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v7.4-rc1
513 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Josef Bacik
|
aa6439028d
|
writeback: don't kick a missing wb for dontcache writes
With CONFIG_CGROUP_WRITEBACK, inode->i_wb stays NULL until the inode is
dirtied for the first time (folio_account_dirtied(), __mark_inode_dirty()
or wbc_attach_fdatawrite_inode() attach it). generic_write_sync() calls
filemap_dontcache_kick_writeback() for every IOCB_DONTCACHE write,
including O_DIRECT ones, which never dirty the page cache. The function
then passes the NULL returned by unlocked_inode_to_wb_begin() to
wb_has_dirty_io():
fd = open("/dev/ram0", O_WRONLY | O_DIRECT);
pwritev2(fd, &iov, 1, 0, RWF_DONTCACHE);
BUG: KASAN: null-ptr-deref in filemap_dontcache_kick_writeback+0xec
Oops: general protection fault, probably for non-canonical address
RIP: 0010:filemap_dontcache_kick_writeback+0xfd/0x7a0
The task dies inside rcu_read_lock(). blkdev_write_iter() gets there for
any block device whose page cache has not been dirtied yet.
nfs_file_direct_write() calls generic_write_sync() the same way.
An inode without a wb has never had dirty pages, so there is nothing to
flush: skip the kick.
Fixes:
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||
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Liz Fong-Jones
|
90c9661246
|
writeback: keep cleanup_offline_cgwb()'s scan out of syncs
On a filesystem mounted with lazytime, sync() and syncfs() can return without persisting timestamp updates of inodes attached to a dying cgroup wb, so a crash after the sync loses them. File data and sizes are not affected. Since commit |
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|
Christian Brauner
|
46e66d41fa
|
Merge patch series "writeback: fix timestamp and dirty-state handling in wb switches"
Julian Sun <sunjunchao@bytedance.com> says: This series fixes two issues when moving inodes between writeback structures: 1. Update dirtied_when rather than dirtied_time_when when inserting an inode at the newest end of the target dirty list. This maintains the list ordering without resetting the lazytime expiration timestamp. 2. Clear the source wb's dirty-I/O state and bandwidth contribution when inode migration leaves its dirty-I/O lists empty. * patches from https://patch.msgid.link/20261016115230.3640770-1-sunjunchao@bytedance.com: writeback: clear old wb dirty state after inode switches writeback: reset dirtied_when when switching wbs Link: https://patch.msgid.link/20261016115230.3640770-1-sunjunchao@bytedance.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> |
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Julian Sun
|
a396fe9f74
|
writeback: clear old wb dirty state after inode switches
Switching an inode to another wb updates the target wb's dirty-I/O state,
but no longer checks whether the source wb's dirty-I/O lists became empty.
The check was lost when inode_io_list_del_locked(inode, old_wb) was
removed to support tracking clean attached inodes.
If the last dirty inode is moved, WB_has_dirty_io remains set on the old
wb and its bandwidth contribution remains in bdi->tot_write_bandwidth.
This can keep an empty wb scheduled for periodic writeback and overstate
the total bandwidth used to distribute writeback work.
Call wb_io_lists_depopulated() on the old wb after the batch of inode
switches, while its list_lock is still held. This clears the flag and
removes the bandwidth contribution if its dirty-I/O lists are empty.
Fixes:
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Julian Sun
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13b9a606dd
|
writeback: reset dirtied_when when switching wbs
When switching a dirty inode to another wb, inode_do_switch_wbs() puts
it at the newest end of the target b_dirty list instead of searching
for its sorted position. This requires updating dirtied_when, which
move_expired_inodes() uses to decide where to stop scanning.
However, the switch updates dirtied_time_when instead. This leaves
b_dirty out of order and can make the scan stop before reaching older
inodes. It also resets the lazytime expiration timestamp, potentially
delaying timestamp writeback.
Update dirtied_when instead, preserving both the constant-time insertion
and the lazytime expiration timestamp. Correct the field name in the
comment and document the distinction between the two inode timestamps.
Fixes:
|
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Linus Torvalds
|
7ed37e9d5c |
vfs-7.4-rc1.misc
Please consider pulling these changes from the signed vfs-7.4-rc1.misc tag.
Thanks!
Christian
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Merge tag 'vfs-7.4-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Fixes:
- aio: a keyed poll completion on an epoll instance could recurse
into the same epoll waitqueue lock when the result eventfd is
watched by that very instance. An unprivileged process could make a
CPU spin on the recursive lock. eventfd-backed poll completions are
always deferred now.
- fsnotify_inoderemove() is only called once the inode is really
dead, no nlink and no aliases, and open_by_handle_at() can't add an
alias to a dead inode anymore. The race could crash fsnotify or
lose inode mark notifications.
- devtmpfs: the conversion of the public instance to ->get_tree()
broke reconfiguring the shared superblock's options on later mounts
which made the boot time defaults permanent. A reconfigure context
is kept in fc->fs_private so the parse ops can forward options to
the underlying filesystem.
- ufs truncated the 64-bit directory size to an unsigned int in
ufs_last_byte(). A crafted image with a 4 GiB directory produced an
out-of-folio read in ufs_find_entry() and, with
CONFIG_UFS_FS_WRITE, a write into an adjacent page.
- devpts rejects max=0 instead of silently lifting the per-instance
pty limit. The value wrapped into ida_alloc_max() and became
unlimited.
- fs_pin publishes pins with the rcu list helpers so the kill paths
reading the lists under rcu see the initialization.
- dentry_kill() reports a Tasks-RCU quiescent state. Its
cond_resched() is the only reschedule point on the dentry teardown
path and cond_resched() isn't a quiescent state for Tasks-RCU, so
Meta kept seeing rcu_tasks stalls in btrfs subvolume deletion.
- writeback sizes foreign flushes by the target wb's dirty pages
instead of the memcg-wide count which over or undersized a single
bdi flush.
- nfsd READ emitted two fsnotify access events on the iterator path
since vfs_iocb_iter_read() already sends one. A READ on a krb5i or
krb5p mount showed up twice in inotify.
- pipe and splice pass a poll key when waking readers and writers so
epoll, poll() and select() waiters only wake for the event they
asked for.
- the iso8859-14 Unicode to charset tables had page01 duplicated as
page1e so 29 code points mapped to the wrong bytes and 22 that
aren't in the charset were accepted.
- orangefs doesn't wait for an unmount service operation that never
returns on system shutdown and uses ssize_t for strscpy() errors.
- __register_chrdev() checks the kobject_set_name() return value.
- selftest fixes: the openat2 tests hardcoded O_LARGEFILE to 0x8000
which is O_NOFOLLOW on powerpc, resolve_test makes /tmp a
mountpoint so RESOLVE_NO_XDEV has a boundary to trip over,
file_stressor moves into its own directory with a 30 minute
timeout, the kernfs listxattr test skips when SELinux exposes
security.selinux, the namespaces active reference tests wait for
the thread via a PIDFD_THREAD pidfd since pthread_join() returns
before exit_nsproxy_namespaces(), the idmapped_tmpfile test chowns
its directory into the mapped range, the clone3 CLONE_CLEAR_SIGHAND
test adds CLONE_VM so it fails for the intended reason, the pidfd
PPID error message prints the values it compares and fscontext_ns
gets a .gitignore.
Cleanups:
- vmcore prints the release of the crashed kernel from the VMCOREINFO
note so a kdump that dies before the dump lands still says which
kernel it was for.
- initramfs allocates hardlink hash entries with the validated cpio
name length instead of PATH_MAX, which put every entry in
kmalloc-8k.
- the unused dax_layout_busy_page() is removed,
dax_layout_busy_page_range() becomes static and dax_folio_init()
drops a redundant list initialization.
- vfs_empty_path() is removed, it has had no callers since
getname_maybe_null().
