NFSv4.1: Clean up the removal of pnfs_layout_hdr from the server list

Move the code into pnfs_free_layout_hdr(), and add checks to
get_layout_by_fh_locked to ensure that they don't reference a layout
that is being freed.

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

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 24252fe..76b4a7a 100644 (file)
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -122,7 +122,15 @@ static struct pnfs_layout_hdr * get_layout_by_fh_locked(struct nfs_client *clp,
                        ino = igrab(lo->plh_inode);
                        if (!ino)
                                continue;
+                       spin_lock(&ino->i_lock);
+                       /* Is this layout in the process of being freed? */
+                       if (NFS_I(ino)->layout != lo) {
+                               spin_unlock(&ino->i_lock);
+                               iput(ino);
+                               continue;
+                       }
                        pnfs_get_layout_hdr(lo);
+                       spin_unlock(&ino->i_lock);
                        return lo;
                }
        }
@@ -196,9 +204,18 @@ static u32 initiate_bulk_draining(struct nfs_client *clp,
                        continue;
 
                list_for_each_entry(lo, &server->layouts, plh_layouts) {
-                       if (!igrab(lo->plh_inode))
+                       ino = igrab(lo->plh_inode);
+                       if (ino)
+                               continue;
+                       spin_lock(&ino->i_lock);
+                       /* Is this layout in the process of being freed? */
+                       if (NFS_I(ino)->layout != lo) {
+                               spin_unlock(&ino->i_lock);
+                               iput(ino);
                                continue;
+                       }
                        pnfs_get_layout_hdr(lo);
+                       spin_unlock(&ino->i_lock);
                        BUG_ON(!list_empty(&lo->plh_bulk_recall));
                        list_add(&lo->plh_bulk_recall, &recall_list);
                }

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 0866314..11cc0ad 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -207,7 +207,16 @@ pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 static void
 pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 {
-       struct pnfs_layoutdriver_type *ld = NFS_SERVER(lo->plh_inode)->pnfs_curr_ld;
+       struct nfs_server *server = NFS_SERVER(lo->plh_inode);
+       struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
+
+       if (!list_empty(&lo->plh_layouts)) {
+               struct nfs_client *clp = server->nfs_client;
+
+               spin_lock(&clp->cl_lock);
+               list_del_init(&lo->plh_layouts);
+               spin_unlock(&clp->cl_lock);
+       }
        put_rpccred(lo->plh_lc_cred);
        return ld->alloc_layout_hdr ? ld->free_layout_hdr(lo) : kfree(lo);
 }
@@ -217,7 +226,6 @@ pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 {
        struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
        dprintk("%s: freeing layout cache %p\n", __func__, lo);
-       BUG_ON(!list_empty(&lo->plh_layouts));
        nfsi->layout = NULL;
        /* Reset MDS Threshold I/O counters */
        nfsi->write_io = 0;
@@ -480,22 +488,10 @@ void
 pnfs_free_lseg_list(struct list_head *free_me)
 {
        struct pnfs_layout_segment *lseg, *tmp;
-       struct pnfs_layout_hdr *lo;
 
        if (list_empty(free_me))
                return;
 
-       lo = list_first_entry(free_me, struct pnfs_layout_segment,
-                             pls_list)->pls_layout;
-
-       if (test_bit(NFS_LAYOUT_DESTROYED, &lo->plh_flags)) {
-               struct nfs_client *clp;
-
-               clp = NFS_SERVER(lo->plh_inode)->nfs_client;
-               spin_lock(&clp->cl_lock);
-               list_del_init(&lo->plh_layouts);
-               spin_unlock(&clp->cl_lock);
-       }
        list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
                list_del(&lseg->pls_list);
                free_lseg(lseg);
@@ -1148,11 +1144,6 @@ pnfs_update_layout(struct inode *ino,
                arg.length = PAGE_CACHE_ALIGN(arg.length);
 
        lseg = send_layoutget(lo, ctx, &arg, gfp_flags);
-       if (!lseg && first) {
-               spin_lock(&clp->cl_lock);
-               list_del_init(&lo->plh_layouts);
-               spin_unlock(&clp->cl_lock);
-       }
        atomic_dec(&lo->plh_outstanding);
 out_put_layout_hdr:
        pnfs_put_layout_hdr(lo);