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Commit 88dd9c16 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block 

* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [PATCH] vfs: add splice_write and splice_read to documentation
  [PATCH] Remove sys_ prefix of new syscalls from __NR_sys_*
  [PATCH] splice: warning fix
  [PATCH] another round of fs/pipe.c cleanups
  [PATCH] splice: comment styles
  [PATCH] splice: add Ingo as addition copyright holder
  [PATCH] splice: unlikely() optimizations
  [PATCH] splice: speedups and optimizations
  [PATCH] pipe.c/fifo.c code cleanups
  [PATCH] get rid of the PIPE_*() macros
  [PATCH] splice: speedup __generic_file_splice_read
  [PATCH] splice: add direct fd <-> fd splicing support
  [PATCH] splice: add optional input and output offsets
  [PATCH] introduce a "kernel-internal pipe object" abstraction
  [PATCH] splice: be smarter about calling do_page_cache_readahead()
  [PATCH] splice: optimize the splice buffer mapping
  [PATCH] splice: cleanup __generic_file_splice_read()
  [PATCH] splice: only call wake_up_interruptible() when we really have to
  [PATCH] splice: potential !page dereference
  [PATCH] splice: mark the io page as accessed
parents 6dde4325 d1195c51

Documentation/filesystems/vfs.txt

+11 −1
Original line number Diff line number Diff line
@@ -694,7 +694,7 @@ struct file_operations 
----------------------



This describes how the VFS can manipulate an open file. As of kernel

2.6.13, the following members are defined:

2.6.17, the following members are defined:



struct file_operations {

	loff_t (*llseek) (struct file *, loff_t, int);
@@ -723,6 +723,10 @@ struct file_operations { 
	int (*check_flags)(int);

	int (*dir_notify)(struct file *filp, unsigned long arg);

	int (*flock) (struct file *, int, struct file_lock *);

	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, size_t, unsigned 

int);

	ssize_t (*splice_read)(struct file *, struct pipe_inode_info *, size_t, unsigned  

int);

};



Again, all methods are called without any locks being held, unless
@@ -790,6 +794,12 @@ otherwise noted. 


  flock: called by the flock(2) system call



  splice_write: called by the VFS to splice data from a pipe to a file. This

		method is used by the splice(2) system call



  splice_read: called by the VFS to splice data from file to a pipe. This

	       method is used by the splice(2) system call



Note that the file operations are implemented by the specific

filesystem in which the inode resides. When opening a device node

(character or block special) most filesystems will call special

fs/fifo.c

+35 −30
Original line number Diff line number Diff line
@@ -18,8 +18,9 @@ 
static void wait_for_partner(struct inode* inode, unsigned int *cnt)

{

	int cur = *cnt;	



	while (cur == *cnt) {

		pipe_wait(inode);

		pipe_wait(inode->i_pipe);

		if (signal_pending(current))

			break;

	}
@@ -27,18 +28,22 @@ static void wait_for_partner(struct inode* inode, unsigned int* cnt) 


static void wake_up_partner(struct inode* inode)

{

	wake_up_interruptible(PIPE_WAIT(*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(PIPE_MUTEX(*inode));

	if (!inode->i_pipe) {

	mutex_lock(&inode->i_mutex);

	pipe = inode->i_pipe;

	if (!pipe) {

		ret = -ENOMEM;

		if(!pipe_new(inode))

		pipe = alloc_pipe_info(inode);

		if (!pipe)

			goto err_nocleanup;

		inode->i_pipe = pipe;

	}

	filp->f_version = 0;
@@ -53,18 +58,18 @@ static int fifo_open(struct inode *inode, struct file *filp) 
	 *  opened, even when there is no process writing the FIFO.

