| Message ID | 20180227165557.20442-8-colyli@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
LGTM, applying On 02/27/2018 08:55 AM, Coly Li wrote: > In order to catch I/O error of backing device, a separate bi_end_io > call back is required. Then a per backing device counter can record I/O > errors number and retire the backing device if the counter reaches a > per backing device I/O error limit. > > This patch adds backing_request_endio() to bcache backing device I/O code > path, this is a preparation for further complicated backing device failure > handling. So far there is no real code logic change, I make this change a > separate patch to make sure it is stable and reliable for further work. > > Changelog: > v2: Fix code comments typo, remove a redundant bch_writeback_add() line > added in v4 patch set. > v1: indeed this is new added in this patch set. > > Signed-off-by: Coly Li <colyli@suse.de> > Reviewed-by: Hannes Reinecke <hare@suse.com> > Cc: Junhui Tang <tang.junhui@zte.com.cn> > Cc: Michael Lyle <mlyle@lyle.org> > --- > drivers/md/bcache/request.c | 93 +++++++++++++++++++++++++++++++++++-------- > drivers/md/bcache/super.c | 1 + > drivers/md/bcache/writeback.c | 1 + > 3 files changed, 79 insertions(+), 16 deletions(-) > > diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c > index 279c9266bf50..0c517dd806a5 100644 > --- a/drivers/md/bcache/request.c > +++ b/drivers/md/bcache/request.c > @@ -139,6 +139,7 @@ static void bch_data_invalidate(struct closure *cl) > } > > op->insert_data_done = true; > + /* get in bch_data_insert() */ > bio_put(bio); > out: > continue_at(cl, bch_data_insert_keys, op->wq); > @@ -630,6 +631,38 @@ static void request_endio(struct bio *bio) > closure_put(cl); > } > > +static void backing_request_endio(struct bio *bio) > +{ > + struct closure *cl = bio->bi_private; > + > + if (bio->bi_status) { > + struct search *s = container_of(cl, struct search, cl); > + /* > + * If a bio has REQ_PREFLUSH for writeback mode, it is > + * speically assembled in cached_dev_write() for a non-zero > + * write request which has REQ_PREFLUSH. we don't set > + * s->iop.status by this failure, the status will be decided > + * by result of bch_data_insert() operation. > + */ > + if (unlikely(s->iop.writeback && > + bio->bi_opf & REQ_PREFLUSH)) { > + char buf[BDEVNAME_SIZE]; > + > + bio_devname(bio, buf); > + pr_err("Can't flush %s: returned bi_status %i", > + buf, bio->bi_status); > + } else { > + /* set to orig_bio->bi_status in bio_complete() */ > + s->iop.status = bio->bi_status; > + } > + s->recoverable = false; > + /* should count I/O error for backing device here */ > + } > + > + bio_put(bio); > + closure_put(cl); > +} > + > static void bio_complete(struct search *s) > { > if (s->orig_bio) { > @@ -644,13 +677,21 @@ static void bio_complete(struct search *s) > } > } > > -static void do_bio_hook(struct search *s, struct bio *orig_bio) > +static void do_bio_hook(struct search *s, > + struct bio *orig_bio, > + bio_end_io_t *end_io_fn) > { > struct bio *bio = &s->bio.bio; > > bio_init(bio, NULL, 0); > __bio_clone_fast(bio, orig_bio); > - bio->bi_end_io = request_endio; > + /* > + * bi_end_io can be set separately somewhere else, e.g. the > + * variants in, > + * - cache_bio->bi_end_io from cached_dev_cache_miss() > + * - n->bi_end_io from cache_lookup_fn() > + */ > + bio->bi_end_io = end_io_fn; > bio->bi_private = &s->cl; > > bio_cnt_set(bio, 3); > @@ -676,7 +717,7 @@ static inline struct search *search_alloc(struct bio *bio, > s = mempool_alloc(d->c->search, GFP_NOIO); > > closure_init(&s->cl, NULL); > - do_bio_hook(s, bio); > + do_bio_hook(s, bio, request_endio); > > s->orig_bio = bio; > s->cache_miss = NULL; > @@ -743,10 +784,11 @@ static void cached_dev_read_error(struct closure *cl) > trace_bcache_read_retry(s->orig_bio); > > s->iop.status = 