[PATCH 10/36] fs: cleanup do_pollfd

Christoph Hellwig
2018-03-05T21:40:00Z

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 686de7b3a1db..c6c504a814f9 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 = EPOLLNVAL;
- if (f.file) {
- /* userland u16 ->events contains POLL... bitmap */
- __poll_t filter = demangle_poll(pollfd->events) |
- EPOLLERR | EPOLLHUP;
- 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);
- }
+ int fd = pollfd->fd;
+ __poll_t mask = 0, filter;
+ struct fd f;
+
+ if (fd < 0)
+ goto out;
+ mask = EPOLLNVAL;
+ f = fdget(fd);
+ if (!f.file)
+ goto out;
+
+ /* userland u16 ->events contains POLL... bitmap */
+ filter = demangle_poll(pollfd->events) | EPOLLERR | EPOLLHUP;
+ 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 &= filter; /* Mask out unneeded events. */
+ fdput(f);
+
+out:
/* ... and so does ->revents */
pollfd->revents = mangle_poll(mask);
-
return mask;
}

--
2.14.2