WSL2-Linux-Kernel/fs
John Stultz 295f3fcaa8 pstore: Revert pmsg_lock back to a normal mutex
[ Upstream commit 5239a89b06 ]

This reverts commit 76d62f24db.

So while priority inversion on the pmsg_lock is an occasional
problem that an rt_mutex would help with, in uses where logging
is writing to pmsg heavily from multiple threads, the pmsg_lock
can be heavily contended.

After this change landed, it was reported that cases where the
mutex locking overhead was commonly adding on the order of 10s
of usecs delay had suddenly jumped to ~msec delay with rtmutex.

It seems the slight differences in the locks under this level
of contention causes the normal mutexes to utilize the spinning
optimizations, while the rtmutexes end up in the sleeping
slowpath (which allows additional threads to pile on trying
to take the lock).

In this case, it devolves to a worse case senerio where the lock
acquisition and scheduling overhead dominates, and each thread
is waiting on the order of ~ms to do ~us of work.

Obviously, having tons of threads all contending on a single
lock for logging is non-optimal, so the proper fix is probably
reworking pstore pmsg to have per-cpu buffers so we don't have
contention.

Additionally, Steven Rostedt has provided some furhter
optimizations for rtmutexes that improves the rtmutex spinning
path, but at least in my testing, I still see the test tripping
into the sleeping path on rtmutexes while utilizing the spinning
path with mutexes.

But in the short term, lets revert the change to the rt_mutex
and go back to normal mutexes to avoid a potentially major
performance regression. And we can work on optimizations to both
rtmutexes and finer-grained locking for pstore pmsg in the
future.