	 */

		filp->f_op = &read_fifo_fops;

		PIPE_RCOUNTER(*inode)++;

		if (PIPE_READERS(*inode)++ == 0)

		pipe->r_counter++;

		if (pipe->readers++ == 0)

			wake_up_partner(inode);



		if (!PIPE_WRITERS(*inode)) {

		if (!pipe->writers) {

			if ((filp->f_flags & O_NONBLOCK)) {

				/* suppress POLLHUP until we have

				 * seen a writer */

				filp->f_version = PIPE_WCOUNTER(*inode);

				filp->f_version = pipe->w_counter;

			} else 

			{

				wait_for_partner(inode, &PIPE_WCOUNTER(*inode));

				wait_for_partner(inode, &pipe->w_counter);

				if(signal_pending(current))

					goto err_rd;

			}
@@ -78,16 +83,16 @@ static int fifo_open(struct inode *inode, struct file *filp) 
	 *  errno=ENXIO when there is no process reading the FIFO.

	 */

		ret = -ENXIO;

		if ((filp->f_flags & O_NONBLOCK) && !PIPE_READERS(*inode))

		if ((filp->f_flags & O_NONBLOCK) && !pipe->readers)

			goto err;



		filp->f_op = &write_fifo_fops;

		PIPE_WCOUNTER(*inode)++;

		if (!PIPE_WRITERS(*inode)++)

		pipe->w_counter++;

		if (!pipe->writers++)

			wake_up_partner(inode);



		if (!PIPE_READERS(*inode)) {

			wait_for_partner(inode, &PIPE_RCOUNTER(*inode));

		if (!pipe->readers) {

			wait_for_partner(inode, &pipe->r_counter);

			if (signal_pending(current))

				goto err_wr;

		}
@@ -102,11 +107,11 @@ static int fifo_open(struct inode *inode, struct file *filp) 
	 */

		filp->f_op = &rdwr_fifo_fops;



		PIPE_READERS(*inode)++;

		PIPE_WRITERS(*inode)++;

		PIPE_RCOUNTER(*inode)++;

		PIPE_WCOUNTER(*inode)++;

		if (PIPE_READERS(*inode) == 1 || PIPE_WRITERS(*inode) == 1)

		pipe->readers++;

		pipe->writers++;

		pipe->r_counter++;

		pipe->w_counter++;

		if (pipe->readers == 1 || pipe->writers == 1)

			wake_up_partner(inode);

		break;
@@ -116,27 +121,27 @@ static int fifo_open(struct inode *inode, struct file *filp) 
	}



	/* Ok! */

	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_unlock(&inode->i_mutex);

	return 0;



err_rd:

	if (!--PIPE_READERS(*inode))

		wake_up_interruptible(PIPE_WAIT(*inode));

	if (!--pipe->readers)

		wake_up_interruptible(&pipe->wait);

	ret = -ERESTARTSYS;

	goto err;



err_wr:

	if (!--PIPE_WRITERS(*inode))

		wake_up_interruptible(PIPE_WAIT(*inode));

	if (!--pipe->writers)

		wake_up_interruptible(&pipe->wait);

	ret = -ERESTARTSYS;

	goto err;



err:

	if (!PIPE_READERS(*inode) && !PIPE_WRITERS(*inode))

	if (!pipe->readers && !pipe->writers)

		free_pipe_info(inode);



err_nocleanup:

	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_unlock(&inode->i_mutex);

	return ret;

}

fs/pipe.c

+171 −139
Original line number Diff line number Diff line
@@ -36,7 +36,7 @@ 
 */



/* Drop the inode semaphore and wait for a pipe event, atomically */

void pipe_wait(struct inode * inode)

void pipe_wait(struct pipe_inode_info *pipe)

{

	DEFINE_WAIT(wait);
@@ -44,11 +44,14 @@ void pipe_wait(struct inode * inode) 
	 * Pipes are system-local resources, so sleeping on them

	 * is considered a noninteractive wait:

