nfs4.1: fix several problems with _pnfs_return_layout

_pnfs_return_layout had the following problems:

- it did not call pnfs_free_lseg_list on all paths
- it unintentionally did a forgetful return when there was no outstanding io
- it raced with concurrent LAYOUTGETS

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 289c539..5879b23 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5706,6 +5706,7 @@ static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata)
 {
        struct nfs4_layoutreturn *lrp = calldata;
        struct nfs_server *server;
+       struct pnfs_layout_hdr *lo = NFS_I(lrp->args.inode)->layout;
 
        dprintk("--> %s\n", __func__);
 
@@ -5717,16 +5718,15 @@ static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata)
                nfs_restart_rpc(task, lrp->clp);
                return;
        }
+       spin_lock(&lo->plh_inode->i_lock);
        if (task->tk_status == 0) {
-               struct pnfs_layout_hdr *lo = NFS_I(lrp->args.inode)->layout;
-
                if (lrp->res.lrs_present) {
-                       spin_lock(&lo->plh_inode->i_lock);
                        pnfs_set_layout_stateid(lo, &lrp->res.stateid, true);
-                       spin_unlock(&lo->plh_inode->i_lock);
                } else
                        BUG_ON(!list_empty(&lo->plh_segs));
        }
+       lo->plh_block_lgets--;
+       spin_unlock(&lo->plh_inode->i_lock);
        dprintk("<-- %s\n", __func__);
 }
 

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 8c1309d..25de6b2 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -634,12 +634,14 @@ _pnfs_return_layout(struct inode *ino)
 
        spin_lock(&ino->i_lock);
        lo = nfsi->layout;
-       if (!lo || !mark_matching_lsegs_invalid(lo, &tmp_list, NULL)) {
+       if (!lo) {
                spin_unlock(&ino->i_lock);
-               dprintk("%s: no layout segments to return\n", __func__);
-               goto out;
+               dprintk("%s: no layout to return\n", __func__);
+               return status;
        }
        stateid = nfsi->layout->plh_stateid;
+       mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
+       lo->plh_block_lgets++;
        /* Reference matched in nfs4_layoutreturn_release */
        get_layout_hdr(lo);
        spin_unlock(&ino->i_lock);