diff options
Diffstat (limited to 'fs/aio.c')
-rw-r--r-- | fs/aio.c | 65 |
1 files changed, 36 insertions, 29 deletions
@@ -160,7 +160,7 @@ static int aio_setup_ring(struct kioctx *ctx) info->nr = nr_events; /* trusted copy */ - ring = kmap_atomic(info->ring_pages[0], KM_USER0); + ring = kmap_atomic(info->ring_pages[0]); ring->nr = nr_events; /* user copy */ ring->id = ctx->user_id; ring->head = ring->tail = 0; @@ -168,32 +168,32 @@ static int aio_setup_ring(struct kioctx *ctx) ring->compat_features = AIO_RING_COMPAT_FEATURES; ring->incompat_features = AIO_RING_INCOMPAT_FEATURES; ring->header_length = sizeof(struct aio_ring); - kunmap_atomic(ring, KM_USER0); + kunmap_atomic(ring); return 0; } /* aio_ring_event: returns a pointer to the event at the given index from - * kmap_atomic(, km). Release the pointer with put_aio_ring_event(); + * kmap_atomic(). Release the pointer with put_aio_ring_event(); */ #define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event)) #define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event)) #define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE) -#define aio_ring_event(info, nr, km) ({ \ +#define aio_ring_event(info, nr) ({ \ unsigned pos = (nr) + AIO_EVENTS_OFFSET; \ struct io_event *__event; \ __event = kmap_atomic( \ - (info)->ring_pages[pos / AIO_EVENTS_PER_PAGE], km); \ + (info)->ring_pages[pos / AIO_EVENTS_PER_PAGE]); \ __event += pos % AIO_EVENTS_PER_PAGE; \ __event; \ }) -#define put_aio_ring_event(event, km) do { \ +#define put_aio_ring_event(event) do { \ struct io_event *__event = (event); \ (void)__event; \ - kunmap_atomic((void *)((unsigned long)__event & PAGE_MASK), km); \ + kunmap_atomic((void *)((unsigned long)__event & PAGE_MASK)); \ } while(0) static void ctx_rcu_free(struct rcu_head *head) @@ -228,12 +228,6 @@ static void __put_ioctx(struct kioctx *ctx) call_rcu(&ctx->rcu_head, ctx_rcu_free); } -static inline void get_ioctx(struct kioctx *kioctx) -{ - BUG_ON(atomic_read(&kioctx->users) <= 0); - atomic_inc(&kioctx->users); -} - static inline int try_get_ioctx(struct kioctx *kioctx) { return atomic_inc_not_zero(&kioctx->users); @@ -273,7 +267,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) mm = ctx->mm = current->mm; atomic_inc(&mm->mm_count); - atomic_set(&ctx->users, 1); + atomic_set(&ctx->users, 2); spin_lock_init(&ctx->ctx_lock); spin_lock_init(&ctx->ring_info.ring_lock); init_waitqueue_head(&ctx->wait); @@ -476,14 +470,23 @@ static void kiocb_batch_init(struct kiocb_batch *batch, long total) batch->count = total; } -static void kiocb_batch_free(struct kiocb_batch *batch) +static void kiocb_batch_free(struct kioctx *ctx, struct kiocb_batch *batch) { struct kiocb *req, *n; + if (list_empty(&batch->head)) + return; + + spin_lock_irq(&ctx->ctx_lock); list_for_each_entry_safe(req, n, &batch->head, ki_batch) { list_del(&req->ki_batch); + list_del(&req->ki_list); kmem_cache_free(kiocb_cachep, req); + ctx->reqs_active--; } + if (unlikely(!ctx->reqs_active && ctx->dead)) + wake_up_all(&ctx->wait); + spin_unlock_irq(&ctx->ctx_lock); } /* @@ -600,11 +603,16 @@ static void aio_fput_routine(struct work_struct *data) fput(req->ki_filp); /* Link the iocb into the context's free list */ + rcu_read_lock(); spin_lock_irq(&ctx->ctx_lock); really_put_req(ctx, req); + /* + * at that point ctx might've been killed, but actual + * freeing is RCU'd + */ spin_unlock_irq(&ctx->ctx_lock); + rcu_read_unlock(); - put_ioctx(ctx); spin_lock_irq(&fput_lock); } spin_unlock_irq(&fput_lock); @@ -635,7 +643,6 @@ static int __aio_put_req(struct kioctx *ctx, struct kiocb *req) * this function will be executed w/out any aio kthread wakeup. */ if (unlikely(!fput_atomic(req->ki_filp))) { - get_ioctx(ctx); spin_lock(&fput_lock); list_add(&req->ki_list, &fput_head); spin_unlock(&fput_lock); @@ -1012,10 +1019,10 @@ int aio_complete(struct kiocb *iocb, long res, long res2) if (kiocbIsCancelled(iocb)) goto put_rq; - ring = kmap_atomic(info->ring_pages[0], KM_IRQ1); + ring = kmap_atomic(info->ring_pages[0]); tail = info->tail; - event = aio_ring_event(info, tail, KM_IRQ0); + event = aio_ring_event(info, tail); if (++tail >= info->nr) tail = 0; @@ -1036,8 +1043,8 @@ int aio_complete(struct kiocb *iocb, long res, long res2) info->tail = tail; ring->tail = tail; - put_aio_ring_event(event, KM_IRQ0); - kunmap_atomic(ring, KM_IRQ1); + put_aio_ring_event(event); + kunmap_atomic(ring); pr_debug("added to ring %p at [%lu]\n", iocb, tail); @@ -1082,7 +1089,7 @@ static int aio_read_evt(struct kioctx *ioctx, struct io_event *ent) unsigned long head; int ret = 0; - ring = kmap_atomic(info->ring_pages[0], KM_USER0); + ring = kmap_atomic(info->ring_pages[0]); dprintk("in aio_read_evt h%lu t%lu m%lu\n", (unsigned long)ring->head, (unsigned long)ring->tail, (unsigned long)ring->nr); @@ -1094,18 +1101,18 @@ static int aio_read_evt(struct kioctx *ioctx, struct io_event *ent) head = ring->head % info->nr; if (head != ring->tail) { - struct io_event *evp = aio_ring_event(info, head, KM_USER1); + struct io_event *evp = aio_ring_event(info, head); *ent = *evp; head = (head + 1) % info->nr; smp_mb(); /* finish reading the event before updatng the head */ ring->head = head; ret = 1; - put_aio_ring_event(evp, KM_USER1); + put_aio_ring_event(evp); } spin_unlock(&info->ring_lock); out: - kunmap_atomic(ring, KM_USER0); + kunmap_atomic(ring); dprintk("leaving aio_read_evt: %d h%lu t%lu\n", ret, (unsigned long)ring->head, (unsigned long)ring->tail); return ret; @@ -1329,10 +1336,10 @@ SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp) ret = PTR_ERR(ioctx); if (!IS_ERR(ioctx)) { ret = put_user(ioctx->user_id, ctxp); - if (!ret) + if (!ret) { + put_ioctx(ioctx); return 0; - - get_ioctx(ioctx); /* io_destroy() expects us to hold a ref */ + } io_destroy(ioctx); } @@ -1742,7 +1749,7 @@ long do_io_submit(aio_context_t ctx_id, long nr, } blk_finish_plug(&plug); - kiocb_batch_free(&batch); + kiocb_batch_free(ctx, &batch); put_ioctx(ctx); return i ? i : ret; } |