f2fs: compress: fix to relocate check condition in f2fs_{release,reserve}_compress_blocks()

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

Fixes: 4c8ff70 ("f2fs: support data compression")
Reported-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Closes: https://lore.kernel.org/linux-f2fs-devel/CAHJ8P3LdZXLc2rqeYjvymgYHr2+YLuJ0sLG9DdsJZmwO7deuhw@mail.gmail.com
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Author: chaseyu

fs/f2fs/file.c

@@ -3543,9 +3543,6 @@ 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;
 
@@ -3564,7 +3561,8 @@ 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;
 	}
@@ -3725,9 +3723,6 @@ 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;
 
@@ -3739,7 +3734,8 @@ 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;
 	}