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Merge branch 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

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Pull splice updates from Al Viro:
 "Christoph's assorted splice cleanups"

* 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: rename pipe_buf ->steal to ->try_steal
  fs: make the pipe_buf_operations ->confirm operation optional
  fs: make the pipe_buf_operations ->steal operation optional
  trace: remove tracing_pipe_buf_ops
  pipe: merge anon_pipe_buf*_ops
  fs: simplify do_splice_from
  fs: simplify do_splice_to
This commit is contained in:
Linus Torvalds
2020-06-03 15:52:19 -07:00
parent 039aeb9deb c928f642c2
commit ae03c53d00
8 changed files with 77 additions and 170 deletions
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40
include/linux/pipe_fs_i.h
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@@ -8,6 +8,7 @@
#define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */
#define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */
#define PIPE_BUF_FLAG_PACKET 0x08 /* read() as a packet */
#define PIPE_BUF_FLAG_CAN_MERGE 0x10 /* can merge buffers */
/**
* struct pipe_buffer - a linux kernel pipe buffer
@@ -69,11 +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 {
/*
@@ -81,7 +82,7 @@ struct pipe_buf_operations {
* and that the contents are good. If the pages in the pipe belong
* to a file system, we may need to wait for IO completion in this
* hook. Returns 0 for good, or a negative error value in case of
* error.
* error. If not present all pages are considered good.
*/
int (*confirm)(struct pipe_inode_info *, struct pipe_buffer *);
@@ -93,13 +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.
@@ -194,18 +195,22 @@ static inline void pipe_buf_release(struct pipe_inode_info *pipe,
static inline int pipe_buf_confirm(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
if (!buf->ops->confirm)
return 0;
return buf->ops->confirm(pipe, buf);
}
/**
* 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,
struct pipe_buffer *buf)
static inline bool pipe_buf_try_steal(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
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
@@ -229,11 +234,8 @@ 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_confirm(struct pipe_inode_info *, struct pipe_buffer *);
int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);
int generic_pipe_buf_nosteal(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 *);
void pipe_buf_mark_unmergeable(struct pipe_buffer *buf);
extern const struct pipe_buf_operations nosteal_pipe_buf_ops;