@@ -2742,6 +2742,57 @@ build_unc_path_to_root(const struct smb_vol *volume_info,
full_path[unc_len + cifs_sb->prepathlen] = 0; /* add trailing null */
return full_path;
}
+
+/*
+ * Perform a dfs referral query for a share and (optionally) prefix
+ *
+ * If a referral is found, mount_data will be set to point at a newly
+ * allocated string containing updated options for the submount.
+ * Otherwise it will be left untouched.
+ *
+ * Returns the rc from get_dfs_path to the caller, which can be used to
+ * determine whether there were referrals.
+ */
+static int
+expand_dfs_referral(int xid, struct cifs_ses *pSesInfo,
+ struct smb_vol *volume_info, struct cifs_sb_info *cifs_sb,
+ char **mount_data, int check_prefix)
+{
+ int rc;
+ unsigned int num_referrals = 0;
+ struct dfs_info3_param *referrals = NULL;
+ char *full_path = NULL, *ref_path = NULL, *mdata = NULL;
+
+ full_path = build_unc_path_to_root(volume_info, cifs_sb);
+ if (IS_ERR(full_path))
+ return PTR_ERR(full_path);
+
+ /* For DFS paths, skip the first '\' of the UNC */
+ ref_path = check_prefix ? full_path + 1 : volume_info->UNC + 1;
+
+ rc = get_dfs_path(xid, pSesInfo , ref_path, cifs_sb->local_nls,
+ &num_referrals, &referrals,
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+
+ if (!rc && num_referrals > 0) {
+ char *fake_devname = NULL;
+
+ mdata = cifs_compose_mount_options(cifs_sb->mountdata,
+ full_path + 1, referrals,
+ &fake_devname);
+
+ free_dfs_info_array(referrals, num_referrals);
+ kfree(fake_devname);
+
+ if (IS_ERR(mdata)) {
+ rc = PTR_ERR(mdata);
+ mdata = NULL;
+ }
+ *mount_data = mdata;
+ }
+ kfree(full_path);
+ return rc;
+}
#endif
int
@@ -2758,10 +2809,19 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
char *mount_data = mount_data_global;
struct tcon_link *tlink;
#ifdef CONFIG_CIFS_DFS_UPCALL
- struct dfs_info3_param *referrals = NULL;
- unsigned int num_referrals = 0;
int referral_walks_count = 0;
try_mount_again:
+
+ /* cleanup activities if we're chasing a referral */
+ if (referral_walks_count) {
+ if (tcon)
+ cifs_put_tcon(tcon);
+ else if (pSesInfo)
+ cifs_put_smb_ses(pSesInfo);
+
+ cleanup_volume_info(&volume_info);
+ FreeXid(xid);
+ }
#endif
rc = 0;
tcon = NULL;
@@ -2876,49 +2936,17 @@ try_mount_again:
remote_path_check:
#ifdef CONFIG_CIFS_DFS_UPCALL
/*
- * Perform an unconditional check for whether there are
- * DFS referrals for this path (without prefix), to provide
- * some limited support for domain DFS referrals on w2k8
+ * Perform an unconditional check for whether there are DFS
+ * referrals for this path without prefix, to provide support
+ * for DFS referrals from w2k8 servers which don't seem to respond
+ * with PATH_NOT_COVERED to requests that include the prefix.
+ * Chase the referral if found, otherwise continue normally.
*/
if (referral_walks_count == 0) {
- cFYI(1, "Getting referral for: %s", volume_info->UNC);
- rc = get_dfs_path(xid, pSesInfo , volume_info->UNC + 1,
- cifs_sb->local_nls, &num_referrals, &referrals,
- cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
- if (!rc && num_referrals > 0) {
- char *fake_devname = NULL;
-
- full_path = build_unc_path_to_root(volume_info,
- cifs_sb);
- if (IS_ERR(full_path)) {
- rc = PTR_ERR(full_path);
- goto mount_fail_check;
- }
-
- if (mount_data != mount_data_global)
- kfree(mount_data);
-
- mount_data = cifs_compose_mount_options(
- cifs_sb->mountdata, full_path + 1,
- referrals, &fake_devname);
-
- free_dfs_info_array(referrals, num_referrals);
- kfree(fake_devname);
-
- if (IS_ERR(mount_data)) {
- rc = PTR_ERR(mount_data);
- mount_data = NULL;
- goto mount_fail_check;
- }
-
- if (tcon)
- cifs_put_tcon(tcon);
- else if (pSesInfo)
- cifs_put_smb_ses(pSesInfo);
-
- cleanup_volume_info(&volume_info);
+ int refrc = expand_dfs_referral(xid, pSesInfo, volume_info,
+ cifs_sb, &mount_data, false);
+ if (!refrc) {
referral_walks_count++;
- FreeXid(xid);
goto try_mount_again;
}
}
@@ -2957,46 +2985,19 @@ remote_path_check:
if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) == 0)
convert_delimiter(cifs_sb->prepath,
CIFS_DIR_SEP(cifs_sb));
- full_path = build_unc_path_to_root(volume_info, cifs_sb);
- if (IS_ERR(full_path)) {
- rc = PTR_ERR(full_path);
- goto mount_fail_check;
- }
-
- cFYI(1, "Getting referral for: %s", full_path);
- rc = get_dfs_path(xid, pSesInfo , full_path + 1,
- cifs_sb->local_nls, &num_referrals, &referrals,
- cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
- if (!rc && num_referrals > 0) {
- char *fake_devname = NULL;
-
- if (mount_data != mount_data_global)
- kfree(mount_data);
-
- mount_data = cifs_compose_mount_options(
- cifs_sb->mountdata, full_path + 1,
- referrals, &fake_devname);
- free_dfs_info_array(referrals, num_referrals);
- kfree(fake_devname);
- kfree(full_path);
-
- if (IS_ERR(mount_data)) {
- rc = PTR_ERR(mount_data);
- mount_data = NULL;
- goto mount_fail_check;
- }
+ if (mount_data != mount_data_global)
+ kfree(mount_data);
- if (tcon)
- cifs_put_tcon(tcon);
- else if (pSesInfo)
- cifs_put_smb_ses(pSesInfo);
+ rc = expand_dfs_referral(xid, pSesInfo, volume_info, cifs_sb,
+ &mount_data, true);
- cleanup_volume_info(&volume_info);
+ if (!rc) {
referral_walks_count++;
- FreeXid(xid);
goto try_mount_again;
}
+ mount_data = NULL;
+ goto mount_fail_check;
#else /* No DFS support, return error on mount */
rc = -EOPNOTSUPP;
#endif
@@ -3029,7 +3030,7 @@ remote_path_check:
mount_fail_check:
/* on error free sesinfo and tcon struct if needed */
if (rc) {
- if (mount_data != mount_data_global)
+ if (mount_data != NULL && mount_data != mount_data_global)
kfree(mount_data);
/* If find_unc succeeded then rc == 0 so we can not end */
/* up accidently freeing someone elses tcon struct */