| Message ID | 20200428112756.1892137-4-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/4] block: improve the submit_bio and generic_make_request documentation | expand |
On 28/04/2020 13:28, Christoph Hellwig wrote: > @@ -607,12 +607,14 @@ static inline bool blkcg_bio_issue_check(struct request_queue *q, > u64_stats_update_begin(&bis->sync); > > /* > - * If the bio is flagged with BIO_QUEUE_ENTERED it means this > - * is a split bio and we would have already accounted for the > - * size of the bio. > + * If the bio is flagged with BIO_CGROUP_ACCT it means this is a > + * split bio and we would have already accounted for the size of > + * the bio. > */ > - if (!bio_flagged(bio, BIO_QUEUE_ENTERED)) > + if (!bio_flagged(bio, BIO_CGROUP_ACCT)) { > + bio_set_flag(bio, BIO_CGROUP_ACCT); > bis->cur.bytes[rwd] += bio->bi_iter.bi_size; > + } > bis->cur.ios[rwd]++; > > u64_stats_update_end(&bis->sync); This is completely unrelated to the patch, but why is blkcg_bio_issue_check() static inline? It's only called in generic_make_request_checks().
On Tue, Apr 28, 2020 at 02:23:52PM +0000, Johannes Thumshirn wrote: > This is completely unrelated to the patch, but why is > blkcg_bio_issue_check() static inline? It's only called in > generic_make_request_checks(). The whole blk-cgroup group is just crazy :( This isn't even the worst part of it.
On 28/04/2020 16:25, Christoph Hellwig wrote: > On Tue, Apr 28, 2020 at 02:23:52PM +0000, Johannes Thumshirn wrote: >> This is completely unrelated to the patch, but why is >> blkcg_bio_issue_check() static inline? It's only called in >> generic_make_request_checks(). > > The whole blk-cgroup group is just crazy :( This isn't even the worst > part of it. > Uff, sounds like the next cleanup desperately needed.
diff --git a/block/blk-merge.c b/block/blk-merge.c index c49eb3bdd0be8..a04e991b5ded9 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -336,16 +336,6 @@ void __blk_queue_split(struct request_queue *q, struct bio **bio, /* there isn't chance to merge the splitted bio */ split->bi_opf |= REQ_NOMERGE; - /* - * Since we're recursing into make_request here, ensure - * that we mark this bio as already having entered the queue. - * If not, and the queue is going away, we can get stuck - * forever on waiting for the queue reference to drop. But - * that will never happen, as we're already holding a - * reference to it. - */ - bio_set_flag(*bio, BIO_QUEUE_ENTERED); - bio_chain(split, *bio); trace_block_split(q, split, (*bio)->bi_iter.bi_sector); generic_make_request(*bio); diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 35f8ffe92b702..4deb8bb7b6afa 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -607,12 +607,14 @@ static inline bool blkcg_bio_issue_check(struct request_queue *q, u64_stats_update_begin(&bis->sync); /* - * If the bio is flagged with BIO_QUEUE_ENTERED it means this - * is a split bio and we would have already accounted for the - * size of the bio. + * If the bio is flagged with BIO_CGROUP_ACCT it means this is a + * split bio and we would have already accounted for the size of + * the bio. */ - if (!bio_flagged(bio, BIO_QUEUE_ENTERED)) + if (!bio_flagged(bio, BIO_CGROUP_ACCT)) { + bio_set_flag(bio, BIO_CGROUP_ACCT); bis->cur.bytes[rwd] += bio->bi_iter.bi_size; + } bis->cur.ios[rwd]++; u64_stats_update_end(&bis->sync); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 31eb92876be7c..90895d594e647 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -220,7 +220,7 @@ enum { * throttling rules. Don't do it again. */ BIO_TRACE_COMPLETION, /* bio_endio() should trace the final completion * of this bio. */ - BIO_QUEUE_ENTERED, /* can use blk_queue_enter_live() */ + BIO_CGROUP_ACCT, /* has been accounted to a cgroup */ BIO_TRACKED, /* set if bio goes through the rq_qos path */ BIO_FLAG_LAST };
BIO_QUEUE_ENTERED is only used for cgroup accounting now, so rename the flag and move setting it into the cgroup code. Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/blk-merge.c | 10 ---------- include/linux/blk-cgroup.h | 10 ++++++---- include/linux/blk_types.h | 2 +- 3 files changed, 7 insertions(+), 15 deletions(-)