	 */

	prepare_to_wait(PIPE_WAIT(*inode), &wait, TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE);

	mutex_unlock(PIPE_MUTEX(*inode));

	prepare_to_wait(&pipe->wait, &wait,

			TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE);

	if (pipe->inode)

		mutex_unlock(&pipe->inode->i_mutex);

	schedule();

	finish_wait(PIPE_WAIT(*inode), &wait);

	mutex_lock(PIPE_MUTEX(*inode));

	finish_wait(&pipe->wait, &wait);

	if (pipe->inode)

		mutex_lock(&pipe->inode->i_mutex);

}



static int
@@ -91,7 +94,8 @@ pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len) 
	return 0;

}



static void anon_pipe_buf_release(struct pipe_inode_info *info, struct pipe_buffer *buf)

static void anon_pipe_buf_release(struct pipe_inode_info *pipe,

				  struct pipe_buffer *buf)

{

	struct page *page = buf->page;
@@ -100,30 +104,27 @@ static void anon_pipe_buf_release(struct pipe_inode_info *info, struct pipe_buff 
	/*

	 * If nobody else uses this page, and we don't already have a

	 * temporary page, let's keep track of it as a one-deep

	 * allocation cache

	 */

	if (page_count(page) == 1 && !info->tmp_page) {

		info->tmp_page = page;

		return;

	}



	/*

	 * Otherwise just release our reference to it

	 * allocation cache. (Otherwise just release our reference to it)

	 */

	if (page_count(page) == 1 && !pipe->tmp_page)

		pipe->tmp_page = page;

	else

		page_cache_release(page);

}



static void *anon_pipe_buf_map(struct file *file, struct pipe_inode_info *info, struct pipe_buffer *buf)

static void * anon_pipe_buf_map(struct file *file, struct pipe_inode_info *pipe,

				struct pipe_buffer *buf)

{

	return kmap(buf->page);

}



static void anon_pipe_buf_unmap(struct pipe_inode_info *info, struct pipe_buffer *buf)

static void anon_pipe_buf_unmap(struct pipe_inode_info *pipe,

				struct pipe_buffer *buf)

{

	kunmap(buf->page);

}



static int anon_pipe_buf_steal(struct pipe_inode_info *info,

static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,

			       struct pipe_buffer *buf)

{

	buf->flags |= PIPE_BUF_FLAG_STOLEN;
@@ -143,7 +144,7 @@ pipe_readv(struct file *filp, const struct iovec *_iov, 
	   unsigned long nr_segs, loff_t *ppos)

{

	struct inode *inode = filp->f_dentry->d_inode;

	struct pipe_inode_info *info;

	struct pipe_inode_info *pipe;

	int do_wakeup;

	ssize_t ret;

	struct iovec *iov = (struct iovec *)_iov;
@@ -156,13 +157,13 @@ pipe_readv(struct file *filp, const struct iovec *_iov, 


	do_wakeup = 0;

	ret = 0;

	mutex_lock(PIPE_MUTEX(*inode));

	info = inode->i_pipe;

	mutex_lock(&inode->i_mutex);

	pipe = inode->i_pipe;

	for (;;) {

		int bufs = info->nrbufs;

		int bufs = pipe->nrbufs;

		if (bufs) {

			int curbuf = info->curbuf;

			struct pipe_buffer *buf = info->bufs + curbuf;

			int curbuf = pipe->curbuf;

			struct pipe_buffer *buf = pipe->bufs + curbuf;

			struct pipe_buf_operations *ops = buf->ops;

			void *addr;

			size_t chars = buf->len;
@@ -171,16 +172,17 @@ pipe_readv(struct file *filp, const struct iovec *_iov, 
			if (chars > total_len)

				chars = total_len;



			addr = ops->map(filp, info, buf);

			addr = ops->map(filp, pipe, buf);

			if (IS_ERR(addr)) {

				if (!ret)

					ret = PTR_ERR(addr);

				break;

			}

			error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars);

			ops->unmap(info, buf);

			ops->unmap(pipe, buf);

			if (unlikely(error)) {

				if (!ret) ret = -EFAULT;

				if (!ret)

					ret = -EFAULT;

				break;

