Messages in this thread Patch in this message | | | Subject | [RFC PATCH 10/10] pipe: Check for ring full inside of the spinlock in pipe_write() [ver #2] | From | David Howells <> | Date | Wed, 23 Oct 2019 21:18:36 +0100 |
| |
Make pipe_write() check to see if the ring has become full between it taking the pipe mutex, checking the ring status and then taking the spinlock.
This can happen if a notification is written into the pipe as that happens without the pipe mutex.
Signed-off-by: David Howells <dhowells@redhat.com> ---
fs/pipe.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/fs/pipe.c b/fs/pipe.c index 3df93990dd9d..6a982a88f658 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -462,6 +462,11 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) spin_lock_irq(&pipe->wait.lock); head = pipe->head; + if (pipe_full(head, pipe->tail, max_usage)) { + spin_unlock_irq(&pipe->wait.lock); + continue; + } + pipe_commit_write(pipe, head + 1); /* Always wake up, even if the copy fails. Otherwise
| |