285 lines
9.6 KiB
C
285 lines
9.6 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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
|
|
* Copyright (c) 2013 by Delphix. All rights reserved.
|
|
* Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
|
|
* Copyright 2013 Nexenta Systems, Inc. All rights reserved.
|
|
*/
|
|
|
|
#ifndef _SYS_ARC_IMPL_H
|
|
#define _SYS_ARC_IMPL_H
|
|
|
|
#include <sys/arc.h>
|
|
#include <sys/zio_crypt.h>
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/*
|
|
* Note that buffers can be in one of 6 states:
|
|
* ARC_anon - anonymous (discussed below)
|
|
* ARC_mru - recently used, currently cached
|
|
* ARC_mru_ghost - recentely used, no longer in cache
|
|
* ARC_mfu - frequently used, currently cached
|
|
* ARC_mfu_ghost - frequently used, no longer in cache
|
|
* ARC_l2c_only - exists in L2ARC but not other states
|
|
* When there are no active references to the buffer, they are
|
|
* are linked onto a list in one of these arc states. These are
|
|
* the only buffers that can be evicted or deleted. Within each
|
|
* state there are multiple lists, one for meta-data and one for
|
|
* non-meta-data. Meta-data (indirect blocks, blocks of dnodes,
|
|
* etc.) is tracked separately so that it can be managed more
|
|
* explicitly: favored over data, limited explicitly.
|
|
*
|
|
* Anonymous buffers are buffers that are not associated with
|
|
* a DVA. These are buffers that hold dirty block copies
|
|
* before they are written to stable storage. By definition,
|
|
* they are "ref'd" and are considered part of arc_mru
|
|
* that cannot be freed. Generally, they will acquire a DVA
|
|
* as they are written and migrate onto the arc_mru list.
|
|
*
|
|
* The ARC_l2c_only state is for buffers that are in the second
|
|
* level ARC but no longer in any of the ARC_m* lists. The second
|
|
* level ARC itself may also contain buffers that are in any of
|
|
* the ARC_m* states - meaning that a buffer can exist in two
|
|
* places. The reason for the ARC_l2c_only state is to keep the
|
|
* buffer header in the hash table, so that reads that hit the
|
|
* second level ARC benefit from these fast lookups.
|
|
*/
|
|
|
|
typedef struct arc_state {
|
|
/*
|
|
* list of evictable buffers
|
|
*/
|
|
multilist_t *arcs_list[ARC_BUFC_NUMTYPES];
|
|
/*
|
|
* total amount of evictable data in this state
|
|
*/
|
|
zfs_refcount_t arcs_esize[ARC_BUFC_NUMTYPES];
|
|
/*
|
|
* total amount of data in this state; this includes: evictable,
|
|
* non-evictable, ARC_BUFC_DATA, and ARC_BUFC_METADATA.
