Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French: "Small set of cifs fixes" * 'for-next' of git://git.samba.org/sfrench/cifs-2.6: Move check for prefix path to within cifs_get_root() Compare prepaths when comparing superblocks Fix memory leaks in cifs_do_mount()
vieko · Sep 17, 2016 · 4d2899d · 4d2899d
2 parents 87ee128 + 348c1bf
commit 4d2899d
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Showing 3 changed files with 42 additions and 20 deletions.
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
@@ -609,6 +609,9 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb)
 	char *s, *p;
 	char sep;
 
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
+		return dget(sb->s_root);
+
 	full_path = cifs_build_path_to_root(vol, cifs_sb,
 					    cifs_sb_master_tcon(cifs_sb));
 	if (full_path == NULL)
@@ -686,26 +689,22 @@ cifs_do_mount(struct file_system_type *fs_type,
 	cifs_sb->mountdata = kstrndup(data, PAGE_SIZE, GFP_KERNEL);
 	if (cifs_sb->mountdata == NULL) {
 		root = ERR_PTR(-ENOMEM);
-		goto out_cifs_sb;
+		goto out_free;
 	}
 
-	if (volume_info->prepath) {
-		cifs_sb->prepath = kstrdup(volume_info->prepath, GFP_KERNEL);
-		if (cifs_sb->prepath == NULL) {
-			root = ERR_PTR(-ENOMEM);
-			goto out_cifs_sb;
-		}
+	rc = cifs_setup_cifs_sb(volume_info, cifs_sb);
+	if (rc) {
+		root = ERR_PTR(rc);
+		goto out_free;
 	}
 
-	cifs_setup_cifs_sb(volume_info, cifs_sb);
-
 	rc = cifs_mount(cifs_sb, volume_info);
 	if (rc) {
 		if (!(flags & MS_SILENT))
 			cifs_dbg(VFS, "cifs_mount failed w/return code = %d\n",
 				 rc);
 		root = ERR_PTR(rc);
-		goto out_mountdata;
+		goto out_free;
 	}
 
 	mnt_data.vol = volume_info;
@@ -735,11 +734,7 @@ cifs_do_mount(struct file_system_type *fs_type,
 		sb->s_flags |= MS_ACTIVE;
 	}
 
-	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
-		root = dget(sb->s_root);
-	else
-		root = cifs_get_root(volume_info, sb);
-
+	root = cifs_get_root(volume_info, sb);
 	if (IS_ERR(root))
 		goto out_super;
 
@@ -752,9 +747,9 @@ cifs_do_mount(struct file_system_type *fs_type,
 	cifs_cleanup_volume_info(volume_info);
 	return root;
 
-out_mountdata:
+out_free:
+	kfree(cifs_sb->prepath);
 	kfree(cifs_sb->mountdata);
-out_cifs_sb:
 	kfree(cifs_sb);
 out_nls:
 	unload_nls(volume_info->local_nls);

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
@@ -184,7 +184,7 @@ extern int cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 			         unsigned int to_read);
 extern int cifs_read_page_from_socket(struct TCP_Server_Info *server,
 				      struct page *page, unsigned int to_read);
-extern void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
+extern int cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
 			       struct cifs_sb_info *cifs_sb);
 extern int cifs_match_super(struct super_block *, void *);
 extern void cifs_cleanup_volume_info(struct smb_vol *pvolume_info);

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
@@ -2781,6 +2781,24 @@ compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
 	return 1;
 }
 
+static int
+match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
+{
+	struct cifs_sb_info *old = CIFS_SB(sb);
+	struct cifs_sb_info *new = mnt_data->cifs_sb;
+
+	if (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) {
+		if (!(new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH))
+			return 0;
+		/* The prepath should be null terminated strings */
+		if (strcmp(new->prepath, old->prepath))
+			return 0;
+
+		return 1;
+	}
+	return 0;
+}
+
 int
 cifs_match_super(struct super_block *sb, void *data)
 {
@@ -2808,7 +2826,8 @@ cifs_match_super(struct super_block *sb, void *data)
 
 	if (!match_server(tcp_srv, volume_info) ||
 	    !match_session(ses, volume_info) ||
-	    !match_tcon(tcon, volume_info->UNC)) {
+	    !match_tcon(tcon, volume_info->UNC) ||
+	    !match_prepath(sb, mnt_data)) {
 		rc = 0;
 		goto out;
 	}
@@ -3222,7 +3241,7 @@ void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
 	}
 }
 
-void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
+int cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
 			struct cifs_sb_info *cifs_sb)
 {
 	INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
@@ -3316,6 +3335,14 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
 
 	if ((pvolume_info->cifs_acl) && (pvolume_info->dynperm))
 		cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
+
+	if (pvolume_info->prepath) {
+		cifs_sb->prepath = kstrdup(pvolume_info->prepath, GFP_KERNEL);
+		if (cifs_sb->prepath == NULL)
+			return -ENOMEM;
+	}
+
+	return 0;
 }
 
 static void