xfs: switch to NOFS allocation under i_lock in xfs_getbmap

xfs_getbmap allocates memory with i_lock held, but i_lock is taken in
reclaim context so all allocations under it must avoid recursions into
the filesystem.

Reported by the new reclaim context tracing in lockdep.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>

diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 7928b9983c1d53e6d0ca3c2719ce361bb95175f8..8ee5b5a76a2aff78995fb5a86926a0c9b1546bbd 100644 (file)
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -6009,7 +6009,7 @@ xfs_getbmap(
         */
        error = ENOMEM;
        subnex = 16;
-       map = kmem_alloc(subnex * sizeof(*map), KM_MAYFAIL);
+       map = kmem_alloc(subnex * sizeof(*map), KM_MAYFAIL | KM_NOFS);
        if (!map)
                goto out_unlock_ilock;