			}

			ret += chars;
@@ -188,10 +190,10 @@ pipe_readv(struct file *filp, const struct iovec *_iov, 
			buf->len -= chars;

			if (!buf->len) {

				buf->ops = NULL;

				ops->release(info, buf);

				ops->release(pipe, buf);

				curbuf = (curbuf + 1) & (PIPE_BUFFERS-1);

				info->curbuf = curbuf;

				info->nrbufs = --bufs;

				pipe->curbuf = curbuf;

				pipe->nrbufs = --bufs;

				do_wakeup = 1;

			}

			total_len -= chars;
@@ -200,9 +202,9 @@ pipe_readv(struct file *filp, const struct iovec *_iov, 
		}

		if (bufs)	/* More to do? */

			continue;

		if (!PIPE_WRITERS(*inode))

		if (!pipe->writers)

			break;

		if (!PIPE_WAITING_WRITERS(*inode)) {

		if (!pipe->waiting_writers) {

			/* syscall merging: Usually we must not sleep

			 * if O_NONBLOCK is set, or if we got some data.

			 * But if a writer sleeps in kernel space, then
@@ -216,20 +218,22 @@ pipe_readv(struct file *filp, const struct iovec *_iov, 
			}

		}

		if (signal_pending(current)) {

			if (!ret) ret = -ERESTARTSYS;

			if (!ret)

				ret = -ERESTARTSYS;

			break;

		}

		if (do_wakeup) {

			wake_up_interruptible_sync(PIPE_WAIT(*inode));

 			kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT);

			wake_up_interruptible_sync(&pipe->wait);

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

		}

		pipe_wait(inode);

		pipe_wait(pipe);

	}

	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_unlock(&inode->i_mutex);



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

	if (do_wakeup) {

		wake_up_interruptible(PIPE_WAIT(*inode));

		kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT);

		wake_up_interruptible(&pipe->wait);

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

	}

	if (ret > 0)

		file_accessed(filp);
@@ -240,6 +244,7 @@ static ssize_t 
pipe_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)

{

	struct iovec iov = { .iov_base = buf, .iov_len = count };



	return pipe_readv(filp, &iov, 1, ppos);

}
@@ -248,7 +253,7 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 
	    unsigned long nr_segs, loff_t *ppos)

{

	struct inode *inode = filp->f_dentry->d_inode;

	struct pipe_inode_info *info;

	struct pipe_inode_info *pipe;

	ssize_t ret;

	int do_wakeup;

	struct iovec *iov = (struct iovec *)_iov;
@@ -262,10 +267,10 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 


	do_wakeup = 0;

	ret = 0;

	mutex_lock(PIPE_MUTEX(*inode));

	info = inode->i_pipe;

	mutex_lock(&inode->i_mutex);

	pipe = inode->i_pipe;



	if (!PIPE_READERS(*inode)) {

	if (!pipe->readers) {

		send_sig(SIGPIPE, current, 0);

		ret = -EPIPE;

		goto out;
@@ -273,23 +278,25 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 


	/* We try to merge small writes */

	chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */

	if (info->nrbufs && chars != 0) {

		int lastbuf = (info->curbuf + info->nrbufs - 1) & (PIPE_BUFFERS-1);

		struct pipe_buffer *buf = info->bufs + lastbuf;

	if (pipe->nrbufs && chars != 0) {

		int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) &

							(PIPE_BUFFERS-1);

		struct pipe_buffer *buf = pipe->bufs + lastbuf;

		struct pipe_buf_operations *ops = buf->ops;

		int offset = buf->offset + buf->len;



		if (ops->can_merge && offset + chars <= PAGE_SIZE) {

			void *addr;

			int error;



			addr = ops->map(filp, info, buf);

			addr = ops->map(filp, pipe, buf);

			if (IS_ERR(addr)) {

				error = PTR_ERR(addr);

				goto out;