- comment and documentation fixes in aio, bpf_fs_kfuncs,
fs-writeback, inode, read_write, squashfs and the vfs.rst copy of
struct file_system_type"
* tag 'vfs-7.4-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits)
selftests/filesystems: Fix idmapped_tmpfile layer dir ownership
selftests/namespaces: Wait for thread exit via pidfd in active-ref tests
writeback: size foreign flushes by target wb dirty pages
initramfs: Reduce hardlink hash allocation sizes
fs: remove unused vfs_empty_path()
dcache: report a Tasks-RCU quiescent state in dentry_kill()
vmcore: report the release of the crashed kernel
splice: pass a poll key when waking pipe readers and writers
pipe: pass a poll key when waking writers after a resize
orangefs: use ssize_t instead of size_t for error codes...
orangefs_super: don't wait on service operation on system shutdown.
docs/vfs: Fix the struct file_system_type copy
nls: fix the Unicode to charset tables of iso8859-14
selftests/filesystems/openat2: make /tmp a mountpoint inside private namespace
selftests/filesystems/openat2: fix O_LARGEFILE definitions for non-arm64 architectures
fs: fix misleading comments in read_write.c
squashfs: fix inode number description in documentation
fs: fix typos in comments
fs/dax: Make dax_layout_busy_page_range() static
fs/dax: Remove unused dax_layout_busy_page()
...
|
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|
Xin Yin
|
168a8c1315
|
writeback: size foreign flushes by target wb dirty pages
Foreign dirty tracking records the bdi and wb memcg IDs of recently
dirtied foreign inodes. When the source memcg needs foreign writeback,
mem_cgroup_flush_foreign() queues WB_REASON_FOREIGN_FLUSH to the
recorded target bdi_writeback.
cgroup_writeback_by_id() currently sizes this best-effort work from the
target memcg's NR_FILE_DIRTY counter. The work is scoped to one target
wb, so a memcg-wide dirty count can over-size a single-bdi flush when
the target memcg has dirty pages on other devices. It can also under-size
the flush when the target wb has dirty pages charged to other memcgs.
Over-sizing keeps the target wb busy longer and can delay later
writeback work. Under-sizing can finish before enough pages are written
back for the source memcg.
Use the target wb's WB_RECLAIMABLE counter and keep the existing 25%
headroom. This keeps the budget aligned with the writeback object being
queued.
Fixes:
|
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Patrick Lu (Anthropic)
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f6988c9067
|
writeback: bound cleanup_offline_cgwb() rescans by rotating scanned inodes
cleanup_offline_cgwb() prepares at most WB_MAX_INODES_PER_ISW inodes
per call and is called again until the dying wb is drained, but every
call walks wb->b_attached and then wb->b_dirty_time from the same end.
Inodes already prepared (they stay on the list with I_WB_SWITCH set
until the switch worker runs) and inodes that cannot be switched
(I_FREEING, I_WILL_FREE, !SB_ACTIVE, DAX, already on the target wb)
stay where they are, so each pass rescans a growing run of them under
wb->list_lock and a full drain is quadratic in the number of inodes on
the list. With ~17M inodes attached to one dying cgwb we saw this end
in soft lockups, with CPUs reported stuck for 21-48s.
Walk both lists from the oldest end and move every scanned inode to
the newest end, so the next pass starts where the previous one stopped
and the drain becomes linear. b_attached is unordered, so nobody sees
the reorder there. b_dirty_time is ordered by dirtied_when, but the
oldest unscanned inode stays at the end move_expired_inodes() picks
from, sync takes the whole list regardless of order, and prepared
inodes leave the list as soon as the switch work runs and get a new
dirtied_time_when on the new wb anyway, so the only inodes left out of
order are the ones that can never switch (DAX), and only on the dying
wb.
Fixes:
|
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Hemanth Selam
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21a62663d4
|
fs: fix typos in comments
Fix typos in comments, reported by scripts/checkpatch.pl using the misspelling list in scripts/spelling.txt. Only touches comments, no code changes. Signed-off-by: Hemanth Selam <hemanth.selam@gmail.com> Link: https://patch.msgid.link/20260907063252.21433-1-hemanth.selam@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> |
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Manush Prajwal
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270b35c987
|
fs: fix comment typo in fs-writeback.c
Fix "paramters" -> "parameters" in the foreign-inode-detection comment above wb_wait_for_completion(). No functional change. Signed-off-by: Manush Prajwal <manushprajwal555@gmail.com> Link: https://patch.msgid.link/20260813093431.410-1-manushprajwal555@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> |
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Linus Torvalds
|
55ab7e1422 |
for-7.3/block-20260819
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Merge tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull block updates from Jens Axboe:
- NVMe updates via Keith:
- Enable Clang context analysis for the nvme host driver, adding
context annotations across core, fabrics, rdma, tcp and pci
- nvmet reservation state exposed through a new namespace-level
debugfs directory, plus ABI documentation for the host sysfs and
target configfs interfaces
- nvme-tcp host memory disclosure fixes on the read path: reject a
read that transferred too few bytes, don't accept C2HData based
on blk_rq_payload_bytes() alone, and fix the R2T case for a read
command
- Parallelize nvme-rdma I/O queue allocation and startup (Surabhi)
- Apple nvme fixes and quirks: page aligned admin queue buffers,
destroy the admin queue on removal, and various DMA/NVMMU
correctness fixes
- A large pile of nvmet and host fixes for out-of-bounds reads,
refcount/resource leaks, and NULL derefs across auth, zns,
passthru, pci-epf, rdma and configfs
- Various other fixes and cleanups
- MD updates via Yu Kuai:
- llbitmap reshape support, the large series wiring exact bitmap
mapping and reshape lifecycle through raid5 and raid10, growing
the page cache in place, and remapping checkpointed bits as
reshape progresses
- raid5 fixes for lockless max_nr_stripes and recovery_offset
accesses, a reshape deadlock with more failed devices than max
degraded, and bitmap batch counter consistency
- Atomic write handling for raid1/raid10, and removal of the
REQ_NOWAIT support from raid1/10/456
- raid5-ppl use-after-free fix in ppl_do_flush()
- A batch of smaller fixes across md core and the bitmap code
- s390/dasd ESE full-track write support and the surrounding
infrastructure, plus enabling CONTEXT_ANALYSIS for s390/block
- RWF_DONTCACHE support for block devices, built on new task-context
bio completion infrastructure, and wiring it up for the iomap and
buffer dropbehind writeback paths
- Async io_uring zone reset all, plus zone management command cleanups
allowing REQ_NOWAIT and tightening conventional zone rejection
- Block integrity refactoring: lift BIP_CHECK_FLAGS to the shared
header, handle nogenerate/noverify properly in fs-integrity, and drop
the blk-integrity.h include from bdev.c
- Split out a new blk_plug.h header
- ublk improvements: add UBLK_F_IO_DESC_SIZE, split request validation
from io_desc init, reject non-power-of-2 zone sizes in SET_PARAMS,
and a series of hardening fixes around map/unmap and auto buf reg
- null_blk cleanups and configfs serialization fixes
- nbd queue freeze removal on the setup paths, and a new
pre_defined_connections module parameter for pre-created devices
- blk-cgroup fixes for the race between policy activation and blkg
destruction, and accounting per-cpu stats over possible CPUs across
blk-stat, iolatency, iocost and kyber
- Various dio fixes: leak on metadata mapping error, validate user
space vectors during extraction, and set dma_alignment from the
backing file for loop and zloop direct I/O
- bio cleanups
- Various other fixes and cleanups all over
* tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (241 commits)
nbd: add pre_defined_connections module parameter for pre-created devices
nbd: remove queue freeze for newly created nbd from netlink path
nbd: factor out a nbd_genl_foreach_sock
nbd: skip queue freeze when setting size at device startup
nbd: remove queue freeze in nbd_add_socket
nbd: clear queue limits on disconnect
nbd: disallow NBD_SET_SOCK on an active device
nbd: simplify find_fallback() by removing redundant logic
blk-mq: add missing call to srcu_barrier() in blk_mq_free_tag_set()
block: mtip32xx: synchronize ioctls with device removal
ublk: avoid teardown retry loop on xarray allocation failure
null_blk: fix UBSAN shift-out-of-bounds when zone_size is 0 or overflows
block: don't include blk-integrity.h in bdev.c
xfs: avoid double deferrals for RWF_DONTCACHE writes
loop: Fix recently introduced lock inversion
block: set QUEUE_FLAG_DYING unconditionally in blk_mark_disk_dead()
swim3: Add missing MODULE_DESCRIPTION
selftests: ublk: add SET_PARAMS validation test
selftests: ublk: add helper for SET_PARAMS
ublk: reject non-power-of-2 zone sizes in SET_PARAMS
...
