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-rw-r--r--fs/aio.c65
1 files changed, 22 insertions, 43 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 5b600cb..c7acaf3 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -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);
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