diff options
| author | David Howells <dhowells@redhat.com> | 2020-01-14 17:07:11 +0000 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2020-05-19 15:38:18 +0100 |
| commit | 8cfba76383e902acbed95092163052b1572f17a8 (patch) | |
| tree | f454a431df62749357767cf70feba3c2022b5cb0 /kernel | |
| parent | f5b5a164f9a11aab5b225f082b33a8f03c07516c (diff) | |
| download | lwn-8cfba76383e902acbed95092163052b1572f17a8.tar.gz lwn-8cfba76383e902acbed95092163052b1572f17a8.zip | |
pipe: Allow buffers to be marked read-whole-or-error for notifications
Allow a buffer to be marked such that read() must return the entire buffer
in one go or return ENOBUFS. Multiple buffers can be amalgamated into a
single read, but a short read will occur if the next "whole" buffer won't
fit.
This is useful for watch queue notifications to make sure we don't split a
notification across multiple reads, especially given that we need to
fabricate an overrun record under some circumstances - and that isn't in
the buffers.
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/watch_queue.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c index c103e34f8705..ad64ea300f6d 100644 --- a/kernel/watch_queue.c +++ b/kernel/watch_queue.c @@ -115,7 +115,7 @@ static bool post_one_notification(struct watch_queue *wqueue, buf->ops = &watch_queue_pipe_buf_ops; buf->offset = offset; buf->len = len; - buf->flags = 0; + buf->flags = PIPE_BUF_FLAG_WHOLE; pipe->head = head + 1; if (!test_and_clear_bit(note, wqueue->notes_bitmap)) { |