			}

			error = pipe_iov_copy_from_user(offset + addr, iov,

							chars);

			ops->unmap(info, buf);

			ops->unmap(pipe, buf);

			ret = error;

			do_wakeup = 1;

			if (error)
@@ -304,16 +311,18 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 


	for (;;) {

		int bufs;

		if (!PIPE_READERS(*inode)) {



		if (!pipe->readers) {

			send_sig(SIGPIPE, current, 0);

			if (!ret) ret = -EPIPE;

			if (!ret)

				ret = -EPIPE;

			break;

		}

		bufs = info->nrbufs;

		bufs = pipe->nrbufs;

		if (bufs < PIPE_BUFFERS) {

			int newbuf = (info->curbuf + bufs) & (PIPE_BUFFERS-1);

			struct pipe_buffer *buf = info->bufs + newbuf;

			struct page *page = info->tmp_page;

			int newbuf = (pipe->curbuf + bufs) & (PIPE_BUFFERS-1);

			struct pipe_buffer *buf = pipe->bufs + newbuf;

			struct page *page = pipe->tmp_page;

			int error;



			if (!page) {
@@ -322,7 +331,7 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 
					ret = ret ? : -ENOMEM;

					break;

				}

				info->tmp_page = page;

				pipe->tmp_page = page;

			}

			/* Always wake up, even if the copy fails. Otherwise

			 * we lock up (O_NONBLOCK-)readers that sleep due to
@@ -337,7 +346,8 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 
			error = pipe_iov_copy_from_user(kmap(page), iov, chars);

			kunmap(page);

			if (unlikely(error)) {

				if (!ret) ret = -EFAULT;

				if (!ret)

					ret = -EFAULT;

				break;

			}

			ret += chars;
@@ -347,8 +357,8 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 
			buf->ops = &anon_pipe_buf_ops;

			buf->offset = 0;

			buf->len = chars;

			info->nrbufs = ++bufs;

			info->tmp_page = NULL;

			pipe->nrbufs = ++bufs;

			pipe->tmp_page = NULL;



			total_len -= chars;

			if (!total_len)
@@ -357,27 +367,29 @@ pipe_writev(struct file *filp, const struct iovec *_iov, 
		if (bufs < PIPE_BUFFERS)

			continue;

		if (filp->f_flags & O_NONBLOCK) {

			if (!ret) ret = -EAGAIN;

			if (!ret)

				ret = -EAGAIN;

			break;

		}

		if (signal_pending(current)) {

			if (!ret) ret = -ERESTARTSYS;

			if (!ret)

				ret = -ERESTARTSYS;

			break;

		}

		if (do_wakeup) {

			wake_up_interruptible_sync(PIPE_WAIT(*inode));

			kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN);

			wake_up_interruptible_sync(&pipe->wait);

			kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);

			do_wakeup = 0;

		}

		PIPE_WAITING_WRITERS(*inode)++;

		pipe_wait(inode);

		PIPE_WAITING_WRITERS(*inode)--;

		pipe->waiting_writers++;

		pipe_wait(pipe);

		pipe->waiting_writers--;

	}

out:

	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_unlock(&inode->i_mutex);

	if (do_wakeup) {

		wake_up_interruptible(PIPE_WAIT(*inode));

		kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN);

		wake_up_interruptible(&pipe->wait);

		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);

	}

	if (ret > 0)

		file_update_time(filp);
@@ -389,6 +401,7 @@ pipe_write(struct file *filp, const char __user *buf, 
	   size_t count, loff_t *ppos)

{

	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };



	return pipe_writev(filp, &iov, 1, ppos);

}
@@ -399,7 +412,8 @@ bad_pipe_r(struct file *filp, char __user *buf, size_t count, loff_t *ppos) 
}



static ssize_t

bad_pipe_w(struct file *filp, const char __user *buf, size_t count, loff_t *ppos)

bad_pipe_w(struct file *filp, const char __user *buf, size_t count,

	   loff_t *ppos)