Cc: Wei Wang <wvw@google.com>
Cc: Midas Chien<midaschieh@google.com>
Cc: "Chunhui Li (李春辉)" <chunhui.li@mediatek.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: kernel-team@android.com
Fixes: 76d62f24db ("pstore: Switch pmsg_lock to an rt_mutex to avoid priority inversion")
Reported-by: "Chunhui Li (李春辉)" <chunhui.li@mediatek.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230308204043.2061631-1-jstultz@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-11 23:00:31 +09:00
..
9p 9p: fix a bunch of checkpatch warnings 2022-08-17 14:24:07 +02:00
adfs mm: require ->set_page_dirty to be explicitly wired up 2021-06-29 10:53:48 -07:00
affs affs: initialize fsdata in affs_truncate() 2023-02-01 08:27:06 +01:00
afs afs: Fix lost servers_outstanding count 2022-12-31 13:14:45 +01:00
autofs autofs: fix wait name hash calculation in autofs_wait() 2021-10-20 21:09:02 -04:00
befs isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
bfs mm: require ->set_page_dirty to be explicitly wired up 2021-06-29 10:53:48 -07:00
btrfs btrfs: fix fast csum implementation detection 2023-04-20 12:13:52 +02:00
cachefiles fs: add is_idmapped_mnt() helper 2022-07-02 16:41:14 +02:00
ceph ceph: update the time stamps and try to drop the suid/sgid 2023-03-10 09:40:08 +01:00
cifs cifs: sanitize paths in cifs_update_super_prepath. 2023-04-13 16:48:24 +02:00
coda coda: Avoid partial allocation of sig_inputArgs 2023-03-10 09:39:50 +01:00
configfs configfs: fix possible memory leak in configfs_create_dir() 2022-12-31 13:14:15 +01:00
cramfs
crypto fscrypt: fix keyring memory leak on mount failure 2022-11-10 18:15:37 +01:00
debugfs debugfs: fix error when writing negative value to atomic_t debugfs file 2022-12-31 13:14:03 +01:00
devpts fsnotify: fix fsnotify hooks in pseudo filesystems 2022-02-01 17:27:01 +01:00
dlm fs: dlm: start midcomms before scand 2023-03-17 08:48:50 +01:00
ecryptfs fs: add is_idmapped_mnt() helper 2022-07-02 16:41:14 +02:00
efivarfs
efs
erofs erofs: fix potential overflow calculating xattr_isize 2023-05-11 23:00:20 +09:00
exfat exfat: fix inode->i_blocks for non-512 byte sector size device 2023-03-10 09:39:58 +01:00
exportfs exportfs: support idmapped mounts 2022-06-09 10:23:32 +02:00
ext2 ext2: Use kvmalloc() for group descriptor array 2022-10-26 12:35:51 +02:00
ext4 ext4: use ext4_journal_start/stop for fast commit transactions 2023-05-11 23:00:16 +09:00
f2fs f2fs: fix to avoid use-after-free for cached IPU bio 2023-05-11 23:00:27 +09:00
fat fat: add ratelimit to fat*_ent_bread() 2022-06-09 10:22:42 +02:00
freevxfs
fscache fscache: Remove an unused static variable 2021-10-04 22:13:12 +01:00
fuse fuse: fix deadlock between atomic O_TRUNC and page invalidation 2023-04-26 13:51:54 +02:00
gfs2 gfs2: Improve gfs2_make_fs_rw error handling 2023-03-10 09:39:53 +01:00
hfs hfs: fix missing hfs_bnode_get() in __hfs_bnode_create 2023-03-10 09:39:57 +01:00
hfsplus fs: hfsplus: fix UAF issue in hfsplus_put_super 2023-03-10 09:39:57 +01:00
hostfs hostfs: support splice_write 2021-08-26 22:28:02 +02:00
hpfs hpfs: use iomap_fiemap to implement ->fiemap 2021-07-27 11:00:36 +02:00
hugetlbfs hugetlbfs: fix null-ptr-deref in hugetlbfs_parse_param() 2022-12-31 13:14:44 +01:00
iomap iomap: iomap_write_failed fix 2022-06-09 10:22:55 +02:00
isofs isofs: Fix out of bound access for corrupted isofs image 2021-11-12 15:05:50 +01:00
jbd2 jdb2: Don't refuse invalidation of already invalidated buffers 2023-05-11 23:00:29 +09:00
jffs2 jffs2: correct logic when creating a hole in jffs2_write_begin 2023-03-22 13:31:30 +01:00
jfs fs/jfs: fix shift exponent db_agl2size negative 2023-03-11 13:57:22 +01:00
kernfs kernfs: fix use-after-free in __kernfs_remove 2022-11-03 23:59:13 +09:00
ksmbd ksmbd: fix memleak in session setup 2023-05-11 23:00:18 +09:00
lockd lockd: set file_lock start and end when decoding nlm4 testargs 2023-03-30 12:47:56 +02:00
