From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 4 Dec 2018 16:44:49 +0000 (-0700)
Subject: aio: don't zero entire aio_kiocb aio_get_req()
X-Git-Tag: v4.19.38~33
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=ef529eead8cfc11c051b90d239e7137f7141ea94;p=thirdparty%2Fkernel%2Fstable.git

aio: don't zero entire aio_kiocb aio_get_req()

commit 2bc4ca9bb600cbe36941da2b2a67189fc4302a04 upstream.

It's 192 bytes, fairly substantial. Most items don't need to be cleared,
especially not upfront. Clear the ones we do need to clear, and leave
the other ones for setup when the iocb is prepared and submitted.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/aio.c b/fs/aio.c
index b9e0df08277b1..2547f17b4fef8 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1010,14 +1010,15 @@ static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
 {
 	struct aio_kiocb *req;
 
-	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
+	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);
 	if (unlikely(!req))
 		return NULL;
 
 	percpu_ref_get(&ctx->reqs);
+	req->ki_ctx = ctx;
 	INIT_LIST_HEAD(&req->ki_list);
 	refcount_set(&req->ki_refcnt, 0);
-	req->ki_ctx = ctx;
+	req->ki_eventfd = NULL;
 	return req;
 }
 
@@ -1738,6 +1739,10 @@ static ssize_t aio_poll(struct aio_kiocb *aiocb, struct iocb *iocb)
 	if (unlikely(!req->file))
 		return -EBADF;
 
+	req->head = NULL;
+	req->woken = false;
+	req->cancelled = false;
+
 	apt.pt._qproc = aio_poll_queue_proc;
 	apt.pt._key = req->events;
 	apt.iocb = aiocb;