f2fs: flush dirty pages before starting atomic writes

If somebody wrote some data before atomic writes, we should flush them in order
to handle atomic data in a right period.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index ed389f6..7de90e6 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1369,7 +1369,16 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
        set_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
        f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 
-       return 0;
+       if (!get_dirty_pages(inode))
+               return 0;
+
+       f2fs_msg(F2FS_I_SB(inode)->sb, KERN_WARNING,
+               "Unexpected flush for atomic writes: ino=%lu, npages=%u",
+                                       inode->i_ino, get_dirty_pages(inode));
+       ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
+       if (ret)
+               clear_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
+       return ret;
 }
 
 static int f2fs_ioc_commit_atomic_write(struct file *filp)