ceph: validate correctness of some mount options

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/super.c

@@ -243,21 +243,33 @@ static int parse_fsopt_token(char *c, void *private)
 		fsopt->rsize = ALIGN(intval, PAGE_SIZE);
 		break;
 	case Opt_rasize:
-		fsopt->rasize = intval;
+		if (intval < 0)
+			return -EINVAL;
+		fsopt->rasize = ALIGN(intval + PAGE_SIZE - 1, PAGE_SIZE);
 		break;
 	case Opt_caps_wanted_delay_min:
+		if (intval < 1)
+			return -EINVAL;
 		fsopt->caps_wanted_delay_min = intval;
 		break;
 	case Opt_caps_wanted_delay_max:
+		if (intval < 1)
+			return -EINVAL;
 		fsopt->caps_wanted_delay_max = intval;
 		break;
 	case Opt_readdir_max_entries:
+		if (intval < 1)
+			return -EINVAL;
 		fsopt->max_readdir = intval;
 		break;
 	case Opt_readdir_max_bytes:
+		if (intval < PAGE_SIZE && intval != 0)
+			return -EINVAL;
 		fsopt->max_readdir_bytes = intval;
 		break;
 	case Opt_congestion_kb:
+		if (intval < 1024) /* at least 1M */
+			return -EINVAL;
 		fsopt->congestion_kb = intval;
 		break;
 	case Opt_dirstat:
@@ -946,12 +958,7 @@ static int ceph_setup_bdi(struct super_block *sb, struct ceph_fs_client *fsc)
 		return err;
 
 	/* set ra_pages based on rasize mount option? */
-	if (fsc->mount_options->rasize >= PAGE_SIZE)
-		sb->s_bdi->ra_pages =
-			(fsc->mount_options->rasize + PAGE_SIZE - 1)
-			>> PAGE_SHIFT;
-	else
-		sb->s_bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
+	sb->s_bdi->ra_pages = fsc->mount_options->rasize >> PAGE_SHIFT;
 
 	/* set io_pages based on max osd read size */
 	sb->s_bdi->io_pages = fsc->mount_options->rsize >> PAGE_SHIFT;

fs/ceph/super.h

@@ -56,6 +56,15 @@
 #define CEPH_MAX_READDIR_BYTES_DEFAULT  (512*1024)
 #define CEPH_SNAPDIRNAME_DEFAULT        ".snap"
 
+/*
+ * Delay telling the MDS we no longer want caps, in case we reopen
+ * the file.  Delay a minimum amount of time, even if we send a cap
+ * message for some other reason.  Otherwise, take the oppotunity to
+ * update the mds to avoid sending another message later.
+ */
+#define CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT      5  /* cap release delay */
+#define CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT     60  /* cap release delay */
+
 struct ceph_mount_options {
 	int flags;
 	int sb_flags;

include/linux/ceph/libceph.h

@@ -84,16 +84,6 @@ struct ceph_options {
 
 #define CEPH_AUTH_NAME_DEFAULT   "guest"
 
-/*
- * Delay telling the MDS we no longer want caps, in case we reopen
- * the file.  Delay a minimum amount of time, even if we send a cap
- * message for some other reason.  Otherwise, take the oppotunity to
- * update the mds to avoid sending another message later.
- */
-#define CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT      5  /* cap release delay */
-#define CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT     60  /* cap release delay */
-
-
 /* mount state */
 enum {
 	CEPH_MOUNT_MOUNTING,