On 2017/12/5 10:45, Joseph Qi wrote:
>
>
> On 17/12/5 10:36, alex chen wrote:
>> Hi Joseph,
>>
>> Thanks for your reviews.
>>
>> On 2017/12/5 10:21, Joseph Qi wrote:
>>>
>>>
>>> On 17/12/5 09:41, alex chen wrote:
>>>> We need to check the free number of the records in each loop to mark
>>>> extent written, because the last extent block may be changed through
>>>> many times marking extent written and the 'num_free_extents' also be
>>>> changed. In the worst case, the 'num_free_extents' may become less
>>>> than the beginning of the loop. So we should not estimate the free
>>>> number of the records at the beginning of the loop to mark extent
>>>> written.
>>>>
>>>> Reported-by: John Lightsey <j...@nixnuts.net>
>>>> Signed-off-by: Alex Chen <alex.c...@huawei.com>
>>>> Reviewed-by: Jun Piao <piao...@huawei.com>
>>>> ---
>>>> fs/ocfs2/aops.c | 76
>>>> ++++++++++++++++++++++++++++++++++++++++++++++++---------
>>>> 1 file changed, 64 insertions(+), 12 deletions(-)
>>>>
>>>> diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
>>>> index d151632..702aebc 100644
>>>> --- a/fs/ocfs2/aops.c
>>>> +++ b/fs/ocfs2/aops.c
>>>> @@ -2272,6 +2272,35 @@ static int ocfs2_dio_wr_get_block(struct inode
>>>> *inode, sector_t iblock,
>>>> return ret;
>>>> }
>>>>
>>>> +static int ocfs2_dio_should_restart(struct ocfs2_extent_tree *et,
>>>> + struct ocfs2_alloc_context *meta_ac, int max_rec_needed)
>>>> +{
>>>> + int status = 0, free_extents;
>>>> +
>>>> + free_extents = ocfs2_num_free_extents(et);
>>>> + if (free_extents < 0) {
>>>> + status = free_extents;
>>>> + mlog_errno(status);
>>>> + return status;
>>>> + }
>>>> +
>>>> + /*
>>>> + * there are two cases which could cause us to EAGAIN in the
>>>> + * we-need-more-metadata case:
>>>> + * 1) we haven't reserved *any*
>>>> + * 2) we are so fragmented, we've needed to add metadata too
>>>> + * many times.
>>>> + */
>>>> + if (free_extents < max_rec_needed) {
>>>> + if (!meta_ac || (ocfs2_alloc_context_bits_left(meta_ac)
>>>> + < ocfs2_extend_meta_needed(et->et_root_el)))
>>>> + status = 1;
>>>> + }
>>>> +
>>>> + return status;
>>>> +}
>>>> +
>>>> +#define OCFS2_MAX_REC_NEEDED_SPLIT 2
>>>> static int ocfs2_dio_end_io_write(struct inode *inode,
>>>> struct ocfs2_dio_write_ctxt *dwc,
>>>> loff_t offset,
>>>> @@ -2281,14 +2310,13 @@ static int ocfs2_dio_end_io_write(struct inode
>>>> *inode,
>>>> struct ocfs2_extent_tree et;
>>>> struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>>>> struct ocfs2_inode_info *oi = OCFS2_I(inode);
>>>> - struct ocfs2_unwritten_extent *ue = NULL;
>>>> + struct ocfs2_unwritten_extent *ue = NULL, *tmp_ue;
>>>> struct buffer_head *di_bh = NULL;
>>>> struct ocfs2_dinode *di;
>>>> - struct ocfs2_alloc_context *data_ac = NULL;
>>>> struct ocfs2_alloc_context *meta_ac = NULL;
>>>> handle_t *handle = NULL;
>>>> loff_t end = offset + bytes;
>>>> - int ret = 0, credits = 0, locked = 0;
>>>> + int ret = 0, credits = 0, locked = 0, restart = 0;
>>>>
>>>> ocfs2_init_dealloc_ctxt(&dealloc);
>>>>
>>>> @@ -2330,8 +2358,9 @@ static int ocfs2_dio_end_io_write(struct inode
>>>> *inode,
>>>>
>>> Should we restart here?
>>
>> OK. we should restart before initialized the inode extent tree.
