f2fs: fix to avoid potential deadlock

We should always check F2FS_I(inode)->cp_task condition in prior to other
conditions in __should_serialize_io() to avoid deadloop described in
commit 040d2bb318d1 ("f2fs: fix to avoid deadloop if data_flush is on"),
however we break this rule when we support compression, fix it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 326e6342c578e44012b243aa4fbcc342605f1649..bb66faf09eeaffeb399ce2ccad111c2b07b80985 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2962,15 +2962,17 @@ next:
 static inline bool __should_serialize_io(struct inode *inode,
                                        struct writeback_control *wbc)
 {
+       /* to avoid deadlock in path of data flush */
+       if (F2FS_I(inode)->cp_task)
+               return false;
+
        if (!S_ISREG(inode->i_mode))
                return false;
-       if (f2fs_compressed_file(inode))
-               return true;
        if (IS_NOQUOTA(inode))
                return false;
-       /* to avoid deadlock in path of data flush */
-       if (F2FS_I(inode)->cp_task)
-               return false;
+
+       if (f2fs_compressed_file(inode))
+               return true;
        if (wbc->sync_mode != WB_SYNC_ALL)
                return true;
        if (get_dirty_pages(inode) >= SM_I(F2FS_I_SB(inode))->min_seq_blocks)