Commit ebec73f4 authored by Al Viro's avatar Al Viro
Browse files

introduce variants of pipe_lock/pipe_unlock for real pipes/FIFOs 



fs/pipe.c file_operations methods *know* that pipe is not an internal one;
no need to check pipe->inode for those callers.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent de32ec4c

fs/pipe.c

+25 −15
Original line number Diff line number Diff line
@@ -75,6 +75,16 @@ void pipe_unlock(struct pipe_inode_info *pipe) 
}

EXPORT_SYMBOL(pipe_unlock);



static inline void __pipe_lock(struct pipe_inode_info *pipe)

{

	mutex_lock_nested(&pipe->mutex, I_MUTEX_PARENT);

}



static inline void __pipe_unlock(struct pipe_inode_info *pipe)

{

	mutex_unlock(&pipe->mutex);

}



void pipe_double_lock(struct pipe_inode_info *pipe1,

		      struct pipe_inode_info *pipe2)

{
@@ -376,7 +386,7 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov, 


	do_wakeup = 0;

	ret = 0;

	pipe_lock(pipe);

	__pipe_lock(pipe);

	for (;;) {

		int bufs = pipe->nrbufs;

		if (bufs) {
@@ -464,7 +474,7 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov, 
		}

		pipe_wait(pipe);

	}

	pipe_unlock(pipe);

	__pipe_unlock(pipe);



	/* Signal writers asynchronously that there is more room. */

	if (do_wakeup) {
@@ -500,7 +510,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov, 


	do_wakeup = 0;

	ret = 0;

	pipe_lock(pipe);

	__pipe_lock(pipe);



	if (!pipe->readers) {

		send_sig(SIGPIPE, current, 0);
@@ -647,7 +657,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov, 
		pipe->waiting_writers--;

	}

out:

	pipe_unlock(pipe);

	__pipe_unlock(pipe);

	if (do_wakeup) {

		wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM);

		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
@@ -667,7 +677,7 @@ static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 


	switch (cmd) {

		case FIONREAD:

			pipe_lock(pipe);

			__pipe_lock(pipe);

			count = 0;

			buf = pipe->curbuf;

			nrbufs = pipe->nrbufs;
@@ -675,7 +685,7 @@ static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 
				count += pipe->bufs[buf].len;

				buf = (buf+1) & (pipe->buffers - 1);

			}

			pipe_unlock(pipe);

			__pipe_unlock(pipe);



			return put_user(count, (int __user *)arg);

		default:
@@ -721,7 +731,7 @@ pipe_release(struct inode *inode, struct file *file) 
	struct pipe_inode_info *pipe = inode->i_pipe;

	int kill = 0;



	pipe_lock(pipe);

	__pipe_lock(pipe);

	if (file->f_mode & FMODE_READ)

		pipe->readers--;

	if (file->f_mode & FMODE_WRITE)
@@ -738,7 +748,7 @@ pipe_release(struct inode *inode, struct file *file) 
		kill = 1;

	}

	spin_unlock(&inode->i_lock);

	pipe_unlock(pipe);

	__pipe_unlock(pipe);



	if (kill)

		__free_pipe_info(pipe);
@@ -752,7 +762,7 @@ pipe_fasync(int fd, struct file *filp, int on) 
	struct pipe_inode_info *pipe = filp->private_data;

	int retval = 0;



	pipe_lock(pipe);

	__pipe_lock(pipe);

	if (filp->f_mode & FMODE_READ)

		retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);

	if ((filp->f_mode & FMODE_WRITE) && retval >= 0) {
@@ -761,7 +771,7 @@ pipe_fasync(int fd, struct file *filp, int on) 
			/* this can happen only if on == T */

			fasync_helper(-1, filp, 0, &pipe->fasync_readers);

	}

	pipe_unlock(pipe);

	__pipe_unlock(pipe);

	return retval;

}
@@ -1040,7 +1050,7 @@ static int fifo_open(struct inode *inode, struct file *filp) 
	filp->private_data = pipe;

	/* OK, we have a pipe and it's pinned down */



	pipe_lock(pipe);

	__pipe_lock(pipe);



	/* We can only do regular read/write on fifos */

	filp->f_mode &= (FMODE_READ | FMODE_WRITE);
@@ -1110,7 +1120,7 @@ static int fifo_open(struct inode *inode, struct file *filp) 
	}



	/* Ok! */

	pipe_unlock(pipe);

	__pipe_unlock(pipe);

	return 0;



err_rd:
@@ -1132,7 +1142,7 @@ static int fifo_open(struct inode *inode, struct file *filp) 
		kill = 1;

	}

	spin_unlock(&inode->i_lock);

	pipe_unlock(pipe);

	__pipe_unlock(pipe);

	if (kill)

		__free_pipe_info(pipe);

	return ret;
@@ -1248,7 +1258,7 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) 
	if (!pipe)

		return -EBADF;



	pipe_lock(pipe);

	__pipe_lock(pipe);



	switch (cmd) {

	case F_SETPIPE_SZ: {
@@ -1277,7 +1287,7 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) 
	}



out:

	pipe_unlock(pipe);

	__pipe_unlock(pipe);

	return ret;

}