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From: Christoph Hellwig <hch@lst.de>
To: viro@zeniv.linux.org.uk
Cc: Avi Kivity <avi@scylladb.com>,
	linux-aio@kvack.org, linux-fsdevel@vger.kernel.org,
	linux-api@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/7] aio: sanitize ki_list handling
Date: Wed,  2 May 2018 23:14:44 +0200	[thread overview]
Message-ID: <20180502211448.18276-4-hch@lst.de> (raw)
In-Reply-To: <20180502211448.18276-1-hch@lst.de>

Instead of handcoded non-null checks always initialize ki_list to an
empty list and use list_empty / list_empty_careful on it.  While we're
at it also error out on a double call to kiocb_set_cancel_fn instead
of ignoring it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/aio.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 7c1855afd723..18507743757a 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -553,13 +553,12 @@ void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
 	struct kioctx *ctx = req->ki_ctx;
 	unsigned long flags;
 
-	spin_lock_irqsave(&ctx->ctx_lock, flags);
-
-	if (!req->ki_list.next)
-		list_add(&req->ki_list, &ctx->active_reqs);
+	if (WARN_ON_ONCE(!list_empty(&req->ki_list)))
+		return;
 
+	spin_lock_irqsave(&ctx->ctx_lock, flags);
+	list_add_tail(&req->ki_list, &ctx->active_reqs);
 	req->ki_cancel = cancel;
-
 	spin_unlock_irqrestore(&ctx->ctx_lock, flags);
 }
 EXPORT_SYMBOL(kiocb_set_cancel_fn);
@@ -1039,7 +1038,7 @@ static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
 		goto out_put;
 
 	percpu_ref_get(&ctx->reqs);
-
+	INIT_LIST_HEAD(&req->ki_list);
 	req->ki_ctx = ctx;
 	return req;
 out_put:
@@ -1107,7 +1106,7 @@ static void aio_complete(struct kiocb *kiocb, long res, long res2)
 		file_end_write(file);
 	}
 
-	if (iocb->ki_list.next) {
+	if (!list_empty_careful(&iocb->ki_list)) {
 		unsigned long flags;
 
 		spin_lock_irqsave(&ctx->ctx_lock, flags);
-- 
2.17.0


  parent reply	other threads:[~2018-05-02 21:16 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-02 21:14 io_pgetevents & aio fsync V4 Christoph Hellwig
2018-05-02 21:14 ` [PATCH 1/7] aio: don't print the page size at boot time Christoph Hellwig
2018-05-02 21:14 ` [PATCH 2/7] aio: remove an outdated BUG_ON and comment in aio_complete Christoph Hellwig
2018-05-02 21:14 ` Christoph Hellwig [this message]
2018-05-02 21:14 ` [PATCH 4/7] aio: remove the extra get_file/fput pair in io_submit_one Christoph Hellwig
2018-05-02 22:04   ` Darrick J. Wong
2018-05-02 21:14 ` [PATCH 5/7] aio: refactor read/write iocb setup Christoph Hellwig
2018-05-02 21:14 ` [PATCH 6/7] aio: implement IOCB_CMD_FSYNC and IOCB_CMD_FDSYNC Christoph Hellwig
2018-05-02 21:14 ` [PATCH 7/7] aio: implement io_pgetevents Christoph Hellwig
2018-05-18  8:28   ` James Hogan
2018-05-18  8:57     ` Christoph Hellwig
2018-07-04 14:21   ` Adrian Reber
2018-07-08 20:44     ` Christoph Hellwig
2018-07-09 17:20       ` Stephan Müller
2018-07-09 19:21       ` Stephan Müller
2018-07-10 12:51         ` Christoph Hellwig
2018-07-10  5:11       ` Andrei Vagin
2018-05-10 18:05 ` io_pgetevents & aio fsync V4 Al Viro
  -- strict thread matches above, loose matches on Subject: below --
2018-04-15 15:01 io_pgetevents & aio fsync V3 Christoph Hellwig
2018-04-15 15:01 ` [PATCH 3/7] aio: sanitize ki_list handling Christoph Hellwig

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