Change log from v1:
o fix bug
>From 8cd63b5e91daeeccc1f158425c74de0f462c96af Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Date: Mon, 30 Nov 2015 16:26:44 -0800
Subject: [PATCH] f2fs: avoid deadlock in f2fs_shrink_extent_tree
While handling extent trees, we can enter into a reclaiming path anytime.
If it tries to release some extent nodes in the same extent tree,
write_lock(&et->lock) would be hanged.
In order to avoid the deadlock, we can just skip it.
Note that, if it is an unreferenced tree, we should get write_lock(&et->lock)
successfully and release all of therein nodes.
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/extent_cache.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 7ddba81..de063f2 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -615,9 +615,10 @@ unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
for (i = 0; i < found; i++) {
struct extent_tree *et = treevec[i];
- write_lock(&et->lock);
- node_cnt += __free_extent_tree(sbi, et, false);
- write_unlock(&et->lock);
+ if (write_trylock(&et->lock)) {
+ node_cnt += __free_extent_tree(sbi, et, false);
+ write_unlock(&et->lock);
+ }
if (node_cnt + tree_cnt >= nr_shrink)
goto unlock_out;
--
2.4.9 (Apple Git-60)
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