minix minix: fix bug when opening a file with O_DIRECT 2022-04-13 20:59:10 +02:00
netfs netfs: fix parameter of cleanup() 2021-12-29 12:28:59 +01:00
nfs NFSv4: Fix hangs when recovering open state after a server reboot 2023-04-05 11:25:00 +02:00
nfs_common nfs: Fix kerneldoc warning shown up by W=1 2021-10-04 22:02:17 +01:00
nfsd NFSD: callback request does not use correct credential for AUTH_SYS 2023-04-13 16:48:19 +02:00
nilfs2 nilfs2: initialize unused bytes in segment summary blocks 2023-04-26 13:51:51 +02:00
nls
notify fsnotify: fix wrong lockdep annotations 2022-06-09 10:22:50 +02:00
ntfs ntfs: check overflow when iterating ATTR_RECORDs 2022-11-26 09:24:52 +01:00
ntfs3 fs/ntfs3: Validate attribute data and valid sizes 2023-02-09 11:26:47 +01:00
ocfs2 ocfs2: fix freeing uninitialized resource on ocfs2_dlm_shutdown 2023-04-13 16:48:26 +02:00
omfs mm: require ->set_page_dirty to be explicitly wired up 2021-06-29 10:53:48 -07:00
openpromfs
orangefs orangefs: Fix kmemleak in orangefs_{kernel,client}_debug_init() 2022-12-31 13:14:44 +01:00
overlayfs ovl: Use "buf" flexible array for memcpy() destination 2023-02-09 11:26:47 +01:00
proc mm: hugetlb: proc: check for hugetlb shared PMD in /proc/PID/smaps 2023-02-09 11:26:44 +01:00
pstore pstore: Revert pmsg_lock back to a normal mutex 2023-05-11 23:00:31 +09:00
qnx4 qnx4: work around gcc false positive warning bug 2021-09-21 08:36:48 -07:00
qnx6
quota ext4: fix bug_on in __es_tree_search caused by bad quota inode 2023-01-12 11:59:01 +01:00
ramfs fs: move ramfs_aops to libfs 2021-06-29 10:53:48 -07:00
reiserfs reiserfs: Add security prefix to xattr name in reiserfs_security_write() 2023-05-11 23:00:17 +09:00
romfs
smbfs_common cifs: Fix crash on unload of cifs_arc4.ko 2021-12-14 10:57:12 +01:00
squashfs revert "squashfs: harden sanity check in squashfs_read_xattr_id_table" 2023-02-22 12:57:07 +01:00
sysfs sysfs: Allow deferred execution of iomem_get_mapping() 2021-08-06 13:05:28 +02:00
sysv fs: sysv: Fix sysv_nblocks() returns wrong value 2022-12-31 13:14:05 +01:00
tracefs tracefs: Only clobber mode/uid/gid on remount if asked 2022-09-20 12:39:43 +02:00
ubifs ubifs: Free memory for tmpfile name 2023-05-11 23:00:18 +09:00
udf udf: Fix off-by-one error when discarding preallocation 2023-03-17 08:48:50 +01:00
ufs isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
unicode
vboxsf vboxfs: fix broken legacy mount signature checking 2021-09-27 11:26:21 -07:00
verity fsverity: don't drop pagecache at end of FS_IOC_ENABLE_VERITY 2023-04-05 11:24:51 +02:00
xfs xfs: don't consider future format versions valid 2023-05-11 23:00:18 +09:00
zonefs zonefs: Fix error message in zonefs_file_dio_append() 2023-04-05 11:25:01 +02:00
Kconfig 4 cifs/smb3 fixes, one for DFS reconnect, and one to begin creating common headers for server and client and the other two to rename the cifs_common directory to smbfs_common to be more consistent ie change use of the name cifs to smb which is more accurate 2021-09-12 10:10:21 -07:00
Kconfig.binfmt binfmt: remove support for em86 (alpha only) 2021-07-25 22:33:03 -07:00
Makefile io_uring: move to separate directory 2022-12-14 11:37:31 +01:00
aio.c aio: fix mremap after fork null-deref 2023-02-22 12:57:05 +01:00
anon_inodes.c
attr.c attr: use consistent sgid stripping checks 2023-03-17 08:49:01 +01:00
bad_inode.c vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
binfmt_aout.c binfmt: a.out: Fix bogus semicolon 2021-09-05 10:15:05 -07:00
binfmt_elf.c fs/binfmt_elf: Fix memory leak in load_elf_binary() 2022-11-03 23:59:12 +09:00
binfmt_elf_fdpic.c binfmt: Fix error return code in load_elf_fdpic_binary() 2023-01-12 11:58:46 +01:00
binfmt_flat.c binfmt_flat: do not stop relocating GOT entries prematurely on riscv 2022-06-09 10:22:26 +02:00
binfmt_misc.c binfmt_misc: fix shift-out-of-bounds in check_special_flags 2022-12-31 13:14:39 +01:00
