zfs-builds-mm/zfs-0.8.1/include/sys/abd.h
2019-07-06 23:40:11 +02:00

178 lines
4.7 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2014 by Chunwei Chen. All rights reserved.
* Copyright (c) 2016 by Delphix. All rights reserved.
*/
#ifndef _ABD_H
#define _ABD_H
#include <sys/isa_defs.h>
#include <sys/debug.h>
#include <sys/refcount.h>
#ifdef _KERNEL
#include <linux/mm.h>
#include <linux/bio.h>
#include <sys/uio.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif
typedef enum abd_flags {
ABD_FLAG_LINEAR = 1 << 0, /* is buffer linear (or scattered)? */
ABD_FLAG_OWNER = 1 << 1, /* does it own its data buffers? */
ABD_FLAG_META = 1 << 2, /* does this represent FS metadata? */
ABD_FLAG_MULTI_ZONE = 1 << 3, /* pages split over memory zones */
ABD_FLAG_MULTI_CHUNK = 1 << 4 /* pages split over multiple chunks */
} abd_flags_t;
typedef struct abd {
abd_flags_t abd_flags;
uint_t abd_size; /* excludes scattered abd_offset */
struct abd *abd_parent;
zfs_refcount_t abd_children;
union {
struct abd_scatter {
uint_t abd_offset;
uint_t abd_nents;
struct scatterlist *abd_sgl;
} abd_scatter;
struct abd_linear {
void *abd_buf;
} abd_linear;
} abd_u;
} abd_t;
typedef int abd_iter_func_t(void *buf, size_t len, void *private);
typedef int abd_iter_func2_t(void *bufa, void *bufb, size_t len, void *private);
extern int zfs_abd_scatter_enabled;
static inline boolean_t
abd_is_linear(abd_t *abd)
{
return ((abd->abd_flags & ABD_FLAG_LINEAR) != 0 ? B_TRUE : B_FALSE);
}
/*
* Allocations and deallocations
*/
abd_t *abd_alloc(size_t, boolean_t);
abd_t *abd_alloc_linear(size_t, boolean_t);
abd_t *abd_alloc_for_io(size_t, boolean_t);
abd_t *abd_alloc_sametype(abd_t *, size_t);
void abd_free(abd_t *);
abd_t *abd_get_offset(abd_t *, size_t);
abd_t *abd_get_offset_size(abd_t *, size_t, size_t);
abd_t *abd_get_from_buf(void *, size_t);
void abd_put(abd_t *);
/*
* Conversion to and from a normal buffer
*/
void *abd_to_buf(abd_t *);
void *abd_borrow_buf(abd_t *, size_t);
void *abd_borrow_buf_copy(abd_t *, size_t);
void abd_return_buf(abd_t *, void *, size_t);
void abd_return_buf_copy(abd_t *, void *, size_t);
void abd_take_ownership_of_buf(abd_t *, boolean_t);
void abd_release_ownership_of_buf(abd_t *);
/*
* ABD operations
*/
int abd_iterate_func(abd_t *, size_t, size_t, abd_iter_func_t *, void *);
int abd_iterate_func2(abd_t *, abd_t *, size_t, size_t, size_t,
abd_iter_func2_t *, void *);
void abd_copy_off(abd_t *, abd_t *, size_t, size_t, size_t);
void abd_copy_from_buf_off(abd_t *, const void *, size_t, size_t);
void abd_copy_to_buf_off(void *, abd_t *, size_t, size_t);
int abd_cmp(abd_t *, abd_t *);
int abd_cmp_buf_off(abd_t *, const void *, size_t, size_t);
void abd_zero_off(abd_t *, size_t, size_t);
#if defined(_KERNEL)
unsigned int abd_scatter_bio_map_off(struct bio *, abd_t *, unsigned int,
size_t);
unsigned long abd_nr_pages_off(abd_t *, unsigned int, size_t);
#endif
void abd_raidz_gen_iterate(abd_t **cabds, abd_t *dabd,
ssize_t csize, ssize_t dsize, const unsigned parity,
void (*func_raidz_gen)(void **, const void *, size_t, size_t));
void abd_raidz_rec_iterate(abd_t **cabds, abd_t **tabds,
ssize_t tsize, const unsigned parity,
void (*func_raidz_rec)(void **t, const size_t tsize, void **c,
const unsigned *mul),
const unsigned *mul);
/*
* Wrappers for calls with offsets of 0
*/
static inline void
abd_copy(abd_t *dabd, abd_t *sabd, size_t size)
{
abd_copy_off(dabd, sabd, 0, 0, size);
}
static inline void
abd_copy_from_buf(abd_t *abd, const void *buf, size_t size)
{
abd_copy_from_buf_off(abd, buf, 0, size);
}
static inline void
abd_copy_to_buf(void* buf, abd_t *abd, size_t size)
{
abd_copy_to_buf_off(buf, abd, 0, size);
}
static inline int
abd_cmp_buf(abd_t *abd, const void *buf, size_t size)
{
return (abd_cmp_buf_off(abd, buf, 0, size));
}
static inline void
abd_zero(abd_t *abd, size_t size)
{
abd_zero_off(abd, 0, size);
}
/*
* Module lifecycle
*/
void abd_init(void);
void abd_fini(void);
#ifdef __cplusplus
}
#endif
#endif /* _ABD_H */