From fcd1f065daca593badb7f99d473639cf3b551795 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Tue, 6 Mar 2012 00:06:18 +0100 Subject: [PATCH] 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 --- fs/btrfs/disk-io.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) 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 @@ int open_ctree(struct super_block *sb, /* 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 @@ out: 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 (btrfs_super_csum_type(fs_info->super_copy) >= ARRAY_SIZE(btrfs_csum_sizes)) { + printk(KERN_ERR "btrfs: unsupported checksum algorithm\n"); + return -EINVAL; + } + if (read_only) - return; + return 0; - if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) + 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) -- 2.7.4