fix-block-bitmap-validation-when-bigalloc,not-flex_bg

   1 ext4: fix block bitmap validation when bigalloc, ^flex_bg
   2
   3 From: "Darrick J. Wong" <darrick.wong@oracle.com>
   4
   5 On a bigalloc,^flex_bg filesystem, the ext4_valid_block_bitmap
   6 function fails to convert from blocks to clusters when spot-checking
   7 the validity of the bitmap block that we've just read from disk.  This
   8 causes ext4 to think that the bitmap is garbage, which results in the
   9 block group being taken offline when it's not necessary.  Add in the
  10 necessary EXT4_B2C() calls to perform the conversions.
  11
  12 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
  13 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
  14 ---
  15  fs/ext4/balloc.c |   12 +++++++-----
  16  1 file changed, 7 insertions(+), 5 deletions(-)
  17
  18
  19 diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
  20 index a4950e9..59c3ba8 100644
  21 --- a/fs/ext4/balloc.c
  22 +++ b/fs/ext4/balloc.c
  23 @@ -307,6 +307,7 @@ static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb,
  24                                             ext4_group_t block_group,
  25                                             struct buffer_head *bh)
  26  {
  27 +       struct ext4_sb_info *sbi = EXT4_SB(sb);
  28         ext4_grpblk_t offset;
  29         ext4_grpblk_t next_zero_bit;
  30         ext4_fsblk_t blk;
  31 @@ -326,14 +327,14 @@ static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb,
  32         /* check whether block bitmap block number is set */
  33         blk = ext4_block_bitmap(sb, desc);
  34         offset = blk - group_first_block;
  35 -       if (!ext4_test_bit(offset, bh->b_data))
  36 +       if (!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data))
  37                 /* bad block bitmap */
  38                 return blk;
  39
  40         /* check whether the inode bitmap block number is set */
  41         blk = ext4_inode_bitmap(sb, desc);
  42         offset = blk - group_first_block;
  43 -       if (!ext4_test_bit(offset, bh->b_data))
  44 +       if (!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data))
  45                 /* bad block bitmap */
  46                 return blk;
  47
  48 @@ -341,9 +342,10 @@ static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb,
  49         blk = ext4_inode_table(sb, desc);
  50         offset = blk - group_first_block;
  51         next_zero_bit = ext4_find_next_zero_bit(bh->b_data,
  52 -                               offset + EXT4_SB(sb)->s_itb_per_group,
  53 -                               offset);
  54 -       if (next_zero_bit < offset + EXT4_SB(sb)->s_itb_per_group)
  55 +                       EXT4_B2C(sbi, offset + EXT4_SB(sb)->s_itb_per_group),
  56 +                       EXT4_B2C(sbi, offset));
  57 +       if (next_zero_bit <
  58 +           EXT4_B2C(sbi, offset + EXT4_SB(sb)->s_itb_per_group))
  59                 /* bad bitmap for inode tables */
  60                 return blk;
  61         return 0;
  62
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