Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / fs / cifs / cifs_dfs_ref.c

diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index c68a056f27fd52e29764c3a5524b4e4393a0e586..0a265ad9e426ef0e9ec217604454db666290ff10 100644 (file)
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -255,35 +255,6 @@ static struct vfsmount *cifs_dfs_do_refmount(struct cifs_sb_info *cifs_sb,
 
 }
 
-static int add_mount_helper(struct vfsmount *newmnt, struct nameidata *nd,
-                               struct list_head *mntlist)
-{
-       /* stolen from afs code */
-       int err;
-
-       mntget(newmnt);
-       err = do_add_mount(newmnt, &nd->path, nd->path.mnt->mnt_flags | MNT_SHRINKABLE, mntlist);
-       switch (err) {
-       case 0:
-               path_put(&nd->path);
-               nd->path.mnt = newmnt;
-               nd->path.dentry = dget(newmnt->mnt_root);
-               schedule_delayed_work(&cifs_dfs_automount_task,
-                                     cifs_dfs_mountpoint_expiry_timeout);
-               break;
-       case -EBUSY:
-               /* someone else made a mount here whilst we were busy */
-               while (d_mountpoint(nd->path.dentry) &&
-                      follow_down(&nd->path))
-                       ;
-               err = 0;
-       default:
-               mntput(newmnt);
-               break;
-       }
-       return err;
-}
-
 static void dump_referral(const struct dfs_info3_param *ref)
 {
        cFYI(1, "DFS: ref path: %s", ref->path_name);
@@ -293,27 +264,23 @@ static void dump_referral(const struct dfs_info3_param *ref)
                                ref->path_consumed);
 }
 
-
-static void*
-cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
+/*
+ * Create a vfsmount that we can automount
+ */
+static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
 {
        struct dfs_info3_param *referrals = NULL;
        unsigned int num_referrals = 0;
        struct cifs_sb_info *cifs_sb;
        struct cifsSesInfo *ses;
-       char *full_path = NULL;
+       char *full_path;
        int xid, i;
-       int rc = 0;
-       struct vfsmount *mnt = ERR_PTR(-ENOENT);
+       int rc;
+       struct vfsmount *mnt;
        struct tcon_link *tlink;
 
        cFYI(1, "in %s", __func__);
-       BUG_ON(IS_ROOT(dentry));
-
-       xid = GetXid();
-
-       dput(nd->path.dentry);
-       nd->path.dentry = dget(dentry);
+       BUG_ON(IS_ROOT(mntpt));
 
        /*
         * The MSDFS spec states that paths in DFS referral requests and
@@ -321,66 +288,83 @@ cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
         * the double backslashes usually used in the UNC. This function
         * gives us the latter, so we must adjust the result.
         */
-       full_path = build_path_from_dentry(dentry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
-               goto out_err;
-       }
+       mnt = ERR_PTR(-ENOMEM);
+       full_path = build_path_from_dentry(mntpt);
+       if (full_path == NULL)
+               goto cdda_exit;
 
-       cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
+       cifs_sb = CIFS_SB(mntpt->d_inode->i_sb);
        tlink = cifs_sb_tlink(cifs_sb);
        if (IS_ERR(tlink)) {
-               rc = PTR_ERR(tlink);
-               goto out_err;
+               mnt = ERR_CAST(tlink);
+               goto free_full_path;
        }
        ses = tlink_tcon(tlink)->ses;
 
+       xid = GetXid();
        rc = get_dfs_path(xid, ses, full_path + 1, cifs_sb->local_nls,
                &num_referrals, &referrals,
                cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+       FreeXid(xid);
 
        cifs_put_tlink(tlink);
 
+       mnt = ERR_PTR(-ENOENT);
        for (i = 0; i < num_referrals; i++) {
                int len;
-               dump_referral(referrals+i);
+               dump_referral(referrals + i);
                /* connect to a node */
                len = strlen(referrals[i].node_name);
                if (len < 2) {
                        cERROR(1, "%s: Net Address path too short: %s",
                                        __func__, referrals[i].node_name);
-                       rc = -EINVAL;
-                       goto out_err;
+                       mnt = ERR_PTR(-EINVAL);
+                       break;
                }
                mnt = cifs_dfs_do_refmount(cifs_sb,
                                full_path, referrals + i);
                cFYI(1, "%s: cifs_dfs_do_refmount:%s , mnt:%p", __func__,
                                        referrals[i].node_name, mnt);
-
-               /* complete mount procedure if we accured submount */
                if (!IS_ERR(mnt))
-                       break;
+                       goto success;
        }
 
-       /* we need it cause for() above could exit without valid submount */
-       rc = PTR_ERR(mnt);
-       if (IS_ERR(mnt))
-               goto out_err;
+       /* no valid submounts were found; return error from get_dfs_path() by
+        * preference */
+       if (rc != 0)
+               mnt = ERR_PTR(rc);
 
-       rc = add_mount_helper(mnt, nd, &cifs_dfs_automount_list);
-
-out:
-       FreeXid(xid);
+success:
        free_dfs_info_array(referrals, num_referrals);
+free_full_path:
        kfree(full_path);
+cdda_exit:
        cFYI(1, "leaving %s" , __func__);
-       return ERR_PTR(rc);
-out_err:
-       path_put(&nd->path);
-       goto out;
+       return mnt;
+}
+
+/*
+ * Attempt to automount the referral
+ */
+struct vfsmount *cifs_dfs_d_automount(struct path *path)
+{
+       struct vfsmount *newmnt;
+
+       cFYI(1, "in %s", __func__);
+
+       newmnt = cifs_dfs_do_automount(path->dentry);
+       if (IS_ERR(newmnt)) {
+               cFYI(1, "leaving %s [automount failed]" , __func__);
+               return newmnt;
+       }
+
+       mntget(newmnt); /* prevent immediate expiration */
+       mnt_set_expiry(newmnt, &cifs_dfs_automount_list);
+       schedule_delayed_work(&cifs_dfs_automount_task,
+                             cifs_dfs_mountpoint_expiry_timeout);
+       cFYI(1, "leaving %s [ok]" , __func__);
+       return newmnt;
 }
 
 const struct inode_operations cifs_dfs_referral_inode_operations = {
-       .follow_link = cifs_dfs_follow_mountpoint,
 };
-