Commit c928f642 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Al Viro
Browse files

fs: rename pipe_buf ->steal to ->try_steal 



And replace the arcane return value convention with a simple bool
where true means success and false means failure.

[AV: braino fix folded in]

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent b8d9e7f2

drivers/char/virtio_console.c

+1 −1
Original line number Diff line number Diff line
@@ -871,7 +871,7 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 
		return 0;



	/* Try lock this page */

	if (pipe_buf_steal(pipe, buf) == 0) {

	if (pipe_buf_try_steal(pipe, buf)) {

		/* Get reference and unlock page for moving */

		get_page(buf->page);

		unlock_page(buf->page);

fs/fuse/dev.c

+1 −1
Original line number Diff line number Diff line
@@ -805,7 +805,7 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) 
	if (cs->len != PAGE_SIZE)

		goto out_fallback;



	if (pipe_buf_steal(cs->pipe, buf) != 0)

	if (!pipe_buf_try_steal(cs->pipe, buf))

		goto out_fallback;



	newpage = buf->page;

fs/pipe.c

+16 −18
Original line number Diff line number Diff line
@@ -140,21 +140,20 @@ static void anon_pipe_buf_release(struct pipe_inode_info *pipe, 
		put_page(page);

}



static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,

static bool anon_pipe_buf_try_steal(struct pipe_inode_info *pipe,

		struct pipe_buffer *buf)

{

	struct page *page = buf->page;



	if (page_count(page) == 1) {

	if (page_count(page) != 1)

		return false;

	memcg_kmem_uncharge_page(page, 0);

	__SetPageLocked(page);

		return 0;

	}

	return 1;

	return true;

}



/**

 * generic_pipe_buf_steal - attempt to take ownership of a &pipe_buffer

 * generic_pipe_buf_try_steal - attempt to take ownership of a &pipe_buffer

 * @pipe:	the pipe that the buffer belongs to

 * @buf:	the buffer to attempt to steal

 *
@@ -165,7 +164,7 @@ static int anon_pipe_buf_steal(struct pipe_inode_info *pipe, 
 *	he wishes; the typical use is insertion into a different file

 *	page cache.

 */

int generic_pipe_buf_steal(struct pipe_inode_info *pipe,

bool generic_pipe_buf_try_steal(struct pipe_inode_info *pipe,

		struct pipe_buffer *buf)

{

	struct page *page = buf->page;
@@ -177,12 +176,11 @@ int generic_pipe_buf_steal(struct pipe_inode_info *pipe, 
	 */

	if (page_count(page) == 1) {

		lock_page(page);

		return 0;

		return true;

	}



	return 1;

	return false;

}

EXPORT_SYMBOL(generic_pipe_buf_steal);

EXPORT_SYMBOL(generic_pipe_buf_try_steal);



/**

 * generic_pipe_buf_get - get a reference to a &struct pipe_buffer
@@ -217,7 +215,7 @@ EXPORT_SYMBOL(generic_pipe_buf_release); 


static const struct pipe_buf_operations anon_pipe_buf_ops = {

	.release	= anon_pipe_buf_release,

	.steal = anon_pipe_buf_steal,

	.try_steal	= anon_pipe_buf_try_steal,

	.get		= generic_pipe_buf_get,

};

fs/splice.c

+20 −20
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ 
 * addition of remove_mapping(). If success is returned, the caller may

 * attempt to reuse this page for another destination.

 */

static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,

static bool page_cache_pipe_buf_try_steal(struct pipe_inode_info *pipe,

		struct pipe_buffer *buf)

{

	struct page *page = buf->page;
@@ -76,7 +76,7 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe, 
		 */

		if (remove_mapping(mapping, page)) {

			buf->flags |= PIPE_BUF_FLAG_LRU;

			return 0;

			return true;

		}

	}
@@ -86,7 +86,7 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe, 
	 */

out_unlock:

	unlock_page(page);

	return 1;

	return false;

}



static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe,
@@ -141,23 +141,23 @@ error: 
const struct pipe_buf_operations page_cache_pipe_buf_ops = {

