OpenCloudOS-Kernel/fs
Brian Foster cbfc844cbe vfs: don't mod negative dentry count when on shrinker list
[ Upstream commit aabfe57ebaa75841db47ea59091ec3c5a06d2f52 ]

The nr_dentry_negative counter is intended to only account negative
dentries that are present on the superblock LRU. Therefore, the LRU
add, remove and isolate helpers modify the counter based on whether
the dentry is negative, but the shrinker list related helpers do not
modify the counter, and the paths that change a dentry between
positive and negative only do so if DCACHE_LRU_LIST is set.

The problem with this is that a dentry on a shrinker list still has
DCACHE_LRU_LIST set to indicate ->d_lru is in use. The additional
DCACHE_SHRINK_LIST flag denotes whether the dentry is on LRU or a
shrink related list. Therefore if a relevant operation (i.e. unlink)
occurs while a dentry is present on a shrinker list, and the
associated codepath only checks for DCACHE_LRU_LIST, then it is
technically possible to modify the negative dentry count for a
dentry that is off the LRU. Since the shrinker list related helpers
do not modify the negative dentry count (because non-LRU dentries
should not be included in the count) when the dentry is ultimately
removed from the shrinker list, this can cause the negative dentry
count to become permanently inaccurate.

This problem can be reproduced via a heavy file create/unlink vs.
drop_caches workload. On an 80xcpu system, I start 80 tasks each
running a 1k file create/delete loop, and one task spinning on
drop_caches. After 10 minutes or so of runtime, the idle/clean cache
negative dentry count increases from somewhere in the range of 5-10
entries to several hundred (and increasingly grows beyond
nr_dentry_unused).

Tweak the logic in the paths that turn a dentry negative or positive
to filter out the case where the dentry is present on a shrink
related list. This allows the above workload to maintain an accurate
negative dentry count.

