Multi write opens will go into __fscache_disable_cookie and cookie->n_active
may be zero for a short window. Move this assertion under locking to avoid
assert failure for ASSERTCMP(atomic_read(&cookie->n_active), >, 0).
stack is as following:
fscache_disable_cookie include/linux/fscache.h:854 [inline]
nfs_fscache_open_file+0x3ba/0x430 fs/nfs/fscache.c:319
nfs4_file_open+0x4ff/0x780 fs/nfs/nfs4file.c:90
do_dentry_open+0x6ea/0x1170 fs/open.c:826
do_open.isra.0+0x9dc/0xf50 fs/namei.c:3316
path_openat+0x336/0x810 fs/namei.c:3434
do_filp_open+0x1b9/0x290 fs/namei.c:3461
do_sys_openat2+0x5be/0x9b0 fs/open.c:1231
do_sys_open+0xc8/0x150 fs/open.c:1248
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x67/0xd1
Signed-off-by: zhangjian <zhangjian496@xxxxxxxxxx>
---
fs/fscache/cookie.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 6104f627c..30f0e2b41 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -703,6 +703,9 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie,
_enter("%p,%u", cookie, invalidate);
+ wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK,
+ TASK_UNINTERRUPTIBLE);
+
trace_fscache_disable(cookie);
ASSERTCMP(atomic_read(&cookie->n_active), >, 0);
@@ -713,9 +716,6 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie,
BUG();
}
- wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK,
- TASK_UNINTERRUPTIBLE);
-
fscache_update_aux(cookie, aux_data);
if (!test_and_clear_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags))
--
2.33.0
