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authorDavid Howells <dhowells@redhat.com>2020-01-14 17:07:11 +0000
committerDavid Howells <dhowells@redhat.com>2020-05-19 15:38:18 +0100
commit8cfba76383e902acbed95092163052b1572f17a8 (patch)
treef454a431df62749357767cf70feba3c2022b5cb0 /kernel
parentf5b5a164f9a11aab5b225f082b33a8f03c07516c (diff)
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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.c2
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)) {