{

	return -EBADF;

}
@@ -409,21 +423,22 @@ pipe_ioctl(struct inode *pino, struct file *filp, 
	   unsigned int cmd, unsigned long arg)

{

	struct inode *inode = filp->f_dentry->d_inode;

	struct pipe_inode_info *info;

	struct pipe_inode_info *pipe;

	int count, buf, nrbufs;



	switch (cmd) {

		case FIONREAD:

			mutex_lock(PIPE_MUTEX(*inode));

			info =  inode->i_pipe;

			mutex_lock(&inode->i_mutex);

			pipe = inode->i_pipe;

			count = 0;

			buf = info->curbuf;

			nrbufs = info->nrbufs;

			buf = pipe->curbuf;

			nrbufs = pipe->nrbufs;

			while (--nrbufs >= 0) {

				count += info->bufs[buf].len;

				count += pipe->bufs[buf].len;

				buf = (buf+1) & (PIPE_BUFFERS-1);

			}

			mutex_unlock(PIPE_MUTEX(*inode));

			mutex_unlock(&inode->i_mutex);



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

		default:

			return -EINVAL;
@@ -436,17 +451,17 @@ pipe_poll(struct file *filp, poll_table *wait) 
{

	unsigned int mask;

	struct inode *inode = filp->f_dentry->d_inode;

	struct pipe_inode_info *info = inode->i_pipe;

	struct pipe_inode_info *pipe = inode->i_pipe;

	int nrbufs;



	poll_wait(filp, PIPE_WAIT(*inode), wait);

	poll_wait(filp, &pipe->wait, wait);



	/* Reading only -- no need for acquiring the semaphore.  */

	nrbufs = info->nrbufs;

	nrbufs = pipe->nrbufs;

	mask = 0;

	if (filp->f_mode & FMODE_READ) {

		mask = (nrbufs > 0) ? POLLIN | POLLRDNORM : 0;

		if (!PIPE_WRITERS(*inode) && filp->f_version != PIPE_WCOUNTER(*inode))

		if (!pipe->writers && filp->f_version != pipe->w_counter)

			mask |= POLLHUP;

	}
@@ -456,7 +471,7 @@ pipe_poll(struct file *filp, poll_table *wait) 
		 * Most Unices do not set POLLERR for FIFOs but on Linux they

		 * behave exactly like pipes for poll().

		 */

		if (!PIPE_READERS(*inode))

		if (!pipe->readers)

			mask |= POLLERR;

	}
@@ -466,17 +481,21 @@ pipe_poll(struct file *filp, poll_table *wait) 
static int

pipe_release(struct inode *inode, int decr, int decw)

{

	mutex_lock(PIPE_MUTEX(*inode));

	PIPE_READERS(*inode) -= decr;

	PIPE_WRITERS(*inode) -= decw;

	if (!PIPE_READERS(*inode) && !PIPE_WRITERS(*inode)) {

	struct pipe_inode_info *pipe;



	mutex_lock(&inode->i_mutex);

	pipe = inode->i_pipe;

	pipe->readers -= decr;

	pipe->writers -= decw;



	if (!pipe->readers && !pipe->writers) {

		free_pipe_info(inode);

	} else {

		wake_up_interruptible(PIPE_WAIT(*inode));

		kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN);

		kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT);

		wake_up_interruptible(&pipe->wait);

		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);

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

	}

	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_unlock(&inode->i_mutex);



	return 0;

}
@@ -487,9 +506,9 @@ pipe_read_fasync(int fd, struct file *filp, int on) 
	struct inode *inode = filp->f_dentry->d_inode;

	int retval;



	mutex_lock(PIPE_MUTEX(*inode));

	retval = fasync_helper(fd, filp, on, PIPE_FASYNC_READERS(*inode));

