On 11/03/2015 04:15 PM, Gang He wrote:
> Hello Junxiao,
>
> See my comments inline.
>
>
>>>>
>> Hi Gang,
>>
>> This is not like a right patch.
>> First, online file check only checks inode's block number, valid flag,
>> fs generation value, and meta ecc. I never see a real corruption
>> happened only on this field, if these fields are corrupted, that means
>> something bad may happen on other place. So fix this field may not help
>> and even cause corruption more hard.
> This online file check/fix feature is used to check/fix some light file meta
> block corruption, instead of turning a file system off and using fsck.ocfs2.
What's light meta block corruption? Do you have a case about it?
> e.g. meta ecc error, we really need not to use fsck.ocfs2.
> of course, this feature does not replace fsck.ocfs2 and touch some
> complicated meta block problems, if there is some potential problem in some
> areas, we can discuss them one by one.
>
>
>
>> Second, the repair way is wrong. In
>> ocfs2_filecheck_repair_inode_block(), if these fields in disk don't
>> match the ones in memory, the ones in memory are used to update the disk
>> fields. The question is how do you know these field in memory are
>> right(they may be the real corrupted ones)?
> Here, if the inode block was corrupted, the file system is not able to load
> it into the memory.
How do you know inode block corrupted? If bh for inode block is
overwritten, i mean bh corrupted, the repair will corrupted a good inode
block.
Thanks,
Junxiao.
> ocfs2_filecheck_repair_inode_block() will able to load it into the memory,
> since it try to fix these light-level problem before loading.
> if the fix is OK, the changed meta-block can pass the block-validate function
> and load into the memory as a inode object.
> Since the file system is under a cluster environment, we have to use some
> existing function and code path to keep these block operation under a cluster
> lock.
>
>
> Thanks
> Gang
>
>>
>> Thanks,
>> Junxiao.
>> On 10/28/2015 02:26 PM, Gang He wrote:
>>> +static int ocfs2_filecheck_repair_inode_block(struct super_block *sb,
>>> + struct buffer_head *bh)
>>> +{
>>> + int rc;
>>> + int changed = 0;
>>> + struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;
>>> +
>>> + rc = ocfs2_filecheck_validate_inode_block(sb, bh);
>>> + /* Can't fix invalid inode block */
>>> + if (!rc || rc == -OCFS2_FILECHECK_ERR_INVALIDINO)
>>> + return rc;
>>> +
>>> + trace_ocfs2_filecheck_repair_inode_block(
>>> + (unsigned long long)bh->b_blocknr);
>>> +
>>> + if (ocfs2_is_hard_readonly(OCFS2_SB(sb)) ||
>>> + ocfs2_is_soft_readonly(OCFS2_SB(sb))) {
>>> + mlog(ML_ERROR,
>>> + "Filecheck: try to repair dinode #%llu on readonly
>>> filesystem\n",
>>> + (unsigned long long)bh->b_blocknr);
>>> + return -OCFS2_FILECHECK_ERR_READONLY;
>>> + }
>>> +
>>> + if (le64_to_cpu(di->i_blkno) != bh->b_blocknr) {
>>> + di->i_blkno = cpu_to_le64(bh->b_blocknr);
>>> + changed = 1;
>>> + mlog(ML_ERROR,
>>> + "Filecheck: reset dinode #%llu: i_blkno to %llu\n",
>>> + (unsigned long long)bh->b_blocknr,
>>> + (unsigned long long)le64_to_cpu(di->i_blkno));
>>> + }
>>> +
>>> + if (!(di->i_flags & cpu_to_le32(OCFS2_VALID_FL))) {
>>> + di->i_flags |= cpu_to_le32(OCFS2_VALID_FL);
>>> + changed = 1;
>>> + mlog(ML_ERROR,
>>> + "Filecheck: reset dinode #%llu: OCFS2_VALID_FL is
>>> set\n",
>>> + (unsigned long long)bh->b_blocknr);
>>> + }
>>> +
>>> + if (le32_to_cpu(di->i_fs_generation) !=
>>> + OCFS2_SB(sb)->fs_generation) {
>>> + di->i_fs_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
>>> + changed = 1;
>>> + mlog(ML_ERROR,
>>> + "Filecheck: reset dinode #%llu: fs_generation to %u\n",
>>> + (unsigned long long)bh->b_blocknr,
>>> + le32_to_cpu(di->i_fs_generation));
>>> + }
>>> +
>>> + if (changed ||
>>> + ocfs2_validate_meta_ecc(sb, bh->b_data, &di->i_check)) {
>>> + ocfs2_compute_meta_ecc(sb, bh->b_data, &di->i_check);
>>> + mark_buffer_dirty(bh);
>>> + mlog(ML_ERROR,
>>> + "Filecheck: reset dinode #%llu: compute meta ecc\n",
>>> + (unsigned long long)bh->b_blocknr);
>>> + }
>>> +
>>> + return 0;
>>> +}
>
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