Merge tag 'nfs-for-4.7-2' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client bugfixes from Anna Schumaker:
 "Stable bugfixes:
   - Fix _cancel_empty_pagelist
   - Fix a double page unlock
   - Make nfs_atomic_open() call d_drop() on all ->open_context() errors.
   - Fix another OPEN_DOWNGRADE bug

  Other bugfixes:
   - Ensure we handle delegation errors in nfs4_proc_layoutget()
   - Layout stateids start out as being invalid
   - Add sparse lock annotations for pnfs_find_alloc_layout
   - Handle bad delegation stateids in nfs4_layoutget_handle_exception
   - Fix up O_DIRECT results
   - Fix potential use after free of state in nfs4_do_reclaim.
   - Mark the layout stateid invalid when all segments are removed
   - Don't let readdirplus revalidate an inode that was marked as stale
   - Fix potential race in nfs_fhget()
   - Fix an unused variable warning"

* tag 'nfs-for-4.7-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  NFS: Fix another OPEN_DOWNGRADE bug
  make nfs_atomic_open() call d_drop() on all ->open_context() errors.
  NFS: Fix an unused variable warning
  NFS: Fix potential race in nfs_fhget()
  NFS: Don't let readdirplus revalidate an inode that was marked as stale
  NFSv4.1/pnfs: Mark the layout stateid invalid when all segments are removed
  NFS: Fix a double page unlock
  pnfs_nfs: fix _cancel_empty_pagelist
  nfs4: Fix potential use after free of state in nfs4_do_reclaim.
  NFS: Fix up O_DIRECT results
  NFS/pnfs: handle bad delegation stateids in nfs4_layoutget_handle_exception
  NFSv4.1/pnfs: Add sparse lock annotations for pnfs_find_alloc_layout
  NFSv4.1/pnfs: Layout stateids start out as being invalid
  NFSv4.1/pnfs: Ensure we handle delegation errors in nfs4_proc_layoutget()

1 files changed, 7 insertions, 3 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 0c7e0d45a4de..0fbe734cc38c 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -361,8 +361,10 @@ pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 	list_del_init(&lseg->pls_list);
 	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 	atomic_dec(&lo->plh_refcount);
-	if (list_empty(&lo->plh_segs))
+	if (list_empty(&lo->plh_segs)) {
+		set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
+	}
 	rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq);
 }
 
@@ -1290,6 +1292,7 @@ alloc_init_layout_hdr(struct inode *ino,
 	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
 	lo->plh_inode = ino;
 	lo->plh_lc_cred = get_rpccred(ctx->cred);
+	lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
 	return lo;
 }
 
@@ -1297,6 +1300,8 @@ static struct pnfs_layout_hdr *
 pnfs_find_alloc_layout(struct inode *ino,
 		       struct nfs_open_context *ctx,
 		       gfp_t gfp_flags)
+	__releases(&ino->i_lock)
+	__acquires(&ino->i_lock)
 {
 	struct nfs_inode *nfsi = NFS_I(ino);
 	struct pnfs_layout_hdr *new = NULL;
@@ -1565,8 +1570,7 @@ lookup_again:
 	 * stateid, or it has been invalidated, then we must use the open
 	 * stateid.
 	 */
-	if (lo->plh_stateid.seqid == 0 ||
-	    test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
+	if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
 
 		/*
 		 * The first layoutget for the file. Need to serialize per