1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #ifndef _DFETCH_H 27 #define _DFETCH_H 28 29 #include <sys/zfs_context.h> 30 31 #ifdef __cplusplus 32 extern "C" { 33 #endif 34 35 extern uint64_t zfetch_array_rd_sz; 36 37 struct dnode; /* so we can reference dnode */ 38 39 typedef enum zfetch_dirn { 40 ZFETCH_FORWARD = 1, /* prefetch increasing block numbers */ 41 ZFETCH_BACKWARD = -1 /* prefetch decreasing block numbers */ 42 } zfetch_dirn_t; 43 44 typedef struct zstream { 45 uint64_t zst_offset; /* offset of starting block in range */ 46 uint64_t zst_len; /* length of range, in blocks */ 47 zfetch_dirn_t zst_direction; /* direction of prefetch */ 48 uint64_t zst_stride; /* length of stride, in blocks */ 49 uint64_t zst_ph_offset; /* prefetch offset, in blocks */ 50 uint64_t zst_cap; /* prefetch limit (cap), in blocks */ 51 kmutex_t zst_lock; /* protects stream */ 52 clock_t zst_last; /* lbolt of last prefetch */ 53 avl_node_t zst_node; /* embed avl node here */ 54 } zstream_t; 55 56 typedef struct zfetch { 57 krwlock_t zf_rwlock; /* protects zfetch structure */ 58 list_t zf_stream; /* AVL tree of zstream_t's */ 59 struct dnode *zf_dnode; /* dnode that owns this zfetch */ 60 uint32_t zf_stream_cnt; /* # of active streams */ 61 uint64_t zf_alloc_fail; /* # of failed attempts to alloc strm */ 62 } zfetch_t; 63 64 void zfetch_init(void); 65 void zfetch_fini(void); 66 67 void dmu_zfetch_init(zfetch_t *, struct dnode *); 68 void dmu_zfetch_rele(zfetch_t *); 69 void dmu_zfetch(zfetch_t *, uint64_t, uint64_t, int); 70 71 72 #ifdef __cplusplus 73 } 74 #endif 75 76 #endif /* _DFETCH_H */ 77