Commit d4c3cca9 authored by Eric Dumazet's avatar Eric Dumazet Committed by Linus Torvalds
Browse files

[PATCH] constify pipe_buf_operations 



- pipe/splice should use const pipe_buf_operations and file_operations

- struct pipe_inode_info has an unused field "start" : get rid of it.

Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 426d62e2

fs/pipe.c

+6 −6
Original line number Diff line number Diff line
@@ -207,7 +207,7 @@ int generic_pipe_buf_pin(struct pipe_inode_info *info, struct pipe_buffer *buf) 
	return 0;

}



static struct pipe_buf_operations anon_pipe_buf_ops = {

static const struct pipe_buf_operations anon_pipe_buf_ops = {

	.can_merge = 1,

	.map = generic_pipe_buf_map,

	.unmap = generic_pipe_buf_unmap,
@@ -243,7 +243,7 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov, 
		if (bufs) {

			int curbuf = pipe->curbuf;

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

			struct pipe_buf_operations *ops = buf->ops;

			const struct pipe_buf_operations *ops = buf->ops;

			void *addr;

			size_t chars = buf->len;

			int error, atomic;
@@ -365,7 +365,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov, 
		int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) &

							(PIPE_BUFFERS-1);

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

		struct pipe_buf_operations *ops = buf->ops;

		const struct pipe_buf_operations *ops = buf->ops;

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



		if (ops->can_merge && offset + chars <= PAGE_SIZE) {
@@ -756,7 +756,7 @@ const struct file_operations rdwr_fifo_fops = { 
	.fasync		= pipe_rdwr_fasync,

};



static struct file_operations read_pipe_fops = {

static const struct file_operations read_pipe_fops = {

	.llseek		= no_llseek,

	.read		= do_sync_read,

	.aio_read	= pipe_read,
@@ -768,7 +768,7 @@ static struct file_operations read_pipe_fops = { 
	.fasync		= pipe_read_fasync,

};



static struct file_operations write_pipe_fops = {

static const struct file_operations write_pipe_fops = {

	.llseek		= no_llseek,

	.read		= bad_pipe_r,

	.write		= do_sync_write,
@@ -780,7 +780,7 @@ static struct file_operations write_pipe_fops = { 
	.fasync		= pipe_write_fasync,

};



static struct file_operations rdwr_pipe_fops = {

static const struct file_operations rdwr_pipe_fops = {

	.llseek		= no_llseek,

	.read		= do_sync_read,

	.aio_read	= pipe_read,

fs/splice.c

+4 −4
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ struct splice_pipe_desc { 
	struct partial_page *partial;	/* pages[] may not be contig */

	int nr_pages;			/* number of pages in map */

	unsigned int flags;		/* splice flags */

	struct pipe_buf_operations *ops;/* ops associated with output pipe */

	const struct pipe_buf_operations *ops;/* ops associated with output pipe */

};



/*
@@ -139,7 +139,7 @@ error: 
	return err;

}



static struct pipe_buf_operations page_cache_pipe_buf_ops = {

static const struct pipe_buf_operations page_cache_pipe_buf_ops = {

	.can_merge = 0,

	.map = generic_pipe_buf_map,

	.unmap = generic_pipe_buf_unmap,
@@ -159,7 +159,7 @@ static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, 
	return generic_pipe_buf_steal(pipe, buf);

}



static struct pipe_buf_operations user_page_pipe_buf_ops = {

static const struct pipe_buf_operations user_page_pipe_buf_ops = {

	.can_merge = 0,

	.map = generic_pipe_buf_map,

	.unmap = generic_pipe_buf_unmap,
@@ -724,7 +724,7 @@ static ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, 
	for (;;) {

		if (pipe->nrbufs) {

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

			struct pipe_buf_operations *ops = buf->ops;

			const struct pipe_buf_operations *ops = buf->ops;



			sd.len = buf->len;

			if (sd.len > sd.total_len)

include/linux/pipe_fs_i.h

+1 −2
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ 
struct pipe_buffer {

	struct page *page;

	unsigned int offset, len;

	struct pipe_buf_operations *ops;

	const struct pipe_buf_operations *ops;

	unsigned int flags;

};
@@ -43,7 +43,6 @@ struct pipe_inode_info { 
	unsigned int nrbufs, curbuf;

	struct pipe_buffer bufs[PIPE_BUFFERS];

	struct page *tmp_page;

	unsigned int start;

	unsigned int readers;

	unsigned int writers;

	unsigned int waiting_writers;

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