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| author | Srinivas Eeda <srinivas.eeda@oracle.com> | 2010-10-05 15:53:06 -0700 |
|---|---|---|
| committer | Joel Becker <joel.becker@oracle.com> | 2010-10-11 13:43:24 -0700 |
| commit | 9b5cd10e4c14a1a642076ace6a73be3d33c91fb6 (patch) | |
| tree | 92f0f09460a9574d1dbe53b2c376cd4193d19d91 /fs/ocfs2 | |
| parent | 93f3b86fb1bd0ad7b4a5eb1ad1fdae2b290633b7 (diff) | |
| download | lwn-9b5cd10e4c14a1a642076ace6a73be3d33c91fb6.tar.gz lwn-9b5cd10e4c14a1a642076ace6a73be3d33c91fb6.zip | |
ocfs2: validate bg_free_bits_count after update
This patch adds a safe check to ensure bg_free_bits_count doesn't exceed
bg_bits in a group descriptor. This is to avoid on disk corruption that was
seen recently.
debugfs: group <52803072>
Group Chain: 179 Parent Inode: 11 Generation: 2959379682
CRC32: 00000000 ECC: 0000
## Block# Total Used Free Contig Size
0 52803072 32256 4294965350 34202 18207 4032
......
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Diffstat (limited to 'fs/ocfs2')
| -rw-r--r-- | fs/ocfs2/suballoc.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index 8a286f54dca1..64f2c50a1c37 100644 --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -1380,6 +1380,14 @@ static inline int ocfs2_block_group_set_bits(handle_t *handle, } le16_add_cpu(&bg->bg_free_bits_count, -num_bits); + if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) { + ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit" + " count %u but claims %u are freed. num_bits %d", + (unsigned long long)le64_to_cpu(bg->bg_blkno), + le16_to_cpu(bg->bg_bits), + le16_to_cpu(bg->bg_free_bits_count), num_bits); + return -EROFS; + } while(num_bits--) ocfs2_set_bit(bit_off++, bitmap); @@ -2419,6 +2427,14 @@ static int ocfs2_block_group_clear_bits(handle_t *handle, (unsigned long *) undo_bg->bg_bitmap); } le16_add_cpu(&bg->bg_free_bits_count, num_bits); + if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) { + ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit" + " count %u but claims %u are freed. num_bits %d", + (unsigned long long)le64_to_cpu(bg->bg_blkno), + le16_to_cpu(bg->bg_bits), + le16_to_cpu(bg->bg_free_bits_count), num_bits); + return -EROFS; + } if (undo_fn) jbd_unlock_bh_state(group_bh); |