The io_cancel() syscall allows for cancellation of iocbs in flight to generate a completion event. The current behaviour of batch_complete_aio() is to suppress all completion events. Some types of asynchronous operations cannot be cancelled synchronously, and must generate a completion event at some point after the io_cancel() syscall. Instead, only suppress completion events during kioctx teardown by free_ioctx().
Signed-off-by: Benjamin LaHaise <[email protected]> --- fs/aio.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index 46f9dd0..1bcb818 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -81,6 +81,7 @@ struct kioctx { /* sys_io_setup currently limits this to an unsigned int */ unsigned max_reqs; + unsigned dead; unsigned long mmap_base; unsigned long mmap_size; @@ -311,6 +312,7 @@ static void free_ioctx(struct kioctx *ctx) struct kiocb *req; unsigned cpu, head, avail; + ctx->dead = 1; spin_lock_irq(&ctx->ctx_lock); while (!list_empty(&ctx->active_reqs)) { @@ -749,7 +751,9 @@ void batch_complete_aio(struct batch_complete *batch) n = rb_parent(n); } - if (unlikely(xchg(&req->ki_cancel, + /* Suppress cancelled events if free_ioctx() is in progress. */ + if (unlikely(req->ki_ctx->dead && + xchg(&req->ki_cancel, KIOCB_CANCELLED) == KIOCB_CANCELLED)) { /* * Can't use the percpu reqs_available here - could race -- 1.7.4.1 -- "Thought is the essence of where you are now." -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
