From 52bce91165e5f2db422b2b972e83d389e5e4725c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 21 Dec 2016 10:59:34 -0800 Subject: splice: reinstate SIGPIPE/EPIPE handling 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 Debugged-by: Al Viro Cc: stable@kernel.org # v4.9 Signed-off-by: Linus Torvalds --- fs/splice.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index 8ed7c9d..873d831 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -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, -- cgit v1.1