[PATCH 5/7] xfs: use xfs_ilock_map_shared in xfs_attr_get

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

We might not have read in the extent list at this point, so make sure we
take the ilock exclusively if we have to do so.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Index: xfs/fs/xfs/xfs_attr.c
===================================================================
--- xfs.orig/fs/xfs/xfs_attr.c  2013-12-05 22:19:26.087829792 +0100
+++ xfs/fs/xfs/xfs_attr.c       2013-12-05 22:23:54.307824288 +0100
@@ -164,6 +164,7 @@ xfs_attr_get(
 {
        int             error;
        struct xfs_name xname;
+       uint            lock_mode;
 
        XFS_STATS_INC(xs_attr_get);
 
@@ -174,9 +175,9 @@ xfs_attr_get(
        if (error)
                return error;
 
-       xfs_ilock(ip, XFS_ILOCK_SHARED);
+       lock_mode = xfs_ilock_map_shared(ip);
        error = xfs_attr_get_int(ip, &xname, value, valuelenp, flags);
-       xfs_iunlock(ip, XFS_ILOCK_SHARED);
+       xfs_iunlock_map_shared(ip, lock_mode);
        return(error);
 }