1 files changed, 47 insertions, 24 deletions

diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index d2c8eef84f3c..e1c18362ba46 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -106,7 +106,8 @@ static char *cifs_get_share_name(const char *node_name)
 /**
  * compose_mount_options        -       creates mount options for refferral
  * @sb_mountdata:       parent/root DFS mount options (template)
- * @ref_unc:            refferral server UNC
+ * @dentry:             point where we are going to mount
+ * @ref:                server's referral
  * @devname:            pointer for saving device name
  *
  * creates mount options for submount based on template options sb_mountdata
@@ -116,7 +117,8 @@ static char *cifs_get_share_name(const char *node_name)
  * Caller is responcible for freeing retunrned value if it is not error.
  */
 static char *compose_mount_options(const char *sb_mountdata,
-                                   const char *ref_unc,
+                                   struct dentry *dentry,
+                                   const struct dfs_info3_param *ref,
                                    char **devname)
 {
         int rc;
@@ -126,11 +128,12 @@ static char *compose_mount_options(const char *sb_mountdata,
         char *srvIP = NULL;
         char sep = ',';
         int off, noff;
+        char *fullpath;
 
         if (sb_mountdata == NULL)
                 return ERR_PTR(-EINVAL);
 
-        *devname = cifs_get_share_name(ref_unc);
+        *devname = cifs_get_share_name(ref->node_name);
         rc = dns_resolve_server_name_to_ip(*devname, &srvIP);
         if (rc != 0) {
                 cERROR(1, ("%s: Failed to resolve server part of %s to IP",
@@ -138,7 +141,12 @@ static char *compose_mount_options(const char *sb_mountdata,
                 mountdata = ERR_PTR(rc);
                 goto compose_mount_options_out;
         }
-        md_len = strlen(sb_mountdata) + strlen(srvIP) + strlen(ref_unc) + 3;
+        /* md_len = strlen(...) + 12 for 'sep+prefixpath='
+         * assuming that we have 'unc=' and 'ip=' in
+         * the original sb_mountdata
+         */
+        md_len = strlen(sb_mountdata) + strlen(srvIP) +
+                strlen(ref->node_name) + 12;
         mountdata = kzalloc(md_len+1, GFP_KERNEL);
         if (mountdata == NULL) {
                 mountdata = ERR_PTR(-ENOMEM);
@@ -152,41 +160,56 @@ static char *compose_mount_options(const char *sb_mountdata,
                         strncpy(mountdata, sb_mountdata, 5);
                         off += 5;
         }
-        while ((tkn_e = strchr(sb_mountdata+off, sep))) {
-                noff = (tkn_e - (sb_mountdata+off)) + 1;
-                if (strnicmp(sb_mountdata+off, "unc=", 4) == 0) {
+
+        do {
+                tkn_e = strchr(sb_mountdata + off, sep);
+                if (tkn_e == NULL)
+                        noff = strlen(sb_mountdata + off);
+                else
+                        noff = tkn_e - (sb_mountdata + off) + 1;
+
+                if (strnicmp(sb_mountdata + off, "unc=", 4) == 0) {
                         off += noff;
                         continue;
                 }
-                if (strnicmp(sb_mountdata+off, "ip=", 3) == 0) {
+                if (strnicmp(sb_mountdata + off, "ip=", 3) == 0) {
                         off += noff;
                         continue;
                 }
-                if (strnicmp(sb_mountdata+off, "prefixpath=", 3) == 0) {
+                if (strnicmp(sb_mountdata + off, "prefixpath=", 11) == 0) {
                         off += noff;
                         continue;
                 }
-                strncat(mountdata, sb_mountdata+off, noff);
+                strncat(mountdata, sb_mountdata + off, noff);
                 off += noff;
-        }
-        strcat(mountdata, sb_mountdata+off);
+        } while (tkn_e);
+        strcat(mountdata, sb_mountdata + off);
         mountdata[md_len] = '\0';
 
         /* copy new IP and ref share name */
-        strcat(mountdata, ",ip=");
+        if (mountdata[strlen(mountdata) - 1] != sep)
+                strncat(mountdata, &sep, 1);
+        strcat(mountdata, "ip=");
         strcat(mountdata, srvIP);
-        strcat(mountdata, ",unc=");
+        strncat(mountdata, &sep, 1);
+        strcat(mountdata, "unc=");
         strcat(mountdata, *devname);
 
         /* find & copy prefixpath */
-        tkn_e = strchr(ref_unc+2, '\\');
-        if (tkn_e) {
-                tkn_e = strchr(tkn_e+1, '\\');
-                if (tkn_e) {
-                        strcat(mountdata, ",prefixpath=");
-                        strcat(mountdata, tkn_e+1);
-                }
+        tkn_e = strchr(ref->node_name + 2, '\\');
+        if (tkn_e == NULL) /* invalid unc, missing share name*/
+                goto compose_mount_options_out;
+
+        fullpath = build_path_from_dentry(dentry);
+        tkn_e = strchr(tkn_e + 1, '\\');
+        if (tkn_e || strlen(fullpath) - (ref->path_consumed)) {
+                strncat(mountdata, &sep, 1);
+                strcat(mountdata, "prefixpath=");
+                if (tkn_e)
+                        strcat(mountdata, tkn_e + 1);
+                strcat(mountdata, fullpath + (ref->path_consumed));
         }
+        kfree(fullpath);
 
         /*cFYI(1,("%s: parent mountdata: %s", __func__,sb_mountdata));*/
         /*cFYI(1, ("%s: submount mountdata: %s", __func__, mountdata ));*/
@@ -198,7 +221,7 @@ compose_mount_options_out:
 
 
 static struct vfsmount *cifs_dfs_do_refmount(const struct vfsmount *mnt_parent,
-                struct dentry *dentry, char *ref_unc)
+                struct dentry *dentry, const struct dfs_info3_param *ref)
 {
         struct cifs_sb_info *cifs_sb;
         struct vfsmount *mnt;
@@ -207,7 +230,7 @@ static struct vfsmount *cifs_dfs_do_refmount(const struct vfsmount *mnt_parent,
 
         cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
         mountdata = compose_mount_options(cifs_sb->mountdata,
-                                                ref_unc, &devname);
+                                                dentry, ref, &devname);
 
         if (IS_ERR(mountdata))
                 return (struct vfsmount *)mountdata;
@@ -310,7 +333,7 @@ cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
                         }
                         mnt = cifs_dfs_do_refmount(nd->path.mnt,
                                                 nd->path.dentry,
-                                                referrals[i].node_name);
+                                                referrals + i);
                         cFYI(1, ("%s: cifs_dfs_do_refmount:%s , mnt:%p",
                                          __func__,
                                         referrals[i].node_name, mnt));