Commit 03e04f04 authored May 24, 2013 by Benjamin LaHaise Committed by Linus Torvalds May 24, 2013

aio: fix kioctx not being freed after cancellation at exit time



The recent changes overhauling fs/aio.c introduced a bug that results in
the kioctx not being freed when outstanding kiocbs are cancelled at
exit_aio() time.  Specifically, a kiocb that is cancelled has its
completion events discarded by batch_complete_aio(), which then fails to
wake up the process stuck in free_ioctx().  Fix this by modifying the
wait_event() condition in free_ioctx() appropriately.

This patch was tested with the cancel operation in the thread based code
posted yesterday.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Zach Brown <zab@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent a9ff785e

fs/aio.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -307,7 +307,9 @@ static void free_ioctx(struct kioctx *ctx)
		kunmap_atomic(ring);

		while (atomic_read(&ctx->reqs_active) > 0) {
		wait_event(ctx->wait, head != ctx->tail);
		wait_event(ctx->wait,
		head != ctx->tail \|\|
		atomic_read(&ctx->reqs_active) <= 0);

		avail = (head <= ctx->tail ? ctx->tail : ctx->nr_events) - head;

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