commands")
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Bernd Schubert <bschubert@ddn.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Fix afs_atcell_get_link() to check if the workstation cell is unset before
doing the RCU pathwalk bit where we dereference that.
Fixes: 823869e1e616 ("afs: Fix afs_atcell_get_link() to handle RCU pathwalk")
Reported-by: syzbot+76a6f18e3af82e84f264@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/2481796.1742296819@warthog.procyon.org.uk
Tested-by: syzbot+76a6f18e3af82e84f264@syzkaller.appspotmail.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Loosen the permission check on forced umount to allow users holding
CAP_SYS_ADMIN privileges in namespaces that are privileged with respect
to the userns that originally mounted the filesystem.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Link: https://lore.kernel.org/r/12f212d4ef983714d065a6bb372fbb378753bf4c.1742315194.git.trond.myklebust@hammerspace.com
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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