tmpfs_mem.c revision 1.2.2.3
1 1.2.2.2 rmind /* $NetBSD: tmpfs_mem.c,v 1.2.2.3 2011/05/31 03:04:59 rmind Exp $ */ 2 1.2.2.2 rmind 3 1.2.2.2 rmind /* 4 1.2.2.3 rmind * Copyright (c) 2010, 2011 The NetBSD Foundation, Inc. 5 1.2.2.2 rmind * All rights reserved. 6 1.2.2.2 rmind * 7 1.2.2.3 rmind * This code is derived from software contributed to The NetBSD Foundation 8 1.2.2.3 rmind * by Mindaugas Rasiukevicius. 9 1.2.2.3 rmind * 10 1.2.2.2 rmind * Redistribution and use in source and binary forms, with or without 11 1.2.2.2 rmind * modification, are permitted provided that the following conditions 12 1.2.2.2 rmind * are met: 13 1.2.2.2 rmind * 1. Redistributions of source code must retain the above copyright 14 1.2.2.2 rmind * notice, this list of conditions and the following disclaimer. 15 1.2.2.2 rmind * 2. Redistributions in binary form must reproduce the above copyright 16 1.2.2.2 rmind * notice, this list of conditions and the following disclaimer in the 17 1.2.2.2 rmind * documentation and/or other materials provided with the distribution. 18 1.2.2.2 rmind * 19 1.2.2.2 rmind * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.2.2.2 rmind * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.2.2.2 rmind * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.2.2.2 rmind * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.2.2.2 rmind * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.2.2.2 rmind * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.2.2.2 rmind * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.2.2.2 rmind * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.2.2.2 rmind * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.2.2.2 rmind * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.2.2.2 rmind * POSSIBILITY OF SUCH DAMAGE. 30 1.2.2.2 rmind */ 31 1.2.2.2 rmind 32 1.2.2.2 rmind /* 33 1.2.2.2 rmind * tmpfs memory allocation routines. 34 1.2.2.2 rmind * Implements memory usage accounting and limiting. 35 1.2.2.2 rmind */ 36 1.2.2.2 rmind 37 1.2.2.2 rmind #include <sys/cdefs.h> 38 1.2.2.2 rmind __KERNEL_RCSID(0, "$NetBSD: tmpfs_mem.c,v 1.2.2.3 2011/05/31 03:04:59 rmind Exp $"); 39 1.2.2.2 rmind 40 1.2.2.2 rmind #include <sys/param.h> 41 1.2.2.2 rmind #include <sys/atomic.h> 42 1.2.2.2 rmind #include <sys/kmem.h> 43 1.2.2.2 rmind #include <sys/namei.h> 44 1.2.2.2 rmind #include <sys/pool.h> 45 1.2.2.2 rmind 46 1.2.2.2 rmind #include <fs/tmpfs/tmpfs.h> 47 1.2.2.2 rmind 48 1.2.2.3 rmind extern struct pool tmpfs_dirent_pool; 49 1.2.2.3 rmind extern struct pool tmpfs_node_pool; 50 1.2.2.3 rmind 51 1.2.2.2 rmind void 52 1.2.2.2 rmind tmpfs_mntmem_init(struct tmpfs_mount *mp, uint64_t memlimit) 53 1.2.2.2 rmind { 54 1.2.2.2 rmind 55 1.2.2.2 rmind mutex_init(&mp->tm_acc_lock, MUTEX_DEFAULT, IPL_NONE); 56 1.2.2.2 rmind mp->tm_mem_limit = memlimit; 57 1.2.2.2 rmind mp->tm_bytes_used = 0; 58 1.2.2.2 rmind } 59 1.2.2.2 rmind 60 1.2.2.2 rmind void 61 1.2.2.2 rmind tmpfs_mntmem_destroy(struct tmpfs_mount *mp) 62 1.2.2.2 rmind { 63 1.2.2.2 rmind 64 1.2.2.2 rmind KASSERT(mp->tm_bytes_used == 0); 65 1.2.2.2 rmind mutex_destroy(&mp->tm_acc_lock); 66 1.2.2.2 rmind } 67 1.2.2.2 rmind 68 1.2.2.2 rmind /* 69 1.2.2.2 rmind * tmpfs_mem_info: return the number of available memory pages. 