[2/2] pipe: avoid repeat check of pipe->readers with pipe lock held
Commit Message
Change to pipe->readers is protected by pipe_lock. Only recheck
pipe->reader after relock to avoid repeat check of pipe->readers with
pipe lock held.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
---
fs/pipe.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
@@ -479,13 +479,6 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
}
for (;;) {
- if (!pipe->readers) {
- send_sig(SIGPIPE, current, 0);
- if (!ret)
- ret = -EPIPE;
- break;
- }
-
head = pipe->head;
if (!pipe_full(head, pipe->tail, pipe->max_usage)) {
unsigned int mask = pipe->ring_size - 1;
@@ -573,6 +566,12 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
__pipe_lock(pipe);
was_empty = pipe_empty(pipe->head, pipe->tail);
wake_next_writer = true;
+ if (!pipe->readers) {
+ send_sig(SIGPIPE, current, 0);
+ if (!ret)
+ ret = -EPIPE;
+ break;
+ }
}
out:
if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))