Joseph Qi
2017-Dec-05 02:21 UTC
[Ocfs2-devel] [PATCH] ocfs2: check the metadate alloc before marking extent written
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 <john at nixnuts.net> > Signed-off-by: Alex Chen <alex.chen at huawei.com> > Reviewed-by: Jun Piao <piaojun at 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?> 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.> } > 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.Thanks, Joseph> ocfs2_run_deallocs(osb, &dealloc); > if (locked) > inode_unlock(inode); >
alex chen
2017-Dec-05 02:36 UTC
[Ocfs2-devel] [PATCH] ocfs2: check the metadate alloc before marking extent written
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 <john at nixnuts.net> >> Signed-off-by: Alex Chen <alex.chen at huawei.com> >> Reviewed-by: Jun Piao <piaojun at 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. 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. > > Thanks, > Joseph > >> ocfs2_run_deallocs(osb, &dealloc); >> if (locked) >> inode_unlock(inode); >> > > . >