Commit 52bce911 authored Dec 21, 2016 by Linus Torvalds

splice: reinstate SIGPIPE/EPIPE handling



Commit 8924feff ("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: 8924feff ("splice: lift pipe_lock out of splice_to_pipe()")
Reported-and-tested-by: Andreas Schwab <schwab@linux-m68k.org>
Debugged-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org   # v4.9
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0c961c55

fs/splice.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -1087,7 +1087,13 @@ 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))
		@@ -1096,7 +1102,6 @@ static int wait_for_space(struct pipe_inode_info *pipe, unsigned flags)
		pipe_wait(pipe);
		pipe->waiting_writers--;
		}
		return 0;
		}

		static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,

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