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: ECC:
## Block#TotalUsed Free Contig Size
052803072 322564294965350 34202182074032
..
Signed-off-by: Srinivas Eeda srinivas.e...@oracle.com
---
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 849c2f0..d606a79 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 -EIO;
+ }
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 -EIO;
+ }
if (undo_fn)
jbd_unlock_bh_state(group_bh);
--
1.5.6.5
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