|
|
*/
|
|
zfs_refcount_t arcs_size;
|
|
/*
|
|
* supports the "dbufs" kstat
|
|
*/
|
|
arc_state_type_t arcs_state;
|
|
} arc_state_t;
|
|
|
|
typedef struct arc_callback arc_callback_t;
|
|
|
|
struct arc_callback {
|
|
void *acb_private;
|
|
arc_read_done_func_t *acb_done;
|
|
arc_buf_t *acb_buf;
|
|
boolean_t acb_encrypted;
|
|
boolean_t acb_compressed;
|
|
boolean_t acb_noauth;
|
|
zbookmark_phys_t acb_zb;
|
|
zio_t *acb_zio_dummy;
|
|
zio_t *acb_zio_head;
|
|
arc_callback_t *acb_next;
|
|
};
|
|
|
|
typedef struct arc_write_callback arc_write_callback_t;
|
|
|
|
struct arc_write_callback {
|
|
void *awcb_private;
|
|
arc_write_done_func_t *awcb_ready;
|
|
arc_write_done_func_t *awcb_children_ready;
|
|
arc_write_done_func_t *awcb_physdone;
|
|
arc_write_done_func_t *awcb_done;
|
|
arc_buf_t *awcb_buf;
|
|
};
|
|
|
|
/*
|
|
* ARC buffers are separated into multiple structs as a memory saving measure:
|
|
* - Common fields struct, always defined, and embedded within it:
|
|
* - L2-only fields, always allocated but undefined when not in L2ARC
|
|
* - L1-only fields, only allocated when in L1ARC
|
|
*
|
|
* Buffer in L1 Buffer only in L2
|
|
* +------------------------+ +------------------------+
|
|
* | arc_buf_hdr_t | | arc_buf_hdr_t |
|
|
* | | | |
|
|
* | | | |
|
|
* | | | |
|
|
* +------------------------+ +------------------------+
|
|
* | l2arc_buf_hdr_t | | l2arc_buf_hdr_t |
|
|
* | (undefined if L1-only) | | |
|
|
* +------------------------+ +------------------------+
|
|
* | l1arc_buf_hdr_t |
|
|
* | |
|
|
* | |
|
|
* | |
|
|
* | |
|
|
* +------------------------+
|
|
*
|
|
* Because it's possible for the L2ARC to become extremely large, we can wind
|
|
* up eating a lot of memory in L2ARC buffer headers, so the size of a header
|
|
* is minimized by only allocating the fields necessary for an L1-cached buffer
|
|
* when a header is actually in the L1 cache. The sub-headers (l1arc_buf_hdr and
|
|
* l2arc_buf_hdr) are embedded rather than allocated separately to save a couple
|
|
* words in pointers. arc_hdr_realloc() is used to switch a header between
|
|
* these two allocation states.
|
|
*/
|
|
typedef struct l1arc_buf_hdr {
|
|
kmutex_t b_freeze_lock;
|
|
zio_cksum_t *b_freeze_cksum;
|
|
|
|
arc_buf_t *b_buf;
|
|
uint32_t b_bufcnt;
|
|
/* for waiting on writes to complete */
|
|
kcondvar_t b_cv;
|
|
uint8_t b_byteswap;
|
|
|
|
|
|
/* protected by arc state mutex */
|
|
arc_state_t *b_state;
|
|
multilist_node_t b_arc_node;
|
|
|
|
/* updated atomically */
|
|
clock_t b_arc_access;
|
|
uint32_t b_mru_hits;
|
|
uint32_t b_mru_ghost_hits;
|
|
uint32_t b_mfu_hits;
|
|
uint32_t b_mfu_ghost_hits;
|
|
uint32_t b_l2_hits;
|
|
|
|
/* self protecting */
|
|
zfs_refcount_t b_refcnt;
|
|
|
|
arc_callback_t *b_acb;
|
|
abd_t *b_pabd;
|
|
} l1arc_buf_hdr_t;
|
|
|
|
/*
|
|
* Encrypted blocks will need to be stored encrypted on the L2ARC
|
|
* disk as they appear in the main pool. In order for this to work we
|
|
* need to pass around the encryption parameters so they can be used
|
|
* to write data to the L2ARC. This struct is only defined in the
|
|
* arc_buf_hdr_t if the L1 header is defined and has the ARC_FLAG_ENCRYPTED
|
|
* flag set.
|
|
*/
|
|
typedef struct arc_buf_hdr_crypt {
|
|
abd_t *b_rabd; /* raw encrypted data */
|
|
dmu_object_type_t b_ot; /* object type */
|
|
uint32_t b_ebufcnt; /* count of encrypted buffers */
|
|
|
|
/* dsobj for looking up encryption key for l2arc encryption */
|
|
uint64_t b_dsobj;
|
|
|
|
/* encryption parameters */
|
|
uint8_t b_salt[ZIO_DATA_SALT_LEN];
|
|
uint8_t b_iv[ZIO_DATA_IV_LEN];
|
|
|
|
/*
|
|
* Technically this could be removed since we will always be able to
|
|
* get the mac from the bp when we need it. However, it is inconvenient
|
|
* for callers of arc code to have to pass a bp in all the time. This
|
|
* also allows us to assert that L2ARC data is properly encrypted to
|
|
* match the data in the main storage pool.
