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From:   Al Viro <viro@ZenIV.linux.org.uk>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Eric Dumazet <eric.dumazet@gmail.com>,
        David Miller <davem@davemloft.net>,
        Jason Baron <jbaron@akamai.com>, kgraul@linux.ibm.com,
        ktkhai@virtuozzo.com, kyeongdon.kim@lge.com,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
        Netdev <netdev@vger.kernel.org>, pabeni@redhat.com,
        syzkaller-bugs@googlegroups.com, xiyou.wangcong@gmail.com,
        Christoph Hellwig <hch@lst.de>,
        zhengbin <zhengbin13@huawei.com>, bcrl@kvack.org,
        linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
        houtao1@huawei.com, yi.zhang@huawei.com
Subject: [PATCH 7/8] deal with get_reqs_available() in aio_get_req() itself
Date:   Thu,  7 Mar 2019 00:03:15 +0000
Message-Id: <20190307000316.31133-7-viro@ZenIV.linux.org.uk>
In-Reply-To: <20190307000316.31133-1-viro@ZenIV.linux.org.uk>
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 <20190307000316.31133-1-viro@ZenIV.linux.org.uk>
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From: Al Viro <viro@zeniv.linux.org.uk>

simplifies the caller

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/aio.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 5837a29e63fe..af51b1360305 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1029,6 +1029,11 @@ static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
 	if (unlikely(!req))
 		return NULL;
 
+	if (unlikely(!get_reqs_available(ctx))) {
+		kfree(req);
+		return NULL;
+	}
+
 	percpu_ref_get(&ctx->reqs);
 	req->ki_ctx = ctx;
 	INIT_LIST_HEAD(&req->ki_list);
@@ -1805,13 +1810,9 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
 		return -EINVAL;
 	}
 
-	if (!get_reqs_available(ctx))
-		return -EAGAIN;
-
-	ret = -EAGAIN;
 	req = aio_get_req(ctx);
 	if (unlikely(!req))
-		goto out_put_reqs_available;
+		return -EAGAIN;
 
 	req->ki_filp = fget(iocb->aio_fildes);
 	ret = -EBADF;
@@ -1883,7 +1884,6 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
 	return 0;
 out_put_req:
 	iocb_put(req);
-out_put_reqs_available:
 	put_reqs_available(ctx, 1);
 	return ret;
 }
-- 
2.11.0