git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From 10950929e994c5ecee149ff0873388d3c98f12b5 Mon Sep 17 00:00:00 2001
   2 From: Qu Wenruo <wqu@suse.com>
   3 Date: Fri, 23 Nov 2018 09:06:36 +0800
   4 Subject: btrfs: tree-checker: Don't check max block group size as current max chunk size limit is unreliable
   5
   6 From: Qu Wenruo <wqu@suse.com>
   7
   8 commit 10950929e994c5ecee149ff0873388d3c98f12b5 upstream.
   9
  10 [BUG]
  11 A completely valid btrfs will refuse to mount, with error message like:
  12   BTRFS critical (device sdb2): corrupt leaf: root=2 block=239681536 slot=172 \
  13     bg_start=12018974720 bg_len=10888413184, invalid block group size, \
  14     have 10888413184 expect (0, 10737418240]
  15
  16 This has been reported several times as the 4.19 kernel is now being
  17 used. The filesystem refuses to mount, but is otherwise ok and booting
  18 4.18 is a workaround.
  19
  20 Btrfs check returns no error, and all kernels used on this fs is later
  21 than 2011, which should all have the 10G size limit commit.
  22
  23 [CAUSE]
  24 For a 12 devices btrfs, we could allocate a chunk larger than 10G due to
  25 stripe stripe bump up.
  26
  27 __btrfs_alloc_chunk()
  28 |- max_stripe_size = 1G
  29 |- max_chunk_size = 10G
  30 |- data_stripe = 11
  31 |- if (1G * 11 > 10G) {
  32        stripe_size = 976128930;
  33        stripe_size = round_up(976128930, SZ_16M) = 989855744
  34
  35 However the final stripe_size (989855744) * 11 = 10888413184, which is
  36 still larger than 10G.
  37
  38 [FIX]
  39 For the comprehensive check, we need to do the full check at chunk read
  40 time, and rely on bg <-> chunk mapping to do the check.
  41
  42 We could just skip the length check for now.
  43
  44 Fixes: fce466eab7ac ("btrfs: tree-checker: Verify block_group_item")
  45 Cc: stable@vger.kernel.org # v4.19+
  46 Reported-by: Wang Yugui <wangyugui@e16-tech.com>
  47 Signed-off-by: Qu Wenruo <wqu@suse.com>
  48 Reviewed-by: David Sterba <dsterba@suse.com>
  49 Signed-off-by: David Sterba <dsterba@suse.com>
  50 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  51
  52 ---
  53  fs/btrfs/tree-checker.c |    8 +++-----
  54  1 file changed, 3 insertions(+), 5 deletions(-)
  55
  56 --- a/fs/btrfs/tree-checker.c
  57 +++ b/fs/btrfs/tree-checker.c
  58 @@ -348,13 +348,11 @@ static int check_block_group_item(struct
  59
  60         /*
  61          * Here we don't really care about alignment since extent allocator can
  62 -        * handle it.  We care more about the size, as if one block group is
  63 -        * larger than maximum size, it's must be some obvious corruption.
  64 +        * handle it.  We care more about the size.
  65          */
  66 -       if (key->offset > BTRFS_MAX_DATA_CHUNK_SIZE || key->offset == 0) {
  67 +       if (key->offset == 0) {
  68                 block_group_err(fs_info, leaf, slot,
  69 -                       "invalid block group size, have %llu expect (0, %llu]",
  70 -                               key->offset, BTRFS_MAX_DATA_CHUNK_SIZE);
  71 +                               "invalid block group size 0");
  72                 return -EUCLEAN;
  73         }
  74