| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: zoned: fix deadlock waiting for ticket during data relocation
When performing data relocation on a zoned filesystem, BTRFS can deadlock
in handle_reserve_tickets(). The relocation process is waiting on a space
reservation ticket that can never be fulfilled, because the relocation
itself is the operation responsible for freeing up that space.
Fix this by introducing a new flush state,
BTRFS_RESERVE_FLUSH_ZONED_RELOCATION, specifically for data chunk
allocation during zoned relocation. Like
BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE, this state uses
priority_reclaim_data_space() instead of the normal flushing path, which
avoids re-entering the relocation code and breaking the deadlock cycle.
In btrfs_alloc_data_chunk_ondemand(), select this new flush state when the
inode belongs to a data relocation root on a zoned filesystem. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix deadlock cloning inline extent when using flushoncommit
In commit b48c980b6a7e ("btrfs: fix deadlock between reflink and
transaction commit when using flushoncommit") a deadlock was fixed
between reflinks and transaction commits when the fs is mounted with the
flushoncommit option. This happened when we had to copy an inline extent's
data to the destination file. However the issue was fixed only for the
case where the destination offset is 0, it missed the case when the offset
is greater than zero.
Fix this by ensuring we get i_size update whenever we copied an inline
extent's data into the destination file.
Syzbot reported this with the following trace:
INFO: task kworker/u8:3:57 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3 state:D stack:21600 pid:57 tgid:57 ppid:2 task_flags:0x4208160 flags:0x00080000
Workqueue: writeback wb_workfn (flush-btrfs-129)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
wait_extent_bit fs/btrfs/extent-io-tree.c:905 [inline]
btrfs_lock_extent_bits+0x59c/0x700 fs/btrfs/extent-io-tree.c:2008
btrfs_lock_extent fs/btrfs/extent-io-tree.h:152 [inline]
btrfs_invalidate_folio+0x440/0xc00 fs/btrfs/inode.c:7718
extent_writepage fs/btrfs/extent_io.c:1848 [inline]
extent_write_cache_pages fs/btrfs/extent_io.c:2552 [inline]
btrfs_writepages+0x12f3/0x2410 fs/btrfs/extent_io.c:2684
do_writepages+0x32e/0x550 mm/page-writeback.c:2571
__writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056
wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241
wb_do_writeback fs/fs-writeback.c:2388 [inline]
wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2428
process_one_work+0x98b/0x1630 kernel/workqueue.c:3318
process_scheduled_works kernel/workqueue.c:3401 [inline]
worker_thread+0xb49/0x1140 kernel/workqueue.c:3482
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
INFO: task syz.0.145:8523 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.145 state:D stack:22752 pid:8523 tgid:8522 ppid:5850 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
__writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2847
try_to_writeback_inodes_sb+0x9a/0xc0 fs/fs-writeback.c:2895
btrfs_start_delalloc_flush fs/btrfs/transaction.c:2182 [inline]
btrfs_commit_transaction+0x813/0x2fc0 fs/btrfs/transaction.c:2371
btrfs_sync_file+0xdf4/0x1230 fs/btrfs/file.c:1822
generic_write_sync include/linux/fs.h:2663 [inline]
btrfs_do_write_iter+0x6a9/0x840 fs/btrfs/file.c:1473
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x629/0xba0 fs/read_write.c:688
ksys_write+0x156/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a0bdece59
RSP: 002b:00007f5a0b446028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5a0c065fa0 RCX: 00007f5a0bdece59
RDX: 000000000000029f RSI: 0000200000
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Take mmap_lock in zap_pages()
zap_vma_range() requires the owning mm's mmap_lock to be held.
Taking mmap_read_lock under arena->lock would AB-BA against
arena_vm_close() and arena_map_mmap(), both of which run with
mmap_write_lock held and then acquire arena->lock. Instead drop
arena->lock, mmget_not_zero() the vma's mm, take mmap_read_lock, and
re-resolve the vma via find_vma() since it may have been unmapped or
replaced while waiting.
Track processed vmls with a per-call generation in vml->zap_gen and
serialize zap_pages() callers with a new arena->zap_mutex so
concurrent callers on different uaddr ranges do not mark each other's
vmls processed before the zap is done. |
| In the Linux kernel, the following vulnerability has been resolved:
media: uvcvideo: Fix deadlock if uvc_status_stop is called from async_ctrl.work
If a UVC camera has an asynchronous control, uvc_status_stop may be
called from async_ctrl.work:
uvc_ctrl_status_event_work()
uvc_ctrl_status_event()
uvc_ctrl_clear_handle()
uvc_pm_put()
uvc_status_put()
uvc_status_stop()
cancel_work_sync()
This will cause a deadlock, since cancel_work_sync will wait for
uvc_ctrl_status_event_work to complete before returning.