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Christoph Hellwig
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758b86f7bc |
block: split out a new blk_plug.h header
blkdev.h gets included in various places outside the block layer just for struct blk_plug and related plugging functions. Split blk_plug into a separate helper to reduce the amount of code that needs to get rebuilt when blkdev.h changes and to slightly reduce compile times. In io_uring this requires pulling in a few other headers explicitly that previously were implicitly included through blkdev.h. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner (Amutable) <brauner@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://patch.msgid.link/20260804125524.740996-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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Christian Brauner
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974d0be0cb
|
writeback: Export __inode_attach_wb()
Commit |
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Jan Kara
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c474bc56b6
|
fs: Provide way for filesystem to wait for metadata writeback
Currently, inode and in general metadata writeback is handled in a lazy manner. When inode is dirty, __writeback_single_inode() calls .write_inode method which for lots of filesystems just copies inode metadata into the underlying block buffer. Writeback of other metadata associated with the inode (as well as buffers underlying inodes) is usually handled completely separately and implicitely during writeback of block device inode. This is good for efficiency of WB_SYNC_NONE writeback or sync(2). However it becomes problematic for situations where we want to make sure inode and its metadata is really persistent on disk. fsync(2) is the most pronounced example of this and thus we have grown a special file operation and various helper functions to assist with this task. However fsync(2) is not the only case, For example directories with DIRSYNC flag need similar functionality and current use of sync_inode_metadata() for this task in filesystems generally misses writeout of necessary metadata. Furthermore even fsync(2) handling as implemented by simple_fsync() or similar helpers is racy and can fail to properly persist the inode. The problem is that WB_SYNC_NONE writeback can copy inode metadata into underlying buffer and clean inode dirty bits. Following fsync(2) will see inode is clean and will fail to make sure underlying buffer is written out. When multiple fsync(2) calls race, there's also another type of race involving mmb_fsync(). There the problem is buffers already submitted to the disk are no longer tracked in the mmb list and so racing mmb_sync() can return before all of the IO completes. Provide a new inode state bit I_METADATA_WRITEBACK tracking whether writeback of inode related metadata may be needed for successful data integrity sync and if this bit is set __writeback_single_inode() for data integrity writeback will call new superblock operation .sync_inode_metadata whose task is to make sure all metadata associated with the inode (including the inode itself) is properly persisted. This will allow filesystems to address the data integrity issues described above and at the same time somewhat simplify our fsync implementations. Issues with racing fsync(2) calls will be addressed by synchronization on I_SYNC inode state which is set while calling .sync_inode_metadata, issues with missed inode buffer writeback are fixed by filesystems looking up corresponding buffer head and writing it out if needed. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260727104923.3828017-25-jack@suse.cz Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> |
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Jeff Layton
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e1bf796284
|
mm: kick writeback flusher for IOCB_DONTCACHE with targeted dirty tracking
The IOCB_DONTCACHE writeback path in generic_write_sync() calls
filemap_flush_range() on every write, submitting writeback inline in
the writer's context. Perf lock contention profiling shows the
performance problem is not lock contention but the writeback submission
work itself — walking the page tree and submitting I/O blocks the writer
for milliseconds, inflating p99.9 latency from 23ms (buffered) to 93ms
(dontcache).
Replace the inline filemap_flush_range() call with a flusher kick that
drains dirty pages in the background. This moves writeback submission
completely off the writer's hot path.
To avoid flushing unrelated buffered dirty data, add a dedicated
WB_start_dontcache bit and wb_check_start_dontcache() handler that uses
the per-wb WB_DONTCACHE_DIRTY counter to determine how many pages to
write back. The flusher writes back that many pages from the oldest dirty
inodes (not restricted to dontcache-specific inodes). This helps
preserve I/O batching while limiting the scope of expedited writeback.
Like WB_start_all, the WB_start_dontcache bit coalesces multiple
DONTCACHE writes into a single flusher wakeup without per-write
allocations. Use test_and_clear_bit to atomically consume the kick
request before reading the dirty counter and starting writeback, so that
concurrent DONTCACHE writes during writeback can re-set the bit and
schedule a follow-up flusher run.
Read the dirty counter with wb_stat_sum() (aggregating per-CPU batches)
rather than wb_stat() (which reads only the global counter) to ensure
small writes below the percpu batch threshold are visible to the flusher.
In filemap_dontcache_kick_writeback(), set the WB_start_dontcache bit
inside the unlocked_inode_to_wb_begin/end section for correct cgroup
writeback domain targeting, but defer the wb_wakeup() call until after
the section ends, since wb_wakeup() uses spin_unlock_irq() which would
unconditionally re-enable interrupts while the i_pages xa_lock may still
be held under irqsave during a cgroup writeback switch. Pin the wb with
wb_get() inside the RCU critical section before calling wb_wakeup()
outside it, since cgroup bdi_writeback structures are RCU-freed and the
wb pointer could become invalid after unlocked_inode_to_wb_end() drops
the RCU read lock.
Also add WB_REASON_DONTCACHE as a new writeback reason for tracing
visibility.
dontcache-bench results (same host, T6F_SKL_1920GBF, 251 GiB RAM,
xfs on NVMe, fio io_uring):
Buffered and direct I/O paths are unaffected by this patchset. All
improvements are confined to the dontcache path:
Single-stream throughput (MB/s):
Before After Change
seq-write/dontcache 298 897 +201%
rand-write/dontcache 131 236 +80%
Tail latency improvements (seq-write/dontcache):
p99: 135,266 us -> 23,986 us (-82%)
p99.9: 8,925,479 us -> 28,443 us (-99.7%)
Multi-writer (4 jobs, sequential write):
Before After Change
dontcache aggregate (MB/s) 2,529 4,532 +79%
dontcache p99 (us) 8,553 1,002 -88%
dontcache p99.9 (us) 109,314 1,057 -99%
Dontcache multi-writer throughput now matches buffered (4,532 vs
4,616 MB/s).
32-file write (Axboe test):
Before After Change
dontcache aggregate (MB/s) 1,548 3,499 +126%
dontcache p99 (us) 10,170 602 -94%
Peak dirty pages (MB) 1,837 213 -88%
Dontcache now reaches 81% of buffered throughput (was 35%).
Competing writers (dontcache vs buffered, separate files):
Before After
buffered writer 868 433 MB/s
dontcache writer 415 433 MB/s
Aggregate 1,284 866 MB/s
Previously the buffered writer starved the dontcache writer 2:1.
With per-bdi_writeback tracking, both writers now receive equal
bandwidth. The aggregate matches the buffered-vs-buffered baseline
(863 MB/s), indicating fair sharing regardless of I/O mode.
The dontcache writer's p99.9 latency collapsed from 119 ms to
33 ms (-73%), eliminating the severe periodic stalls seen in the
baseline. Both writers now share identical latency profiles,
matching the buffered-vs-buffered pattern.
The per-bdi_writeback dirty tracking dramatically reduces peak dirty
pages in dontcache workloads, with the 32-file test dropping from
1.8 GB to 213 MB. Dontcache sequential write throughput triples and
multi-writer throughput reaches parity with buffered I/O, with tail
latencies collapsing by 1-2 orders of magnitude.
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260511-dontcache-v7-3-2848ddce8090@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
||
|
Jeff Layton
|
88d6f128d0
|
mm: track DONTCACHE dirty pages per bdi_writeback
Add a per-wb WB_DONTCACHE_DIRTY counter that tracks the number of dirty pages with the dropbehind flag set (i.e., pages dirtied via RWF_DONTCACHE writes). Increment the counter alongside WB_RECLAIMABLE in folio_account_dirtied() when the folio has the dropbehind flag set, and decrement it in folio_clear_dirty_for_io() and folio_account_cleaned(). Also decrement it when a non-DONTCACHE lookup atomically clears the dropbehind flag on a dirty folio in __filemap_get_folio_mpol(), using folio_test_clear_dropbehind() to prevent concurrent lookups from double-decrementing the counter, and guarding the decrement with mapping_can_writeback() to match the increment path. Transfer the counter alongside WB_RECLAIMABLE in inode_do_switch_wbs() so that the stat is properly migrated when an inode switches cgroup writeback domains. The counter will be used by the writeback flusher to determine how many pages to write back when expediting writeback for IOCB_DONTCACHE writes, without flushing the entire BDI's dirty pages. Suggested-by: Jan Kara <jack@suse.cz> Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260511-dontcache-v7-2-2848ddce8090@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> |
||
|
Baokun Li
|
31c1d19ead
|
writeback: use a per-sb counter to drain inode wb switches at umount
Tracking in-flight inode wb switches with a single global counter
(isw_nr_in_flight) plus a synchronize_rcu() based wait in
cgroup_writeback_umount() forces every umount to take a global hit
whenever any other superblock on the system has wb switches in flight,
even if the superblock being unmounted has none of its own.
