This is a note to let you know that I've just added the patch titled
splice: reinstate SIGPIPE/EPIPE handling
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
splice-reinstate-sigpipe-epipe-handling.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 52bce91165e5f2db422b2b972e83d389e5e4725c Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Wed, 21 Dec 2016 10:59:34 -0800
Subject: splice: reinstate SIGPIPE/EPIPE handling
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
commit 52bce91165e5f2db422b2b972e83d389e5e4725c upstream.
Commit 8924feff66f3 ("splice: lift pipe_lock out of splice_to_pipe()")
caused a regression when there were no more readers left on a pipe that
was being spliced into: rather than the expected SIGPIPE and -EPIPE
return value, the writer would end up waiting forever for space to free
up (which obviously was not going to happen with no readers around).
Fixes: 8924feff66f3 ("splice: lift pipe_lock out of splice_to_pipe()")
Reported-and-tested-by: Andreas Schwab <schwab@xxxxxxxxxxxxxx>
Debugged-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/splice.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1086,7 +1086,13 @@ EXPORT_SYMBOL(do_splice_direct);
static int wait_for_space(struct pipe_inode_info *pipe, unsigned flags)
{
- while (pipe->nrbufs == pipe->buffers) {
+ for (;;) {
+ if (unlikely(!pipe->readers)) {
+ send_sig(SIGPIPE, current, 0);
+ return -EPIPE;
+ }
+ if (pipe->nrbufs != pipe->buffers)
+ return 0;
if (flags & SPLICE_F_NONBLOCK)
return -EAGAIN;
if (signal_pending(current))
@@ -1095,7 +1101,6 @@ static int wait_for_space(struct pipe_in
pipe_wait(pipe);
pipe->waiting_writers--;
}
- return 0;
}
static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
Patches currently in stable-queue which might be from torvalds@xxxxxxxxxxxxxxxxxxxx are
queue-4.9/mm-page_alloc-keep-pcp-count-and-list-contents-in-sync-if-struct-page-is-corrupted.patch
queue-4.9/splice-reinstate-sigpipe-epipe-handling.patch
queue-4.9/mm-vmscan.c-set-correct-defer-count-for-shrinker.patch
queue-4.9/vfs-mm-fix-return-value-of-read-at-s_maxbytes.patch
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