Gentle ping.

Please put this patch into current release as the new block group size limit check introduced in v4.19 is causing at least 2 reports in mail list.

Thanks, Qu

On 2018/11/23 上午9:06, Qu Wenruo wrote:

[BUG] A completely valid btrfs will refuse to mount, with error message like: BTRFS critical (device sdb2): corrupt leaf: root=2 block=239681536 slot=172 \ bg_start=12018974720 bg_len=10888413184, invalid block group size, \ have 10888413184 expect (0, 10737418240]

Btrfs check returns no error, and all kernels used on this fs is later than 2011, which should all have the 10G size limit commit.

[CAUSE] For a 12 devices btrfs, we could allocate a chunk larger than 10G due to stripe stripe bump up.

__btrfs_alloc_chunk() |- max_stripe_size = 1G |- max_chunk_size = 10G |- data_stripe = 11 |- if (1G * 11 > 10G) { stripe_size = 976128930; stripe_size = round_up(976128930, SZ_16M) = 989855744

However the final stripe_size (989855744) * 11 = 10888413184, which is still larger than 10G.

[FIX] For the comprehensive check, we need to do the full check at chunk read time, and rely on bg <-> chunk mapping to do the check.

We could just skip the length check for now.

Fixes: fce466eab7ac ("btrfs: tree-checker: Verify block_group_item") Cc: stable@vger.kernel.org # v4.19+ Reported-by: Wang Yugui wangyugui@e16-tech.com Signed-off-by: Qu Wenruo wqu@suse.com

---

fs/btrfs/tree-checker.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index cab0b1f1f741..d8bd5340fbbc 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -389,13 +389,11 @@ static int check_block_group_item(struct btrfs_fs_info *fs_info, /* * Here we don't really care about alignment since extent allocator can

• * handle it.  We care more about the size, as if one block group is
  

• * larger than maximum size, it's must be some obvious corruption.
  

• * handle it.  We care more about the size.
  

  */

• if (key->offset > BTRFS_MAX_DATA_CHUNK_SIZE || key->offset == 0) {

• if (key->offset == 0) { block_group_err(fs_info, leaf, slot,

• 	"invalid block group size, have %llu expect (0, %llu]",
  

• 		key->offset, BTRFS_MAX_DATA_CHUNK_SIZE);
  

• 		"invalid block group size 0");
  

  return -EUCLEAN; }