Re: [PATCH 0/3] vmsplice: make vmsplice a trivial wrapper for preadv2/pwritev2
From: Askar Safin <hidden>
Date: 2026-06-24 07:12:34
Also in:
fuse-devel, linux-fsdevel, linux-mm, linux-patches, lkml, netdev
Andrei Vagin [off-list ref]:
quoted hunk ↗ jump to hunk
The CRIU fifo test fails with this change. The problem is that vmsplice with SPLICE_F_NONBLOCK to a fifo file descriptor fails with -EOPNOTSUPP. It seems we need a fix like this one:diff --git a/fs/pipe.c b/fs/pipe.c index 429b0714ec57..6fc49e933727 100644 --- a/fs/pipe.c +++ b/fs/pipe.c@@ -1253,6 +1253,7 @@ static int fifo_open(struct inode *inode, structfile *filp) /* We can only do regular read/write on fifos */ stream_open(inode, filp); + filp->f_mode |= FMODE_NOWAIT; switch (filp->f_mode & (FMODE_READ | FMODE_WRITE)) { case FMODE_READ:
Does CRIU actually rely on ability to do SPLICE_F_NONBLOCK vmsplice into named fifos? Or this is merely a test? If this is just a test, I think we need not to preserve this behavior. I did debian code search with regex "vmsplice.*SPLICE_F_NONBLOCK" and I found very few packages. And it seems all them use pipes, not named fifos. (On speed: I still think that my vmsplice patches are good thing, despite performance regressions in CRIU.) -- Askar Safin