|
|
*/
|
|
uint8_t b_mac[ZIO_DATA_MAC_LEN];
|
|
} arc_buf_hdr_crypt_t;
|
|
|
|
typedef struct l2arc_dev {
|
|
vdev_t *l2ad_vdev; /* vdev */
|
|
spa_t *l2ad_spa; /* spa */
|
|
uint64_t l2ad_hand; /* next write location */
|
|
uint64_t l2ad_start; /* first addr on device */
|
|
uint64_t l2ad_end; /* last addr on device */
|
|
boolean_t l2ad_first; /* first sweep through */
|
|
boolean_t l2ad_writing; /* currently writing */
|
|
kmutex_t l2ad_mtx; /* lock for buffer list */
|
|
list_t l2ad_buflist; /* buffer list */
|
|
list_node_t l2ad_node; /* device list node */
|
|
zfs_refcount_t l2ad_alloc; /* allocated bytes */
|
|
} l2arc_dev_t;
|
|
|
|
typedef struct l2arc_buf_hdr {
|
|
/* protected by arc_buf_hdr mutex */
|
|
l2arc_dev_t *b_dev; /* L2ARC device */
|
|
uint64_t b_daddr; /* disk address, offset byte */
|
|
uint32_t b_hits;
|
|
|
|
list_node_t b_l2node;
|
|
} l2arc_buf_hdr_t;
|
|
|
|
typedef struct l2arc_write_callback {
|
|
l2arc_dev_t *l2wcb_dev; /* device info */
|
|
arc_buf_hdr_t *l2wcb_head; /* head of write buflist */
|
|
} l2arc_write_callback_t;
|
|
|
|
struct arc_buf_hdr {
|
|
/* protected by hash lock */
|
|
dva_t b_dva;
|
|
uint64_t b_birth;
|
|
|
|
arc_buf_contents_t b_type;
|
|
arc_buf_hdr_t *b_hash_next;
|
|
arc_flags_t b_flags;
|
|
|
|
/*
|
|
* This field stores the size of the data buffer after
|
|
* compression, and is set in the arc's zio completion handlers.
|
|
* It is in units of SPA_MINBLOCKSIZE (e.g. 1 == 512 bytes).
|
|
*
|
|
* While the block pointers can store up to 32MB in their psize
|
|
* field, we can only store up to 32MB minus 512B. This is due
|
|
* to the bp using a bias of 1, whereas we use a bias of 0 (i.e.
|
|
* a field of zeros represents 512B in the bp). We can't use a
|
|
* bias of 1 since we need to reserve a psize of zero, here, to
|
|
* represent holes and embedded blocks.
|
|
*
|
|
* This isn't a problem in practice, since the maximum size of a
|
|
* buffer is limited to 16MB, so we never need to store 32MB in
|
|
* this field. Even in the upstream illumos code base, the
|
|
* maximum size of a buffer is limited to 16MB.
|
|
*/
|
|
uint16_t b_psize;
|
|
|
|
/*
|
|
* This field stores the size of the data buffer before
|
|
* compression, and cannot change once set. It is in units
|
|
* of SPA_MINBLOCKSIZE (e.g. 2 == 1024 bytes)
|
|
*/
|
|
uint16_t b_lsize; /* immutable */
|
|
uint64_t b_spa; /* immutable */
|
|
|
|
/* L2ARC fields. Undefined when not in L2ARC. */
|
|
l2arc_buf_hdr_t b_l2hdr;
|
|
/* L1ARC fields. Undefined when in l2arc_only state */
|
|
l1arc_buf_hdr_t b_l1hdr;
|
|
/*
|
|
* Encryption parameters. Defined only when ARC_FLAG_ENCRYPTED
|
|
* is set and the L1 header exists.
|
|
*/
|
|
arc_buf_hdr_crypt_t b_crypt_hdr;
|
|
};
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* _SYS_ARC_IMPL_H */
|