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authorLinus Torvalds <torvalds@linux-foundation.org>2020-02-22 11:12:55 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-02-22 11:12:55 -0800
commitb88025ea47ec8aea47f0c283d182ab26bae2970d (patch)
tree653b575f66d4fe2bfb64c7f6890c783e19aeae47
parentf6c69b7f51456a914da11c4ad1b14eba933d36aa (diff)
parentc7849be9cc2dd2754c48ddbaca27c2de6d80a95d (diff)
downloadlinux-sh-b88025ea47ec8aea47f0c283d182ab26bae2970d.tar.gz
Merge tag 'io_uring-5.6-2020-02-22' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe: "Here's a small collection of fixes that were queued up: - Remove unnecessary NULL check (Dan) - Missing io_req_cancelled() call in fallocate (Pavel) - Put the cleanup check for aux data in the right spot (Pavel) - Two fixes for SQPOLL (Stefano, Xiaoguang)" * tag 'io_uring-5.6-2020-02-22' of git://git.kernel.dk/linux-block: io_uring: fix __io_iopoll_check deadlock in io_sq_thread io_uring: prevent sq_thread from spinning when it should stop io_uring: fix use-after-free by io_cleanup_req() io_uring: remove unnecessary NULL checks io_uring: add missing io_req_cancelled()
-rw-r--r--fs/io_uring.c65
1 files changed, 30 insertions, 35 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 5a826017ebb8..de650df9ac53 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1260,6 +1260,9 @@ static void __io_req_aux_free(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
+ if (req->flags & REQ_F_NEED_CLEANUP)
+ io_cleanup_req(req);
+
kfree(req->io);
if (req->file) {
if (req->flags & REQ_F_FIXED_FILE)
@@ -1275,9 +1278,6 @@ static void __io_free_req(struct io_kiocb *req)
{
__io_req_aux_free(req);
- if (req->flags & REQ_F_NEED_CLEANUP)
- io_cleanup_req(req);
-
if (req->flags & REQ_F_INFLIGHT) {
struct io_ring_ctx *ctx = req->ctx;
unsigned long flags;
@@ -1672,11 +1672,17 @@ static void io_iopoll_reap_events(struct io_ring_ctx *ctx)
mutex_unlock(&ctx->uring_lock);
}
-static int __io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
- long min)
+static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
+ long min)
{
int iters = 0, ret = 0;
+ /*
+ * We disallow the app entering submit/complete with polling, but we
+ * still need to lock the ring to prevent racing with polled issue
+ * that got punted to a workqueue.
+ */
+ mutex_lock(&ctx->uring_lock);
do {
int tmin = 0;
@@ -1712,21 +1718,6 @@ static int __io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
ret = 0;
} while (min && !*nr_events && !need_resched());
- return ret;
-}
-
-static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
- long min)
-{
- int ret;
-
- /*
- * We disallow the app entering submit/complete with polling, but we
- * still need to lock the ring to prevent racing with polled issue
- * that got punted to a workqueue.
- */
- mutex_lock(&ctx->uring_lock);
- ret = __io_iopoll_check(ctx, nr_events, min);
mutex_unlock(&ctx->uring_lock);
return ret;
}
@@ -2517,6 +2508,9 @@ static void io_fallocate_finish(struct io_wq_work **workptr)
struct io_kiocb *nxt = NULL;
int ret;
+ if (io_req_cancelled(req))
+ return;
+
ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
req->sync.len);
if (ret < 0)
@@ -2904,6 +2898,7 @@ static void io_close_finish(struct io_wq_work **workptr)
struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
struct io_kiocb *nxt = NULL;
+ /* not cancellable, don't do io_req_cancelled() */
__io_close_finish(req, &nxt);
if (nxt)
io_wq_assign_next(workptr, nxt);
@@ -3071,7 +3066,7 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
if (req->io)
return -EAGAIN;
if (io_alloc_async_ctx(req)) {
- if (kmsg && kmsg->iov != kmsg->fast_iov)
+ if (kmsg->iov != kmsg->fast_iov)
kfree(kmsg->iov);
return -ENOMEM;
}
@@ -3225,7 +3220,7 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
if (req->io)
return -EAGAIN;
if (io_alloc_async_ctx(req)) {
- if (kmsg && kmsg->iov != kmsg->fast_iov)
+ if (kmsg->iov != kmsg->fast_iov)
kfree(kmsg->iov);
return -ENOMEM;
}
@@ -5114,7 +5109,7 @@ static int io_sq_thread(void *data)
*/
mutex_lock(&ctx->uring_lock);
if (!list_empty(&ctx->poll_list))
- __io_iopoll_check(ctx, &nr_events, 0);
+ io_iopoll_getevents(ctx, &nr_events, 0);
else
inflight = 0;
mutex_unlock(&ctx->uring_lock);
@@ -5139,6 +5134,18 @@ static int io_sq_thread(void *data)
*/
if (!to_submit || ret == -EBUSY) {
/*
+ * Drop cur_mm before scheduling, we can't hold it for
+ * long periods (or over schedule()). Do this before
+ * adding ourselves to the waitqueue, as the unuse/drop
+ * may sleep.
+ */
+ if (cur_mm) {
+ unuse_mm(cur_mm);
+ mmput(cur_mm);
+ cur_mm = NULL;
+ }
+
+ /*
* We're polling. If we're within the defined idle
* period, then let us spin without work before going
* to sleep. The exception is if we got EBUSY doing
@@ -5152,18 +5159,6 @@ static int io_sq_thread(void *data)
continue;
}
- /*
- * Drop cur_mm before scheduling, we can't hold it for
- * long periods (or over schedule()). Do this before
- * adding ourselves to the waitqueue, as the unuse/drop
- * may sleep.
- */
- if (cur_mm) {
- unuse_mm(cur_mm);
- mmput(cur_mm);
- cur_mm = NULL;
- }
-
prepare_to_wait(&ctx->sqo_wait, &wait,
TASK_INTERRUPTIBLE);