Btrfs: enhance superblock sanity checks
Validate checksum algorithm during mount and prevent BUG_ON later in
btrfs_super_csum_size.
Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 438993e..38c2ee1 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -48,7 +48,7 @@
static struct extent_io_ops btree_extent_io_ops;
static void end_workqueue_fn(struct btrfs_work *work);
static void free_fs_root(struct btrfs_root *root);
-static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
+static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
int read_only);
static void btrfs_destroy_ordered_operations(struct btrfs_root *root);
static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
@@ -2135,7 +2135,12 @@
/* check FS state, whether FS is broken. */
fs_info->fs_state |= btrfs_super_flags(disk_super);
- btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
+ ret = btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
+ if (ret) {
+ printk(KERN_ERR "btrfs: superblock contains fatal errors\n");
+ err = ret;
+ goto fail_alloc;
+ }
/*
* run through our array of backup supers and setup
@@ -3324,15 +3329,23 @@
return 0;
}
-static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
+static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
int read_only)
{
- if (read_only)
- return;
+ if (btrfs_super_csum_type(fs_info->super_copy) >= ARRAY_SIZE(btrfs_csum_sizes)) {
+ printk(KERN_ERR "btrfs: unsupported checksum algorithm\n");
+ return -EINVAL;
+ }
- if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
+ if (read_only)
+ return 0;
+
+ if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
printk(KERN_WARNING "warning: mount fs with errors, "
"running btrfsck is recommended\n");
+ }
+
+ return 0;
}
int btrfs_error_commit_super(struct btrfs_root *root)