Replace the global synchronize_rcu()/flush_workqueue() pair with a
per-sb counter, s_isw_nr_in_flight, plus three small helpers:
- cgroup_writeback_pin(sb) - increment counter
- cgroup_writeback_unpin(sb) - decrement and wake drainer if last
- cgroup_writeback_drain(sb) - wait for counter to reach zero
The wiring is:
- inode_prepare_wbs_switch() pins before checking SB_ACTIVE and
grabbing the inode; failure paths unpin before returning. A
lockless SB_ACTIVE check at the top of the function lets us skip
the atomic_inc/smp_mb dance once SB_ACTIVE has been cleared (it
is monotonic and never set back).
- process_inode_switch_wbs() unpins after the matching iput().
- cgroup_writeback_umount() drains the per-sb counter via
wait_var_event().
The smp_mb() pair between inode_prepare_wbs_switch() and
cgroup_writeback_umount() keeps the SB_ACTIVE / counter ordering:
either the umounter sees a non-zero counter and waits, or the
switcher sees SB_ACTIVE cleared and aborts before grabbing the
inode.
The global isw_nr_in_flight is left in place, since it is still used
to throttle in-flight switches via WB_FRN_MAX_IN_FLIGHT.
The rcu_read_lock() extension in inode_switch_wbs() and
cleanup_offline_cgwb() that the race fix added is no longer needed
and is reverted; the synchronize_rcu() that the race fix added to
cgroup_writeback_umount() is dropped as well.
The following numbers were measured on a 16 vCPU QEMU guest with 4
background superblocks each churning "create memcg -> write 1 MiB ->
rmdir memcg" to keep the global isw_nr_in_flight non-zero. Latencies
are wall-clock around umount(8); only the target sb's umount is
measured.
Target sb runs its own cgwb churn:
p50 p95 p99 max
global synchronize_rcu() 67.6 ms 88.3 ms 88.3 ms 96.8 ms
per-sb counter (this) 7.9 ms 10.0 ms 10.0 ms 10.1 ms
Idle target umount latency under cross-sb cgwb-switch pressure:
p50 p95 p99 max
global synchronize_rcu() 62.7 ms 95.4 ms 108.1 ms 108.6 ms
per-sb counter (this) 5.3 ms 6.9 ms 7.4 ms 7.4 ms
no-pressure baseline 4.9 ms 5.9 ms 6.3 ms 6.7 ms
8 concurrent umounts of idle sbs under the same pressure:
p50 p95 max
global synchronize_rcu() 61.3 ms 99.5 ms 113.7 ms
per-sb counter (this) 8.1 ms 9.1 ms 9.5 ms
In-kernel cgroup_writeback_umount() time across the same run
(bpftrace, ~340 calls covering all scenarios):
global synchronize_rcu() 12371 ms total (~36 ms / call)
per-sb counter (this) 1.37 ms total ( ~4 us / call)
Suggested-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/177910456953.488929.2169908940676707307.b4-review@b4
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260521095016.2791354-4-libaokun@linux.alibaba.com
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
||
|
Baokun Li
|
e90a6d668e
|
writeback: drop now-unnecessary rcu_barrier() in cgroup_writeback_umount()
Commit |
||
|
Baokun Li
|
cba38ec4cb
|
writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs()
When a container exits, the following BUG_ON() is occasionally triggered: ================================================================== VFS: Busy inodes after unmount of sdb (ext4) ------------[ cut here ]------------ kernel BUG at fs/super.c:695! CPU: 3 PID: 6 Comm: containerd-shim Tainted: G OE K 6.6 #1 pstate: 63400009 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : generic_shutdown_super+0xf0/0x100 lr : generic_shutdown_super+0xf0/0x100 Call trace: generic_shutdown_super+0xf0/0x100 kill_block_super+0x20/0x48 ext4_kill_sb+0x28/0x60 deactivate_locked_super+0x54/0x130 deactivate_super+0x84/0xa0 cleanup_mnt+0xa4/0x140 __cleanup_mnt+0x18/0x28 task_work_run+0x78/0xe0 do_notify_resume+0x204/0x240 ================================================================== The root cause is a race between cgroup_writeback_umount() and inode_switch_wbs()/cleanup_offline_cgwb(). There is a window between inode_prepare_wbs_switch() returning true and the subsequent wb_queue_isw() call. Following is the process that triggers the issue: CPU A (umount) | CPU B (writeback) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ inode_switch_wbs/cleanup_offline_cgwb atomic_inc(&isw_nr_in_flight) inode_prepare_wbs_switch -> passes SB_ACTIVE check __iget(inode) generic_shutdown_super sb->s_flags &= ~SB_ACTIVE cgroup_writeback_umount(sb) smp_mb() atomic_read(&isw_nr_in_flight) rcu_barrier() -> no pending RCU callbacks flush_workqueue(isw_wq) -> nothing queued, returns evict_inodes(sb) -> Inode skipped as isw still holds a ref. sop->put_super(sb) /* destroys percpu counters */ -> VFS: Busy inodes after unmount! wb_queue_isw() queue_work(isw_wq, ...) /* later in work function */ inode_switch_wbs_work_fn process_inode_switch_wbs iput() -> evict percpu_counter_dec() // UAF! Fix this by extending the RCU read-side critical section in inode_switch_wbs() and cleanup_offline_cgwb() to cover from inode_prepare_wbs_switch() through wb_queue_isw(). Since there is no sleep in this window, rcu_read_lock() can be used. Then add a synchronize_rcu() in cgroup_writeback_umount() before the existing rcu_barrier(), so that all in-flight switchers that have passed the SB_ACTIVE check have completed queue_work() before flush_workqueue() is called. The existing rcu_barrier() is intentionally retained so this fix can be backported unchanged to stable kernels (5.10.y, 6.6.y, ...) that still queue switches via queue_rcu_work(). It is a no-op on current mainline (since commit |
||
|
Linus Torvalds
|
dd6c438c3e |
vfs-7.1-rc1.fixes
Please consider pulling these changes from the signed vfs-7.1-rc1.fixes tag.
Thanks!
Christian
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Merge tag 'vfs-7.1-rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- eventpoll: fix ep_remove() UAF and follow-up cleanup
- fs: aio: set VMA_DONTCOPY_BIT in mmap to fix NULL-pointer-dereference
error
- writeback: Fix use after free in inode_switch_wbs_work_fn()
- fuse: reject oversized dirents in page cache
- fs: aio: reject partial mremap to avoid Null-pointer-dereference
error
- nstree: fix func. parameter kernel-doc warnings
- fs: Handle multiply claimed blocks more gracefully with mmb
* tag 'vfs-7.1-rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
eventpoll: drop vestigial epi->dying flag
eventpoll: drop dead bool return from ep_remove_epi()
eventpoll: refresh eventpoll_release() fast-path comment
eventpoll: move f_lock acquisition into ep_remove_file()
eventpoll: fix ep_remove struct eventpoll / struct file UAF
eventpoll: move epi_fget() up
eventpoll: rename ep_remove_safe() back to ep_remove()
eventpoll: drop vestigial __ prefix from ep_remove_{file,epi}()
eventpoll: kill __ep_remove()
eventpoll: split __ep_remove()
eventpoll: use hlist_is_singular_node() in __ep_remove()
fs: Handle multiply claimed blocks more gracefully with mmb
nstree: fix func. parameter kernel-doc warnings
fs: aio: reject partial mremap to avoid Null-pointer-dereference error
fuse: reject oversized dirents in page cache
writeback: Fix use after free in inode_switch_wbs_work_fn()
fs: aio: set VMA_DONTCOPY_BIT in mmap to fix NULL-pointer-dereference error
|
||
|
Jan Kara
|
6689f01d67
|
writeback: Fix use after free in inode_switch_wbs_work_fn()
inode_switch_wbs_work_fn() has a loop like:
wb_get(new_wb);
while (1) {
list = llist_del_all(&new_wb->switch_wbs_ctxs);
/* Nothing to do? */
if (!list)
break;
... process the items ...
