Imported Upstream version 1.2.3

[nfs-utils.git] / utils / mount / stropts.c

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index 024140082fcf56f65968453ca912158ab73f3668..50a1a2a06626a72ba2c09fe656df3331e66a85b1 100644 (file)
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -302,11 +302,16 @@ static int nfs_set_version(struct nfsmount_info *mi)
 
        if (strncmp(mi->type, "nfs4", 4) == 0)
                mi->version = 4;
-       else {
-               char *option = po_get(mi->options, "proto");
-               if (option && strcmp(option, "rdma") == 0)
-                       mi->version = 3;
-       }
+
+       /*
+        * Before 2.6.32, the kernel NFS client didn't
+        * support "-t nfs vers=4" mounts, so NFS version
+        * 4 cannot be included when autonegotiating
+        * while running on those kernels.
+        */
+       if (mi->version == 0 &&
+           linux_version_code() <= MAKE_VERSION(2, 6, 31))
+               mi->version = 3;
 
        /*
         * If we still don't know, check for version-specific
@@ -490,14 +495,18 @@ nfs_rewrite_pmap_mount_options(struct mount_options *options)
        union nfs_sockaddr mnt_address;
        struct sockaddr *mnt_saddr = &mnt_address.sa;
        socklen_t mnt_salen = sizeof(mnt_address);
+       unsigned long protocol;
        struct pmap mnt_pmap;
-       char *option;
 
        /*
-        * Skip option negotiation for proto=rdma mounts.
+        * Version and transport negotiation is not required
+        * and does not work for RDMA mounts.
         */
-       option = po_get(options, "proto");
-       if (option && strcmp(option, "rdma") == 0)
+       if (!nfs_nfs_protocol(options, &protocol)) {
+               errno = EINVAL;
+               return 0;
+       }
+       if (protocol == NFSPROTO_RDMA)
                goto out;
 
        /*
@@ -746,6 +755,47 @@ static int nfs_try_mount_v4(struct nfsmount_info *mi)
        return ret;
 }
 
+/*
+ * Handle NFS version and transport protocol
+ * autonegotiation.
+ *
+ * When no version or protocol is specified on the
+ * command line, mount.nfs negotiates with the server
+ * to determine appropriate settings for the new
+ * mount point.
+ *
+ * Returns TRUE if successful, otherwise FALSE.
+ * "errno" is set to reflect the individual error.
+ */
+static int nfs_autonegotiate(struct nfsmount_info *mi)
+{
+       int result;
+
+       result = nfs_try_mount_v4(mi);
+       if (result)
+               return result;
+               
+       switch (errno) {
+       case EPROTONOSUPPORT:
+               /* A clear indication that the server or our
+                * client does not support NFS version 4. */
+               goto fall_back;
+       case ENOENT:
+               /* Legacy Linux servers don't export an NFS
+                * version 4 pseudoroot. */
+               goto fall_back;
+       case EPERM:
+               /* Linux servers prior to 2.6.25 may return
+                * EPERM when NFS version 4 is not supported. */
+               goto fall_back;
+       default:
+               return result;
+       }
+
+fall_back:
+       return nfs_try_mount_v3v2(mi);
+}
+
 /*
  * This is a single pass through the fg/bg loop.
  *
@@ -758,20 +808,8 @@ static int nfs_try_mount(struct nfsmount_info *mi)
 
        switch (mi->version) {
        case 0:
-               if (linux_version_code() > MAKE_VERSION(2, 6, 31)) {
-                       errno = 0;
-                       result = nfs_try_mount_v4(mi);
-                       if (errno != EPROTONOSUPPORT) {
-                               /* 
-                                * To deal with legacy Linux servers that don't
-                                * automatically export a pseudo root, retry
-                                * ENOENT errors using version 3. And for
-                                * Linux servers prior to 2.6.25, retry EPERM
-                                */
-                               if (errno != ENOENT && errno != EPERM)
-                                       break;
-                       }
-               }
+               result = nfs_autonegotiate(mi);
+               break;
        case 2:
        case 3:
                result = nfs_try_mount_v3v2(mi);
@@ -928,6 +966,26 @@ static int nfsmount_bg(struct nfsmount_info *mi)
                return nfsmount_child(mi);
 }
 
+/*
+ * Usually all that is needed for an NFS remount is to change
+ * generic mount options like "sync" or "ro".  These generic
+ * options are controlled by mi->flags, not by text-based
+ * options, and no contact with the server is needed.
+ *
+ * Take care with the /etc/mtab entry for this mount; just
+ * calling update_mtab() will change an "-t nfs -o vers=4"
+ * mount to an "-t nfs -o remount" mount, and that will
+ * confuse umount.nfs.
+ *
+ * Returns a valid mount command exit code.
+ */
+static int nfs_remount(struct nfsmount_info *mi)
+{
+       if (nfs_sys_mount(mi, mi->options))
+               return EX_SUCCESS;
+       return EX_FAIL;
+}
+
 /*
  * Process mount options and try a mount system call.
  *
@@ -944,6 +1002,12 @@ static int nfsmount_start(struct nfsmount_info *mi)
        if (!nfs_validate_options(mi))
                return EX_FAIL;
 
+       /*
+        * Avoid retry and negotiation logic when remounting
+        */
+       if (mi->flags & MS_REMOUNT)
+               return nfs_remount(mi);
+
        if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
                return nfsmount_bg(mi);
        else
@@ -960,6 +1024,8 @@ static int nfsmount_start(struct nfsmount_info *mi)
  *             (input and output argument)
  * @fake: flag indicating whether to carry out the whole operation
  * @child: one if this is a mount daemon (bg)
+ *
+ * Returns a valid mount command exit code.
  */
 int nfsmount_string(const char *spec, const char *node, const char *type,
                    int flags, char **extra_opts, int fake, int child)