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 4/6] aio: sanitize ki_list handling
Date: Wed, 28 Mar 2018 09:26:37 +0200 [thread overview]
Message-ID: <20180328072639.16885-5-hch@lst.de> (raw)
In-Reply-To: <20180328072639.16885-1-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 50c4a0554cc6..f35801d73e0b 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -555,13 +555,12 @@ 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);
@@ -1034,7 +1033,7 @@ 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:
@@ -1080,7 +1079,7 @@ static void aio_complete(struct aio_kiocb *iocb, long res, long res2)
unsigned tail, pos, head;
unsigned long flags;
- if (iocb->ki_list.next) {
+ if (!list_empty_careful(&iocb->ki_list)) {
unsigned long flags;
spin_lock_irqsave(&ctx->ctx_lock, flags);
--
2.14.2
next prev parent reply other threads:[~2018-03-28 7:27 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-28 7:26 io_pgetevents & aio fsync V2 Christoph Hellwig
2018-03-28 7:26 ` [PATCH 1/6] aio: don't print the page size at boot time Christoph Hellwig
2018-03-28 7:26 ` [PATCH 2/6] aio: remove an outdated comment in aio_complete Christoph Hellwig
2018-03-28 16:05 ` Darrick J. Wong
2018-03-28 17:05 ` Matthew Wilcox
2018-03-28 7:26 ` [PATCH 3/6] aio: refactor read/write iocb setup Christoph Hellwig
2018-04-06 3:21 ` Al Viro
2018-04-06 7:10 ` Christoph Hellwig
2018-04-06 12:28 ` Al Viro
2018-03-28 7:26 ` Christoph Hellwig [this message]
2018-03-28 7:26 ` [PATCH 5/6] aio: implement IOCB_CMD_FSYNC and IOCB_CMD_FDSYNC Christoph Hellwig
2018-04-06 2:59 ` Al Viro
2018-03-28 7:26 ` [PATCH 6/6] aio: implement io_pgetevents Christoph Hellwig
2018-04-06 3:16 ` io_pgetevents & aio fsync V2 Al Viro
2018-04-06 6:27 ` Christoph Hellwig
2018-04-06 12:57 ` Jeff Moyer
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