btrfs: fix several uncheck memory allocations

To make btrfs more stable, add several missing necessary memory allocation
checks, and when no memory, return proper errno.

We've checked that some of those -ENOMEM errors will be returned to
userspace, and some will be catched by BUG_ON() in the upper callers,
and none will be ignored silently.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 6f0444473594..3220ad1aafc8 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -176,6 +176,8 @@ static struct dentry *btrfs_get_parent(struct dentry *child)
         int ret;
 
         path = btrfs_alloc_path();
+        if (!path)
+                return ERR_PTR(-ENOMEM);
 
         if (dir->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
                 key.objectid = root->root_key.objectid;