Fix this by returning early from uvc_status_stop if we are currently in
the work function. flush_status now remains false until uvc_status_start
is called again, ensuring that uvc_ctrl_status_event_work won't resubmit
the URB. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: mpi3mr: Fix potential deadlock in mpi3mr_fault_uevent_emit
mpi3mr_fault_uevent_emit() runs from the fault watchdog and reset paths
where host I/O may already be blocked. GFP_KERNEL allocations here, both
the local kzalloc_obj() and the ones inside kobject_uevent_env() itself,
can trigger reclaim that waits on that blocked I/O and deadlock.
Use memalloc_noio_save()/restore() to cover the whole call instead of
just the local allocation. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: zoned: fix deadlock between metadata writeback and transaction commit
When writing out metadata extent buffers in a zoned filesystem,
btree_writepages() holds fs_info->zoned_meta_io_lock across the whole
writeback loop, including the call to btrfs_check_meta_write_pointer() ->
check_bg_is_active().
For the tree-log block group, check_bg_is_active() may fail to activate
the zone and fall back to btrfs_zone_finish_one_bg() to free an active
zone. That path waits for the running transaction to commit while still
holding zoned_meta_io_lock, but the committer needs that same lock to
write out the tree extents, so the two tasks deadlock:
Task A (kworker, metadata writeback) Task B (fsstress, transaction commit)
------------------------------------ -------------------------------------
wb_workfn() btrfs_commit_transaction(T)
btree_writepages() btrfs_write_and_wait_transaction()
btrfs_zoned_meta_io_lock() btrfs_write_marked_extents()
btrfs_check_meta_write_pointer() btree_writepages()
check_bg_is_active() [treelog_bg] btrfs_zoned_meta_io_lock()
btrfs_zone_finish_one_bg() <blocks on zoned_meta_io_lock,
btrfs_zone_finish() held by Task A>
do_zone_finish()
btrfs_inc_block_group_ro()
btrfs_wait_for_commit()
<blocks waiting for commit
of transaction T, done by
Task B>
The sibling branch in check_bg_is_active() already drops zoned_meta_io_lock
around do_zone_finish() for this exact reason. Do the same in the tree-log
branch: release the lock around btrfs_zone_finish_one_bg() and re-acquire
it afterwards. The lock only protects fs_info->active_{meta,system}_bg,
which this branch does not touch, and ctx->zoned_bg keeps a reference to
the block group across the unlock, so nothing is lost while the lock
is dropped.
This hang occasionally reproduces with fstests generic/475 on a zoned
btrfs filesystem. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: idxd: fix fdev setup failure cleanup in idxd_cdev_open()
The failed_dev_add and failed_dev_name paths drop the file-device
reference while wq->wq_lock is still held. If put_device(fdev) drops the
last reference, idxd_file_dev_release() runs synchronously and tries to
take wq->wq_lock again, deadlocking.
Those paths also fall through into the later ctx cleanup labels even
though idxd_file_dev_release() owns that cleanup and frees ctx. This can
make idxd_xa_pasid_remove(ctx) and kfree(ctx) operate on a freed context.
Move idxd_wq_get() before file-device setup can fail, since the release
callback always calls idxd_wq_put(). Then unlock wq->wq_lock before
put_device(fdev) and return directly from the file-device setup failure
path, leaving ctx cleanup to the release callback. |
| In the Linux kernel, the following vulnerability has been resolved:
qede: sync udp_tunnel ports outside qede_lock in the recovery path
A TX timeout on a qede NIC that has VXLAN/GENEVE tunnel ports
configured wedges the rtnetlink control plane of the whole machine:
NETDEV WATCHDOG: ens6f1 (qede): transmit queue 2 timed out 10226 ms
[qede_tx_timeout:586(ens6f1)]TX timeout on queue 2!
