mount: make FEATURE_MOUNT_NFS not needed for Linux 2.6.23+

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/util-linux/Config.src b/util-linux/Config.src
index 888bc8f..57a52ce 100644 (file)
--- a/util-linux/Config.src
+++ b/util-linux/Config.src
@@ -485,13 +485,18 @@ config FEATURE_MOUNT_LABEL
          This also enables label or uuid support for swapon.
 
 config FEATURE_MOUNT_NFS
-       bool "Support mounting NFS file systems"
-       default y
+       bool "Support mounting NFS file systems on Linux < 2.6.23"
+       default n
        depends on MOUNT
        select FEATURE_HAVE_RPC
        select FEATURE_SYSLOG
        help
-         Enable mounting of NFS file systems.
+         Enable mounting of NFS file systems on Linux kernels prior
+         to version 2.6.23. Note that in this case mounting of NFS
+         over IPv6 will not be possible.
+
+         Note that this option links in RPC support from libc,
+         which is rather large (~10 kbytes on uclibc).
 
 config FEATURE_MOUNT_CIFS
        bool "Support mounting CIFS/SMB file systems"

diff --git a/util-linux/mount.c b/util-linux/mount.c
index 1dd4c0c..7ae1981 100644 (file)
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -1144,7 +1144,7 @@ static NOINLINE int nfsmount(struct mntent *mp, long vfsflags, char *filteropts)
        pathname = s + 1;
        *s = '\0';
        /* Ignore all but first hostname in replicated mounts
-          until they can be fully supported. (mack@sgi.com) */
+        * until they can be fully supported. (mack@sgi.com) */
        s = strchr(hostname, ',');
        if (s) {
                *s = '\0';
@@ -1683,7 +1683,6 @@ static NOINLINE int nfsmount(struct mntent *mp, long vfsflags, char *filteropts)
 
        /* Perform actual mount */
  do_mount:
-       mp->mnt_type = (char*)"nfs";
        retval = mount_it_now(mp, vfsflags, (char*)&data);
        goto ret;
 
@@ -1708,8 +1707,43 @@ static NOINLINE int nfsmount(struct mntent *mp, long vfsflags, char *filteropts)
 
 #else // !ENABLE_FEATURE_MOUNT_NFS
 
-// Never called. Call should be optimized out.
-int nfsmount(struct mntent *mp, long vfsflags, char *filteropts);
+/* Linux 2.6.23+ supports nfs mounts with options passed as a string.
+ * For older kernels, you must build busybox with ENABLE_FEATURE_MOUNT_NFS.
+ * (However, note that then you lose any chances that NFS over IPv6 would work).
+ */
+static int nfsmount(struct mntent *mp, long vfsflags, char *filteropts)
+{
+       len_and_sockaddr *lsa;
+       char *opts;
+       char *end;
+       char *dotted;
+       int ret;
+
+# if ENABLE_FEATURE_IPV6
+       end = strchr(mp->mnt_fsname, ']');
+       if (end && end[1] == ':')
+               end++;
+       else
+# endif
+               /* mount_main() guarantees that ':' is there */
+               end = strchr(mp->mnt_fsname, ':');
+
+       *end = '\0';
+       lsa = xdotted2sockaddr(mp->mnt_fsname, /*port:*/ 0);
+       *end = ':';
+       dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
+       if (ENABLE_FEATURE_CLEAN_UP) free(lsa);
+       opts = xasprintf("%s%saddr=%s",
+               filteropts ? filteropts : "",
+               filteropts ? "," : "",
+               dotted
+       );
+       if (ENABLE_FEATURE_CLEAN_UP) free(dotted);
+       ret = mount_it_now(mp, vfsflags, opts);
+       if (ENABLE_FEATURE_CLEAN_UP) free(opts);
+
+       return ret;
+}
 
 #endif // !ENABLE_FEATURE_MOUNT_NFS
 
@@ -1800,10 +1834,11 @@ static int singlemount(struct mntent *mp, int ignore_busy)
        }
 
        // Might this be an NFS filesystem?
-       if (ENABLE_FEATURE_MOUNT_NFS
-        && (!mp->mnt_type || strcmp(mp->mnt_type, "nfs") == 0)
+       if ((!mp->mnt_type || strncmp(mp->mnt_type, "nfs", 3) == 0)
         && strchr(mp->mnt_fsname, ':') != NULL
        ) {
+               if (!mp->mnt_type)
+                       mp->mnt_type = (char*)"nfs";
                rc = nfsmount(mp, vfsflags, filteropts);
                goto report_error;
        }