From: Jan Kara <jack@suse.cz>
To: Ted Tso <tytso@mit.edu>
Cc: <linux-ext4@vger.kernel.org>,
Ritesh Harjani <ritesh.list@gmail.com>, Jan Kara <jack@suse.cz>,
stable@vger.kernel.org
Subject: [PATCH 01/10] mbcache: Don't reclaim used entries
Date: Tue, 12 Jul 2022 12:54:20 +0200 [thread overview]
Message-ID: <20220712105436.32204-1-jack@suse.cz> (raw)
In-Reply-To: <20220712104519.29887-1-jack@suse.cz>
Do not reclaim entries that are currently used by somebody from a
shrinker. Firstly, these entries are likely useful. Secondly, we will
need to keep such entries to protect pending increment of xattr block
refcount.
CC: stable@vger.kernel.org
Fixes: 82939d7999df ("ext4: convert to mbcache2")
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/mbcache.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/mbcache.c b/fs/mbcache.c
index 97c54d3a2227..cfc28129fb6f 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -288,7 +288,7 @@ static unsigned long mb_cache_shrink(struct mb_cache *cache,
while (nr_to_scan-- && !list_empty(&cache->c_list)) {
entry = list_first_entry(&cache->c_list,
struct mb_cache_entry, e_list);
- if (entry->e_referenced) {
+ if (entry->e_referenced || atomic_read(&entry->e_refcnt) > 2) {
entry->e_referenced = 0;
list_move_tail(&entry->e_list, &cache->c_list);
continue;
@@ -302,6 +302,14 @@ static unsigned long mb_cache_shrink(struct mb_cache *cache,
spin_unlock(&cache->c_list_lock);
head = mb_cache_entry_head(cache, entry->e_key);
hlist_bl_lock(head);
+ /* Now a reliable check if the entry didn't get used... */
+ if (atomic_read(&entry->e_refcnt) > 2) {
+ hlist_bl_unlock(head);
+ spin_lock(&cache->c_list_lock);
+ list_add_tail(&entry->e_list, &cache->c_list);
+ cache->c_entry_count++;
+ continue;
+ }
if (!hlist_bl_unhashed(&entry->e_hash_list)) {
hlist_bl_del_init(&entry->e_hash_list);
atomic_dec(&entry->e_refcnt);
--
2.35.3
next parent reply other threads:[~2022-07-12 10:54 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220712104519.29887-1-jack@suse.cz>
2022-07-12 10:54 ` Jan Kara [this message]
2022-07-14 11:47 ` [PATCH 01/10] mbcache: Don't reclaim used entries Ritesh Harjani
2022-07-14 14:36 ` Jan Kara
2022-07-14 14:49 ` Ritesh Harjani
2022-07-22 13:58 ` Theodore Ts'o
2022-07-12 10:54 ` [PATCH 02/10] mbcache: Add functions to delete entry if unused Jan Kara
2022-07-14 12:15 ` Ritesh Harjani
2022-07-14 14:49 ` Jan Kara
2022-07-14 15:00 ` Ritesh Harjani
2022-07-12 10:54 ` [PATCH 03/10] ext4: Remove EA inode entry from mbcache on inode eviction Jan Kara
2022-07-12 10:54 ` [PATCH 04/10] ext4: Unindent codeblock in ext4_xattr_block_set() Jan Kara
2022-07-14 12:19 ` Ritesh Harjani
2022-07-12 10:54 ` [PATCH 05/10] ext4: Fix race when reusing xattr blocks Jan Kara
2022-07-14 12:26 ` Ritesh Harjani
2022-07-16 3:00 ` Zhihao Cheng
2022-07-25 15:23 ` Jan Kara
2022-07-26 1:14 ` Zhihao Cheng
[not found] <20220614124146.21594-1-jack@suse.cz>
2022-06-14 16:05 ` [PATCH 01/10] mbcache: Don't reclaim used entries Jan Kara
2022-06-16 14:22 ` Ritesh Harjani
2022-06-16 17:25 ` Jan Kara
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