Change log from v1: o fix bug >From 8cd63b5e91daeeccc1f158425c74de0f462c96af Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim <[email protected]> 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 <[email protected]> --- 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-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
