pnfs: Add barrier to prevent lgopen using LAYOUTGET during recall

Since the LAYOUTGET on OPEN can be sent without prior inode information,
existing methods to prevent LAYOUTGET from being sent while processing
CB_LAYOUTRECALL don't work.  Track if a recall occurred while LAYOUTGET
was being sent, and if so ignore the results.

Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index a50d7813e3ea8dd03dd7c5e02b36574be815ad8b..d561161b7c3ea43269ec3e9e381b0e763b0c739e 100644 (file)
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -322,6 +322,8 @@ static u32 initiate_bulk_draining(struct nfs_client *clp,
 static u32 do_callback_layoutrecall(struct nfs_client *clp,
                                    struct cb_layoutrecallargs *args)
 {
+       write_seqcount_begin(&clp->cl_callback_count);
+       write_seqcount_end(&clp->cl_callback_count);
        if (args->cbl_recall_type == RETURN_FILE)
                return initiate_file_draining(clp, args);
        return initiate_bulk_draining(clp, args);

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 3dfe9fa264a539d99bcb8a07af7541d40c0eb9c5..a29fdea2db910a216dd798bd1e457a13cf160ee3 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1017,6 +1017,7 @@ pnfs_alloc_init_layoutget_args(struct inode *ino,
        nfs4_stateid_copy(&lgp->args.stateid, stateid);
        lgp->gfp_flags = gfp_flags;
        lgp->cred = get_rpccred(ctx->cred);
+       lgp->callback_count = raw_seqcount_begin(&server->nfs_client->cl_callback_count);
        return lgp;
 }
 
@@ -2101,6 +2102,7 @@ void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
 {
        struct pnfs_layout_hdr *lo;
        struct pnfs_layout_segment *lseg;
+       struct nfs_server *srv = NFS_SERVER(ino);
        u32 iomode;
 
        if (!lgp)
@@ -2116,7 +2118,7 @@ void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
                        /* FIXME - Any error not listed above permanently
                         * halts lgopen attempts.
                         */
-                       NFS_SERVER(ino)->caps &= ~NFS_CAP_LGOPEN;
+                       srv->caps &= ~NFS_CAP_LGOPEN;
                }
                return;
        }
@@ -2129,6 +2131,9 @@ void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
                lo = NFS_I(lgp->args.inode)->layout;
        pnfs_get_layout_hdr(lo);
 
+       if (read_seqcount_retry(&srv->nfs_client->cl_callback_count,
+                               lgp->callback_count))
+               goto out;
        lseg = pnfs_layout_process(lgp);
        atomic_dec(&lo->plh_outstanding);
        if (IS_ERR(lseg)) {
@@ -2139,6 +2144,7 @@ void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
                pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
                pnfs_put_lseg(lseg);
        }
+out:
        pnfs_clear_first_layoutget(lo);
        pnfs_put_layout_hdr(lo);
 }

diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 2c18d618604ecfc7f8342236131e227c2003c89a..74ae3e1d19a04a8e3e1fbaa24dc64aa152c75f2d 100644 (file)
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -28,6 +28,7 @@ struct nfs41_impl_id;
 struct nfs_client {
        refcount_t              cl_count;
        atomic_t                cl_mds_count;
+       seqcount_t              cl_callback_count;
        int                     cl_cons_state;  /* current construction state (-ve: init error) */
 #define NFS_CS_READY           0               /* ready to be used */
 #define NFS_CS_INITING         1               /* busy initialising */

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index bc235e50415fed6940c16612db219427f1c960f5..09dc14ac58046dd3454eec9f862ef14ab5d3ec12 100644 (file)
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -271,6 +271,7 @@ struct nfs4_layoutget {
        struct nfs4_layoutget_args args;
        struct nfs4_layoutget_res res;
        struct rpc_cred *cred;
+       unsigned callback_count;
        gfp_t gfp_flags;
 };