}
Now adding of items to the list looks like:
wb_queue_isw()
if (llist_add(&isw->list, &wb->switch_wbs_ctxs))
queue_work(isw_wq, &wb->switch_work);
Because inode_switch_wbs_work_fn() loops when processing isw items, it
can happen that wb->switch_work is pending while wb->switch_wbs_ctxs is
empty. This is a problem because in that case wb can get freed (no isw
items -> no wb reference) while the work is still pending causing
use-after-free issues.
We cannot just fix this by cancelling work when freeing wb because that
could still trigger problematic 0 -> 1 transitions on wb refcount due to
wb_get() in inode_switch_wbs_work_fn(). It could be all handled with
more careful code but that seems unnecessarily complex so let's avoid
that until it is proven that the looping actually brings practical
benefit. Just remove the loop from inode_switch_wbs_work_fn() instead.
That way when wb_queue_isw() queues work, we are guaranteed we have
added the first item to wb->switch_wbs_ctxs and nobody is going to
remove it (and drop the wb reference it holds) until the queued work
runs.
Fixes:
|
||
|
Linus Torvalds
|
40735a683b |
mm.git review status for linus..mm-stable
Everything: Total patches: 121 Reviews/patch: 2.11 Reviewed rate: 90% Excluding DAMON: Total patches: 113 Reviews/patch: 2.25 Reviewed rate: 96% - The 33 patch series "Eliminate Dying Memory Cgroup" from Qi Zheng and Muchun Song addresses the longstanding "dying memcg problem". A situation wherein a no-longer-used memory control group will hang around for an extended period pointlessly consuming memory. The [0/N] changelog has a good overview of this work. - The 3 patch series "fix unexpected type conversions and potential overflows" from Qi Zheng fixes a couple of potential 32-bit/64-bit issues which were identified during review of the "Eliminate Dying Memory Cgroup" series. - The 6 patch series "kho: history: track previous kernel version and kexec boot count" from Breno Leitao uses Kexec Handover (KHO) to pass the previous kernel's version string and the number of kexec reboots since the last cold boot to the next kernel, and prints it at boot time. - The 4 patch series "liveupdate: prevent double preservation" from Pasha Tatashin teaches LUO to avoid managing the same file across different active sessions. - The 10 patch series "liveupdate: Fix module unloading and unregister API" from Pasha Tatashin addresses an issue with how LUO handles module reference counting and unregistration during module unloading. - The 2 patch series "zswap pool per-CPU acomp_ctx simplifications" from Kanchana Sridhar simplifies and cleans up the zswap crypto compression handling and improves the lifecycle management of zswap pool's per-CPU acomp_ctx resources. - The 2 patch series "mm/damon/core: fix damon_call()/damos_walk() vs kdmond exit race" from SeongJae Park addresses unlikely but possible leaks and deadlocks in damon_call() and damon_walk(). - The 2 patch series "mm/damon/core: validate damos_quota_goal->nid" from SeongJae Park fixes a couple of root-only wild pointer dereferences. - The 2 patch series "Docs/admin-guide/mm/damon: warn commit_inputs vs other params race" from SeongJae Park updates the DAMON documentation to warn operators about potential races which can occur if the commit_inputs parameter is altered at the wrong time. - The 3 patch series "Minor hmm_test fixes and cleanups" from Alistair Popple implements two bugfixes a cleanup for the HMM kernel selftests. - The 6 patch series "Modify memfd_luo code" from Chenghao Duan provides cleanups, simplifications and speedups in the memfd_lou code. - The 4 patch series "mm, kvm: allow uffd support in guest_memfd" from Mike Rapoport enables support for userfaultfd in guest_memfd. - The 6 patch series "selftests/mm: skip several tests when thp is not available" from Chunyu Hu fixes several issues in the selftests code which were causing breakage when the tests were run on CONFIG_THP=n kernels. - The 2 patch series "mm/mprotect: micro-optimization work" from Pedro Falcato implements a couple of nice speedups for mprotect(). - The 3 patch series "MAINTAINERS: update KHO and LIVE UPDATE entries" from Pratyush Yadav reflects upcoming changes in the maintenance of KHO, LUO, memfd_luo, kexec, crash, kdump and probably other kexec-based things - they are being moved out of mm.git and into a new git tree. -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCaeNL/wAKCRDdBJ7gKXxA jt7EAQCEEQvYYTjld+8HJKsCbavY4pEfci7z4SBiQyIPjRracQD/ZfjXnzL7ucc1 b6q6G4TcslvIDBgzVkk9G2BVn2oCoAg= =3ozv -----END PGP SIGNATURE----- Merge tag 'mm-stable-2026-04-18-02-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - "Eliminate Dying Memory Cgroup" (Qi Zheng and Muchun Song) Address the longstanding "dying memcg problem". A situation wherein a no-longer-used memory control group will hang around for an extended period pointlessly consuming memory - "fix unexpected type conversions and potential overflows" (Qi Zheng) Fix a couple of potential 32-bit/64-bit issues which were identified during review of the "Eliminate Dying Memory Cgroup" series - "kho: history: track previous kernel version and kexec boot count" (Breno Leitao) Use Kexec Handover (KHO) to pass the previous kernel's version string and the number of kexec reboots since the last cold boot to the next kernel, and print it at boot time - "liveupdate: prevent double preservation" (Pasha Tatashin) Teach LUO to avoid managing the same file across different active sessions - "liveupdate: Fix module unloading and unregister API" (Pasha Tatashin) Address an issue with how LUO handles module reference counting and unregistration during module unloading - "zswap pool per-CPU acomp_ctx simplifications" (Kanchana Sridhar) Simplify and clean up the zswap crypto compression handling and improve the lifecycle management of zswap pool's per-CPU acomp_ctx resources - "mm/damon/core: fix damon_call()/damos_walk() vs kdmond exit race" (SeongJae Park) Address unlikely but possible leaks and deadlocks in damon_call() and damon_walk() - "mm/damon/core: validate damos_quota_goal->nid" (SeongJae Park) Fix a couple of root-only wild pointer dereferences - "Docs/admin-guide/mm/damon: warn commit_inputs vs other params race" (SeongJae Park) Update the DAMON documentation to warn operators about potential races which can occur if the commit_inputs parameter is altered at the wrong time - "Minor hmm_test fixes and cleanups" (Alistair Popple) Bugfixes and a cleanup for the HMM kernel selftests - "Modify memfd_luo code" (Chenghao Duan) Cleanups, simplifications and speedups to the memfd_lou code - "mm, kvm: allow uffd support in guest_memfd" (Mike Rapoport) Support for userfaultfd in guest_memfd - "selftests/mm: skip several tests when thp is not available" (Chunyu Hu) Fix several issues in the selftests code which were causing breakage when the tests were run on CONFIG_THP=n kernels - "mm/mprotect: micro-optimization work" (Pedro Falcato) A couple of nice speedups for mprotect() - "MAINTAINERS: update KHO and LIVE UPDATE entries" (Pratyush Yadav) Document upcoming changes in the maintenance of KHO, LUO, memfd_luo, kexec, crash, kdump and probably other kexec-based things - they are being moved out of mm.git and into a new git tree * tag 'mm-stable-2026-04-18-02-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (121 commits) MAINTAINERS: add page cache reviewer mm/vmscan: avoid false-positive -Wuninitialized warning MAINTAINERS: update Dave's kdump reviewer email address MAINTAINERS: drop include/linux/liveupdate from LIVE UPDATE MAINTAINERS: drop include/linux/kho/abi/ from KHO MAINTAINERS: update KHO and LIVE UPDATE maintainers MAINTAINERS: update kexec/kdump maintainers entries mm/migrate_device: remove dead migration entry check in migrate_vma_collect_huge_pmd() selftests: mm: skip charge_reserved_hugetlb without killall userfaultfd: allow registration of ranges below mmap_min_addr mm/vmstat: fix vmstat_shepherd double-scheduling vmstat_update mm/hugetlb: fix early boot crash on parameters without '=' separator zram: reject unrecognized type= values in recompress_store() docs: proc: document ProtectionKey in smaps mm/mprotect: special-case small folios when applying permissions mm/mprotect: move softleaf code out of the main function mm: remove '!root_reclaim' checking in should_abort_scan() mm/sparse: fix comment for section map alignment mm/page_io: use sio->len for PSWPIN accounting in sio_read_complete() selftests/mm: transhuge_stress: skip the test when thp not available ... |
||
|
Muchun Song
|
49717c7bd6 |
writeback: prevent memory cgroup release in writeback module
In the near future, a folio will no longer pin its corresponding memory cgroup. To ensure safety, it will only be appropriate to hold the rcu read lock or acquire a reference to the memory cgroup returned by folio_memcg(), thereby preventing it from being released. In the current patch, the function get_mem_cgroup_css_from_folio() and the rcu read lock are employed to safeguard against the release of the memory cgroup. This serves as a preparatory measure for the reparenting of the LRU pages. Link: https://lore.kernel.org/645f99bc344575417f67def3744f975596df2793.1772711148.git.zhengqi.arch@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Allen Pais <apais@linux.microsoft.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chen Ridong <chenridong@huawei.com> Cc: David Hildenbrand <david@kernel.org> Cc: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com> Cc: Hugh Dickins <hughd@google.com> Cc: Imran Khan <imran.f.khan@oracle.com> Cc: Kamalesh Babulal <kamalesh.babulal@oracle.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Koutný <mkoutny@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yosry Ahmed <yosry@kernel.org> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Joanne Koong
|
76f9377cd2
|
writeback: don't block sync for filesystems with no data integrity guarantees
Add a SB_I_NO_DATA_INTEGRITY superblock flag for filesystems that cannot guarantee data persistence on sync (eg fuse). For superblocks with this flag set, sync kicks off writeback of dirty inodes but does not wait for the flusher threads to complete the writeback. This replaces the per-inode AS_NO_DATA_INTEGRITY mapping flag added in commit |