	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_lock(&inode->i_mutex);

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

	mutex_unlock(&inode->i_mutex);



	if (retval < 0)

		return retval;
@@ -504,9 +523,9 @@ pipe_write_fasync(int fd, struct file *filp, int on) 
	struct inode *inode = filp->f_dentry->d_inode;

	int retval;



	mutex_lock(PIPE_MUTEX(*inode));

	retval = fasync_helper(fd, filp, on, PIPE_FASYNC_WRITERS(*inode));

	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_lock(&inode->i_mutex);

	retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers);

	mutex_unlock(&inode->i_mutex);



	if (retval < 0)

		return retval;
@@ -519,16 +538,17 @@ static int 
pipe_rdwr_fasync(int fd, struct file *filp, int on)

{

	struct inode *inode = filp->f_dentry->d_inode;

	struct pipe_inode_info *pipe = inode->i_pipe;

	int retval;



	mutex_lock(PIPE_MUTEX(*inode));

	mutex_lock(&inode->i_mutex);



	retval = fasync_helper(fd, filp, on, PIPE_FASYNC_READERS(*inode));

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



	if (retval >= 0)

		retval = fasync_helper(fd, filp, on, PIPE_FASYNC_WRITERS(*inode));

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



	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_unlock(&inode->i_mutex);



	if (retval < 0)

		return retval;
@@ -567,9 +587,9 @@ pipe_read_open(struct inode *inode, struct file *filp) 
{

	/* We could have perhaps used atomic_t, but this and friends

	   below are the only places.  So it doesn't seem worthwhile.  */

	mutex_lock(PIPE_MUTEX(*inode));

	PIPE_READERS(*inode)++;

	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_lock(&inode->i_mutex);

	inode->i_pipe->readers++;

	mutex_unlock(&inode->i_mutex);



	return 0;

}
@@ -577,9 +597,9 @@ pipe_read_open(struct inode *inode, struct file *filp) 
static int

pipe_write_open(struct inode *inode, struct file *filp)

{

	mutex_lock(PIPE_MUTEX(*inode));

	PIPE_WRITERS(*inode)++;

	mutex_unlock(PIPE_MUTEX(*inode));

	mutex_lock(&inode->i_mutex);

	inode->i_pipe->writers++;

	mutex_unlock(&inode->i_mutex);



	return 0;

}
@@ -587,12 +607,12 @@ pipe_write_open(struct inode *inode, struct file *filp) 
static int

pipe_rdwr_open(struct inode *inode, struct file *filp)

{

	mutex_lock(PIPE_MUTEX(*inode));

	mutex_lock(&inode->i_mutex);

	if (filp->f_mode & FMODE_READ)

		PIPE_READERS(*inode)++;

		inode->i_pipe->readers++;

	if (filp->f_mode & FMODE_WRITE)

		PIPE_WRITERS(*inode)++;

	mutex_unlock(PIPE_MUTEX(*inode));

		inode->i_pipe->writers++;

	mutex_unlock(&inode->i_mutex);



	return 0;

}
@@ -675,37 +695,38 @@ static struct file_operations rdwr_pipe_fops = { 
	.fasync		= pipe_rdwr_fasync,

};



void free_pipe_info(struct inode *inode)

struct pipe_inode_info * alloc_pipe_info(struct inode *inode)

{

	struct pipe_inode_info *pipe;



	pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL);

	if (pipe) {

		init_waitqueue_head(&pipe->wait);

		pipe->r_counter = pipe->w_counter = 1;

		pipe->inode = inode;

	}



	return pipe;

}



void __free_pipe_info(struct pipe_inode_info *pipe)

{

	int i;

	struct pipe_inode_info *info = inode->i_pipe;



	inode->i_pipe = NULL;

	for (i = 0; i < PIPE_BUFFERS; i++) {

		struct pipe_buffer *buf = info->bufs + i;

		struct pipe_buffer *buf = pipe->bufs + i;

		if (buf->ops)

			buf->ops->release(info, buf);

			buf->ops->release(pipe, buf);

	}

	if (info->tmp_page)

		__free_page(info->tmp_page);

	kfree(info);

	if (pipe->tmp_page)

		__free_page(pipe->tmp_page);

	kfree(pipe);

}



struct inode* pipe_new(struct inode* inode)

void free_pipe_info(struct inode *inode)

{

	struct pipe_inode_info *info;



	info = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL);

	if (!info)

		goto fail_page;

	inode->i_pipe = info;



	init_waitqueue_head(PIPE_WAIT(*inode));

	PIPE_RCOUNTER(*inode) = PIPE_WCOUNTER(*inode) = 1;



	return inode;

fail_page:

	return NULL;

	__free_pipe_info(inode->i_pipe);

	inode->i_pipe = NULL;

}



static struct vfsmount *pipe_mnt __read_mostly;
@@ -713,6 +734,7 @@ static int pipefs_delete_dentry(struct dentry *dentry) 
{

	return 1;

}



static struct dentry_operations pipefs_dentry_operations = {

	.d_delete	= pipefs_delete_dentry,

};
@@ -720,13 +742,17 @@ static struct dentry_operations pipefs_dentry_operations = { 
static struct inode * get_pipe_inode(void)

{

	struct inode *inode = new_inode(pipe_mnt->mnt_sb);

	struct pipe_inode_info *pipe;



	if (!inode)

		goto fail_inode;



	if(!pipe_new(inode))

	pipe = alloc_pipe_info(inode);

	if (!pipe)

		goto fail_iput;

	PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 1;

	inode->i_pipe = pipe;



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

	inode->i_fop = &rdwr_pipe_fops;



	/*
@@ -741,10 +767,12 @@ static struct inode * get_pipe_inode(void) 
	inode->i_gid = current->fsgid;

	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;

	inode->i_blksize = PAGE_SIZE;



	return inode;



fail_iput:

	iput(inode);



fail_inode:

	return NULL;

}
@@ -790,6 +818,7 @@ int do_pipe(int *fd) 
	dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &this);

	if (!dentry)

		goto close_f12_inode_i_j;



	dentry->d_op = &pipefs_dentry_operations;

	d_add(dentry, inode);

	f1->f_vfsmnt = f2->f_vfsmnt = mntget(mntget(pipe_mnt));
@@ -813,6 +842,7 @@ int do_pipe(int *fd) 
	fd_install(j, f2);

	fd[0] = i;

	fd[1] = j;



	return 0;



close_f12_inode_i_j:
@@ -837,8 +867,9 @@ no_files: 
 * d_name - pipe: will go nicely and kill the special-casing in procfs.

 */



static struct super_block *pipefs_get_sb(struct file_system_type *fs_type,

	int flags, const char *dev_name, void *data)

static struct super_block *

pipefs_get_sb(struct file_system_type *fs_type, int flags,

	      const char *dev_name, void *data)

{

	return get_sb_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC);

}
@@ -852,6 +883,7 @@ static struct file_system_type pipe_fs_type = { 
static int __init init_pipe_fs(void)

{

	int err = register_filesystem(&pipe_fs_type);



	if (!err) {

		pipe_mnt = kern_mount(&pipe_fs_type);

		if (IS_ERR(pipe_mnt)) {

fs/read_write.c

+1 −1
Original line number Diff line number Diff line
@@ -202,7 +202,7 @@ int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count 
		goto Einval;



	inode = file->f_dentry->d_inode;

	if (inode->i_flock && MANDATORY_LOCK(inode)) {

	if (unlikely(inode->i_flock && MANDATORY_LOCK(inode))) {

		int retval = locks_mandatory_area(

			read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,

			inode, file, pos, count);

fs/splice.c

+338 −154

File changed.

Preview size limit exceeded, changes collapsed.