Merge branch 'xfs-misc-fixes-3-for-3.16' into for-next

1 files changed, 13 insertions, 3 deletions

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 057f671811d6..703b3ec1796c 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -258,14 +258,23 @@ xfs_bmapi_allocate_worker(
         struct xfs_bmalloca     *args = container_of(work,
                                                 struct xfs_bmalloca, work);
         unsigned long           pflags;
+        unsigned long           new_pflags = PF_FSTRANS;
 
-        /* we are in a transaction context here */
-        current_set_flags_nested(&pflags, PF_FSTRANS);
+        /*
+         * we are in a transaction context here, but may also be doing work
+         * in kswapd context, and hence we may need to inherit that state
+         * temporarily to ensure that we don't block waiting for memory reclaim
+         * in any way.
+         */
+        if (args->kswapd)
+                new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD;
+
+        current_set_flags_nested(&pflags, new_pflags);
 
         args->result = __xfs_bmapi_allocate(args);
         complete(args->done);
 
-        current_restore_flags_nested(&pflags, PF_FSTRANS);
+        current_restore_flags_nested(&pflags, new_pflags);
 }
 
 /*
@@ -284,6 +293,7 @@ xfs_bmapi_allocate(
 
 
         args->done = &done;
+        args->kswapd = current_is_kswapd();
         INIT_WORK_ONSTACK(&args->work, xfs_bmapi_allocate_worker);
         queue_work(xfs_alloc_wq, &args->work);
         wait_for_completion(&done);