1 files changed, 19 insertions, 5 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 212cbc22c59d..59ed68bf79fa 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -371,6 +371,14 @@ pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
                 memcpy(&lo->plh_stateid, &new->stateid, sizeof(new->stateid));
 }
 
+/* lget is set to 1 if called from inside send_layoutget call chain */
+static bool
+pnfs_layoutgets_blocked(struct pnfs_layout_hdr *lo, int lget)
+{
+        return (list_empty(&lo->plh_segs) &&
+                 (atomic_read(&lo->plh_outstanding) > lget));
+}
+
 int
 pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
                               struct nfs4_state *open_state)
@@ -379,7 +387,9 @@ pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
 
         dprintk("--> %s\n", __func__);
         spin_lock(&lo->plh_inode->i_lock);
-        if (list_empty(&lo->plh_segs)) {
+        if (pnfs_layoutgets_blocked(lo, 1)) {
+                status = -EAGAIN;
+        } else if (list_empty(&lo->plh_segs)) {
                 int seq;
 
                 do {
@@ -414,10 +424,8 @@ send_layoutget(struct pnfs_layout_hdr *lo,
 
         BUG_ON(ctx == NULL);
         lgp = kzalloc(sizeof(*lgp), GFP_KERNEL);
-        if (lgp == NULL) {
-                put_layout_hdr(lo->plh_inode);
+        if (lgp == NULL)
                 return NULL;
-        }
         lgp->args.minlength = NFS4_MAX_UINT64;
         lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
         lgp->args.range.iomode = iomode;
@@ -613,10 +621,16 @@ pnfs_update_layout(struct inode *ino,
         if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags))
                 goto out_unlock;
 
-        get_layout_hdr_locked(lo); /* Matched in nfs4_layoutget_release */
+        if (pnfs_layoutgets_blocked(lo, 0))
+                goto out_unlock;
+        atomic_inc(&lo->plh_outstanding);
+
+        get_layout_hdr_locked(lo);
         spin_unlock(&ino->i_lock);
 
         lseg = send_layoutget(lo, ctx, iomode);
+        atomic_dec(&lo->plh_outstanding);
+        put_layout_hdr(ino);
 out:
         dprintk("%s end, state 0x%lx lseg %p\n", __func__,
                 nfsi->layout->plh_flags, lseg);