0; > - do_bio_hook(s, s->orig_bio); > + do_bio_hook(s, s->orig_bio, backing_request_endio); > > /* XXX: invalidate cache */ > > + /* I/O request sent to backing device */ > closure_bio_submit(s->iop.c, bio, cl); > } > > @@ -859,7 +901,7 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, > bio_copy_dev(cache_bio, miss); > cache_bio->bi_iter.bi_size = s->insert_bio_sectors << 9; > > - cache_bio->bi_end_io = request_endio; > + cache_bio->bi_end_io = backing_request_endio; > cache_bio->bi_private = &s->cl; > > bch_bio_map(cache_bio, NULL); > @@ -872,14 +914,16 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, > s->cache_miss = miss; > s->iop.bio = cache_bio; > bio_get(cache_bio); > + /* I/O request sent to backing device */ > closure_bio_submit(s->iop.c, cache_bio, &s->cl); > > return ret; > out_put: > bio_put(cache_bio); > out_submit: > - miss->bi_end_io = request_endio; > + miss->bi_end_io = backing_request_endio; > miss->bi_private = &s->cl; > + /* I/O request sent to backing device */ > closure_bio_submit(s->iop.c, miss, &s->cl); > return ret; > } > @@ -943,31 +987,46 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s) > s->iop.bio = s->orig_bio; > bio_get(s->iop.bio); > > - if ((bio_op(bio) != REQ_OP_DISCARD) || > - blk_queue_discard(bdev_get_queue(dc->bdev))) > - closure_bio_submit(s->iop.c, bio, cl); > + if (bio_op(bio) == REQ_OP_DISCARD && > + !blk_queue_discard(bdev_get_queue(dc->bdev))) > + goto insert_data; > + > + /* I/O request sent to backing device */ > + bio->bi_end_io = backing_request_endio; > + closure_bio_submit(s->iop.c, bio, cl); > + > } else if (s->iop.writeback) { > bch_writeback_add(dc); > s->iop.bio = bio; > > if (bio->bi_opf & REQ_PREFLUSH) { > - /* Also need to send a flush to the backing device */ > - struct bio *flush = bio_alloc_bioset(GFP_NOIO, 0, > - dc->disk.bio_split); > - > + /* > + * Also need to send a flush to the backing > + * device. > + */ > + struct bio *flush; > + > + flush = bio_alloc_bioset(GFP_NOIO, 0, > + dc->disk.bio_split); > + if (!flush) { > + s->iop.status = BLK_STS_RESOURCE; > + goto insert_data; > + } > bio_copy_dev(flush, bio); > - flush->bi_end_io = request_endio; > + flush->bi_end_io = backing_request_endio; > flush->bi_private = cl; > flush->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; > - > + /* I/O request sent to backing device */ > closure_bio_submit(s->iop.c, flush, cl); > } > } else { > s->iop.bio = bio_clone_fast(bio, GFP_NOIO, dc->disk.bio_split); > - > + /* I/O request sent to backing device */ > + bio->bi_end_io = backing_request_endio; > closure_bio_submit(s->iop.c, bio, cl); > } > > +insert_data: > closure_call(&s->iop.cl, bch_data_insert, NULL, cl); > continue_at(cl, cached_dev_write_complete, NULL); > } > @@ -981,6 +1040,7 @@ static void cached_dev_nodata(struct closure *cl) > bch_journal_meta(s->iop.c, cl); > > /* If it's a flush, we send the flush to the backing device too */ > + bio->bi_end_io = backing_request_endio; > closure_bio_submit(s->iop.c, bio, cl); > > continue_at(cl, cached_dev_bio_complete, NULL); > @@ -1078,6 +1138,7 @@ static blk_qc_t cached_dev_make_request(struct request_queue *q, > cached_dev_read(dc, s); > } > } else > + /* I/O request sent to backing device */ > detached_dev_do_request(d, bio); > > return BLK_QC_T_NONE; > diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c > index 5c49109a7046..7f029535edff 100644 > --- a/drivers/md/bcache/super.c > +++ b/drivers/md/bcache/super.c > @@ -273,6 +273,7 @@ void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent) > bio->bi_private = dc; > > closure_get(cl); > + /* I/O request sent to backing device */ > __write_super(&dc->sb, bio); > > closure_return_with_destructor(cl, bch_write_bdev_super_unlock); > diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c > index 70092ada68e6..4a9547cdcdc5 100644 > --- a/drivers/md/bcache/writeback.c > +++ b/drivers/md/bcache/writeback.c > @@ -289,6 +289,7 @@ static void write_dirty(struct closure *cl) > bio_set_dev(&io->bio, io->dc->bdev); > io->bio.bi_end_io = dirty_endio; > > + /* I/O request sent to backing device */ > closure_bio_submit(io->dc->disk.c, &io->bio, cl); > } > >
LGTM, applied (sorry if this is duplicated, had mail client problems) On 02/27/2018 08:55 AM, Coly Li wrote: > In order to catch I/O error of backing device, a separate bi_end_io > call back is required. Then a per backing device counter can record I/O > errors number and retire the backing device if the counter reaches a > per backing device I/O error limit. > > This patch adds backing_request_endio() to bcache backing device I/O code > path, this is a preparation for further complicated backing device failure > handling. So far there is no real code logic change, I make this change a > separate patch to make sure it is stable and reliable for further work. > > Changelog: > v2: Fix code comments typo, remove a redundant bch_writeback_add() line > added in v4 patch set. > v1: indeed this is new added in this patch set. > > Signed-off-by: Coly Li <colyli@suse.de> > Reviewed-by: Hannes Reinecke <hare@suse.com> > Cc: Junhui Tang <tang.junhui@zte.com.cn> > Cc: Michael Lyle <mlyle@lyle.org> > --- > drivers/md/bcache/request.c | 93 +++++++++++++++++++++++++++++++++++-------- > drivers/md/bcache/super.c | 1 + > drivers/md/bcache/writeback.c | 1 + > 3 files changed, 79 insertions(+), 16 deletions(-) > > diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c > index 279c9266bf50..0c517dd806a5 100644 > --- a/drivers/md/bcache/request.c > +++ b/drivers/md/bcache/request.c > @@ -139,6 +139,7 @@ static void bch_data_invalidate(struct closure *cl) > } > > op->insert_data_done = true; > + /* get in bch_data_insert() */ > bio_put(bio); > out: > continue_at(cl, bch_data_insert_keys, op->wq); > @@ -630,6 +631,38 @@ static void request_endio(struct bio *bio) > closure_put(cl); > } > > +static void backing_request_endio(struct bio *bio) > +{ > + struct closure *cl = bio->bi_private; > + > + if (bio->bi_status) { > + struct search *s = container_of(cl, struct search, cl); > + /* > + * If a bio has REQ_PREFLUSH for writeback mode, it is > + * speically assembled in cached_dev_write() for a non-zero > + * write request which has REQ_PREFLUSH. we don't set > + * s->iop.status by this failure, the status will be decided > + * by result of bch_data_insert() operation. > + */ > + if (unlikely(s->iop.writeback && > + bio->bi_opf & REQ_PREFLUSH)) { > + char buf[BDEVNAME_SIZE]; > + > + bio_devname(bio, buf); > + pr_err("Can't flush %s: returned bi_status %i", > + buf, bio->bi_status); > + } else { > + /* set to orig_bio->bi_status in bio_complete() */ > + s->iop.status = bio->bi_status; > + } > + s->recoverable = false; > + /* should count I/O error for backing device here */ > + } > + > + bio_put(bio); > + closure_put(cl); > +} > + > static void bio_complete(struct search *s) > { > if (s->orig_bio) { > @@ -644,13 +677,21 @@ static void bio_complete(struct search *s) > } > } > > -static void do_bio_hook(struct search *s, struct bio *orig_bio) > +static void do_bio_hook(struct search *s, > + struct bio *orig_bio, > + bio_end_io_t *end_io_fn) > { > struct bio *bio = &s->bio.bio; > > bio_init(bio, NULL, 0); > __bio_clone_fast(bio, orig_bio); > - bio->bi_end_io = request_endio; > + /* > + * bi_end_io can be set separately somewhere else, e.g. the > + * variants in, > + * - cache_bio->bi_end_io from cached_dev_cache_miss() > + * - n->bi_end_io from cache_lookup_fn() > + */ > + bio->bi_end_io = end_io_fn; > bio->bi_private = &s->cl; > > bio_cnt_set(bio, 3); > @@ -676,7 +717,7 @@ static inline struct search *search_alloc(struct bio *bio, > s = mempool_alloc(d->c->search, GFP_NOIO); > > closure_init(&s->cl, NULL); > - do_bio_hook(s, bio); > + do_bio_hook(s, bio, request_endio); > > s->orig_bio = bio; > s->cache_miss = NULL; > @@ -743,10 +784,11 @@ static void cached_dev_read_error(struct closure *cl) > trace_bcache_read_retry(s->orig_bio); > > s->iop.status = 0; > - do_bio_hook(s, s->orig_bio); > + do_bio_hook(s, s->orig_bio, backing_request_endio); > > /* XXX: invalidate cache */ > > + /* I/O request sent to backing device */ > closure_bio_submit(s->iop.c, bio, cl); > } > > @@ -859,7 +901,7 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, > bio_copy_dev(cache_bio, miss); > cache_bio->bi_iter.bi_size = s->insert_bio_sectors << 9; > > - cache_bio->bi_end_io = request_endio; > + cache_bio->bi_end_io = backing_request_endio; > cache_bio->bi_private = &s->cl; > > bch_bio_map(cache_bio, NULL); > @@ -872,14 +914,16 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, > s->cache_miss = miss; > s->iop.bio = cache_bio; > bio_get(cache_bio); > + /* I/O request sent to backing device */ > closure_bio_submit(s->iop.c, cache_bio, &s->cl); > > return ret; > out_put: > bio_put(cache_bio); > out_submit: > - miss->bi_end_io = request_endio; > + miss->bi_end_io = backing_request_endio; > miss->bi_private = &s->cl; > + /* I/O request sent to backing device */ > closure_bio_submit(s->iop.c, miss, &s->cl); > return ret; > } > @@ -943,31 +987,46 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s) > s->iop.bio = s->orig_bio; > bio_get(s->iop.bio); > > - if ((bio_op(bio) != REQ_OP_DISCARD) || > - blk_queue_discard(bdev_get_queue(dc->bdev))) > - closure_bio_submit(s->iop.c, bio, cl); > + if (bio_op(bio) == REQ_OP_DISCARD && > + !blk_queue_discard(bdev_get_queue(dc->bdev))) > + goto insert_data; > + > + /* I/O request sent to backing device */ > + bio->bi_end_io = backing_request_endio; > + closure_bio_submit(s->iop.c, bio, cl); > + > } else if (s->iop.writeback) { > bch_writeback_add(dc); > s->iop.bio = bio; > > if (bio->bi_opf & REQ_PREFLUSH) { > - /* Also need to send a flush to the backing device */ > - struct bio *flush = bio_alloc_bioset(GFP_NOIO, 0, > - dc->disk.bio_split); > - > + /* > + * Also need to send a flush to the backing > + * device. > + */ > + struct bio *flush; > + > + flush = bio_alloc_bioset(GFP_NOIO, 0, > + dc->disk.bio_split); > + if (!flush) { > + s->iop.status = BLK_STS_RESOURCE; > + goto insert_data; > + } > bio_copy_dev(flush, bio); > - flush->bi_end_io = request_endio; > + flush->bi_end_io = backing_request_endio; > flush->bi_private = cl; > flush->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; > - > + /* I/O request sent to backing device */ > closure_bio_submit(s->iop.c, flush, cl); > } > } else { > s->iop.bio = bio_clone_fast(bio, GFP_NOIO, dc->disk.bio_split); > - > + /* I/O request sent to backing device */ > + bio->bi_end_io = backing_request_endio; > closure_bio_submit(s->iop.c, bio, cl); > } > > +insert_data: > closure_call(&s->iop.cl, bch_data_insert, NULL, cl); > continue_at(cl, cached_dev_write_complete, NULL); > } > @@ -981,6 +1040,7 @@ static void cached_dev_nodata(struct closure *cl) > bch_journal_meta(s->iop.c, cl); > > /* If it's a flush, we send the flush to the backing device too */ > + bio->bi_end_io = backing_request_endio; > closure_bio_submit(s->iop.c, bio, cl); > > continue_at(cl, cached_dev_bio_complete, NULL); > @@ -1078,6 +1138,7 @@ static blk_qc_t cached_dev_make_request(struct request_queue *q, > cached_dev_read(dc, s); > } > } else > + /* I/O request sent to backing device */ > detached_dev_do_request(d, bio); > > return BLK_QC_T_NONE; > diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c > index 5c49109a7046..7f029535edff 100644 > --- a/drivers/md/bcache/super.c > +++ b/drivers/md/bcache/super.c > @@ -273,6 +273,7 @@ void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent) > bio->bi_private = dc; > > closure_get(cl); > + /* I/O request sent to backing device */ > __write_super(&dc->sb, bio); > > closure_return_with_destructor(cl, bch_write_bdev_super_unlock); > diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c > index 70092ada68e6..4a9547cdcdc5 100644 > --- a/drivers/md/bcache/writeback.c > +++ b/drivers/md/bcache/writeback.c > @@ -289,6 +289,7 @@ static void write_dirty(struct closure *cl) > bio_set_dev(&io->bio, io->dc->bdev); > io->bio.bi_end_io = dirty_endio; > > + /* I/O request sent to backing device */ > closure_bio_submit(io->dc->disk.c, &io->bio, cl); > } > >
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index 279c9266bf50..0c517dd806a5 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -139,6 +139,7 @@ static void bch_data_invalidate(struct closure *cl) } op->insert_data_done = true; + /* get in bch_data_insert() */ bio_put(bio); out: continue_at(cl, bch_data_insert_keys, op->wq); @@ -630,6 +631,38 @@ static void request_endio(struct bio *bio) closure_put(cl); } +static void backing_request_endio(struct bio *bio) +{ + struct closure *cl = bio->bi_private; + + if (bio->bi_status) { + struct search *s = container_of(cl, struct search, cl); + /* + * If a bio has REQ_PREFLUSH for writeback mode, it is + * speically assembled in cached_dev_write() for a non-zero + * write request which has REQ_PREFLUSH. we don't set + * s->iop.status by this failure, the status will be decided + * by result of bch_data_insert() operation. + */ + if (unlikely(s->iop.writeback && + bio->bi_opf & REQ_PREFLUSH)) { + char buf[BDEVNAME_SIZE]; + + bio_devname(bio, buf); + pr_err("Can't flush %s: returned bi_status %i", + buf, bio->bi_status); + } else { + /* set to orig_bio->bi_status in bio_complete() */ + s->iop.status = bio->bi_status; + } + s->recoverable = false; + /* should count I/O error for backing device here */ + } + + bio_put(bio); + closure_put(cl); +} + static void bio_complete(struct search *s) { if (s->orig_bio) { @@ -644,13 +677,21 @@ static void bio_complete(struct search *s) } } -static void do_bio_hook(struct search *s, struct bio *orig_bio) +static void do_bio_hook(struct search *s, + struct bio *orig_bio, + bio_end_io_t *end_io_fn) { struct bio *bio = &s->bio.bio; bio_init(bio, NULL, 0); __bio_clone_fast(bio, orig_bio); - bio->bi_end_io = request_endio; + /* + * bi_end_io can be set separately somewhere else, e.g. the + * variants in, + * - cache_bio->bi_end_io from cached_dev_cache_miss() + * - n->bi_end_io from cache_lookup_fn() + */ + bio->bi_end_io = end_io_fn; bio->bi_private = &s->cl; bio_cnt_set(bio, 3); @@ -676,7 +717,7 @@ static inline struct search *search_alloc(struct bio *bio, s = mempool_alloc(d->c->search, GFP_NOIO); closure_init(&s->cl, NULL); - do_bio_hook(s, bio); + do_bio_hook(s, bio, request_endio); s->orig_bio = bio; s->cache_miss = NULL; @@ -743,10 +784,11 @@ static void cached_dev_read_error(struct closure *cl) trace_bcache_read_retry(s->orig_bio); s->iop.status = 0; - do_bio_hook(s, s->orig_bio); + do_bio_hook(s, s->orig_bio, backing_request_endio); /* XXX: invalidate cache */ + /* I/O request sent to backing device */ closure_bio_submit(s->iop.c, bio, cl); } @@ -859,7 +901,7 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, bio_copy_dev(cache_bio, miss); cache_bio->bi_iter.bi_size = s->insert_bio_sectors << 9; - cache_bio->bi_end_io = request_endio; + cache_bio->bi_end_io = backing_request_endio; cache_bio->bi_private = &s->cl; bch_bio_map(cache_bio, NULL); @@ -872,14 +914,16 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s, s->cache_miss = miss; s->iop.bio = cache_bio; bio_get(cache_bio); + /* I/O request sent to backing device */ closure_bio_submit(s->iop.c, cache_bio, &s->cl); return ret; out_put: bio_put(cache_bio); out_submit: - miss->bi_end_io = request_endio; + miss->bi_end_io = backing_request_endio; miss->bi_private = &s->cl; + /* I/O request sent to backing device */ closure_bio_submit(s->iop.c, miss, &s->cl); return ret; } @@ -943,31 +987,46 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s) s->iop.bio = s->orig_bio; bio_get(s->iop.bio); - if ((bio_op(bio) != REQ_OP_DISCARD) || - blk_queue_discard(bdev_get_queue(dc->bdev))) - closure_bio_submit(s->iop.c, bio, cl); + if (bio_op(bio) == REQ_OP_DISCARD && + !blk_queue_discard(bdev_get_queue(dc->bdev))) + goto insert_data; + + /* I/O request sent to backing device */ + bio->bi_end_io = backing_request_endio; + closure_bio_submit(s->iop.c, bio, cl); + } else if (s->iop.writeback) { bch_writeback_add(dc); s->iop.bio = bio; if (bio->bi_opf & REQ_PREFLUSH) { - /* Also need to send a flush to the backing device */ - struct bio *flush = bio_alloc_bioset(GFP_NOIO, 0, - dc->disk.bio_split); - + /* + * Also need to send a flush to the backing + * device. + */ + struct bio *flush; + + flush = bio_alloc_bioset(GFP_NOIO, 0, + dc->disk.bio_split); + if (!flush) { + s->iop.status = BLK_STS_RESOURCE; + goto insert_data; + } bio_copy_dev(flush, bio); - flush->bi_end_io = request_endio; + flush->bi_end_io = backing_request_endio; flush->bi_private = cl; flush->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; - + /* I/O request sent to backing device */ closure_bio_submit(s->iop.c, flush, cl); } } else { s->iop.bio = bio_clone_fast(bio, GFP_NOIO, dc->disk.bio_split); - + /* I/O request sent to backing device */ + bio->bi_end_io = backing_request_endio; closure_bio_submit(s->iop.c, bio, cl); } +insert_data: closure_call(&s->iop.cl, bch_data_insert, NULL, cl); continue_at(cl, cached_dev_write_complete, NULL); } @@ -981,6 +1040,7 @@ static void cached_dev_nodata(struct closure *cl) bch_journal_meta(s->iop.c, cl); /* If it's a flush, we send the flush to the backing device too */ + bio->bi_end_io = backing_request_endio; closure_bio_submit(s->iop.c, bio, cl); continue_at(cl, cached_dev_bio_complete, NULL); @@ -1078,6 +1138,7 @@ static blk_qc_t cached_dev_make_request(struct request_queue *q, cached_dev_read(dc, s); } } else + /* I/O request sent to backing device */ detached_dev_do_request(d, bio); return BLK_QC_T_NONE; diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 5c49109a7046..7f029535edff 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -273,6 +273,7 @@ void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent) bio->bi_private = dc; closure_get(cl); + /* I/O request sent to backing device */ __write_super(&dc->sb, bio); closure_return_with_destructor(cl, bch_write_bdev_super_unlock); diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c index 70092ada68e6..4a9547cdcdc5 100644 --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -289,6 +289,7 @@ static void write_dirty(struct closure *cl) bio_set_dev(&io->bio, io->dc->bdev); io->bio.bi_end_io = dirty_endio; + /* I/O request sent to backing device */ closure_bio_submit(io->dc->disk.c, &io->bio, cl); }
In order to catch I/O error of backing device, a separate bi_end_io call back is required. Then a per backing device counter can record I/O errors number and retire the backing device if the counter reaches a per backing device I/O error limit. This patch adds backing_request_endio() to bcache backing device I/O code path, this is a preparation for further complicated backing device failure handling. So far there is no real code logic change, I make this change a separate patch to make sure it is stable and reliable for further work. Changelog: v2: Fix code comments typo, remove a redundant bch_writeback_add() line added in v4 patch set. v1: indeed this is new added in this patch set. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Junhui Tang <tang.junhui@zte.com.cn> Cc: Michael Lyle <mlyle@lyle.org> --- drivers/md/bcache/request.c | 93 +++++++++++++++++++++++++++++++++++-------- drivers/md/bcache/super.c | 1 + drivers/md/bcache/writeback.c | 1 + 3 files changed, 79 insertions(+), 16 deletions(-)