	.confirm	= page_cache_pipe_buf_confirm,

	.release	= page_cache_pipe_buf_release,

	.steal = page_cache_pipe_buf_steal,

	.try_steal	= page_cache_pipe_buf_try_steal,

	.get		= generic_pipe_buf_get,

};



static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe,

static bool user_page_pipe_buf_try_steal(struct pipe_inode_info *pipe,

		struct pipe_buffer *buf)

{

	if (!(buf->flags & PIPE_BUF_FLAG_GIFT))

		return 1;

		return false;



	buf->flags |= PIPE_BUF_FLAG_LRU;

	return generic_pipe_buf_steal(pipe, buf);

	return generic_pipe_buf_try_steal(pipe, buf);

}



static const struct pipe_buf_operations user_page_pipe_buf_ops = {

	.release	= page_cache_pipe_buf_release,

	.steal = user_page_pipe_buf_steal,

	.try_steal	= user_page_pipe_buf_try_steal,

	.get		= generic_pipe_buf_get,

};
@@ -331,7 +331,7 @@ EXPORT_SYMBOL(generic_file_splice_read); 


const struct pipe_buf_operations default_pipe_buf_ops = {

	.release	= generic_pipe_buf_release,

	.steal = generic_pipe_buf_steal,

	.try_steal	= generic_pipe_buf_try_steal,

	.get		= generic_pipe_buf_get,

};

include/linux/pipe_fs_i.h

+17 −17
Original line number Diff line number Diff line
@@ -70,11 +70,11 @@ struct pipe_inode_info { 
 * Note on the nesting of these functions:

 *

 * ->confirm()

 *	->steal()

 *	->try_steal()

 *

 * That is, ->steal() must be called on a confirmed buffer.

 * See below for the meaning of each operation. Also see kerneldoc

 * in fs/pipe.c for the pipe and generic variants of these hooks.

 * That is, ->try_steal() must be called on a confirmed buffer.  See below for

 * the meaning of each operation.  Also see the kerneldoc in fs/pipe.c for the

 * pipe and generic variants of these hooks.

 */

struct pipe_buf_operations {

	/*
@@ -94,13 +94,13 @@ struct pipe_buf_operations { 


	/*

	 * Attempt to take ownership of the pipe buffer and its contents.

	 * ->steal() returns 0 for success, in which case the contents

	 * of the pipe (the buf->page) is locked and now completely owned

	 * by the caller. The page may then be transferred to a different

	 * mapping, the most often used case is insertion into different

	 * file address space cache.

	 * ->try_steal() returns %true for success, in which case the contents

	 * of the pipe (the buf->page) is locked and now completely owned by the

	 * caller. The page may then be transferred to a different mapping, the

	 * most often used case is insertion into different file address space

	 * cache.

	 */

	int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);

	bool (*try_steal)(struct pipe_inode_info *, struct pipe_buffer *);



	/*

	 * Get a reference to the pipe buffer.
@@ -201,16 +201,16 @@ static inline int pipe_buf_confirm(struct pipe_inode_info *pipe, 
}



/**

 * pipe_buf_steal - attempt to take ownership of a pipe_buffer

 * pipe_buf_try_steal - attempt to take ownership of a pipe_buffer

 * @pipe:	the pipe that the buffer belongs to

 * @buf:	the buffer to attempt to steal

 */

static inline int pipe_buf_steal(struct pipe_inode_info *pipe,

static inline bool pipe_buf_try_steal(struct pipe_inode_info *pipe,

		struct pipe_buffer *buf)

{

	if (!buf->ops->steal)

		return 1;

	return buf->ops->steal(pipe, buf);

	if (!buf->ops->try_steal)

		return false;

	return buf->ops->try_steal(pipe, buf);

}



/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
@@ -234,7 +234,7 @@ void free_pipe_info(struct pipe_inode_info *); 


/* Generic pipe buffer ops functions */

bool generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);

int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);

bool generic_pipe_buf_try_steal(struct pipe_inode_info *, struct pipe_buffer *);

void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *);



extern const struct pipe_buf_operations nosteal_pipe_buf_ops;

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