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| 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 /include/linux | |
| parent | Add sample notification program (diff) | |
| download | wireguard-linux-8cfba76383e902acbed95092163052b1572f17a8.tar.xz wireguard-linux-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 'include/linux')
| -rw-r--r-- | include/linux/pipe_fs_i.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index 1d3eaa233f4a..eaff59a2f074 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -8,6 +8,7 @@ #define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */ #define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */ #define PIPE_BUF_FLAG_PACKET 0x08 /* read() as a packet */ +#define PIPE_BUF_FLAG_WHOLE 0x10 /* read() must return entire buffer or error */ /** * struct pipe_buffer - a linux kernel pipe buffer |