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authorDavid Howells <dhowells@redhat.com>2019-09-24 16:09:04 +0100
committerDavid Howells <dhowells@redhat.com>2019-11-15 16:22:54 +0000
commitb667b867344301e24f21d4a4c844675ff61d89e1 (patch)
treeeb01278af88b386a56fee12ced51cb1764d70aaa /fs/pipe.c
parent6718b6f855a0b4962d54bd625be2718cb820cec6 (diff)
downloadlinux-b667b867344301e24f21d4a4c844675ff61d89e1.tar.bz2
pipe: Advance tail pointer inside of wait spinlock in pipe_read()
Advance the pipe ring tail pointer inside of wait spinlock in pipe_read() so that the pipe can be written into with kernel notifications from contexts where pipe->mutex cannot be taken. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/pipe.c')
-rw-r--r--fs/pipe.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/pipe.c b/fs/pipe.c
index 69afeab8a73a..ea134f69a292 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -325,9 +325,14 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to)
if (!buf->len) {
pipe_buf_release(pipe, buf);
+ spin_lock_irq(&pipe->wait.lock);
tail++;
pipe->tail = tail;
- do_wakeup = 1;
+ do_wakeup = 0;
+ wake_up_interruptible_sync_poll_locked(
+ &pipe->wait, EPOLLOUT | EPOLLWRNORM);
+ spin_unlock_irq(&pipe->wait.lock);
+ kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
}
total_len -= chars;
if (!total_len)
@@ -359,6 +364,7 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to)
if (do_wakeup) {
wake_up_interruptible_sync_poll(&pipe->wait, EPOLLOUT | EPOLLWRNORM);
kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
+ do_wakeup = 0;
}
pipe_wait(pipe);
}