[qede_recovery_handler:2665(ens6f0)]Starting a recovery process
The recovery path deadlocks on the driver's own mutex:
qede_sp_task
rtnl_lock()
mutex_lock(&edev->qede_lock) <- taken
qede_recovery_handler
qede_load
udp_tunnel_nic_reset_ntf
__udp_tunnel_nic_device_sync
info->sync_table == qede_udp_tunnel_sync
mutex_lock(&edev->qede_lock) <- same task: deadlock
The mutex is not recursive, so the kworker blocks on itself with
rtnl_lock held, and neither lock is ever released. Every task that
calls rtnl_lock() afterwards (ip, ovs-vswitchd, lldpad, IPv6
addrconf, sshd) blocks forever while the node still answers ping.
In a vmcore from an affected production node rtnl_mutex.owner
decodes to the very kworker blocked at the innermost mutex_lock()
above.
Re-sync the tunnel ports from qede_sp_task() after the internal lock
is dropped, still under rtnl_lock as the udp_tunnel API requires.
This mirrors qede_open(), which calls udp_tunnel_nic_reset_ntf()
under rtnl without the internal lock.
qede_recovery_handler() now returns whether it has successfully
reloaded an open device, and the caller re-syncs the ports only in
that case. This keeps the old gating exactly: a device that was down
or a failed recovery returns false, as those paths never reached the
udp_tunnel_nic_reset_ntf() call before either.
This was the only user of the qede_lock()/qede_unlock() helpers, so
remove them. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: libsas: Fix HA resume deadlock and hisi_sas disk-wake race
Commit fbefe22811c3 ("scsi: libsas: Don't always drain event workqueue
for HA resume") introduced sas_resume_ha_no_sync() to avoid a deadlock:
the PHYE_RESUME_TIMEOUT handler, running on the HA event workqueue,
calls sas_deform_port() -> sas_destruct_devices(), which removes SCSI
devices and waits for the host to become runtime-active. But the host
cannot resume until sas_resume_ha() -> sas_drain_work() returns, and the
drain is blocked on that very handler.
However skipping the drain reintroduces a race: hisi_sas returns from
resume before all PHY UP work and libsas discovery work finish. The
controller may then autosuspend while disks are still waking up. The
disks issue IO to a suspended controller, the IO fails, and the disks
get disabled.
Fix the deadlock at its source by moving the PHYE_RESUME_TIMEOUT
notification to after sas_drain_work(). By then the host resume is about
to complete, so device removal through device_link no longer blocks on
the resume and the cycle is broken.
With the deadlock gone, restore sas_resume_ha() (the draining variant)
in hisi_sas and remove sas_resume_ha_no_sync().
The reorder is safe for the other libsas consumers (isci, pm8001,
aic94xx, mvsas). During suspend, sas_suspend_devices() calls
sas_notify_lldd_dev_gone() for each device, which sets dev->lldd_dev to
NULL. When scsi_unblock_requests re-enables I/O in resume, any I/O to a
timed-out phy's disk is immediately rejected by the LLDD before reaching
hardware: isci returns SAS_DEVICE_UNKNOWN (mapped to DID_BAD_TARGET),
and pm8001 returns SAS_PHY_DOWN (mapped to DID_NO_CONNECT). Both
complete directly via scsi_done() without entering SCSI EH. This is
identical in both the old and new ordering since lldd_dev_gone runs
during suspend, before resume. The reorder only affects when the
PHYE_RESUME_TIMEOUT handler runs (synchronized by sas_drain_work()
vs. asynchronous after resume returns), not whether I/O can reach the
device. aic94xx and mvsas do not register any PM ops and never reach
this code path. |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: skip extent mft records in writeback to prevent deadlock
This patch fixes the ABBA deadlock between extent_lock and extent
mrec_lock triggered by xfstests generic/113, that occurs since the commit
6994acf33bae ("ntfs: use base mft_no when looking up base inode for
extent record").
Path A (inode writeback):
VFS writeback
-> ntfs_write_inode()
-> __ntfs_write_inode()
-> mutex_lock(&ni->extent_lock)
-> mutex_lock(&tni->mrec_lock)
Path B (MFT folio writeback):
VFS writeback of $MFT dirty folios
-> ntfs_mft_writepages()
-> ntfs_write_mft_block()
-> ntfs_may_write_mft_record()
-> holds one extent mrec_lock from a previous iteration
-> tries to acquire another base inode extent_lock
By removing all extent_lock and extent mrec_lock acquisition from the MFT
folio writeback path, the ABBA lock ordering is eliminated:
Path A: __ntfs_write_inode(): extent_lock -> mrec_lock
Path B (removed): ntfs_write_mft_block(): mrec_lock -> extent_lock
Path B is always redundant for extent records because:
1. mark_mft_record_dirty(ext_ni) does NOT dirty the MFT folio.
