diff options
| author | Jan Kara <jack@suse.cz> | 2022-07-12 12:54:21 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-14 10:16:43 +0100 |
| commit | 27c08673978ebf31d56a822b3fb3aa74c8e1e4f2 (patch) | |
| tree | 7560fd56b04247f8e9acaf425e25a2a06135c97f /include | |
| parent | fb59d12ae7f9f7584e6702d4c2e26ce10210af3d (diff) | |
mbcache: add functions to delete entry if unused
[ Upstream commit 3dc96bba65f53daa217f0a8f43edad145286a8f5 ]
Add function mb_cache_entry_delete_or_get() to delete mbcache entry if
it is unused and also add a function to wait for entry to become unused
- mb_cache_entry_wait_unused(). We do not share code between the two
deleting function as one of them will go away soon.
CC: stable@vger.kernel.org
Fixes: 82939d7999df ("ext4: convert to mbcache2")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220712105436.32204-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: a44e84a9b776 ("ext4: fix deadlock due to mbcache entry corruption")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mbcache.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/include/linux/mbcache.h b/include/linux/mbcache.h index 20f1e3ff6013..8eca7f25c432 100644 --- a/include/linux/mbcache.h +++ b/include/linux/mbcache.h @@ -30,15 +30,23 @@ void mb_cache_destroy(struct mb_cache *cache); int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key, u64 value, bool reusable); void __mb_cache_entry_free(struct mb_cache_entry *entry); +void mb_cache_entry_wait_unused(struct mb_cache_entry *entry); static inline int mb_cache_entry_put(struct mb_cache *cache, struct mb_cache_entry *entry) { - if (!atomic_dec_and_test(&entry->e_refcnt)) + unsigned int cnt = atomic_dec_return(&entry->e_refcnt); + + if (cnt > 0) { + if (cnt <= 3) + wake_up_var(&entry->e_refcnt); return 0; + } __mb_cache_entry_free(entry); return 1; } +struct mb_cache_entry *mb_cache_entry_delete_or_get(struct mb_cache *cache, + u32 key, u64 value); void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value); struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key, u64 value); |