| Message ID | 20210211083828.6835-1-l@damenly.su (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: initialize btrfs_fs_info::csum_size earlier in open_ctree() | expand |
On Thu, Feb 11, 2021 at 04:38:28PM +0800, Su Yue wrote: > User reported that btrfs-progs misc-tests/028-superblock-recover fails: > [TEST/misc] 028-superblock-recover > unexpected success: mounted fs with corrupted superblock > test failed for case 028-superblock-recover > > The test case expects that a broken image with bad superblock will be > rejected to be mounted. However, the test image just passed csum check > of superblock and was successfully mounted. > > Commit 55fc29bed8dd ("btrfs: use cached value of fs_info::csum_size > everywhere") replaces all calls to btrfs_super_csum_size by > fs_info::csum_size. The calls include the place where fs_info->csum_size > is not initialized. So btrfs_check_super_csum() passes because memcmp() > with len 0 always returns 0. > > Fix it by caching csum size in btrfs_fs_info::csum_size once we know the > csum type in superblock is valid in open_ctree(). > > Link: https://github.com/kdave/btrfs-progs/issues/250 > Fixes: 55fc29bed8dd ("btrfs: use cached value of fs_info::csum_size everywhere") That's a new commit in 5.11 and the bug looks serious, I'll need to send one more pull request. Thanks for the fix.
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 6b35b7e88136..07a2b4f69b10 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3044,6 +3044,8 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device goto fail_alloc; } + fs_info->csum_size = btrfs_super_csum_size(disk_super); + ret = btrfs_init_csum_hash(fs_info, csum_type); if (ret) { err = ret; @@ -3161,7 +3163,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device fs_info->nodesize = nodesize; fs_info->sectorsize = sectorsize; fs_info->sectorsize_bits = ilog2(sectorsize); - fs_info->csum_size = btrfs_super_csum_size(disk_super); fs_info->csums_per_leaf = BTRFS_MAX_ITEM_SIZE(fs_info) / fs_info->csum_size; fs_info->stripesize = stripesize;
User reported that btrfs-progs misc-tests/028-superblock-recover fails: [TEST/misc] 028-superblock-recover unexpected success: mounted fs with corrupted superblock test failed for case 028-superblock-recover The test case expects that a broken image with bad superblock will be rejected to be mounted. However, the test image just passed csum check of superblock and was successfully mounted. Commit 55fc29bed8dd ("btrfs: use cached value of fs_info::csum_size everywhere") replaces all calls to btrfs_super_csum_size by fs_info::csum_size. The calls include the place where fs_info->csum_size is not initialized. So btrfs_check_super_csum() passes because memcmp() with len 0 always returns 0. Fix it by caching csum size in btrfs_fs_info::csum_size once we know the csum type in superblock is valid in open_ctree(). Link: https://github.com/kdave/btrfs-progs/issues/250 Fixes: 55fc29bed8dd ("btrfs: use cached value of fs_info::csum_size everywhere") Signed-off-by: Su Yue <l@damenly.su> --- fs/btrfs/disk-io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)