Fixes: af0c9af1b3 ("fs/dcache: Track & report number of negative dentries")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Link: https://lore.kernel.org/r/20240703121301.247680-1-bfoster@redhat.com
Acked-by: Ian Kent <ikent@redhat.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:21:12 +02:00
..
9p 9p: add missing locking around taking dentry fid list 2024-06-16 13:47:37 +02:00
adfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
affs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
afs afs: Don't cross .backup mountpoint from backup volume 2024-06-16 13:47:30 +02:00
autofs v6.6-vfs.autofs 2023-08-28 11:39:14 -07:00
befs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
bfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
btrfs btrfs: fix adding block group to a reclaim list and the unused list during reclaim 2024-07-11 12:49:15 +02:00
cachefiles cachefiles: add missing lock protection when polling 2024-07-18 13:21:11 +02:00
ceph ceph: redirty page before returning AOP_WRITEPAGE_ACTIVATE 2024-04-27 17:11:29 +02:00
coda v6.6-vfs.ctime 2023-08-28 09:31:32 -07:00
configfs configfs: convert to ctime accessor functions 2023-07-13 10:28:05 +02:00
cramfs v6.6-vfs.super 2023-08-28 11:04:18 -07:00
crypto
debugfs debugfs: fix automount d_fsdata usage 2024-01-20 11:51:37 +01:00
devpts v6.6-vfs.misc 2023-08-28 10:17:14 -07:00
dlm dlm: fix user space lock decision to copy lvb 2024-06-12 11:11:38 +02:00
ecryptfs ecryptfs: Fix buffer size for tag 66 packet 2024-06-12 11:11:31 +02:00
efivarfs efivarfs: Request at most 512 bytes for variable names 2024-03-06 14:48:41 +00:00
efs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
erofs erofs: fix NULL dereference of dif->bdev_handle in fscache mode 2024-07-05 09:34:05 +02:00
exfat exfat: support handle zero-size directory 2023-11-28 17:19:44 +00:00
exportfs exportfs: remove kernel-doc warnings in exportfs 2023-08-29 17:45:22 -04:00
ext2 quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:19:46 -04:00
ext4 ext4: fix slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists() 2024-06-27 13:49:10 +02:00
f2fs f2fs: Add inline to f2fs_build_fault_attr() stub 2024-07-11 12:49:15 +02:00
fat fat: fix uninitialized field in nostale filehandles 2024-04-03 15:28:20 +02:00
freevxfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
fscache netfs, fscache: Prevent Oops in fscache_put_cache() 2024-01-31 16:19:01 -08:00
fuse fuse: fix leaked ENOSYS error on first statx call 2024-04-27 17:11:42 +02:00
gfs2 gfs2: Fix NULL pointer dereference in gfs2_log_flush 2024-07-05 09:33:52 +02:00
hfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
hfsplus for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
hostfs hostfs: convert to ctime accessor functions 2023-07-24 10:30:00 +02:00
hpfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
hugetlbfs mm: hugetlb pages should not be reserved by shmat() if SHM_NORESERVE 2024-02-23 09:25:16 +01:00
iomap iomap: fault in smaller chunks for non-large folio mappings 2024-06-16 13:47:40 +02:00
isofs isofs: handle CDs with bad root inode but good Joliet root directory 2024-04-13 13:07:34 +02:00
jbd2 jbd2: fix soft lockup in journal_finish_inode_data_buffers() 2024-01-20 11:51:43 +01:00
jffs2 jffs2: Fix potential illegal address access in jffs2_free_inode 2024-07-11 12:49:09 +02:00
jfs jfs: xattr: fix buffer overflow for invalid xattr 2024-06-21 14:38:24 +02:00
kernfs kernfs: RCU protect kernfs_nodes and avoid kernfs_idr_lock in kernfs_find_and_get_node_by_id() 2024-04-13 13:07:38 +02:00
lockd SUNRPC: Add enum svc_auth_status 2023-08-29 17:45:22 -04:00
minix for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
netfs netfs: Only call folio_start_fscache() one time for each folio 2023-09-18 12:03:46 -07:00
nfs nfs: drop the incorrect assertion in nfs_swap_rw() 2024-07-05 09:33:55 +02:00
nfs_common
nfsd knfsd: LOOKUP can return an illegal error value 2024-06-21 14:38:40 +02:00
nilfs2 nilfs2: fix incorrect inode allocation from reserved inodes 2024-07-11 12:49:22 +02:00
nls nls: Hide new NLS_UCS2_UTILS 2023-08-31 12:07:34 -05:00
notify fanotify: limit reporting of event with non-decodeable file handles 2023-10-19 16:19:20 +02:00
ntfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
ntfs3 fs/ntfs3: Mark volume as dirty if xattr is broken 2024-07-11 12:49:19 +02:00
ocfs2 ocfs2: fix DIO failure due to insufficient transaction credits 2024-07-05 09:33:54 +02:00
omfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
openpromfs openpromfs: finish conversion to the new mount API 2024-06-12 11:11:30 +02:00
orangefs orangefs: fix out-of-bounds fsid access 2024-07-11 12:49:08 +02:00
overlayfs ovl: fix encoding fid for lower only root 2024-06-27 13:49:12 +02:00
proc fs/proc: fix softlockup in __read_vmcore 2024-06-21 14:38:41 +02:00
pstore pstore/zone: Add a null pointer check to the psz_kmsg_read 2024-04-13 13:07:31 +02:00
qnx4 for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
qnx6 for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
quota quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:19:46 -04:00
ramfs ramfs: convert to ctime accessor functions 2023-07-24 10:30:04 +02:00
