projects/linux·commit 83c68bbc

btrfs: initialize fs_info::csum_size earlier in open_ctree

83c68bbc · Su Yue <[email protected]> · 2021-02-11 16:38:28 +08:00

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 <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Commit
83c68bbcb6ac2dbbcaf12e2281a29a9f73b97d0f
Parents
9ad6d91f

Changes

1 files changed · +2 −1

FileStatusAddDelContent
fs/btrfs/disk-io.cmodified+2−1View file

fs/btrfs/disk-io.c

View file
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 6b35b7e..07a2b4f 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;