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 4/9] aio: sanitize ki_list handling Date: Wed, 21 Mar 2018 08:32:27 +0100 [thread overview] Message-ID: <20180321073232.13366-5-hch@lst.de> (raw) In-Reply-To: <20180321073232.13366-1-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: 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 6295fc00f104..c32c315f05b5 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.next)) { unsigned long flags; spin_lock_irqsave(&ctx->ctx_lock, flags); -- 2.14.2
WARNING: multiple messages have this Message-ID (diff)
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 4/9] aio: sanitize ki_list handling Date: Wed, 21 Mar 2018 08:32:27 +0100 [thread overview] Message-ID: <20180321073232.13366-5-hch@lst.de> (raw) In-Reply-To: <20180321073232.13366-1-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: 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 6295fc00f104..c32c315f05b5 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.next)) { unsigned long flags; spin_lock_irqsave(&ctx->ctx_lock, flags); -- 2.14.2 -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: <a href=mailto:"aart@kvack.org">aart@kvack.org</a>
next prev parent reply other threads:[~2018-03-21 7:34 UTC|newest] Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-03-21 7:32 io_pgetevents & aio fsync Christoph Hellwig 2018-03-21 7:32 ` Christoph Hellwig 2018-03-21 7:32 ` [PATCH 1/9] aio: don't print the page size at boot time Christoph Hellwig 2018-03-21 7:32 ` Christoph Hellwig 2018-03-21 9:12 ` Greg KH 2018-03-21 9:12 ` Greg KH 2018-03-21 7:32 ` [PATCH 2/9] aio: remove an outdated comment in aio_complete Christoph Hellwig 2018-03-21 7:32 ` Christoph Hellwig 2018-03-21 9:14 ` Greg KH 2018-03-21 9:14 ` Greg KH 2018-03-21 9:17 ` Christoph Hellwig 2018-03-21 9:17 ` Christoph Hellwig 2018-03-21 7:32 ` [PATCH 3/9] aio: refactor read/write iocb setup Christoph Hellwig 2018-03-21 7:32 ` Christoph Hellwig 2018-03-21 9:15 ` Greg KH 2018-03-21 9:15 ` Greg KH 2018-03-21 7:32 ` Christoph Hellwig [this message] 2018-03-21 7:32 ` [PATCH 4/9] aio: sanitize ki_list handling Christoph Hellwig 2018-03-21 9:16 ` Greg KH 2018-03-21 9:16 ` Greg KH 2018-03-22 15:24 ` Al Viro 2018-03-22 15:24 ` Al Viro 2018-03-22 17:04 ` Christoph Hellwig 2018-03-22 17:04 ` Christoph Hellwig 2018-03-21 7:32 ` [PATCH 5/9] aio: simplify cancellation Christoph Hellwig 2018-03-21 7:32 ` Christoph Hellwig 2018-03-21 9:17 ` Greg KH 2018-03-21 9:17 ` Greg KH 2018-03-21 16:23 ` Darrick J. Wong 2018-03-21 16:23 ` Darrick J. Wong 2018-03-21 7:32 ` [PATCH 6/9] aio: delete iocbs from the active_reqs list in kiocb_cancel Christoph Hellwig 2018-03-21 7:32 ` Christoph Hellwig 2018-03-21 9:17 ` Greg KH 2018-03-21 9:17 ` Greg KH 2018-03-21 16:23 ` Darrick J. Wong 2018-03-21 16:23 ` Darrick J. Wong 2018-03-21 7:32 ` [PATCH 7/9] aio: add delayed cancel support Christoph Hellwig 2018-03-21 7:32 ` Christoph Hellwig 2018-03-21 9:18 ` Greg KH 2018-03-21 9:18 ` Greg KH 2018-03-21 16:23 ` Darrick J. Wong 2018-03-21 16:23 ` Darrick J. Wong 2018-03-22 16:33 ` Al Viro 2018-03-22 16:33 ` Al Viro 2018-03-21 7:32 ` [PATCH 8/9] aio: implement io_pgetevents Christoph Hellwig 2018-03-21 7:32 ` Christoph Hellwig 2018-03-21 9:24 ` Greg KH 2018-03-21 9:24 ` Greg KH 2018-03-21 9:29 ` Christoph Hellwig 2018-03-21 9:29 ` Christoph Hellwig 2018-03-21 14:39 ` Greg KH 2018-03-21 14:39 ` Greg KH 2018-03-21 16:26 ` Darrick J. Wong 2018-03-21 16:26 ` Darrick J. Wong 2018-03-21 7:32 ` [PATCH 9/9] aio: implement IOCB_CMD_FSYNC and IOCB_CMD_FDSYNC Christoph Hellwig 2018-03-21 7:32 ` Christoph Hellwig 2018-03-21 9:27 ` Greg KH 2018-03-21 9:27 ` Greg KH 2018-03-21 9:30 ` Christoph Hellwig 2018-03-21 9:30 ` Christoph Hellwig 2018-03-21 16:26 ` Darrick J. Wong 2018-03-21 16:26 ` Darrick J. Wong 2018-03-22 16:36 ` io_pgetevents & aio fsync Al Viro 2018-03-22 16:36 ` Al Viro 2018-03-22 16:36 ` Al Viro 2018-03-22 16:36 ` Al Viro
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