[PATCH] vfs: replace WARN(down_read_trylock, ...) abuse with proper asserts

From: Mateusz Guzik
Date: Sun Jun 02 2024 - 08:37:43 EST


Note the macro used here works regardless of LOCKDEP.

Signed-off-by: Mateusz Guzik <mjguzik@xxxxxxxxx>
---
fs/dcache.c | 2 +-
fs/quota/dquot.c | 8 ++------
2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 407095188f83..a0a944fd3a1c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1548,7 +1548,7 @@ void shrink_dcache_for_umount(struct super_block *sb)
{
struct dentry *dentry;

- WARN(down_read_trylock(&sb->s_umount), "s_umount should've been locked");
+ rwsem_assert_held_write(&sb->s_umount);

dentry = sb->s_root;
sb->s_root = NULL;
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 627eb2f72ef3..a2b256dac36e 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2246,9 +2246,7 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
int cnt;
struct quota_info *dqopt = sb_dqopt(sb);

- /* s_umount should be held in exclusive mode */
- if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
- up_read(&sb->s_umount);
+ rwsem_assert_held_write(&sb->s_umount);

/* Cannot turn off usage accounting without turning off limits, or
* suspend quotas and simultaneously turn quotas off. */
@@ -2510,9 +2508,7 @@ int dquot_resume(struct super_block *sb, int type)
int ret = 0, cnt;
unsigned int flags;

- /* s_umount should be held in exclusive mode */
- if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount)))
- up_read(&sb->s_umount);
+ rwsem_assert_held_write(&sb->s_umount);

for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
if (type != -1 && cnt != type)
--
2.39.2