diff options
author | Benjamin LaHaise <bcrl@kvack.org> | 2013-02-20 13:16:58 +1100 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-02-20 16:54:13 +1100 |
commit | 65ccfc3a5fdb49d41eb534fdefd0819f712b7472 (patch) | |
tree | f9ca554a5a0a20379f19099e7cdf51b21bffa89c | |
parent | 17d68acec3e53bc4dca6958147017a3def893b80 (diff) |
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 removing the event suppression in
batch_complete_aio() and modify the wait_event() condition in free_ioctx()
appropriately.
This patch was tested with the cancel operation in the thread based code
posted yesterday.
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
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>
-rw-r--r-- | fs/aio.c | 15 |
1 files changed, 3 insertions, 12 deletions
@@ -335,7 +335,9 @@ static void free_ioctx(struct kioctx *ctx) kunmap_atomic(ring); while (atomic_read(&ctx->reqs_available) < ctx->nr) { - wait_event(ctx->wait, head != ctx->shadow_tail); + wait_event(ctx->wait, + (head != ctx->shadow_tail) || + (atomic_read(&ctx->reqs_available) >= ctr->nr)); avail = (head <= ctx->shadow_tail ? ctx->shadow_tail : ctx->nr) - head; @@ -748,17 +750,6 @@ void batch_complete_aio(struct batch_complete *batch) n = rb_parent(n); } - if (unlikely(xchg(&req->ki_cancel, - KIOCB_CANCELLED) == KIOCB_CANCELLED)) { - /* - * Can't use the percpu reqs_available here - could race - * with free_ioctx() - */ - atomic_inc(&req->ki_ctx->reqs_available); - aio_put_req(req); - continue; - } - if (unlikely(req->ki_eventfd != eventfd)) { if (eventfd) { /* Make event visible */ |