70 1.2.2.2 rmind * 71 1.2.2.2 rmind * => If 'total' is true, then return _total_ amount of pages. 72 1.2.2.2 rmind * => If false, then return the amount of _free_ memory pages. 73 1.2.2.2 rmind * 74 1.2.2.2 rmind * Remember to remove TMPFS_PAGES_RESERVED from the returned value to avoid 75 1.2.2.2 rmind * excessive memory usage. 76 1.2.2.2 rmind */ 77 1.2.2.2 rmind size_t 78 1.2.2.2 rmind tmpfs_mem_info(bool total) 79 1.2.2.2 rmind { 80 1.2.2.2 rmind size_t size = 0; 81 1.2.2.2 rmind 82 1.2.2.2 rmind /* XXX: unlocked */ 83 1.2.2.2 rmind size += uvmexp.swpgavail; 84 1.2.2.2 rmind if (!total) { 85 1.2.2.2 rmind size -= uvmexp.swpgonly; 86 1.2.2.2 rmind } 87 1.2.2.2 rmind size += uvmexp.free; 88 1.2.2.2 rmind size += uvmexp.filepages; 89 1.2.2.2 rmind if (size > uvmexp.wired) { 90 1.2.2.2 rmind size -= uvmexp.wired; 91 1.2.2.2 rmind } else { 92 1.2.2.2 rmind size = 0; 93 1.2.2.2 rmind } 94 1.2.2.2 rmind return size; 95 1.2.2.2 rmind } 96 1.2.2.2 rmind 97 1.2.2.2 rmind uint64_t 98 1.2.2.2 rmind tmpfs_bytes_max(struct tmpfs_mount *mp) 99 1.2.2.2 rmind { 100 1.2.2.2 rmind size_t freepages = tmpfs_mem_info(false); 101 1.2.2.2 rmind uint64_t avail_mem; 102 1.2.2.2 rmind 103 1.2.2.2 rmind if (freepages < TMPFS_PAGES_RESERVED) { 104 1.2.2.2 rmind freepages = 0; 105 1.2.2.2 rmind } else { 106 1.2.2.2 rmind freepages -= TMPFS_PAGES_RESERVED; 107 1.2.2.2 rmind } 108 1.2.2.2 rmind avail_mem = round_page(mp->tm_bytes_used) + (freepages << PAGE_SHIFT); 109 1.2.2.2 rmind return MIN(mp->tm_mem_limit, avail_mem); 110 1.2.2.2 rmind } 111 1.2.2.2 rmind 112 1.2.2.2 rmind size_t 113 1.2.2.2 rmind tmpfs_pages_avail(struct tmpfs_mount *mp) 114 1.2.2.2 rmind { 115 1.2.2.2 rmind 116 1.2.2.2 rmind return (tmpfs_bytes_max(mp) - mp->tm_bytes_used) >> PAGE_SHIFT; 117 1.2.2.2 rmind } 118 1.2.2.2 rmind 119 1.2.2.2 rmind bool 120 1.2.2.2 rmind tmpfs_mem_incr(struct tmpfs_mount *mp, size_t sz) 121 1.2.2.2 rmind { 122 1.2.2.2 rmind uint64_t lim; 123 1.2.2.2 rmind 124 1.2.2.2 rmind mutex_enter(&mp->tm_acc_lock); 125 1.2.2.2 rmind lim = tmpfs_bytes_max(mp); 126 1.2.2.2 rmind if (mp->tm_bytes_used + sz >= lim) { 127 1.2.2.2 rmind mutex_exit(&mp->tm_acc_lock); 128 1.2.2.2 rmind return false; 129 1.2.2.2 rmind } 130 1.2.2.2 rmind mp->tm_bytes_used += sz; 131 1.2.2.2 rmind mutex_exit(&mp->tm_acc_lock); 132 1.2.2.2 rmind return true; 133 1.2.2.2 rmind } 134 1.2.2.2 rmind 135 1.2.2.2 rmind void 136 1.2.2.2 rmind tmpfs_mem_decr(struct tmpfs_mount *mp, size_t sz) 137 1.2.2.2 rmind { 138 1.2.2.2 rmind 139 1.2.2.2 rmind mutex_enter(&mp->tm_acc_lock); 140 1.2.2.2 rmind KASSERT(mp->tm_bytes_used >= sz); 141 1.2.2.2 rmind mp->tm_bytes_used -= sz; 142 1.2.2.2 rmind mutex_exit(&mp->tm_acc_lock); 143 1.2.2.2 rmind } 144 1.2.2.2 rmind 145 1.2.2.2 rmind struct tmpfs_dirent * 146 1.2.2.2 rmind tmpfs_dirent_get(struct tmpfs_mount *mp) 147 1.2.2.2 rmind { 148 1.2.2.2 rmind 149 1.2.2.2 rmind if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_dirent))) { 150 1.2.2.2 rmind return NULL; 151 1.2.2.2 rmind } 152 1.2.2.3 rmind return pool_get(&tmpfs_dirent_pool, PR_WAITOK); 153 1.2.2.2 rmind } 154 1.2.2.2 rmind 155 1.2.2.2 rmind void 156 1.2.2.2 rmind tmpfs_dirent_put(struct tmpfs_mount *mp, struct tmpfs_dirent *de) 157 1.2.2.2 rmind { 158 1.2.2.2 rmind 159 1.2.2.2 rmind tmpfs_mem_decr(mp, sizeof(struct tmpfs_dirent)); 160 1.2.2.3 rmind pool_put(&tmpfs_dirent_pool, de); 161 1.2.2.2 rmind } 162 1.2.2.2 rmind 163 1.2.2.2 rmind struct tmpfs_node * 164 1.2.2.2 rmind tmpfs_node_get(struct tmpfs_mount *mp) 165 1.2.2.2 rmind { 166 1.2.2.2 rmind 167 1.2.2.3 rmind if (atomic_inc_uint_nv(&mp->tm_nodes_cnt) >= mp->tm_nodes_max) { 168 1.2.2.3 rmind atomic_dec_uint(&mp->tm_nodes_cnt); 169 1.2.2.3 rmind return NULL; 170 1.2.2.3 rmind } 171 1.2.2.2 rmind if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_node))) { 172 1.2.2.2 rmind return NULL; 173 1.2.2.2 rmind } 174 1.2.2.3 rmind return pool_get(&tmpfs_node_pool, PR_WAITOK); 175 1.2.2.2 rmind } 176 1.2.2.2 rmind 177 1.2.2.2 rmind void 178 1.2.2.2 rmind tmpfs_node_put(struct tmpfs_mount *mp, struct tmpfs_node *tn) 179 1.2.2.2 rmind { 180 1.2.2.2 rmind 181 1.2.2.3 rmind atomic_dec_uint(&mp->tm_nodes_cnt); 182 1.2.2.2 rmind tmpfs_mem_decr(mp, sizeof(struct tmpfs_node)); 183 1.2.2.3 rmind pool_put(&tmpfs_node_pool, tn); 184 1.2.2.2 rmind } 185 1.2.2.2 rmind 186 1.2.2.2 rmind /* 187 1.2.2.2 rmind * Quantum size to round-up the tmpfs names in order to reduce re-allocations. 188 1.2.2.2 rmind */ 189 1.2.2.2 rmind 190 1.2.2.2 rmind #define TMPFS_NAME_QUANTUM (32) 191 1.2.2.2 rmind 192 1.2.2.2 rmind char * 193 1.2.2.2 rmind tmpfs_strname_alloc(struct tmpfs_mount *mp, size_t len) 194 1.2.2.2 rmind { 195 1.2.2.2 rmind const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); 196 1.2.2.2 rmind 197 1.2.2.2 rmind KASSERT(sz > 0 && sz <= 1024); 198 1.2.2.2 rmind if (!tmpfs_mem_incr(mp, sz)) { 199 1.2.2.2 rmind return NULL; 200 1.2.2.2 rmind } 201 1.2.2.2 rmind return kmem_alloc(sz, KM_SLEEP); 202 1.2.2.2 rmind } 203 1.2.2.2 rmind 204 1.2.2.2 rmind void 205 1.2.2.2 rmind tmpfs_strname_free(struct tmpfs_mount *mp, char *str, size_t len) 206 1.2.2.2 rmind { 207 1.2.2.2 rmind const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); 208 1.2.2.2 rmind 209 1.2.2.2 rmind KASSERT(sz > 0 && sz <= 1024); 210 1.2.2.2 rmind tmpfs_mem_decr(mp, sz); 211 1.2.2.2 rmind kmem_free(str, sz); 212 1.2.2.2 rmind } 213 1.2.2.2 rmind 214 1.2.2.2 rmind bool 215 1.2.2.2 rmind tmpfs_strname_neqlen(struct componentname *fcnp, struct componentname *tcnp) 216 1.2.2.2 rmind { 217 1.2.2.2 rmind const size_t fln = roundup2(fcnp->cn_namelen, TMPFS_NAME_QUANTUM); 218 1.2.2.2 rmind const size_t tln = roundup2(tcnp->cn_namelen, TMPFS_NAME_QUANTUM); 219 1.2.2.2 rmind 220 1.2.2.2 rmind return (fln != tln) || memcmp(fcnp->cn_nameptr, tcnp->cn_nameptr, fln); 221 1.2.2.2 rmind } 222
Indexes created Mon Sep 29 21:09:56 GMT 2025