binfmt_script.c
buffer.c mm: fs: initialize fsdata passed to write_begin/write_end interface 2022-11-26 09:24:51 +01:00
char_dev.c chardev: fix error handling in cdev_device_add() 2022-12-31 13:14:30 +01:00
compat_binfmt_elf.c
coredump.c coredump: Use the vma snapshot in fill_files_note 2022-04-08 14:24:18 +02:00
d_path.c d_path: make 'prepend()' fill up the buffer exactly on overflow 2021-09-02 10:07:29 -07:00
dax.c fsdax: Fix infinite loop in dax_iomap_rw() 2022-09-28 11:11:56 +02:00
dcache.c
direct-io.c
drop_caches.c fs: drop_caches: fix skipping over shadow cache inodes 2021-09-03 09:58:10 -07:00
eventfd.c eventfd: provide a eventfd_signal_mask() helper 2023-01-24 07:22:43 +01:00
eventpoll.c eventpoll: add EPOLL_URING_WAKE poll wakeup flag 2023-01-24 07:22:43 +01:00
exec.c exec: Copy oldsighand->action under spin-lock 2022-11-03 23:59:12 +09:00
fcntl.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
fhandle.c
file.c fs: prevent out-of-bounds array speculation when closing a file descriptor 2023-03-17 08:48:47 +01:00
file_table.c locks: fix TOCTOU race when granting write lease 2022-10-26 12:34:58 +02:00
filesystems.c fs: simplify get_filesystem_list / get_all_fs_names 2021-08-23 01:25:40 -04:00
fs-writeback.c writeback, cgroup: fix null-ptr-deref write in bdi_split_work_to_wbs 2023-05-11 23:00:18 +09:00
fs_context.c vfs: fs_context: fix up param length parsing in legacy_parse_param 2022-01-20 09:13:14 +01:00
fs_parser.c namei: Standardize callers of filename_lookup() 2021-09-07 16:07:47 -04:00
fs_pin.c
fs_struct.c
fs_types.c
fsopen.c
init.c
inode.c attr: use consistent sgid stripping checks 2023-03-17 08:49:01 +01:00
internal.h attr: use consistent sgid stripping checks 2023-03-17 08:49:01 +01:00
ioctl.c fs: fix an infinite loop in iomap_fiemap 2022-05-25 09:57:26 +02:00
kernel_read_file.c vfs: check fd has read access in kernel_read_file_from_fd() 2021-10-18 20:22:03 -10:00
libfs.c libfs: add DEFINE_SIMPLE_ATTRIBUTE_SIGNED for signed value 2022-12-31 13:14:03 +01:00
locks.c filelocks: use mount idmapping for setlease permission check 2023-03-17 08:49:02 +01:00
mbcache.c mbcache: Avoid nesting of cache->c_list_lock under bit locks 2023-01-12 11:59:20 +01:00
mount.h
mpage.c
namei.c fs: move S_ISGID stripping into the vfs_*() helpers 2023-03-17 08:49:00 +01:00
namespace.c fs: drop peer group ids under namespace lock 2023-04-13 16:48:25 +02:00
no-block.c
nsfs.c
open.c attr: use consistent sgid stripping checks 2023-03-17 08:49:01 +01:00
pipe.c pipe: Fix missing lock in pipe_resize_ring() 2022-06-06 08:43:37 +02:00
pnode.c pnode: terminate at peers of source 2023-01-12 11:58:47 +01:00
pnode.h
posix_acl.c fs: fix acl translation 2022-07-02 16:41:17 +02:00
proc_namespace.c fs: add is_idmapped_mnt() helper 2022-07-02 16:41:14 +02:00
read_write.c vfs: fix copy_file_range() averts filesystem freeze protection 2022-12-19 12:36:39 +01:00
readdir.c
remap_range.c fs/remap: constrain dedupe of EOF blocks 2022-07-21 21:24:14 +02:00
select.c select: Fix indefinitely sleeping task in poll_schedule_timeout() 2022-01-29 10:58:25 +01:00
seq_file.c rxrpc: Fix locking issue 2022-07-12 16:35:08 +02:00
signalfd.c signalfd: use wake_up_pollfree() 2021-12-14 10:57:15 +01:00
splice.c Revert "fs: check FMODE_LSEEK to control internal pipe splicing" 2022-10-26 12:34:17 +02:00
stack.c
stat.c stat: fix inconsistency between struct stat and struct compat_stat 2022-04-27 14:38:57 +02:00
statfs.c
super.c fscrypt: destroy keyring after security_sb_delete() 2023-03-30 12:47:56 +02:00
sync.c vfs: make sync_filesystem return errors from ->sync_fs 2022-04-27 14:38:50 +02:00
timerfd.c timerfd: Provide timerfd_resume() 2021-08-10 17:57:22 +02:00
userfaultfd.c userfaultfd: open userfaultfds with O_RDONLY 2022-10-26 12:34:36 +02:00
utimes.c
xattr.c fs: don't audit the capability check in simple_xattr_list() 2022-12-31 13:14:01 +01:00