diff options
Diffstat (limited to 'fs/aio.c')
| -rw-r--r-- | fs/aio.c | 47 |
1 files changed, 32 insertions, 15 deletions
@@ -71,12 +71,6 @@ struct aio_ring_info { struct page *internal_pages[AIO_RING_PAGES]; }; -static inline unsigned aio_ring_avail(struct aio_ring_info *info, - struct aio_ring *ring) -{ - return (ring->head + info->nr - 1 - ring->tail) % info->nr; -} - struct kioctx { atomic_t users; atomic_t dead; @@ -92,7 +86,13 @@ struct kioctx { atomic_t reqs_active; struct list_head active_reqs; /* used for cancellation */ - /* sys_io_setup currently limits this to an unsigned int */ + /* + * This is what userspace passed to io_setup(), it's not used for + * anything but counting against the global max_reqs quota. + * + * The real limit is ring->nr - 1, which will be larger (see + * aio_setup_ring()) + */ unsigned max_reqs; struct aio_ring_info ring_info; @@ -284,8 +284,11 @@ static void free_ioctx_rcu(struct rcu_head *head) */ static void free_ioctx(struct kioctx *ctx) { + struct aio_ring_info *info = &ctx->ring_info; + struct aio_ring *ring; struct io_event res; struct kiocb *req; + unsigned head, avail; spin_lock_irq(&ctx->ctx_lock); @@ -299,7 +302,21 @@ static void free_ioctx(struct kioctx *ctx) spin_unlock_irq(&ctx->ctx_lock); - wait_event(ctx->wait, !atomic_read(&ctx->reqs_active)); + ring = kmap_atomic(info->ring_pages[0]); + head = ring->head; + kunmap_atomic(ring); + + while (atomic_read(&ctx->reqs_active) > 0) { + wait_event(ctx->wait, head != info->tail); + + avail = (head <= info->tail ? info->tail : info->nr) - head; + + atomic_sub(avail, &ctx->reqs_active); + head += avail; + head %= info->nr; + } + + WARN_ON(atomic_read(&ctx->reqs_active) < 0); aio_free_ring(ctx); @@ -548,7 +565,6 @@ static int kiocb_batch_refill(struct kioctx *ctx, struct kiocb_batch *batch) unsigned short allocated, to_alloc; long avail; struct kiocb *req, *n; - struct aio_ring *ring; to_alloc = min(batch->count, KIOCB_BATCH_SIZE); for (allocated = 0; allocated < to_alloc; allocated++) { @@ -563,10 +579,8 @@ static int kiocb_batch_refill(struct kioctx *ctx, struct kiocb_batch *batch) goto out; spin_lock_irq(&ctx->ctx_lock); - ring = kmap_atomic(ctx->ring_info.ring_pages[0]); - avail = aio_ring_avail(&ctx->ring_info, ring) - - atomic_read(&ctx->reqs_active); + avail = ctx->ring_info.nr - atomic_read(&ctx->reqs_active) - 1; BUG_ON(avail < 0); if (avail < allocated) { /* Trim back the number of requests. */ @@ -581,7 +595,6 @@ static int kiocb_batch_refill(struct kioctx *ctx, struct kiocb_batch *batch) batch->count -= allocated; atomic_add(allocated, &ctx->reqs_active); - kunmap_atomic(ring); spin_unlock_irq(&ctx->ctx_lock); out: @@ -688,8 +701,11 @@ void aio_complete(struct kiocb *iocb, long res, long res2) * when the event got cancelled. */ if (unlikely(xchg(&iocb->ki_cancel, - KIOCB_CANCELLED) == KIOCB_CANCELLED)) + KIOCB_CANCELLED) == KIOCB_CANCELLED)) { + atomic_dec(&ctx->reqs_active); + /* Still need the wake_up in case free_ioctx is waiting */ goto put_rq; + } /* * Add a completion event to the ring buffer. Must be done holding @@ -746,7 +762,6 @@ void aio_complete(struct kiocb *iocb, long res, long res2) put_rq: /* everything turned out well, dispose of the aiocb. */ aio_put_req(iocb); - atomic_dec(&ctx->reqs_active); /* * We have to order our ring_info tail store above and test @@ -825,6 +840,8 @@ static long aio_read_events_ring(struct kioctx *ctx, flush_dcache_page(info->ring_pages[0]); pr_debug("%li h%u t%u\n", ret, head, info->tail); + + atomic_sub(ret, &ctx->reqs_active); out: mutex_unlock(&info->ring_lock); |