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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, netdev@vger.kernel.org,
        linux-api@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 10/36] fs: cleanup do_pollfd
Date:   Wed, 17 Jan 2018 20:27:16 +0100
Message-Id: <20180117192742.710-11-hch@lst.de>
In-Reply-To: <20180117192742.710-1-hch@lst.de>
References: <20180117192742.710-1-hch@lst.de>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Use straigline code with failure handling gotos instead of a lot
of nested conditionals.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/select.c | 48 +++++++++++++++++++++++-------------------------
 1 file changed, 23 insertions(+), 25 deletions(-)

diff --git a/fs/select.c b/fs/select.c
index 4e1dccac2702..2ad66647f340 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -806,34 +806,32 @@ static inline __poll_t do_pollfd(struct pollfd *pollfd, poll_table *pwait,
 				     bool *can_busy_poll,
 				     __poll_t busy_flag)
 {
-	__poll_t mask;
-	int fd;
-
-	mask = 0;
-	fd = pollfd->fd;
-	if (fd >= 0) {
-		struct fd f = fdget(fd);
-		mask = POLLNVAL;
-		if (f.file) {
-			/* userland u16 ->events contains POLL... bitmap */
-			__poll_t filter = demangle_poll(pollfd->events) |
-						POLLERR | POLLHUP;
-			mask = DEFAULT_POLLMASK;
-			if (f.file->f_op->poll) {
-				pwait->_key = filter;
-				pwait->_key |= busy_flag;
-				mask = f.file->f_op->poll(f.file, pwait);
-				if (mask & busy_flag)
-					*can_busy_poll = true;
-			}
-			/* Mask out unneeded events. */
-			mask &= filter;
-			fdput(f);
-		}
+	__poll_t mask = 0, filter;
+	struct fd f;
+
+	if (pollfd->fd < 0)
+		goto out;
+	mask = POLLNVAL;
+	f = fdget(pollfd->fd);
+	if (!f.file)
+		goto out;
+
+	/* userland u16 ->events contains POLL... bitmap */
+	filter = demangle_poll(pollfd->events) | POLLERR | POLLHUP;
+	mask = DEFAULT_POLLMASK;
+	if (f.file->f_op->poll) {
+		pwait->_key = filter | busy_flag;
+		mask = f.file->f_op->poll(f.file, pwait);
+		if (mask & busy_flag)
+			*can_busy_poll = true;
 	}
+
+	/* Mask out unneeded events. */
+	mask &= filter;
+	fdput(f);
+out:
 	/* ... and so does ->revents */
 	pollfd->revents = mangle_poll(mask);
-
 	return mask;
 }
 
-- 
2.14.2