From c6f141412d24c8d8a9d98ef45303c0235829044b Mon Sep 17 00:00:00 2001 From: Dominique Martinet Date: Mon, 6 Apr 2020 19:19:32 +0200 Subject: [PATCH] 9p: document short read behaviour with O_NONBLOCK Regular files opened with O_NONBLOCK allow read to return after a single round-trip with the server instead of trying to fill buffer. Add a few lines in 9p documentation to describe that. Link: http://lkml.kernel.org/r/1586193572-1375-1-git-send-email-asmadeus@codewreck.org Signed-off-by: Dominique Martinet --- Documentation/filesystems/9p.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt index fec7144e817c..3fb780ffdf23 100644 --- a/Documentation/filesystems/9p.txt +++ b/Documentation/filesystems/9p.txt @@ -133,6 +133,16 @@ OPTIONS cache tags for existing cache sessions can be listed at /sys/fs/9p/caches. (applies only to cache=fscache) +BEHAVIOR +======== + +This section aims at describing 9p 'quirks' that can be different +from a local filesystem behaviors. + + - Setting O_NONBLOCK on a file will make client reads return as early + as the server returns some data instead of trying to fill the read + buffer with the requested amount of bytes or end of file is reached. + RESOURCES =========