diff options
Diffstat (limited to 'fs/aio.c')
| -rw-r--r-- | fs/aio.c | 65 |
1 files changed, 22 insertions, 43 deletions
@@ -199,16 +199,7 @@ static int aio_setup_ring(struct kioctx *ctx) static void ctx_rcu_free(struct rcu_head *head) { struct kioctx *ctx = container_of(head, struct kioctx, rcu_head); - unsigned nr_events = ctx->max_reqs; - kmem_cache_free(kioctx_cachep, ctx); - - if (nr_events) { - spin_lock(&aio_nr_lock); - BUG_ON(aio_nr - nr_events > aio_nr); - aio_nr -= nr_events; - spin_unlock(&aio_nr_lock); - } } /* __put_ioctx @@ -217,13 +208,19 @@ static void ctx_rcu_free(struct rcu_head *head) */ static void __put_ioctx(struct kioctx *ctx) { + unsigned nr_events = ctx->max_reqs; BUG_ON(ctx->reqs_active); - cancel_delayed_work(&ctx->wq); - cancel_work_sync(&ctx->wq.work); + cancel_delayed_work_sync(&ctx->wq); aio_free_ring(ctx); mmdrop(ctx->mm); ctx->mm = NULL; + if (nr_events) { + spin_lock(&aio_nr_lock); + BUG_ON(aio_nr - nr_events > aio_nr); + aio_nr -= nr_events; + spin_unlock(&aio_nr_lock); + } pr_debug("__put_ioctx: freeing %p\n", ctx); call_rcu(&ctx->rcu_head, ctx_rcu_free); } @@ -247,7 +244,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) { struct mm_struct *mm; struct kioctx *ctx; - int did_sync = 0; + int err = -ENOMEM; /* Prevent overflows */ if ((nr_events > (0x10000000U / sizeof(struct io_event))) || @@ -256,7 +253,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) return ERR_PTR(-EINVAL); } - if ((unsigned long)nr_events > aio_max_nr) + if (!nr_events || (unsigned long)nr_events > aio_max_nr) return ERR_PTR(-EAGAIN); ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL); @@ -280,25 +277,14 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) goto out_freectx; /* limit the number of system wide aios */ - do { - spin_lock_bh(&aio_nr_lock); - if (aio_nr + nr_events > aio_max_nr || - aio_nr + nr_events < aio_nr) - ctx->max_reqs = 0; - else - aio_nr += ctx->max_reqs; - spin_unlock_bh(&aio_nr_lock); - if (ctx->max_reqs || did_sync) - break; - - /* wait for rcu callbacks to have completed before giving up */ - synchronize_rcu(); - did_sync = 1; - ctx->max_reqs = nr_events; - } while (1); - - if (ctx->max_reqs == 0) + spin_lock(&aio_nr_lock); + if (aio_nr + nr_events > aio_max_nr || + aio_nr + nr_events < aio_nr) { + spin_unlock(&aio_nr_lock); goto out_cleanup; + } + aio_nr += ctx->max_reqs; + spin_unlock(&aio_nr_lock); /* now link into global list. */ spin_lock(&mm->ioctx_lock); @@ -310,16 +296,13 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) return ctx; out_cleanup: - __put_ioctx(ctx); - return ERR_PTR(-EAGAIN); - + err = -EAGAIN; + aio_free_ring(ctx); out_freectx: mmdrop(mm); kmem_cache_free(kioctx_cachep, ctx); - ctx = ERR_PTR(-ENOMEM); - - dprintk("aio: error allocating ioctx %p\n", ctx); - return ctx; + dprintk("aio: error allocating ioctx %d\n", err); + return ERR_PTR(err); } /* aio_cancel_all @@ -407,10 +390,6 @@ void exit_aio(struct mm_struct *mm) aio_cancel_all(ctx); wait_for_all_aios(ctx); - /* - * Ensure we don't leave the ctx on the aio_wq - */ - cancel_work_sync(&ctx->wq.work); if (1 != atomic_read(&ctx->users)) printk(KERN_DEBUG @@ -920,7 +899,7 @@ static void aio_kick_handler(struct work_struct *work) unuse_mm(mm); set_fs(oldfs); /* - * we're in a worker thread already, don't use queue_delayed_work, + * we're in a worker thread already; no point using non-zero delay */ if (requeue) queue_delayed_work(aio_wq, &ctx->wq, 0); |