Unverified Commit f2ffc48d authored by Christian Brauner's avatar Christian Brauner
Browse files

Merge patch series "pipe: don't update {a,c,m}time for anonymous pipes" 

Oleg Nesterov <oleg@redhat.com> says:

Don't update {a,c,m}time for anonymous pipes for performance reasons.

* patches from https://lore.kernel.org/r/20250205181716.GA13817@redhat.com:
  pipe: don't update {a,c,m}time for anonymous pipes
  pipe: introduce struct file_operations pipeanon_fops

Link: https://lore.kernel.org/r/20250205181716.GA13817@redhat.com


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parents 2014c95a f017b0a4

fs/pipe.c

+47 −15
Original line number Diff line number Diff line
@@ -248,7 +248,7 @@ static inline unsigned int pipe_update_tail(struct pipe_inode_info *pipe, 
}



static ssize_t

pipe_read(struct kiocb *iocb, struct iov_iter *to)

anon_pipe_read(struct kiocb *iocb, struct iov_iter *to)

{

	size_t total_len = iov_iter_count(to);

	struct file *filp = iocb->ki_filp;
@@ -404,8 +404,15 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) 
	if (wake_next_reader)

		wake_up_interruptible_sync_poll(&pipe->rd_wait, EPOLLIN | EPOLLRDNORM);

	kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);

	return ret;

}



static ssize_t

fifo_pipe_read(struct kiocb *iocb, struct iov_iter *to)

{

	int ret = anon_pipe_read(iocb, to);

	if (ret > 0)

		file_accessed(filp);

		file_accessed(iocb->ki_filp);

	return ret;

}
@@ -426,7 +433,7 @@ static inline bool pipe_writable(const struct pipe_inode_info *pipe) 
}



static ssize_t

pipe_write(struct kiocb *iocb, struct iov_iter *from)

anon_pipe_write(struct kiocb *iocb, struct iov_iter *from)

{

	struct file *filp = iocb->ki_filp;

	struct pipe_inode_info *pipe = filp->private_data;
@@ -604,12 +611,22 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) 
	kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);

	if (wake_next_writer)

		wake_up_interruptible_sync_poll(&pipe->wr_wait, EPOLLOUT | EPOLLWRNORM);

	if (ret > 0 && sb_start_write_trylock(file_inode(filp)->i_sb)) {

	return ret;

}



static ssize_t

fifo_pipe_write(struct kiocb *iocb, struct iov_iter *from)

{

	int ret = anon_pipe_write(iocb, from);

	if (ret > 0) {

		struct file *filp = iocb->ki_filp;

		if (sb_start_write_trylock(file_inode(filp)->i_sb)) {

			int err = file_update_time(filp);

			if (err)

				ret = err;

			sb_end_write(file_inode(filp)->i_sb);

		}

	}

	return ret;

}
@@ -878,6 +895,8 @@ static const struct dentry_operations pipefs_dentry_operations = { 
	.d_dname	= pipefs_dname,

};



static const struct file_operations pipeanon_fops;



static struct inode * get_pipe_inode(void)

{

	struct inode *inode = new_inode_pseudo(pipe_mnt->mnt_sb);
@@ -895,7 +914,7 @@ static struct inode * get_pipe_inode(void) 
	inode->i_pipe = pipe;

	pipe->files = 2;

	pipe->readers = pipe->writers = 1;

	inode->i_fop = &pipefifo_fops;

	inode->i_fop = &pipeanon_fops;



	/*

	 * Mark the inode dirty from the very beginning,
@@ -938,7 +957,7 @@ int create_pipe_files(struct file **res, int flags) 


	f = alloc_file_pseudo(inode, pipe_mnt, "",

				O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT)),

				&pipefifo_fops);

				&pipeanon_fops);

	if (IS_ERR(f)) {

		free_pipe_info(inode->i_pipe);

		iput(inode);
@@ -949,7 +968,7 @@ int create_pipe_files(struct file **res, int flags) 
	f->f_pipe = 0;



	res[0] = alloc_file_clone(f, O_RDONLY | (flags & O_NONBLOCK),

				  &pipefifo_fops);

				  &pipeanon_fops);

	if (IS_ERR(res[0])) {

		put_pipe_info(inode, inode->i_pipe);

		fput(f);
@@ -1107,8 +1126,8 @@ static void wake_up_partner(struct pipe_inode_info *pipe) 


static int fifo_open(struct inode *inode, struct file *filp)

{

	bool is_pipe = inode->i_fop == &pipeanon_fops;

	struct pipe_inode_info *pipe;

	bool is_pipe = inode->i_sb->s_magic == PIPEFS_MAGIC;

	int ret;



	filp->f_pipe = 0;
@@ -1232,8 +1251,19 @@ static int fifo_open(struct inode *inode, struct file *filp) 


const struct file_operations pipefifo_fops = {

	.open		= fifo_open,

	.read_iter	= pipe_read,

	.write_iter	= pipe_write,

	.read_iter	= fifo_pipe_read,

	.write_iter	= fifo_pipe_write,

	.poll		= pipe_poll,

	.unlocked_ioctl	= pipe_ioctl,

	.release	= pipe_release,

	.fasync		= pipe_fasync,

	.splice_write	= iter_file_splice_write,

};



static const struct file_operations pipeanon_fops = {

	.open		= fifo_open,

	.read_iter	= anon_pipe_read,

	.write_iter	= anon_pipe_write,

	.poll		= pipe_poll,

	.unlocked_ioctl	= pipe_ioctl,

	.release	= pipe_release,
@@ -1388,7 +1418,9 @@ struct pipe_inode_info *get_pipe_info(struct file *file, bool for_splice) 
{

	struct pipe_inode_info *pipe = file->private_data;



	if (file->f_op != &pipefifo_fops || !pipe)

	if (!pipe)

		return NULL;

	if (file->f_op != &pipefifo_fops && file->f_op != &pipeanon_fops)

		return NULL;

	if (for_splice && pipe_has_watch_queue(pipe))

		return NULL;