It only sets NInoDirty(ext_ni) and marks the base VFS inode dirty
via __mark_inode_dirty(I_DIRTY_DATASYNC), which triggers Path A.
Therefore, normal extent modifications never create a situation where
the MFT folio is dirty and Path B is not scheduled.
2. The MFT folio only gets dirtied via ntfs_mft_mark_dirty() inside
ntfs_mft_record_alloc(). But all identified callers in attrib.c
(ntfs_attr_add, ntfs_attr_record_move_away,
ntfs_attr_make_non_resident, ntfs_attr_record_resize) follow through
with mark_mft_record_dirty(), which triggers Path A to write the
complete record.
3. ntfs_evict_big_inode() calls ntfs_commit_inode() before freeing extent
inodes, ensuring all dirty extents are flushed via Path A before the
base inode leaves the icache. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Prevent PM resume deadlock in hwctx_sync_debug_bo()
amdxdna_hwctx_sync_debug_bo() invokes the hardware hwctx_sync_debug_bo()
callback while holding xdna->dev_lock.
The callback may call amdxdna_cmd_submit(), which in turn calls
amdxdna_pm_resume_get(). If the device is suspended,
amdxdna_pm_resume_get() may synchronously execute amdxdna_pm_resume(),
which also acquires xdna->dev_lock, resulting in a deadlock.
Avoid the deadlock by calling amdxdna_pm_resume_get() before holding
xdna->dev_lock in both amdxdna_hwctx_sync_debug_bo() and
amdxdna_drm_config_hwctx_ioctl() |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: avoid heap allocation for free-cluster readahead state
get_nr_free_clusters() allocates a temporary file_ra_state before it
publishes the precomputed free cluster count, sets NVolFreeClusterKnown(),
and wakes vol->free_waitq. If that allocation fails, the worker returns
without setting the flag or waking waiters, so callers waiting for the free
count can block indefinitely.
The readahead state is only used synchronously while scanning the bitmap.
Keep it on the stack and pass it by address to the readahead helper. This
eliminates the early allocation failure path instead of adding a special
case that publishes a conservative count and wakes the waitqueue.
Zero-initialize the on-stack state because file_ra_state_init() only sets
ra_pages and prev_pos.
Apply the same treatment to __get_nr_free_mft_records(), which scans the
MFT bitmap with the same short-lived readahead state. |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: fail attrlist updates when the superblock is inactive
generic_shutdown_super() clears SB_ACTIVE before evicting cached inodes.
If eviction selects the fake inode for a base inode's unnamed
$ATTRIBUTE_LIST attribute, ntfs_evict_big_inode() drops the fake inode's
reference on the base inode while the fake inode is still hashed and marked
I_FREEING.
That iput can synchronously write back the base inode. The writeback path
may update mapping pairs and call ntfs_attrlist_update(), which
unconditionally calls ntfs_attr_iget() for the same $ATTRIBUTE_LIST fake
inode. VFS then finds the I_FREEING inode and waits for eviction to finish,
but the current task is still inside that eviction path, causing a
self-deadlock in find_inode().
Fix this by mirroring the teardown guard used by __ntfs_write_inode():
once SB_ACTIVE has been cleared, do not try to iget the attribute-list
fake inode. Return -EIO so teardown aborts the update instead of waiting on
the inode it is evicting. |
| In the Linux kernel, the following vulnerability has been resolved:
dm-integrity: fix a bug if the bio is out of limits
If dm_integrity_check_limits fails, the code would exit with
DM_MAPIO_KILL. However, the range would be already locked at this point,
and it wouldn't be unlocked, resulting in a deadlock. Let's move the
limit check up, so that when it exits, no resources are leaked. |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: fix mrec_lock ABBA deadlock in rename
ntfs_file_fsync(), ntfs_dir_fsync() and __ntfs_write_inode() lock an
inode's mrec_lock before taking the mrec_lock of its parent directory.
ntfs_rename() takes old_ni->mrec_lock and old_dir_ni->mrec_lock
before taking new_ni->mrec_lock for an existing target, or
new_dir_ni->mrec_lock for a cross-directory rename.
This can deadlock when ntfs_file_fsync() or __ntfs_write_inode() holds
the target inode, or when ntfs_dir_fsync() holds a child target
directory, while rename() holds the parent directory and waits for the
target.