||
|
Christoph Hellwig
|
f8b8820a4a
|
fs: clear I_DIRTY_TIME in sync_lazytime
For file systems implementing ->sync_lazytime, I_DIRTY_TIME fails to get
cleared in sync_lazytime, and might cause additional calls to
sync_lazytime during inode deactivation. Use the same pattern as in
__mark_inode_dirty to clear the flag under the inode lock.
Fixes:
|
||
|
Linus Torvalds
|
0e335a7745 |
vfs-7.0-rc2.fixes
Please consider pulling these changes from the signed vfs-7.0-rc2.fixes tag.
Thanks!
Christian
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Merge tag 'vfs-7.0-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- Fix an uninitialized variable in file_getattr().
The flags_valid field wasn't initialized before calling
vfs_fileattr_get(), triggering KMSAN uninit-value reports in fuse
- Fix writeback wakeup and logging timeouts when DETECT_HUNG_TASK is
not enabled.
sysctl_hung_task_timeout_secs is 0 in that case causing spurious
"waiting for writeback completion for more than 1 seconds" warnings
- Fix a null-ptr-deref in do_statmount() when the mount is internal
- Add missing kernel-doc description for the @private parameter in
iomap_readahead()
- Fix mount namespace creation to hold namespace_sem across the mount
copy in create_new_namespace().
The previous drop-and-reacquire pattern was fragile and failed to
clean up mount propagation links if the real rootfs was a shared or
dependent mount
- Fix /proc mount iteration where m->index wasn't updated when
m->show() overflows, causing a restart to repeatedly show the same
mount entry in a rapidly expanding mount table
- Return EFSCORRUPTED instead of ENOSPC in minix_new_inode() when the
inode number is out of range
- Fix unshare(2) when CLONE_NEWNS is set and current->fs isn't shared.
copy_mnt_ns() received the live fs_struct so if a subsequent
namespace creation failed the rollback would leave pwd and root
pointing to detached mounts. Always allocate a new fs_struct when
CLONE_NEWNS is requested
- fserror bug fixes:
- Remove the unused fsnotify_sb_error() helper now that all callers
have been converted to fserror_report_metadata
- Fix a lockdep splat in fserror_report() where igrab() takes
inode::i_lock which can be held in IRQ context.
Replace igrab() with a direct i_count bump since filesystems
should not report inodes that are about to be freed or not yet
exposed
- Handle error pointer in procfs for try_lookup_noperm()
- Fix an integer overflow in ep_loop_check_proc() where recursive calls
returning INT_MAX would overflow when +1 is added, breaking the
recursion depth check
- Fix a misleading break in pidfs
* tag 'vfs-7.0-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
pidfs: avoid misleading break
eventpoll: Fix integer overflow in ep_loop_check_proc()
proc: Fix pointer error dereference
fserror: fix lockdep complaint when igrabbing inode
fsnotify: drop unused helper
unshare: fix unshare_fs() handling
minix: Correct errno in minix_new_inode
namespace: fix proc mount iteration
mount: hold namespace_sem across copy in create_new_namespace()
iomap: Describe @private in iomap_readahead()
statmount: Fix the null-ptr-deref in do_statmount()
writeback: Fix wakeup and logging timeouts for !DETECT_HUNG_TASK
fs: init flags_valid before calling vfs_fileattr_get
|
||
|
Linus Torvalds
|
323bbfcf1e |
Convert 'alloc_flex' family to use the new default GFP_KERNEL argument
This is the exact same thing as the 'alloc_obj()' version, only much smaller because there are a lot fewer users of the *alloc_flex() interface. As with alloc_obj() version, this was done entirely with mindless brute force, using the same script, except using 'flex' in the pattern rather than 'objs*'. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Kees Cook
|
69050f8d6d |
treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org> |
||
|
Huacai Chen
|
9eed043d10
|
writeback: Fix wakeup and logging timeouts for !DETECT_HUNG_TASK
Recent changes of fs-writeback cause such warnings if DETECT_HUNG_TASK is not enabled: INFO: The task sync:1342 has been waiting for writeback completion for more than 1 seconds. The reason is sysctl_hung_task_timeout_secs is 0 when DETECT_HUNG_TASK is not enabled, then it causes the warning message even if the writeback lasts for only one second. Guard the wakeup and logging with "#ifdef CONFIG_DETECT_HUNG_TASK" can eliminate the warning messages. But on the other hand, it is possible that sysctl_hung_task_timeout_secs be also 0 when DETECT_HUNG_TASK is enabled. So let's just check the value of sysctl_hung_task_timeout_secs to decide whether do wakeup and logging. Fixes: |
||
|
Linus Torvalds
|
ff661eeee2 |
cgroup: Changes for v6.20
- cpuset changes:
- Continue separating v1 and v2 implementations by moving more
v1-specific logic into cpuset-v1.c.
- Improve partition handling. Sibling partitions are no longer
invalidated on cpuset.cpus conflict, cpuset.cpus changes no longer
fail in v2, and effective_xcpus computation is made consistent.
- Fix partition effective CPUs overlap that caused a warning on cpuset
removal when sibling partitions shared CPUs.
- Increase the maximum cgroup subsystem count from 16 to 32 to
accommodate future subsystem additions.
- Misc cleanups and selftest improvements including switching to
css_is_online() helper, removing dead code and stale documentation
references, using lockdep_assert_cpuset_lock_held() consistently,
and adding polling helpers for asynchronously updated cgroup
statistics.
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Merge tag 'cgroup-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- cpuset changes:
- Continue separating v1 and v2 implementations by moving more
v1-specific logic into cpuset-v1.c
- Improve partition handling. Sibling partitions are no longer
invalidated on cpuset.cpus conflict, cpuset.cpus changes no longer
fail in v2, and effective_xcpus computation is made consistent
- Fix partition effective CPUs overlap that caused a warning on
cpuset removal when sibling partitions shared CPUs
- Increase the maximum cgroup subsystem count from 16 to 32 to
accommodate future subsystem additions
- Misc cleanups and selftest improvements including switching to
css_is_online() helper, removing dead code and stale documentation
references, using lockdep_assert_cpuset_lock_held() consistently, and
adding polling helpers for asynchronously updated cgroup statistics
* tag 'cgroup-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
cpuset: fix overlap of partition effective CPUs
cgroup: increase maximum subsystem count from 16 to 32
cgroup: Remove stale cpu.rt.max reference from documentation
cpuset: replace direct lockdep_assert_held() with lockdep_assert_cpuset_lock_held()
cgroup/cpuset: Move the v1 empty cpus/mems check to cpuset1_validate_change()
cgroup/cpuset: Don't invalidate sibling partitions on cpuset.cpus conflict
cgroup/cpuset: Don't fail cpuset.cpus change in v2
cgroup/cpuset: Consistently compute effective_xcpus in update_cpumasks_hier()
cgroup/cpuset: Streamline rm_siblings_excl_cpus()
cpuset: remove dead code in cpuset-v1.c
cpuset: remove v1-specific code from generate_sched_domains
cpuset: separate generate_sched_domains for v1 and v2
cpuset: move update_domain_attr_tree to cpuset_v1.c
cpuset: add cpuset1_init helper for v1 initialization
cpuset: add cpuset1_online_css helper for v1-specific operations
cpuset: add lockdep_assert_cpuset_lock_held helper
cpuset: Remove unnecessary checks in rebuild_sched_domains_locked
cgroup: switch to css_is_online() helper
selftests: cgroup: Replace sleep with cg_read_key_long_poll() for waiting on nr_dying_descendants
selftests: cgroup: make test_memcg_sock robust against delayed sock stats
...
|
||
|
Linus Torvalds
|
74554251df |
vfs-7.0-rc1.nonblocking_timestamps
Please consider pulling these changes from the signed vfs-7.0-rc1.nonblocking_timestamps tag.
