From 2c7772b3f2d50c993e93ccb96fdf0feed9c121b3 Mon Sep 17 00:00:00 2001 From: Zhang Qilong Date: Mon, 5 Sep 2022 12:59:17 +0800 Subject: [PATCH] f2fs: fix race condition on setting FI_NO_EXTENT flag [ Upstream commit 07725adc55c0a414c10acb5c8c86cea34b95ddef ] The following scenarios exist. process A: process B: ->f2fs_drop_extent_tree ->f2fs_update_extent_cache_range ->f2fs_update_extent_tree_range ->write_lock ->set_inode_flag ->is_inode_flag_set ->__free_extent_tree // Shouldn't // have been // cleaned up // here ->write_lock In this case, the "FI_NO_EXTENT" flag is set between f2fs_update_extent_tree_range and is_inode_flag_set by other process. it leads to clearing the whole exten tree which should not have happened. And we fix it by move the setting it to the range of write_lock. Fixes:5f281fab9b9a3 ("f2fs: disable extent_cache for fcollapse/finsert inodes") Signed-off-by: Zhang Qilong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/extent_cache.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c index aff6c2ed1c02..042c9d4f73cf 100644 --- a/fs/f2fs/extent_cache.c +++ b/fs/f2fs/extent_cache.c @@ -709,9 +709,8 @@ void f2fs_drop_extent_tree(struct inode *inode) if (!f2fs_may_extent_tree(inode)) return; - set_inode_flag(inode, FI_NO_EXTENT); - write_lock(&et->lock); + set_inode_flag(inode, FI_NO_EXTENT); __free_extent_tree(sbi, et); __drop_largest_extent(inode, 0, UINT_MAX); write_unlock(&et->lock); -- 2.20.1