Merge mainline pipe changes

Mainline now contains various changes to pipes that are relevant for
other pipe work this cycle. So merge them into the respective VFS tree.

Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 20 insertions, 18 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index f2d5427fba8e..47e96192898d 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -230,11 +230,10 @@ static const struct pipe_buf_operations anon_pipe_buf_ops = {
 /* Done while waiting without holding the pipe lock - thus the READ_ONCE() */
 static inline bool pipe_readable(const struct pipe_inode_info *pipe)
 {
-	unsigned int head = READ_ONCE(pipe->head);
-	unsigned int tail = READ_ONCE(pipe->tail);
+	union pipe_index idx = { .head_tail = READ_ONCE(pipe->head_tail) };
 	unsigned int writers = READ_ONCE(pipe->writers);
 
-	return !pipe_empty(head, tail) || !writers;
+	return !pipe_empty(idx.head, idx.tail) || !writers;
 }
 
 static inline unsigned int pipe_update_tail(struct pipe_inode_info *pipe,
@@ -394,7 +393,7 @@ anon_pipe_read(struct kiocb *iocb, struct iov_iter *to)
 		wake_next_reader = true;
 		mutex_lock(&pipe->mutex);
 	}
-	if (pipe_empty(pipe->head, pipe->tail))
+	if (pipe_is_empty(pipe))
 		wake_next_reader = false;
 	mutex_unlock(&pipe->mutex);
 
@@ -423,11 +422,10 @@ static inline int is_packetized(struct file *file)
 /* Done while waiting without holding the pipe lock - thus the READ_ONCE() */
 static inline bool pipe_writable(const struct pipe_inode_info *pipe)
 {
-	unsigned int head = READ_ONCE(pipe->head);
-	unsigned int tail = READ_ONCE(pipe->tail);
+	union pipe_index idx = { .head_tail = READ_ONCE(pipe->head_tail) };
 	unsigned int max_usage = READ_ONCE(pipe->max_usage);
 
-	return !pipe_full(head, tail, max_usage) ||
+	return !pipe_full(idx.head, idx.tail, max_usage) ||
 		!READ_ONCE(pipe->readers);
 }
 
@@ -576,11 +574,11 @@ anon_pipe_write(struct kiocb *iocb, struct iov_iter *from)
 		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
 		wait_event_interruptible_exclusive(pipe->wr_wait, pipe_writable(pipe));
 		mutex_lock(&pipe->mutex);
-		was_empty = pipe_empty(pipe->head, pipe->tail);
+		was_empty = pipe_is_empty(pipe);
 		wake_next_writer = true;
 	}
 out:
-	if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))
+	if (pipe_is_full(pipe))
 		wake_next_writer = false;
 	mutex_unlock(&pipe->mutex);
 
@@ -623,7 +621,7 @@ fifo_pipe_write(struct kiocb *iocb, struct iov_iter *from)
 static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct pipe_inode_info *pipe = filp->private_data;
-	unsigned int count, head, tail, mask;
+	unsigned int count, head, tail;
 
 	switch (cmd) {
 	case FIONREAD:
@@ -631,10 +629,9 @@ static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		count = 0;
 		head = pipe->head;
 		tail = pipe->tail;
-		mask = pipe->ring_size - 1;
 
-		while (tail != head) {
-			count += pipe->bufs[tail & mask].len;
+		while (!pipe_empty(head, tail)) {
+			count += pipe_buf(pipe, tail)->len;
 			tail++;
 		}
 		mutex_unlock(&pipe->mutex);
@@ -666,7 +663,7 @@ pipe_poll(struct file *filp, poll_table *wait)
 {
 	__poll_t mask;
 	struct pipe_inode_info *pipe = filp->private_data;
-	unsigned int head, tail;
+	union pipe_index idx;
 
 	/* Epoll has some historical nasty semantics, this enables them */
 	WRITE_ONCE(pipe->poll_usage, true);
@@ -687,19 +684,18 @@ pipe_poll(struct file *filp, poll_table *wait)
 	 * if something changes and you got it wrong, the poll
 	 * table entry will wake you up and fix it.
 	 */
-	head = READ_ONCE(pipe->head);
-	tail = READ_ONCE(pipe->tail);
+	idx.head_tail = READ_ONCE(pipe->head_tail);
 
 	mask = 0;
 	if (filp->f_mode & FMODE_READ) {
-		if (!pipe_empty(head, tail))
+		if (!pipe_empty(idx.head, idx.tail))
 			mask |= EPOLLIN | EPOLLRDNORM;
 		if (!pipe->writers && filp->f_pipe != pipe->w_counter)
 			mask |= EPOLLHUP;
 	}
 
 	if (filp->f_mode & FMODE_WRITE) {
-		if (!pipe_full(head, tail, pipe->max_usage))
+		if (!pipe_full(idx.head, idx.tail, pipe->max_usage))
 			mask |= EPOLLOUT | EPOLLWRNORM;
 		/*
 		 * Most Unices do not set EPOLLERR for FIFOs but on Linux they
@@ -971,6 +967,12 @@ int create_pipe_files(struct file **res, int flags)
 	res[1] = f;
 	stream_open(inode, res[0]);
 	stream_open(inode, res[1]);
+	/*
+	 * Disable permission and pre-content events, but enable legacy
+	 * inotify events for legacy users.
+	 */
+	file_set_fsnotify_mode(res[0], FMODE_NONOTIFY_PERM);
+	file_set_fsnotify_mode(res[1], FMODE_NONOTIFY_PERM);
 	return 0;
 }