Thanks!
Christian
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Merge tag 'vfs-7.0-rc1.nonblocking_timestamps' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs timestamp updates from Christian Brauner:
"This contains the changes to support non-blocking timestamp updates.
Since commit
|
||
|
Linus Torvalds
|
fcb70a56f4 |
vfs-6.19-rc8.fixes
-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCaXc4IwAKCRCRxhvAZXjc oo0jAQDOV580l4wHiY6eT1QGY2QYa7u8fYDOi6mqfgHa+EH5twD9ETnQ0xQHIKYP oruFJXLf3ihBBsum+pTpAO2XFVjM7Qs= =pM8o -----END PGP SIGNATURE----- Merge tag 'vfs-6.19-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: - Fix the the buggy conversion of fuse_reverse_inval_entry() introduced during the creation rework - Disallow nfs delegation requests for directories by setting simple_nosetlease() - Require an opt-in for getting readdir flag bits outside of S_DT_MASK set in d_type - Fix scheduling delayed writeback work by only scheduling when the dirty time expiry interval is non-zero and cancel the delayed work if the interval is set to zero - Use rounded_jiffies_interval for dirty time work - Check the return value of sb_set_blocksize() for romfs - Wait for batched folios to be stable in __iomap_get_folio() - Use private naming for fuse hash size - Fix the stale dentry cleanup to prevent a race that causes a UAF * tag 'vfs-6.19-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: vfs: document d_dispose_if_unused() fuse: shrink once after all buckets have been scanned fuse: clean up fuse_dentry_tree_work() fuse: add need_resched() before unlocking bucket fuse: make sure dentry is evicted if stale fuse: fix race when disposing stale dentries fuse: use private naming for fuse hash size writeback: use round_jiffies_relative for dirtytime_work iomap: wait for batched folios to be stable in __iomap_get_folio romfs: check sb_set_blocksize() return value docs: clarify that dirtytime_expire_seconds=0 disables writeback writeback: fix 100% CPU usage when dirtytime_expire_interval is 0 readdir: require opt-in for d_type flags vboxsf: don't allow delegations to be set on directories ceph: don't allow delegations to be set on directories gfs2: don't allow delegations to be set on directories 9p: don't allow delegations to be set on directories smb/client: properly disallow delegations on directories nfs: properly disallow delegation requests on directories fuse: fix conversion of fuse_reverse_inval_entry() to start_removing() |
||
|
Joanne Koong
|
f9a49aa302 |
fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()
Above the while() loop in wait_sb_inodes(), we document that we must wait
for all pages under writeback for data integrity. Consequently, if a
mapping, like fuse, traditionally does not have data integrity semantics,
there is no need to wait at all; we can simply skip these inodes.
This restores fuse back to prior behavior where syncs are no-ops. This
fixes a user regression where if a system is running a faulty fuse server
that does not reply to issued write requests, this causes wait_sb_inodes()
to wait forever.
Link: https://lkml.kernel.org/r/20260105211737.4105620-2-joannelkoong@gmail.com
Fixes:
|
||
|
Zhao Mengmeng
|
e93b31d081
|
writeback: use round_jiffies_relative for dirtytime_work
The dirtytime_work is a background housekeeping task that flushes dirty inodes, using round_jiffies_relative() will allow kernel to batch this work with other aligned system tasks, reducing power consumption. Signed-off-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn> Link: https://patch.msgid.link/20260113082614.231580-1-zhaomzhao@126.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christoph Hellwig
|
5cf06ea56e
|
fs: add a ->sync_lazytime method
Allow the file system to explicitly implement lazytime syncing instead of pigging back on generic inode dirtying. This allows to simplify the XFS implementation and prepares for non-blocking lazytime timestamp updates. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260108141934.2052404-8-hch@lst.de Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christoph Hellwig
|
188344c8ac
|
fs: factor out a sync_lazytime helper
Centralize how we synchronize a lazytime update into the actual on-disk timestamp into a single helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260108141934.2052404-7-hch@lst.de Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Laveesh Bansal
|
543467d6fe
|
writeback: fix 100% CPU usage when dirtytime_expire_interval is 0
When vm.dirtytime_expire_seconds is set to 0, wakeup_dirtytime_writeback()
schedules delayed work with a delay of 0, causing immediate execution.
The function then reschedules itself with 0 delay again, creating an
infinite busy loop that causes 100% kworker CPU usage.
Fix by:
- Only scheduling delayed work in wakeup_dirtytime_writeback() when
dirtytime_expire_interval is non-zero
- Cancelling the delayed work in dirtytime_interval_handler() when
the interval is set to 0
- Adding a guard in start_dirtytime_writeback() for defensive coding
Tested by booting kernel in QEMU with virtme-ng:
- Before fix: kworker CPU spikes to ~73%
- After fix: CPU remains at normal levels
- Setting interval back to non-zero correctly resumes writeback
Fixes:
|
||
|
Chen Ridong
|
82d7e59ea7 |
cgroup: switch to css_is_online() helper
Use the new css_is_online() helper that has been introduced to check css online state, instead of testing the CSS_ONLINE flag directly. This improves readability and centralizes the state check logic. No functional changes intended. Signed-off-by: Chen Ridong <chenridong@huawei.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Tejun Heo <tj@kernel.org> |
||
|
Linus Torvalds
|
ebaeabfa5a |
vfs-6.19-rc1.writeback
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Merge tag 'vfs-6.19-rc1.writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull writeback updates from Christian Brauner:
"Features:
- Allow file systems to increase the minimum writeback chunk size.
The relatively low minimal writeback size of 4MiB means that
written back inodes on rotational media are switched a lot. Besides
introducing additional seeks, this also can lead to extreme file
fragmentation on zoned devices when a lot of files are cached
relative to the available writeback bandwidth.
This adds a superblock field that allows the file system to
override the default size, and sets it to the zone size for zoned
XFS.
- Add logging for slow writeback when it exceeds
sysctl_hung_task_timeout_secs. This helps identify tasks waiting
for a long time and pinpoint potential issues. Recording the
starting jiffies is also useful when debugging a crashed vmcore.
- Wake up waiting tasks when finishing the writeback of a chunk
Cleanups:
- filemap_* writeback interface cleanups.
Adding filemap_fdatawrite_wbc ended up being a mistake, as all but
the original btrfs caller should be using better high level
interfaces instead.
This series removes all these low-level interfaces, switches btrfs
to a more specific interface, and cleans up other too low-level
interfaces. With this the writeback_control that is passed to the
writeback code is only initialized in three places.
