ext4: Support setting FMODE_CAN_ATOMIC_WRITE

FS needs to add the fmode capability in order to support atomic writes
during file open (refer kiocb_set_rw_flags()). Set this capability on
a regular file if ext4 can do atomic write.

Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index a7b9b9751a3f165e59cd084c8eb8808bf6aeae4e..96d936f5584bdbf48664e77847b75bccdce91d96 100644 (file)
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -898,6 +898,9 @@ static int ext4_file_open(struct inode *inode, struct file *filp)
                        return ret;
        }
 
+       if (ext4_inode_can_atomic_write(inode))
+               filp->f_mode |= FMODE_CAN_ATOMIC_WRITE;
+
        filp->f_mode |= FMODE_NOWAIT | FMODE_CAN_ODIRECT;
        return dquot_file_open(inode, filp);
 }