>>
>>>
>>>> ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
>>>>
>>>> - ret = ocfs2_lock_allocators(inode, &et, 0, dwc->dw_zero_count*2,
>>>> - &data_ac, &meta_ac);
>>>> +restart_all:
>>>> + ret = ocfs2_lock_allocators(inode, &et, 0, OCFS2_MAX_REC_NEEDED_SPLIT,
>>>> + NULL, &meta_ac);
>>>> if (ret) {
>>>> mlog_errno(ret);
>>>> goto unlock;
>>>> @@ -2343,7 +2372,7 @@ static int ocfs2_dio_end_io_write(struct inode
>>>> *inode,
>>>> if (IS_ERR(handle)) {
>>>> ret = PTR_ERR(handle);
>>>> mlog_errno(ret);
>>>> - goto unlock;
>>>> + goto free_ac;
>>> I don't think it is a necessary change here.
>>
>> we need to free the 'meta_ac' which allocated in ocfs2_lock_allocators()
>> when we
>> start transaction failed.
>>
> As I described in the last mail, just move the restart check after the
> original free meta_ac check.
>
>> Thanks,
>> Alex
>>>
>>>> }
>>>> ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
>>>> OCFS2_JOURNAL_ACCESS_WRITE);
>>>> @@ -2352,7 +2381,17 @@ static int ocfs2_dio_end_io_write(struct inode
>>>> *inode,
>>>> goto commit;
>>>> }
>>>>
>>>> - list_for_each_entry(ue, &dwc->dw_zero_list, ue_node) {
>>>> + list_for_each_entry_safe(ue, tmp_ue, &dwc->dw_zero_list, ue_node) {
>>>> + ret = ocfs2_dio_should_restart(&et, meta_ac,
>>>> + OCFS2_MAX_REC_NEEDED_SPLIT * 2);
>>>> + if (ret < 0) {
>>>> + mlog_errno(ret);
>>>> + break;
>>>> + } else if (ret == 1) {
>>>> + restart = 1;
>>>> + break;
>>>> + }
>>>> +
>>>> ret = ocfs2_mark_extent_written(inode, &et, handle,
>>>> ue->ue_cpos, 1,
>>>> ue->ue_phys,
>>>> @@ -2361,24 +2400,37 @@ static int ocfs2_dio_end_io_write(struct inode
>>>> *inode,
>>>> mlog_errno(ret);
>>>> break;
>>>> }
>>>> +
>>>> + dwc->dw_zero_count--;
>>>> + list_del_init(&ue->ue_node);
>>>> + spin_lock(&oi->ip_lock);
>>>> + list_del_init(&ue->ue_ip_node);
>>>> + spin_unlock(&oi->ip_lock);
>>>> + kfree(ue);
>>>> }
>>>>
>>>> - if (end > i_size_read(inode)) {
>>>> + if (!restart && end > i_size_read(inode)) {
>>>> ret = ocfs2_set_inode_size(handle, inode, di_bh, end);
>>>> if (ret < 0)
>>>> mlog_errno(ret);
>>>> }
>>>> +
>>>> commit:
>>>> ocfs2_commit_trans(osb, handle);
>>>> +free_ac:
>>>> + if (meta_ac) {
>>>> + ocfs2_free_alloc_context(meta_ac);
>>>> + meta_ac = NULL;
>>>> + }
>>>> + if (restart) {
>>>> + restart = 0;
>>>> + goto restart_all;
>>>> + }
>>>> unlock:
>>>> up_write(&oi->ip_alloc_sem);
>>>> ocfs2_inode_unlock(inode, 1);
>>>> brelse(di_bh);
>>>> out:
>>>> - if (data_ac)
>>>> - ocfs2_free_alloc_context(data_ac);
>>> Agree to cleanup the unused data_ac.
>>>
>>>> - if (meta_ac)
>>>> - ocfs2_free_alloc_context(meta_ac);
> Just move the restart logic down is enough.
If we check the restart here, we will unlock the 'ip_alloc_sem' and release the
inode buffer, which we don't need to do.
Thanks,
Alex
>>>
>>> Thanks,
>>> Joseph
>>>
>>>> ocfs2_run_deallocs(osb, &dealloc);
>>>> if (locked)
>>>> inode_unlock(inode);
>>>>
>>>
>>> .
>>>
>>
>
> .
>
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