reiserfs quota: Properly annotate i_dquot arrays with __rcu 2024-03-26 18:19:46 -04:00
romfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
smb cifs: fix typo in module parameter enable_gcm_256 2024-06-27 13:49:11 +02:00
squashfs Squashfs: check the inode number is not the invalid value of zero 2024-05-02 16:32:41 +02:00
sysfs fs: sysfs: Fix reference leak in sysfs_break_active_protection() 2024-04-27 17:11:41 +02:00
sysv sysv: don't call sb_bread() with pointers_lock held 2024-04-13 13:07:34 +02:00
tracefs eventfs: Update all the eventfs_inodes from the events descriptor 2024-06-21 14:38:22 +02:00
ubifs ubifs: Set page uptodate in the correct place 2024-04-03 15:28:20 +02:00
udf udf: udftime: prevent overflow in udf_disk_stamp_to_time() 2024-06-27 13:49:04 +02:00
ufs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
unicode
vboxsf vboxsf: explicitly deny setlease attempts 2024-05-17 12:02:13 +02:00
verity fsverity: use register_sysctl_init() to avoid kmemleak warning 2024-06-16 13:47:33 +02:00
xfs xfs: allow cross-linking special files without project quota 2024-06-21 14:38:45 +02:00
zonefs zonefs: Improve error handling 2024-02-23 09:25:13 +01:00
Kconfig for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
Kconfig.binfmt riscv: support the elf-fdpic binfmt loader 2023-08-23 14:17:43 -07:00
Makefile fs: add CONFIG_BUFFER_HEAD 2023-08-02 09:13:09 -06:00
aio.c fs/aio: Check IOCB_AIO_RW before the struct aio_kiocb conversion 2024-04-03 15:28:44 +02:00
anon_inodes.c
attr.c v6.6-vfs.misc 2023-08-28 10:17:14 -07:00
bad_inode.c fs: drop the timespec64 argument from update_time 2023-08-11 09:04:57 +02:00
binfmt_elf.c Merge branch 'expand-stack' 2023-06-28 20:35:21 -07:00
binfmt_elf_fdpic.c fs: binfmt_elf_efpic: fix personality for ELF-FDPIC 2023-09-29 17:20:45 -07:00
binfmt_elf_test.c
binfmt_flat.c
binfmt_misc.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
binfmt_script.c
buffer.c iomap: add a workaround for racy i_size updates on block devices 2023-09-25 08:55:00 -07:00
char_dev.c
compat_binfmt_elf.c
coredump.c v6.5/vfs.misc 2023-06-26 09:50:21 -07:00
d_path.c
dax.c mm: convert DAX lock/unlock page to lock/unlock folio 2024-01-10 17:16:53 +01:00
dcache.c vfs: don't mod negative dentry count when on shrinker list 2024-07-18 13:21:12 +02:00
direct-io.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
drop_caches.c fs: drop_caches: draining pages before dropping caches 2023-08-18 10:12:11 -07:00
eventfd.c eventfd: prevent underflow for eventfd semaphores 2023-07-11 11:41:34 +02:00
eventpoll.c epoll: be better about file lifetimes 2024-06-12 11:11:30 +02:00
exec.c exec: Fix NOMMU linux_binprm::exec in transfer_args_to_stack() 2024-04-03 15:28:55 +02:00
fcntl.c fs: Fix rw_hint validation 2024-03-26 18:19:17 -04:00
fhandle.c do_sys_name_to_handle(): use kzalloc() to fix kernel-infoleak 2024-03-26 18:19:15 -04:00
file.c v6.6-vfs.misc 2023-08-28 10:17:14 -07:00
file_table.c fs: use __fput_sync in close(2) 2023-08-08 19:36:51 +02:00
filesystems.c
fs-writeback.c fs/writeback: bail out if there is no more inodes for IO and queued once 2024-06-27 13:49:00 +02:00
fs_context.c fs: factor out vfs_parse_monolithic_sep() helper 2023-10-12 18:53:36 +03:00
fs_parser.c
fs_pin.c
fs_struct.c kill do_each_thread() 2023-08-21 13:46:25 -07:00
fs_types.c
fsopen.c fs: add FSCONFIG_CMD_CREATE_EXCL 2023-08-14 18:48:02 +02:00
init.c
inode.c filemap: add a per-mapping stable writes flag 2023-12-03 07:33:03 +01:00
internal.h for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
ioctl.c lsm: new security_file_ioctl_compat() hook 2024-01-31 16:18:54 -08:00
kernel_read_file.c fs: Fix kernel-doc warnings 2023-08-19 12:12:12 +02:00
libfs.c fs: new accessor methods for atime and mtime 2024-01-05 15:19:40 +01:00
locks.c filelock: fix potential use-after-free in posix_lock_inode 2024-07-18 13:21:11 +02:00
mbcache.c
mnt_idmapping.c
mount.h
mpage.c
namei.c rename(): fix the locking of subdirectories 2024-01-31 16:18:57 -08:00
namespace.c fs: relax mount_setattr() permission checks 2024-02-23 09:25:15 +01:00
nsfs.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
open.c ftruncate: pass a signed offset 2024-07-05 09:34:04 +02:00
pipe.c fs/pipe: Fix lockdep false-positive in watchqueue pipe_write() 2024-04-10 16:35:57 +02:00
pnode.c
pnode.h
posix_acl.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
proc_namespace.c
read_write.c fs: Fix one kernel-doc comment 2023-08-15 08:32:45 +02:00
readdir.c vfs: get rid of old '->iterate' directory operation 2023-08-06 15:08:35 +02:00
remap_range.c
select.c fs/select: rework stack allocation hack for clang 2024-03-26 18:19:17 -04:00
seq_file.c
signalfd.c
splice.c - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") 2023-08-29 14:25:26 -07:00
stack.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
stat.c fs: Pass AT_GETATTR_NOSEC flag to getattr interface function 2023-12-03 07:33:03 +01:00
statfs.c
super.c fs: export sget_dev() 2023-08-31 12:47:15 +02:00
sync.c
sysctls.c
timerfd.c
userfaultfd.c mm/userfaultfd: reset ptes when close() for wr-protected ones 2024-05-17 12:02:36 +02:00
utimes.c
xattr.c tmpfs,xattr: GFP_KERNEL_ACCOUNT for simple xattrs 2023-08-22 10:57:46 +02:00