nfs41: fix nfs4_proc_layoutget error handling

nfs4_layoutget_release() drops layout hdr refcnt. Grab the refcnt
early so that it is safe to call .release in case nfs4_alloc_pages
fails.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Fixes: a47970ff78147 ("NFSv4.1: Hold reference to layout hdr in layoutget")
Cc: stable@vger.kernel.org # 3.9+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 15d5eb52cde8..3138913d1cdf 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7702,6 +7702,9 @@ nfs4_proc_layoutget(struct nfs4_layoutget *lgp, gfp_t gfp_flags)
 
         dprintk("--> %s\n", __func__);
 
+        /* nfs4_layoutget_release calls pnfs_put_layout_hdr */
+        pnfs_get_layout_hdr(NFS_I(inode)->layout);
+
         lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
         if (!lgp->args.layout.pages) {
                 nfs4_layoutget_release(lgp);
@@ -7714,9 +7717,6 @@ nfs4_proc_layoutget(struct nfs4_layoutget *lgp, gfp_t gfp_flags)
         lgp->res.seq_res.sr_slot = NULL;
         nfs4_init_sequence(&lgp->args.seq_args, &lgp->res.seq_res, 0);
 
-        /* nfs4_layoutget_release calls pnfs_put_layout_hdr */
-        pnfs_get_layout_hdr(NFS_I(inode)->layout);
-
         task = rpc_run_task(&task_setup_data);
         if (IS_ERR(task))
                 return ERR_CAST(task);