From 3dc96bba65f53daa217f0a8f43edad145286a8f5 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 12 Jul 2022 12:54:21 +0200 Subject: mbcache: add functions to delete entry if unused 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 Link: https://lore.kernel.org/r/20220712105436.32204-2-jack@suse.cz Signed-off-by: Theodore Ts'o --- include/linux/mbcache.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'include') 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); -- cgit v1.2.3