1 files changed, 81 insertions, 2 deletions

diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c
index 38ef9eaec407..0adefc40cc89 100644
--- a/fs/nfs/mount_clnt.c
+++ b/fs/nfs/mount_clnt.c
@@ -209,6 +209,71 @@ out_mnt_err:
         goto out;
 }
 
+/**
+ * nfs_umount - Notify a server that we have unmounted this export
+ * @info: pointer to umount request arguments
+ *
+ * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
+ * use UDP.
+ */
+void nfs_umount(const struct nfs_mount_request *info)
+{
+        static const struct rpc_timeout nfs_umnt_timeout = {
+                .to_initval = 1 * HZ,
+                .to_maxval = 3 * HZ,
+                .to_retries = 2,
+        };
+        struct rpc_create_args args = {
+                .protocol       = IPPROTO_UDP,
+                .address        = info->sap,
+                .addrsize       = info->salen,
+                .timeout        = &nfs_umnt_timeout,
+                .servername     = info->hostname,
+                .program        = &mnt_program,
+                .version        = info->version,
+                .authflavor     = RPC_AUTH_UNIX,
+                .flags          = RPC_CLNT_CREATE_NOPING,
+        };
+        struct mountres result;
+        struct rpc_message msg  = {
+                .rpc_argp       = info->dirpath,
+                .rpc_resp       = &result,
+        };
+        struct rpc_clnt *clnt;
+        int status;
+
+        if (info->noresvport)
+                args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
+
+        clnt = rpc_create(&args);
+        if (unlikely(IS_ERR(clnt)))
+                goto out_clnt_err;
+
+        dprintk("NFS: sending UMNT request for %s:%s\n",
+                (info->hostname ? info->hostname : "server"), info->dirpath);
+
+        if (info->version == NFS_MNT3_VERSION)
+                msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
+        else
+                msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
+
+        status = rpc_call_sync(clnt, &msg, 0);
+        rpc_shutdown_client(clnt);
+
+        if (unlikely(status < 0))
+                goto out_call_err;
+
+        return;
+
+out_clnt_err:
+        dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
+                        PTR_ERR(clnt));
+        return;
+
+out_call_err:
+        dprintk("NFS: UMNT request failed, status=%d\n", status);
+}
+
 /*
  * XDR encode/decode functions for MOUNT
  */
@@ -258,7 +323,7 @@ static int decode_status(struct xdr_stream *xdr, struct mountres *res)
                 return -EIO;
         status = ntohl(*p);
 
-        for (i = 0; i <= ARRAY_SIZE(mnt_errtbl); i++) {
+        for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
                 if (mnt_errtbl[i].status == status) {
                         res->errno = mnt_errtbl[i].errno;
                         return 0;
@@ -309,7 +374,7 @@ static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
                 return -EIO;
         status = ntohl(*p);
 
-        for (i = 0; i <= ARRAY_SIZE(mnt3_errtbl); i++) {
+        for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
                 if (mnt3_errtbl[i].status == status) {
                         res->errno = mnt3_errtbl[i].errno;
                         return 0;
@@ -407,6 +472,13 @@ static struct rpc_procinfo mnt_procedures[] = {
                 .p_statidx      = MOUNTPROC_MNT,
                 .p_name         = "MOUNT",
         },
+        [MOUNTPROC_UMNT] = {
+                .p_proc         = MOUNTPROC_UMNT,
+                .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
+                .p_arglen       = MNT_enc_dirpath_sz,
+                .p_statidx      = MOUNTPROC_UMNT,
+                .p_name         = "UMOUNT",
+        },
 };
 
 static struct rpc_procinfo mnt3_procedures[] = {
@@ -419,6 +491,13 @@ static struct rpc_procinfo mnt3_procedures[] = {
                 .p_statidx      = MOUNTPROC3_MNT,
                 .p_name         = "MOUNT",
         },
+        [MOUNTPROC3_UMNT] = {
+                .p_proc         = MOUNTPROC3_UMNT,
+                .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
+                .p_arglen       = MNT_enc_dirpath_sz,
+                .p_statidx      = MOUNTPROC3_UMNT,
+                .p_name         = "UMOUNT",
+        },
 };