NFS: Use common device name parsing logic for NFSv4 and NFSv2/v3

To support passing a raw IPv6 address as a server hostname, we need to
expand the logic that handles splitting the passed-in device name into
a server hostname and export path

Start by pulling device name parsing out of the mount option validation
functions and into separate helper functions.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index b880db18035bab30e09f1b7e780d89e320f2ac70..c4ee8b3a27c19799ad29e475dee1ab27522178dd 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1195,6 +1195,67 @@ static int nfs_try_mount(struct nfs_parsed_mount_data *args,
        return status;
 }
 
+/*
+ * Split "dev_name" into "hostname:export_path".
+ *
+ * Note: caller frees hostname and export path, even on error.
+ */
+static int nfs_parse_devname(const char *dev_name,
+                            char **hostname, size_t maxnamlen,
+                            char **export_path, size_t maxpathlen)
+{
+       size_t len;
+       char *colon, *comma;
+
+       colon = strchr(dev_name, ':');
+       if (colon == NULL)
+               goto out_bad_devname;
+
+       len = colon - dev_name;
+       if (len > maxnamlen)
+               goto out_hostname;
+
+       /* N.B. caller will free nfs_server.hostname in all cases */
+       *hostname = kstrndup(dev_name, len, GFP_KERNEL);
+       if (!*hostname)
+               goto out_nomem;
+
+       /* kill possible hostname list: not supported */
+       comma = strchr(*hostname, ',');
+       if (comma != NULL) {
+               if (comma == *hostname)
+                       goto out_bad_devname;
+               *comma = '\0';
+       }
+
+       colon++;
+       len = strlen(colon);
+       if (len > maxpathlen)
+               goto out_path;
+       *export_path = kstrndup(colon, len, GFP_KERNEL);
+       if (!*export_path)
+               goto out_nomem;
+
+       dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
+       return 0;
+
+out_bad_devname:
+       dfprintk(MOUNT, "NFS: device name not in host:path format\n");
+       return -EINVAL;
+
+out_nomem:
+       dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
+       return -ENOMEM;
+
+out_hostname:
+       dfprintk(MOUNT, "NFS: server hostname too long\n");
+       return -ENAMETOOLONG;
+
+out_path:
+       dfprintk(MOUNT, "NFS: export pathname too long\n");
+       return -ENAMETOOLONG;
+}
+
 /*
  * Validate the NFS2/NFS3 mount data
  * - fills in the mount root filehandle
@@ -1323,8 +1384,6 @@ static int nfs_validate_mount_data(void *options,
 
                break;
        default: {
-               unsigned int len;
-               char *c;
                int status;
 
                if (nfs_parse_mount_options((char *)options, args) == 0)
@@ -1334,21 +1393,17 @@ static int nfs_validate_mount_data(void *options,
                                                &args->nfs_server.address))
                        goto out_no_address;
 
-               c = strchr(dev_name, ':');
-               if (c == NULL)
-                       return -EINVAL;
-               len = c - dev_name;
-               /* N.B. caller will free nfs_server.hostname in all cases */
-               args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
-               if (!args->nfs_server.hostname)
-                       goto out_nomem;
+               status = nfs_parse_devname(dev_name,
+                                          &args->nfs_server.hostname,
+                                          PAGE_SIZE,
+                                          &args->nfs_server.export_path,
+                                          NFS_MAXPATHLEN);
+               if (!status)
+                       status = nfs_try_mount(args, mntfh);
 
-               c++;
-               if (strlen(c) > NFS_MAXPATHLEN)
-                       return -ENAMETOOLONG;
-               args->nfs_server.export_path = c;
+               kfree(args->nfs_server.export_path);
+               args->nfs_server.export_path = NULL;
 
-               status = nfs_try_mount(args, mntfh);
                if (status)
                        return status;
 
@@ -1958,7 +2013,7 @@ static int nfs4_validate_mount_data(void *options,
 
                break;
        default: {
-               unsigned int len;
+               int status;
 
                if (nfs_parse_mount_options((char *)options, args) == 0)
                        return -EINVAL;
@@ -1977,34 +2032,17 @@ static int nfs4_validate_mount_data(void *options,
                        goto out_inval_auth;
                }
 
-               /*
-                * Split "dev_name" into "hostname:mntpath".
-                */
-               c = strchr(dev_name, ':');
-               if (c == NULL)
-                       return -EINVAL;
-               /* while calculating len, pretend ':' is '\0' */
-               len = c - dev_name;
-               if (len > NFS4_MAXNAMLEN)
-                       return -ENAMETOOLONG;
-               /* N.B. caller will free nfs_server.hostname in all cases */
-               args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
-               if (!args->nfs_server.hostname)
-                       goto out_nomem;
-
-               c++;                    /* step over the ':' */
-               len = strlen(c);
-               if (len > NFS4_MAXPATHLEN)
-                       return -ENAMETOOLONG;
-               args->nfs_server.export_path = kstrndup(c, len, GFP_KERNEL);
-               if (!args->nfs_server.export_path)
-                       goto out_nomem;
-
-               dprintk("NFS: MNTPATH: '%s'\n", args->nfs_server.export_path);
-
                if (args->client_address == NULL)
                        goto out_no_client_address;
 
+               status = nfs_parse_devname(dev_name,
+                                          &args->nfs_server.hostname,
+                                          NFS4_MAXNAMLEN,
+                                          &args->nfs_server.export_path,
+                                          NFS4_MAXPATHLEN);
+               if (status < 0)
+                       return status;
+
                break;
                }
        }
@@ -2020,10 +2058,6 @@ out_inval_auth:
                 data->auth_flavourlen);
        return -EINVAL;
 
-out_nomem:
-       dfprintk(MOUNT, "NFS4: not enough memory to handle mount options\n");
-       return -ENOMEM;
-
 out_no_address:
        dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
        return -EINVAL;