- Remove __filemap_fdatawrite, __filemap_fdatawrite_range, and
filemap_fdatawrite_wbc
- Add filemap_flush_nr helper for btrfs
- Push struct writeback_control into start_delalloc_inodes in btrfs
- Rename filemap_fdatawrite_range_kick to filemap_flush_range
- Stop opencoding filemap_fdatawrite_range in 9p, ocfs2, and mm
- Make wbc_to_tag() inline and use it in fs"
* tag 'vfs-6.19-rc1.writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: Make wbc_to_tag() inline and use it in fs.
xfs: set s_min_writeback_pages for zoned file systems
writeback: allow the file system to override MIN_WRITEBACK_PAGES
writeback: cleanup writeback_chunk_size
mm: rename filemap_fdatawrite_range_kick to filemap_flush_range
mm: remove __filemap_fdatawrite_range
mm: remove filemap_fdatawrite_wbc
mm: remove __filemap_fdatawrite
mm,btrfs: add a filemap_flush_nr helper
btrfs: push struct writeback_control into start_delalloc_inodes
btrfs: use the local tmp_inode variable in start_delalloc_inodes
ocfs2: don't opencode filemap_fdatawrite_range in ocfs2_journal_submit_inode_data_buffers
9p: don't opencode filemap_fdatawrite_range in v9fs_mmap_vm_close
mm: don't opencode filemap_fdatawrite_range in filemap_invalidate_inode
writeback: Add logging for slow writeback (exceeds sysctl_hung_task_timeout_secs)
writeback: Wake up waiting tasks when finishing the writeback of a chunk.
|
||
|
Mateusz Guzik
|
003a660730
|
fs: push list presence check into inode_io_list_del()
For consistency with sb routines. ext4 is the only consumer outside of evict(). Damage-controlling it is outside of the scope of this cleanup. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://patch.msgid.link/20251103230911.516866-1-mjguzik@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Mateusz Guzik
|
4c6b40877b
|
fs: cosmetic fixes to lru handling
1. inode_bit_waitqueue() was somehow placed between __inode_add_lru() and inode_add_lru(). move it up 2. assert ->i_lock is held in __inode_add_lru instead of just claiming it is needed 3. s/__inode_add_lru/__inode_lru_list_add/ for consistency with itself (inode_lru_list_del()) and similar routines for sb and io list management 4. push list presence check into inode_lru_list_del(), just like sb and io list Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://patch.msgid.link/20251029131428.654761-2-mjguzik@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christoph Hellwig
|
90db4d4441
|
writeback: allow the file system to override MIN_WRITEBACK_PAGES
The relatively low minimal writeback size of 4MiB means that written back inodes on rotational media are switched a lot. Besides introducing additional seeks, this also can lead to extreme file fragmentation on zoned devices when a lot of files are cached relative to the available writeback bandwidth. Add a superblock field that allows the file system to override the default size. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20251017034611.651385-3-hch@lst.de Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christoph Hellwig
|
151d0922bf
|
writeback: cleanup writeback_chunk_size
Return the pages directly when calculated instead of first assigning them back to a variable, and directly return for the data integrity / tagged case instead of going through an else clause. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20251017034611.651385-2-hch@lst.de Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christoph Hellwig
|
1bcb413d0c
|
mm: remove filemap_fdatawrite_wbc
Replace filemap_fdatawrite_wbc, which exposes a writeback_control to the callers with a filemap_writeback helper that takes all the possible arguments and declares the writeback_control itself. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20251024080431.324236-9-hch@lst.de Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Julian Sun
|
d6e6215907
|
writeback: Add logging for slow writeback (exceeds sysctl_hung_task_timeout_secs)
When a writeback work lasts for sysctl_hung_task_timeout_secs, we want to identify that there are tasks waiting for a long time-this helps us pinpoint potential issues. Additionally, recording the starting jiffies is useful when debugging a crashed vmcore. Signed-off-by: Julian Sun <sunjunchao@bytedance.com> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Julian Sun
|
1888635532
|
writeback: Wake up waiting tasks when finishing the writeback of a chunk.
Writing back a large number of pages can take a lots of time. This issue is exacerbated when the underlying device is slow or subject to block layer rate limiting, which in turn triggers unexpected hung task warnings. We can trigger a wake-up once a chunk has been written back and the waiting time for writeback exceeds half of sysctl_hung_task_timeout_secs. This action allows the hung task detector to be aware of the writeback progress, thereby eliminating these unexpected hung task warnings. This patch has passed the xfstests 'check -g quick' test based on ext4, with no additional failures introduced. Signed-off-by: Julian Sun <sunjunchao@bytedance.com> Reviewed-by: Jan Kara <jack@suse.cz> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Mateusz Guzik
|
b4dbfd8653
|
Coccinelle-based conversion to use ->i_state accessors
All places were patched by coccinelle with the default expecting that ->i_lock is held, afterwards entries got fixed up by hand to use unlocked variants as needed. The script: @@ expression inode, flags; @@ - inode->i_state & flags + inode_state_read(inode) & flags @@ expression inode, flags; @@ - inode->i_state &= ~flags + inode_state_clear(inode, flags) @@ expression inode, flag1, flag2; @@ - inode->i_state &= ~flag1 & ~flag2 + inode_state_clear(inode, flag1 | flag2) @@ expression inode, flags; @@ - inode->i_state |= flags + inode_state_set(inode, flags) @@ expression inode, flags; @@ - inode->i_state = flags + inode_state_assign(inode, flags) @@ expression inode, flags; @@ - flags = inode->i_state + flags = inode_state_read(inode) @@ expression inode, flags; @@ - READ_ONCE(inode->i_state) & flags + inode_state_read(inode) & flags Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Mateusz Guzik
|
cb5db358ab
|
fs: spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
The incomming helpers don't ship with _release/_acquire variants, for the time being anyway. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Linus Torvalds
|
263e777ee3 |
vfs-6.18-rc1.writeback
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Merge tag 'vfs-6.18-rc1.writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs writeback updates from Christian Brauner:
"This contains work adressing lockups reported by users when a systemd
unit reading lots of files from a filesystem mounted with the lazytime
mount option exits.
With the lazytime mount option enabled we can be switching many dirty
inodes on cgroup exit to the parent cgroup. The numbers observed in
practice when systemd slice of a large cron job exits can easily reach
hundreds of thousands or millions.
The logic in inode_do_switch_wbs() which sorts the inode into
appropriate place in b_dirty list of the target wb however has linear
complexity in the number of dirty inodes thus overall time complexity
of switching all the inodes is quadratic leading to workers being
pegged for hours consuming 100% of the CPU and switching inodes to the
parent wb.
Simple reproducer of the issue:
FILES=10000
# Filesystem mounted with lazytime mount option
MNT=/mnt/
echo "Creating files and switching timestamps"
for (( j = 0; j < 50; j ++ )); do
mkdir $MNT/dir$j
for (( i = 0; i < $FILES; i++ )); do
echo "foo" >$MNT/dir$j/file$i
done
touch -a -t 202501010000 $MNT/dir$j/file*
done
wait
echo "Syncing and flushing"
sync
echo 3 >/proc/sys/vm/drop_caches
echo "Reading all files from a cgroup"
mkdir /sys/fs/cgroup/unified/mycg1 || exit
echo $$ >/sys/fs/cgroup/unified/mycg1/cgroup.procs || exit
for (( j = 0; j < 50; j ++ )); do
cat /mnt/dir$j/file* >/dev/null &
done
wait
echo "Switching wbs"
# Now rmdir the cgroup after the script exits
This can be solved by:
- Avoiding contention on the wb->list_lock when switching inodes by
running a single work item per wb and managing a queue of items
switching to the wb
- Allowing rescheduling when switching inodes over to a different
cgroup to avoid softlockups
- Maintaining the b_dirty list ordering instead of sorting it"
* tag 'vfs-6.18-rc1.writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
writeback: Add tracepoint to track pending inode switches
writeback: Avoid excessively long inode switching times
writeback: Avoid softlockup when switching many inodes
writeback: Avoid contention on wb->list_lock when switching inodes
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Linus Torvalds
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b786405685 |
vfs-6.18-rc1.workqueue
-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCaNZQYgAKCRCRxhvAZXjc olgGAQDWr4sD7kUt8TxifdAXsQNgyGG8qOUkb/BHHSqJ/5mKvAEAlTwJ+81tgNKT hYYdPyvWdbgW6CnWeiQLi0JjpFvUPQU= =uHwG -----END PGP SIGNATURE----- Merge tag 'vfs-6.18-rc1.workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs workqueue updates from Christian Brauner: "This contains various workqueue changes affecting the filesystem layer. Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This replaces the use of system_wq and system_unbound_wq. system_wq is a per-CPU workqueue which isn't very obvious from the name and system_unbound_wq is to be used when locality is not required. So this renames system_wq to system_percpu_wq, and system_unbound_wq to system_dfl_wq. This also adds a new WQ_PERCPU flag to allow the fs subsystem users to explicitly request the use of per-CPU behavior. Both WQ_UNBOUND and WQ_PERCPU flags coexist for one release cycle to allow callers to transition their calls. WQ_UNBOUND will be removed in a next release cycle" * tag 'vfs-6.18-rc1.workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: WQ_PERCPU added to alloc_workqueue users fs: replace use of system_wq with system_percpu_wq fs: replace use of system_unbound_wq with system_dfl_wq |