1 files changed, 54 insertions, 2 deletions

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 093beaa3900d..e9f4ec701092 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -44,6 +44,7 @@
 #include "cifs_fs_sb.h"
 #include <linux/mm.h>
 #include <linux/key-type.h>
+#include "dns_resolve.h"
 #include "cifs_spnego.h"
 #define CIFS_MAGIC_NUMBER 0xFF534D42    /* the first four bytes of SMB PDUs */
 
@@ -96,6 +97,9 @@ cifs_read_super(struct super_block *sb, void *data,
 {
         struct inode *inode;
         struct cifs_sb_info *cifs_sb;
+#ifdef CONFIG_CIFS_DFS_UPCALL
+        int len;
+#endif
         int rc = 0;
 
         /* BB should we make this contingent on mount parm? */
@@ -105,6 +109,25 @@ cifs_read_super(struct super_block *sb, void *data,
         if (cifs_sb == NULL)
                 return -ENOMEM;
 
+#ifdef CONFIG_CIFS_DFS_UPCALL
+        /* copy mount params to sb for use in submounts */
+        /* BB: should we move this after the mount so we
+         * do not have to do the copy on failed mounts?
+         * BB: May be it is better to do simple copy before
+         * complex operation (mount), and in case of fail
+         * just exit instead of doing mount and attempting
+         * undo it if this copy fails?*/
+        len = strlen(data);
+        cifs_sb->mountdata = kzalloc(len + 1, GFP_KERNEL);
+        if (cifs_sb->mountdata == NULL) {
+                kfree(sb->s_fs_info);
+                sb->s_fs_info = NULL;
+                return -ENOMEM;
+        }
+        strncpy(cifs_sb->mountdata, data, len + 1);
+        cifs_sb->mountdata[len] = '\0';
+#endif
+
         rc = cifs_mount(sb, cifs_sb, data, devname);
 
         if (rc) {
@@ -154,6 +177,12 @@ out_no_root:
 
 out_mount_failed:
         if (cifs_sb) {
+#ifdef CONFIG_CIFS_DFS_UPCALL
+                if (cifs_sb->mountdata) {
+                        kfree(cifs_sb->mountdata);
+                        cifs_sb->mountdata = NULL;
+                }
+#endif
                 if (cifs_sb->local_nls)
                         unload_nls(cifs_sb->local_nls);
                 kfree(cifs_sb);
@@ -177,6 +206,13 @@ cifs_put_super(struct super_block *sb)
         if (rc) {
                 cERROR(1, ("cifs_umount failed with return code %d", rc));
         }
+#ifdef CONFIG_CIFS_DFS_UPCALL
+        if (cifs_sb->mountdata) {
+                kfree(cifs_sb->mountdata);
+                cifs_sb->mountdata = NULL;
+        }
+#endif
+
         unload_nls(cifs_sb->local_nls);
         kfree(cifs_sb);
         return;
@@ -435,6 +471,10 @@ static void cifs_umount_begin(struct vfsmount *vfsmnt, int flags)
         struct cifs_sb_info *cifs_sb;
         struct cifsTconInfo *tcon;
 
+#ifdef CONFIG_CIFS_DFS_UPCALL
+        dfs_shrink_umount_helper(vfsmnt);
+#endif /* CONFIG CIFS_DFS_UPCALL */
+
         if (!(flags & MNT_FORCE))
                 return;
         cifs_sb = CIFS_SB(vfsmnt->mnt_sb);
@@ -552,7 +592,7 @@ static loff_t cifs_llseek(struct file *file, loff_t offset, int origin)
         return remote_llseek(file, offset, origin);
 }
 
-static struct file_system_type cifs_fs_type = {
+struct file_system_type cifs_fs_type = {
         .owner = THIS_MODULE,
         .name = "cifs",
         .get_sb = cifs_get_sb,
@@ -1015,11 +1055,16 @@ init_cifs(void)
         if (rc)
                 goto out_unregister_filesystem;
 #endif
+#ifdef CONFIG_CIFS_DFS_UPCALL
+        rc = register_key_type(&key_type_dns_resolver);
+        if (rc)
+                goto out_unregister_key_type;
+#endif
         oplockThread = kthread_run(cifs_oplock_thread, NULL, "cifsoplockd");
         if (IS_ERR(oplockThread)) {
                 rc = PTR_ERR(oplockThread);
                 cERROR(1, ("error %d create oplock thread", rc));
-                goto out_unregister_key_type;
+                goto out_unregister_dfs_key_type;
         }
 
         dnotifyThread = kthread_run(cifs_dnotify_thread, NULL, "cifsdnotifyd");
@@ -1033,7 +1078,11 @@ init_cifs(void)
 
  out_stop_oplock_thread:
         kthread_stop(oplockThread);
+ out_unregister_dfs_key_type:
+#ifdef CONFIG_CIFS_DFS_UPCALL
+        unregister_key_type(&key_type_dns_resolver);
  out_unregister_key_type:
+#endif
 #ifdef CONFIG_CIFS_UPCALL
         unregister_key_type(&cifs_spnego_key_type);
  out_unregister_filesystem:
@@ -1059,6 +1108,9 @@ exit_cifs(void)
 #ifdef CONFIG_PROC_FS
         cifs_proc_clean();
 #endif
+#ifdef CONFIG_CIFS_DFS_UPCALL
+        unregister_key_type(&key_type_dns_resolver);
+#endif
 #ifdef CONFIG_CIFS_UPCALL
         unregister_key_type(&cifs_spnego_key_type);
 #endif