4.19-stable review patch. If anyone has any objections, please let me know.
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From: Qu Wenruo wqu@suse.com
commit 10950929e994c5ecee149ff0873388d3c98f12b5 upstream.
[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]
This has been reported several times as the 4.19 kernel is now being used. The filesystem refuses to mount, but is otherwise ok and booting 4.18 is a workaround.
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 Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/tree-checker.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
--- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -389,13 +389,11 @@ static int check_block_group_item(struct
/* * 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; }