From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 3/7] aio: sanitize ki_list handling Date: Sun, 15 Apr 2018 17:01:04 +0200 Message-ID: <20180415150108.1341-4-hch@lst.de> References: <20180415150108.1341-1-hch@lst.de> Return-path: In-Reply-To: <20180415150108.1341-1-hch@lst.de> Sender: owner-linux-aio@kvack.org To: viro@zeniv.linux.org.uk Cc: Avi Kivity , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-api@vger.kernel.org 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 Acked-by: Jeff Moyer Reviewed-by: Greg Kroah-Hartman Reviewed-by: Darrick J. Wong --- 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 -- 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: aart@kvack.org