[PATCH 1/2] f2fs: compress: fix to relocate check condition in f2fs_{release,reserve}_compress_blocks()

[Chao Yu]

Compress flag should be checked after inode lock held to avoid
racing w/ f2fs_setflags_common(), fix it.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Reported-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
Closes: https://lore.kernel.org/linux-f2fs-devel/CAHJ8P3LdZXLc2rqeYjvymgYHr2+YLuJ0sLG9DdsJZmwO7deuhw@xxxxxxxxxxxxxx
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
 fs/f2fs/file.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 2cd4ca8433e1..ca401cf8152a 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3549,9 +3549,6 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
 	if (!f2fs_sb_has_compression(sbi))
 		return -EOPNOTSUPP;
 
-	if (!f2fs_compressed_file(inode))
-		return -EINVAL;
-
 	if (f2fs_readonly(sbi->sb))
 		return -EROFS;
 
@@ -3570,7 +3567,8 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
 		goto out;
 	}
 
-	if (is_inode_flag_set(inode, FI_COMPRESS_RELEASED)) {
+	if (!f2fs_compressed_file(inode) ||
+		is_inode_flag_set(inode, FI_COMPRESS_RELEASED)) {
 		ret = -EINVAL;
 		goto out;
 	}
@@ -3731,9 +3729,6 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
 	if (!f2fs_sb_has_compression(sbi))
 		return -EOPNOTSUPP;
 
-	if (!f2fs_compressed_file(inode))
-		return -EINVAL;
-
 	if (f2fs_readonly(sbi->sb))
 		return -EROFS;
 
@@ -3745,7 +3740,8 @@ static int f2fs_reserve_compress_blocks(struct file *filp, unsigned long arg)
 
 	inode_lock(inode);
 
-	if (!is_inode_flag_set(inode, FI_COMPRESS_RELEASED)) {
+	if (!f2fs_compressed_file(inode) ||
+		!is_inode_flag_set(inode, FI_COMPRESS_RELEASED)) {
 		ret = -EINVAL;
 		goto unlock_inode;
 	}
-- 
2.40.1