Hi Changwei, I got your point, we should let the caller retry if bio is not enough, right? But some caller like o2hb_issue_node_write() won't retry once error happens, though the bio will always be enough. I think if we could calculate the number of bio we need before calling bio_add_page()?
Thanks Jun On 2018/5/14 11:21, Changwei Ge wrote: > Hi Jun, > > Right now, I am afraid that the easiest and fasted way to fix this issue > is to revert your patch. > > From comments before function bio_add_page(), we can see that it only > fails if either ::bi_vcnt == ::bi_max_vecs or it's a cloned bio. > > > So we can judge if bio is full from its return value is zero or not. > > > Thanks, > > Changwei > > > On 2018/5/10 9:13, Changwei Ge wrote: >> >> >> On 2018/5/10 8:24, piaojun wrote: >>> >>> On 2018/5/9 20:01, Changwei Ge wrote: >>>> Hi Jun, >>>> >>>> >>>> On 2018/5/9 18:08, piaojun wrote: >>>>> Hi Changwei, >>>>> >>>>> On 2018/4/13 13:51, Changwei Ge wrote: >>>>>> If cluster scale exceeds 16 nodes, bio will be full and >>>>>> bio_add_page() >>>>>> returns 0 when adding pages to bio. Returning -EIO to >>>>>> o2hb_read_slots() >>>>>> from o2hb_setup_one_bio() will lead to losing chance to allocate more >>>>>> bios to present all heartbeat region. >>>>>> >>>>>> So o2hb_read_slots() fails. >>>>>> >>>>>> In my test, making fs fails in starting o2cb service. >>>>>> >>>>>> Attach error log: >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 0, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 1, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 2, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 3, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 4, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 5, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 6, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 7, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 8, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 9, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 10, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 11, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 12, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 13, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 14, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 15, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:463 page 16, vec_len = >>>>>> 4096, vec_start = 0 >>>>>> (mkfs.ocfs2,27479,2):o2hb_setup_one_bio:471 ERROR: Adding page[16] >>>>>> to bio failed, page ffffea0002d7ed40, len 0, vec_len 4096, >>>>>> vec_start 0, bi_sector 8192 >>>>>> (mkfs.ocfs2,27479,2):o2hb_read_slots:500 ERROR: status = -5 >>>>>> (mkfs.ocfs2,27479,2):o2hb_populate_slot_data:1911 ERROR: status = -5 >>>>>> (mkfs.ocfs2,27479,2):o2hb_region_dev_write:2012 ERROR: status = -5 >>>>>> >>>>>> Fixes: ba16ddfbeb9d ("ocfs2/o2hb: check len for bio_add_page() to >>>>>> avoid getting incorrect bio" >>>>>> >>>>>> Signed-off-by: Changwei Ge <ge.chang...@h3c.com> >>>>>> --- >>>>>> fs/ocfs2/cluster/heartbeat.c | 8 ++++++-- >>>>>> 1 file changed, 6 insertions(+), 2 deletions(-) >>>>>> >>>>>> diff --git a/fs/ocfs2/cluster/heartbeat.c >>>>>> b/fs/ocfs2/cluster/heartbeat.c >>>>>> index 91a8889abf9b..2809e29d612d 100644 >>>>>> --- a/fs/ocfs2/cluster/heartbeat.c >>>>>> +++ b/fs/ocfs2/cluster/heartbeat.c >>>>>> @@ -540,11 +540,12 @@ static struct bio *o2hb_setup_one_bio(struct >>>>>> o2hb_region *reg, >>>>>> struct bio *bio; >>>>>> struct page *page; >>>>>> +#define O2HB_BIO_VECS 16 >>>>>> /* Testing has shown this allocation to take long enough under >>>>>> * GFP_KERNEL that the local node can get fenced. It would be >>>>>> * nicest if we could pre-allocate these bios and avoid this >>>>>> * all together. */ >>>>>> - bio = bio_alloc(GFP_ATOMIC, 16); >>>>>> + bio = bio_alloc(GFP_ATOMIC, O2HB_BIO_VECS); >>>>>> if (!bio) { >>>>>> mlog(ML_ERROR, "Could not alloc slots BIO!\n"); >>>>>> bio = ERR_PTR(-ENOMEM); >>>>>> @@ -570,7 +571,10 @@ static struct bio *o2hb_setup_one_bio(struct >>>>>> o2hb_region *reg, >>>>>> current_page, vec_len, vec_start); >>>>> Should we check the validity of 'current_page' before >>>>> bio_add_page()? And >>>>> that will prevent error happen. Others looks OK. >>>> If I understand correctly, you mean we should check current page is >>>> NULL or not? >>>> If so I think there is no need since o2hb should guarantee that it has >>>> already reserved enough pages for disk heartbeat read/write behalf. >>> I mean we could check if 'current_page' equals O2HB_BIO_VECS before >>> bio_add_page() to avoid NULL pointer referrence. >> Yes, that might work. >> I find another problem within this patch. >> I will post v2 patch later to fix them all with consideration about >> your suggestion. >> >> Thanks, >> Changwei >> >>> >>> thanks, >>> Jun >>> >>>> Thanks, >>>> Changwei >>>>> thanks, >>>>> Jun >>>>>> len = bio_add_page(bio, page, vec_len, vec_start); >>>>>> - if (len != vec_len) { >>>>>> + if (len == 0 && current_page == O2HB_BIO_VECS) { >>>>>> + /* bio is full now. */ >>>>>> + goto bail; >>>>>> + } else if (len != vec_len) { >>>>>> mlog(ML_ERROR, "Adding page[%d] to bio failed, " >>>>>> "page %p, len %d, vec_len %u, vec_start %u, " >>>>>> "bi_sector %llu\n", current_page, page, len, >>>>>> >>>>> _______________________________________________ >>>>> Ocfs2-devel mailing list >>>>> Ocfs2-devel@oss.oracle.com >>>>> https://oss.oracle.com/mailman/listinfo/ocfs2-devel >> > _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel