Btrfs: add sanity checks regarding to parsing mount options

I just notice the following commands succeed:
	mount <dev> <mnt> -o thread_pool=-1

This is ridiculous, only positive thread_pool makes sense,this
patch adds sanity checks for them, and also catches the error of
ENOMEM if allocating memory fails.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8eb6191..cc00295 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -496,10 +496,15 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                        btrfs_set_opt(info->mount_opt, NOBARRIER);
                        break;
                case Opt_thread_pool:
-                       intarg = 0;
-                       match_int(&args[0], &intarg);
-                       if (intarg)
+                       ret = match_int(&args[0], &intarg);
+                       if (ret) {
+                               goto out;
+                       } else if (intarg > 0) {
                                info->thread_pool_size = intarg;
+                       } else {
+                               ret = -EINVAL;
+                               goto out;
+                       }
                        break;
                case Opt_max_inline:
                        num = match_strdup(&args[0]);
@@ -514,6 +519,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                                }
                                printk(KERN_INFO "btrfs: max_inline at %llu\n",
                                        (unsigned long long)info->max_inline);
+                       } else {
+                               ret = -ENOMEM;
+                               goto out;
                        }
                        break;
                case Opt_alloc_start:
@@ -526,6 +534,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                                printk(KERN_INFO
                                        "btrfs: allocations start at %llu\n",
                                        (unsigned long long)info->alloc_start);
+                       } else {
+                               ret = -ENOMEM;
+                               goto out;
                        }
                        break;
                case Opt_noacl:
@@ -540,12 +551,16 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                        btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
                        break;
                case Opt_ratio:
-                       intarg = 0;
-                       match_int(&args[0], &intarg);
-                       if (intarg) {
+                       ret = match_int(&args[0], &intarg);
+                       if (ret) {
+                               goto out;
+                       } else if (intarg >= 0) {
                                info->metadata_ratio = intarg;
                                printk(KERN_INFO "btrfs: metadata ratio %d\n",
                                       info->metadata_ratio);
+                       } else {
+                               ret = -EINVAL;
+                               goto out;
                        }
                        break;
                case Opt_discard:
@@ -596,13 +611,17 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
                        btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
                        break;
                case Opt_check_integrity_print_mask:
-                       intarg = 0;
-                       match_int(&args[0], &intarg);
-                       if (intarg) {
+                       ret = match_int(&args[0], &intarg);
+                       if (ret) {
+                               goto out;
+                       } else if (intarg >= 0) {
                                info->check_integrity_print_mask = intarg;
                                printk(KERN_INFO "btrfs:"
                                       " check_integrity_print_mask 0x%x\n",
                                       info->check_integrity_print_mask);
+                       } else {
+                               ret = -EINVAL;
+                               goto out;
                        }
                        break;
 #else
@@ -679,17 +698,25 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
                case Opt_subvol:
                        kfree(*subvol_name);
                        *subvol_name = match_strdup(&args[0]);
+                       if (!*subvol_name) {
+                               error = -ENOMEM;
+                               goto out;
+                       }
                        break;
                case Opt_subvolid:
-                       intarg = 0;
                        error = match_int(&args[0], &intarg);
                        if (!error) {
+                               goto out;
+                       } else if (intarg >= 0) {
                                /* we want the original fs_tree */
                                if (!intarg)
                                        *subvol_objectid =
                                                BTRFS_FS_TREE_OBJECTID;
                                else
                                        *subvol_objectid = intarg;
+                       } else {
+                               error = -EINVAL;
+                               goto out;
                        }
                        break;
                case Opt_subvolrootid: