From 533657c190e5a94e585e08d1c4bdd2295c76391a Mon Sep 17 00:00:00 2001 From: Hans Holmberg Date: Fri, 5 Jan 2018 14:16:10 +0100 Subject: [PATCH] lightnvm: pblk: clear flush point on completed writes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Move completion of syncs and clearing of flush points to the write completion path - this ensures that the data has been comitted to the media before completing bios containing syncs. Signed-off-by: Hans Holmberg Signed-off-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe --- drivers/lightnvm/pblk-rb.c | 58 +++++++++++++++++++++---------------------- drivers/lightnvm/pblk-write.c | 17 ++++++++++++- 2 files changed, 44 insertions(+), 31 deletions(-) diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c index 941842e..672ef8c 100644 --- a/drivers/lightnvm/pblk-rb.c +++ b/drivers/lightnvm/pblk-rb.c @@ -353,17 +353,17 @@ static int pblk_rb_flush_point_set(struct pblk_rb *rb, struct bio *bio, unsigned int pos) { struct pblk_rb_entry *entry; - unsigned int subm, flush_point; + unsigned int sync, flush_point; - subm = READ_ONCE(rb->subm); + sync = READ_ONCE(rb->sync); + + if (pos == sync) + return 0; #ifdef CONFIG_NVM_DEBUG atomic_inc(&rb->inflight_flush_point); #endif - if (pos == subm) - return 0; - flush_point = (pos == 0) ? (rb->nr_entries - 1) : (pos - 1); entry = &rb->entries[flush_point]; @@ -606,22 +606,6 @@ try: return NVM_IO_ERR; } - if (flags & PBLK_FLUSH_ENTRY) { - unsigned int flush_point; - - flush_point = READ_ONCE(rb->flush_point); - if (flush_point == pos) { - /* Protect flush points */ - smp_store_release(&rb->flush_point, - EMPTY_ENTRY); - } - - flags &= ~PBLK_FLUSH_ENTRY; -#ifdef CONFIG_NVM_DEBUG - atomic_dec(&rb->inflight_flush_point); -#endif - } - flags &= ~PBLK_WRITTEN_DATA; flags |= PBLK_SUBMITTED_ENTRY; @@ -731,15 +715,24 @@ void pblk_rb_sync_end(struct pblk_rb *rb, unsigned long *flags) unsigned int pblk_rb_sync_advance(struct pblk_rb *rb, unsigned int nr_entries) { - unsigned int sync; - unsigned int i; - + unsigned int sync, flush_point; lockdep_assert_held(&rb->s_lock); sync = READ_ONCE(rb->sync); + flush_point = READ_ONCE(rb->flush_point); - for (i = 0; i < nr_entries; i++) - sync = (sync + 1) & (rb->nr_entries - 1); + if (flush_point != EMPTY_ENTRY) { + unsigned int secs_to_flush; + + secs_to_flush = pblk_rb_ring_count(flush_point, sync, + rb->nr_entries); + if (secs_to_flush < nr_entries) { + /* Protect flush points */ + smp_store_release(&rb->flush_point, EMPTY_ENTRY); + } + } + + sync = (sync + nr_entries) & (rb->nr_entries - 1); /* Protect from counts */ smp_store_release(&rb->sync, sync); @@ -747,22 +740,27 @@ unsigned int pblk_rb_sync_advance(struct pblk_rb *rb, unsigned int nr_entries) return sync; } +/* Calculate how many sectors to submit up to the current flush point. */ unsigned int pblk_rb_flush_point_count(struct pblk_rb *rb) { - unsigned int subm, flush_point; - unsigned int count; + unsigned int subm, sync, flush_point; + unsigned int submitted, to_flush; /* Protect flush points */ flush_point = smp_load_acquire(&rb->flush_point); if (flush_point == EMPTY_ENTRY) return 0; + /* Protect syncs */ + sync = smp_load_acquire(&rb->sync); + subm = READ_ONCE(rb->subm); + submitted = pblk_rb_ring_count(subm, sync, rb->nr_entries); /* The sync point itself counts as a sector to sync */ - count = pblk_rb_ring_count(flush_point, subm, rb->nr_entries) + 1; + to_flush = pblk_rb_ring_count(flush_point, sync, rb->nr_entries) + 1; - return count; + return (submitted < to_flush) ? (to_flush - submitted) : 0; } /* diff --git a/drivers/lightnvm/pblk-write.c b/drivers/lightnvm/pblk-write.c index 018af87..aae86ed 100644 --- a/drivers/lightnvm/pblk-write.c +++ b/drivers/lightnvm/pblk-write.c @@ -21,13 +21,28 @@ static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd, struct pblk_c_ctx *c_ctx) { struct bio *original_bio; + struct pblk_rb *rwb = &pblk->rwb; unsigned long ret; int i; for (i = 0; i < c_ctx->nr_valid; i++) { struct pblk_w_ctx *w_ctx; + int pos = c_ctx->sentry + i; + int flags; + + w_ctx = pblk_rb_w_ctx(rwb, pos); + flags = READ_ONCE(w_ctx->flags); + + if (flags & PBLK_FLUSH_ENTRY) { + flags &= ~PBLK_FLUSH_ENTRY; + /* Release flags on context. Protect from writes */ + smp_store_release(&w_ctx->flags, flags); + +#ifdef CONFIG_NVM_DEBUG + atomic_dec(&rwb->inflight_flush_point); +#endif + } - w_ctx = pblk_rb_w_ctx(&pblk->rwb, c_ctx->sentry + i); while ((original_bio = bio_list_pop(&w_ctx->bios))) bio_endio(original_bio); } -- 2.7.4