From: Max Kellermann <max.kellermann@ionos.com> mainline inclusion from mainline-v6.7-rc1 commit dfaabf916b1ca83cfac856745db2fc9d57d9b13a category: performance bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICZJGM CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- This reverts commit 8df441294dd3 ("pipe: Check for ring full inside of the spinlock in pipe_write()") which was obsoleted by commit c73be61cede ("pipe: Add general notification queue support") because now pipe_write() fails early with -EXDEV if there is a watch_queue. Without a watch_queue, no notifications can be posted to the pipe and mutex protection is enough, as can be seen in splice_pipe_to_pipe() which does not use the spinlock either. Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Message-Id: <20230921075755.1378787-3-max.kellermann@ionos.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- fs/pipe.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index cd7ad6093ce6..e89f293bd375 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -512,16 +512,7 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) * it, either the reader will consume it or it'll still * be there for the next write. */ - spin_lock_irq(&pipe->rd_wait.lock); - - head = pipe->head; - if (pipe_full(head, pipe->tail, pipe->max_usage)) { - spin_unlock_irq(&pipe->rd_wait.lock); - continue; - } - pipe->head = head + 1; - spin_unlock_irq(&pipe->rd_wait.lock); /* Insert it into the buffer array */ buf = &pipe->bufs[head & mask]; -- 2.20.1