[GFS2] Fix locking for Direct I/O reads

We need to hold i_mutex when doing direct i/o reads.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 26db333..27ce301 100644 (file)
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -642,6 +642,7 @@ static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
        struct inode *inode = file->f_mapping->host;
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_sbd *sdp = GFS2_SB(inode);
+       int ret;
 
        if (rw == WRITE)
                return gfs2_direct_IO_write(iocb, iov, offset, nr_segs);
@@ -650,9 +651,12 @@ static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
            gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
                return -EINVAL;
 
-       return __blockdev_direct_IO(READ, iocb, inode, inode->i_sb->s_bdev, iov,
-                                   offset, nr_segs, gfs2_get_block, NULL,
-                                   DIO_OWN_LOCKING);
+       mutex_lock(&inode->i_mutex);
+       ret = __blockdev_direct_IO(READ, iocb, inode, inode->i_sb->s_bdev, iov,
+                                  offset, nr_segs, gfs2_get_block, NULL,
+                                  DIO_OWN_LOCKING);
+       mutex_unlock(&inode->i_mutex);
+       return ret;
 }
 
 const struct address_space_operations gfs2_file_aops = {