diff options
Diffstat (limited to 'fs/fifo.c')
| -rw-r--r-- | fs/fifo.c | 155 | 
1 files changed, 0 insertions, 155 deletions
diff --git a/fs/fifo.c b/fs/fifo.c deleted file mode 100644 index 4e303c22d5e..00000000000 --- a/fs/fifo.c +++ /dev/null @@ -1,155 +0,0 @@ -/* - *  linux/fs/fifo.c - * - *  written by Paul H. Hargrove - * - *  Fixes: - *	10-06-1999, AV: fixed OOM handling in fifo_open(), moved - *			initialization there, switched to external - *			allocation of pipe_inode_info. - */ - -#include <linux/mm.h> -#include <linux/fs.h> -#include <linux/sched.h> -#include <linux/pipe_fs_i.h> - -static void wait_for_partner(struct inode* inode, unsigned int *cnt) -{ -	int cur = *cnt;	 - -	while (cur == *cnt) { -		pipe_wait(inode->i_pipe); -		if (signal_pending(current)) -			break; -	} -} - -static void wake_up_partner(struct inode* inode) -{ -	wake_up_interruptible(&inode->i_pipe->wait); -} - -static int fifo_open(struct inode *inode, struct file *filp) -{ -	struct pipe_inode_info *pipe; -	int ret; - -	mutex_lock(&inode->i_mutex); -	pipe = inode->i_pipe; -	if (!pipe) { -		ret = -ENOMEM; -		pipe = alloc_pipe_info(inode); -		if (!pipe) -			goto err_nocleanup; -		inode->i_pipe = pipe; -	} -	filp->f_version = 0; - -	/* We can only do regular read/write on fifos */ -	filp->f_mode &= (FMODE_READ | FMODE_WRITE); - -	switch (filp->f_mode) { -	case FMODE_READ: -	/* -	 *  O_RDONLY -	 *  POSIX.1 says that O_NONBLOCK means return with the FIFO -	 *  opened, even when there is no process writing the FIFO. -	 */ -		filp->f_op = &read_pipefifo_fops; -		pipe->r_counter++; -		if (pipe->readers++ == 0) -			wake_up_partner(inode); - -		if (!pipe->writers) { -			if ((filp->f_flags & O_NONBLOCK)) { -				/* suppress POLLHUP until we have -				 * seen a writer */ -				filp->f_version = pipe->w_counter; -			} else  -			{ -				wait_for_partner(inode, &pipe->w_counter); -				if(signal_pending(current)) -					goto err_rd; -			} -		} -		break; -	 -	case FMODE_WRITE: -	/* -	 *  O_WRONLY -	 *  POSIX.1 says that O_NONBLOCK means return -1 with -	 *  errno=ENXIO when there is no process reading the FIFO. -	 */ -		ret = -ENXIO; -		if ((filp->f_flags & O_NONBLOCK) && !pipe->readers) -			goto err; - -		filp->f_op = &write_pipefifo_fops; -		pipe->w_counter++; -		if (!pipe->writers++) -			wake_up_partner(inode); - -		if (!pipe->readers) { -			wait_for_partner(inode, &pipe->r_counter); -			if (signal_pending(current)) -				goto err_wr; -		} -		break; -	 -	case FMODE_READ | FMODE_WRITE: -	/* -	 *  O_RDWR -	 *  POSIX.1 leaves this case "undefined" when O_NONBLOCK is set. -	 *  This implementation will NEVER block on a O_RDWR open, since -	 *  the process can at least talk to itself. -	 */ -		filp->f_op = &rdwr_pipefifo_fops; - -		pipe->readers++; -		pipe->writers++; -		pipe->r_counter++; -		pipe->w_counter++; -		if (pipe->readers == 1 || pipe->writers == 1) -			wake_up_partner(inode); -		break; - -	default: -		ret = -EINVAL; -		goto err; -	} - -	/* Ok! */ -	mutex_unlock(&inode->i_mutex); -	return 0; - -err_rd: -	if (!--pipe->readers) -		wake_up_interruptible(&pipe->wait); -	ret = -ERESTARTSYS; -	goto err; - -err_wr: -	if (!--pipe->writers) -		wake_up_interruptible(&pipe->wait); -	ret = -ERESTARTSYS; -	goto err; - -err: -	if (!pipe->readers && !pipe->writers) -		free_pipe_info(inode); - -err_nocleanup: -	mutex_unlock(&inode->i_mutex); -	return ret; -} - -/* - * Dummy default file-operations: the only thing this does - * is contain the open that then fills in the correct operations - * depending on the access mode of the file... - */ -const struct file_operations def_fifo_fops = { -	.open		= fifo_open,	/* will set read_ or write_pipefifo_fops */ -	.llseek		= noop_llseek, -};  | 
