btrfs: use GFP_NOFS instead of GFP_KERNEL

In the filesystem context, we must allocate memory by GFP_NOFS,
or we may start another filesystem operation and make kswap thread hang up.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 5bc658a9d85cb45cca0cbd8c8b68b2dddb8fce04..7922f296420d5b31ed9b506b246984125ad4f4e4 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -471,7 +471,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
        if (load_cache_only)
                return 0;
 
-       caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_KERNEL);
+       caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
        BUG_ON(!caching_ctl);
 
        INIT_LIST_HEAD(&caching_ctl->list);
@@ -1743,7 +1743,7 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
 static void btrfs_issue_discard(struct block_device *bdev,
                                u64 start, u64 len)
 {
-       blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0);
+       blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
 }
 
 static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,