Fix this by locking the existing target inode before taking any parent
directory mrec_lock. For cross-directory renames where the target parent
is a descendant of the source parent, lock the target parent before the
source parent so the directory order matches the child-to-parent order used
by ntfs_file_fsync(), ntfs_dir_fsync(), and __ntfs_write_inode(). |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid1,raid10: fix error-path detection with md_cloned_bio()
Detect the error path using md_cloned_bio() instead of relying
on r1_bio in raid1 or r10_bio->read_slot in raid10, which may be
NULL or -1 after splitting and resubmitting a failed bio.
As a result, the error path may not be recognized and memory
allocations can incorrectly use GFP_NOIO instead of
(GFP_NOIO | __GFP_HIGH), which can lead to a deadlock under
memory pressure. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid1,raid10: fix deadlock in read error recovery path
raid1d and raid10d may resubmit a split md cloned bio while handling
a read error. In this case, resubmitting the bio can lead to a deadlock
if the array is suspended before md_handle_request() acquires an
active_io reference via percpu_ref_tryget_live().
Since the cloned bio already holds an active_io reference,
trying to acquire another reference via percpu_ref_tryget_live()
can lead to a deadlock while the array is suspended.
Fix this by using percpu_ref_get() for md cloned bios. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix NMI/tracepoint re-entry deadlock on lru locks
NMI and tracepoint BPF programs can re-enter the per-CPU or global
LRU lock that bpf_lru_pop_free()/push_free() already hold on the
same CPU, AA-deadlocking. Lockdep reports "inconsistent
{INITIAL USE} -> {IN-NMI}" on &l->lock (syzbot c69a0a2c816716f1e0d5)
and "possible recursive locking detected" on &loc_l->lock (syzbot
18b26edb69b2e19f3b33).
Prior trylock and rqspinlock based fixes (see links) were nacked
because compromised on reliability.
This patch converts every LRU lock site to rqspinlock_t and adds a
recovery path for some failure windows to avoid node leaks.
Failure recovery:
- *_pop_free top-level: return NULL; prealloc_lru_pop() already
treats that as no-free-element (-ENOMEM).
- Cross-CPU steal: skip the victim's locked loc_l, try next CPU.
- Post-steal local lock fail: publish stolen node to lockless
per-CPU free_llist; next pop on this CPU picks it up.
- push_free fail: mark node pending_free=1. __local_list_flush(),
__local_list_pop_pending() reclaim the node from pending_list.
__bpf_lru_list_shrink_inactive() reclaims the node from inactive
list. Nodes from active list are reclaimed by __bpf_lru_list_shrink()
or after __bpf_lru_list_rotate_active() demotes it to the inactive. |
| In the Linux kernel, the following vulnerability has been resolved:
firmware_loader: Fix recursive lock in device_cache_fw_images()
A recursive locking deadlock can occur in the firmware loader's power
management notification handler.
During system suspend or hibernation preparation, fw_pm_notify() calls
device_cache_fw_images(). This function acquires fw_lock to set the
firmware cache state to FW_LOADER_START_CACHE and then iterates over all
devices using dpm_for_each_dev() while still holding the lock.
For each device, dev_cache_fw_image() schedules asynchronous work to cache
the firmware. If memory allocation for the async work entry fails (e.g., in
out-of-memory conditions), async_schedule_node_domain() falls back to
executing the work function synchronously in the current thread.
The synchronous execution path (__async_dev_cache_fw_image() ->
cache_firmware() -> request_firmware() -> assign_fw()) attempts to acquire
fw_lock again. Since the current thread already holds fw_lock, this results
in a recursive locking deadlock.
Fix this by releasing fw_lock immediately after updating the cache state
and before calling dpm_for_each_dev(). The lock is only needed to protect
the state update. Concurrent firmware requests will correctly see the
FW_LOADER_START_CACHE state and use the piggyback mechanism, which is
independently protected by its own fwc->name_lock. |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: avoid self-deadlock during inode eviction
An attribute-list update performed while allocating clusters can drop the
last reference to the temporary attribute inode. Evicting that inode
drops its reference to the base inode and can invoke ntfs_drop_big_inode()
for the base inode from within the base inode's own writeback path.
If the base inode is unlinked, ntfs_drop_big_inode() calls
truncate_setsize(), which waits for the inode's folio writeback to
complete. The same writeback worker is responsible for completing that
writeback, so it waits for itself indefinitely.
Prevent this self-deadlock by grabbing a reference to the base inode at the
beginning of ntfs_writepages() and releasing it at the end of the function.
This defers eviction until all bios have been submitted, allowing the wait
for folio writeback to complete safely. |