1 /* $OpenBSD: tmpfs_mem.c,v 1.7 2015/03/14 03:38:52 jsg Exp $ */ 2 /* $NetBSD: tmpfs_mem.c,v 1.4 2011/05/24 01:09:47 rmind Exp $ */ 3 4 /* 5 * Copyright (c) 2010, 2011 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Mindaugas Rasiukevicius. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * tmpfs memory allocation routines. 35 * Implements memory usage accounting and limiting. 36 */ 37 38 #include <sys/param.h> 39 #include <sys/namei.h> 40 #include <sys/pool.h> 41 #include <sys/vnode.h> 42 #include <sys/malloc.h> 43 44 #include <tmpfs/tmpfs.h> 45 46 extern struct pool tmpfs_dirent_pool; 47 extern struct pool tmpfs_node_pool; 48 49 void 50 tmpfs_mntmem_init(struct tmpfs_mount *mp, uint64_t memlimit) 51 { 52 53 rw_init(&mp->tm_acc_lock, "tacclk"); 54 mp->tm_mem_limit = memlimit; 55 mp->tm_bytes_used = 0; 56 } 57 58 void 59 tmpfs_mntmem_destroy(struct tmpfs_mount *mp) 60 { 61 62 KASSERT(mp->tm_bytes_used == 0); 63 /* mutex_destroy(&mp->tm_acc_lock); */ 64 } 65 66 /* 67 * tmpfs_mem_info: return the number of available memory pages. 68 * 69 * => If 'total' is true, then return _total_ amount of pages. 70 * => If false, then return the amount of _free_ memory pages. 71 * 72 * Remember to remove TMPFS_PAGES_RESERVED from the returned value to avoid 73 * excessive memory usage. 74 */ 75 size_t 76 tmpfs_mem_info(int total) 77 { 78 int size = 0; 79 80 /* XXX: unlocked */ 81 size += uvmexp.swpages; 82 if (!total) { 83 size -= uvmexp.swpgonly; 84 } 85 86 size += uvmexp.free; 87 /* size += uvmexp.filepages; */ 88 if (size > uvmexp.wired) { 89 size -= uvmexp.wired; 90 } else { 91 size = 0; 92 } 93 94 KASSERT(size >= 0); 95 96 return (size_t)size; 97 } 98 99 uint64_t 100 tmpfs_bytes_max(struct tmpfs_mount *mp) 101 { 102 size_t freepages = tmpfs_mem_info(0); 103 uint64_t avail_mem; 104 105 if (freepages < TMPFS_PAGES_RESERVED) { 106 freepages = 0; 107 } else { 108 freepages -= TMPFS_PAGES_RESERVED; 109 } 110 avail_mem = round_page(mp->tm_bytes_used) + (freepages << PAGE_SHIFT); 111 return MIN(mp->tm_mem_limit, avail_mem); 112 } 113 114 uint64_t 115 tmpfs_pages_avail(struct tmpfs_mount *mp) 116 { 117 118 return (tmpfs_bytes_max(mp) - mp->tm_bytes_used) >> PAGE_SHIFT; 119 } 120 121 int 122 tmpfs_mem_incr(struct tmpfs_mount *mp, size_t sz) 123 { 124 uint64_t lim; 125 126 rw_enter_write(&mp->tm_acc_lock); 127 lim = tmpfs_bytes_max(mp); 128 if (mp->tm_bytes_used + sz >= lim) { 129 rw_exit_write(&mp->tm_acc_lock); 130 return 0; 131 } 132 mp->tm_bytes_used += sz; 133 rw_exit_write(&mp->tm_acc_lock); 134 return 1; 135 } 136 137 void 138 tmpfs_mem_decr(struct tmpfs_mount *mp, size_t sz) 139 { 140 141 rw_enter_write(&mp->tm_acc_lock); 142 KASSERT(mp->tm_bytes_used >= sz); 143 mp->tm_bytes_used -= sz; 144 rw_exit_write(&mp->tm_acc_lock); 145 } 146 147 struct tmpfs_dirent * 148 tmpfs_dirent_get(struct tmpfs_mount *mp) 149 { 150 151 if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_dirent))) { 152 return NULL; 153 } 154 return pool_get(&tmpfs_dirent_pool, PR_WAITOK); 155 } 156 157 void 158 tmpfs_dirent_put(struct tmpfs_mount *mp, struct tmpfs_dirent *de) 159 { 160 161 tmpfs_mem_decr(mp, sizeof(struct tmpfs_dirent)); 162 pool_put(&tmpfs_dirent_pool, de); 163 } 164 165 struct tmpfs_node * 166 tmpfs_node_get(struct tmpfs_mount *mp) 167 { 168 169 mp->tm_nodes_cnt++; 170 if (mp->tm_nodes_cnt > mp->tm_nodes_max) { 171 mp->tm_nodes_cnt--; 172 return NULL; 173 } 174 if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_node))) { 175 return NULL; 176 } 177 return pool_get(&tmpfs_node_pool, PR_WAITOK); 178 } 179 180 void 181 tmpfs_node_put(struct tmpfs_mount *mp, struct tmpfs_node *tn) 182 { 183 184 mp->tm_nodes_cnt--; 185 tmpfs_mem_decr(mp, sizeof(struct tmpfs_node)); 186 pool_put(&tmpfs_node_pool, tn); 187 } 188 189 /* 190 * Quantum size to round-up the tmpfs names in order to reduce re-allocations. 191 */ 192 193 #define TMPFS_NAME_QUANTUM (32) 194 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ 195 196 char * 197 tmpfs_strname_alloc(struct tmpfs_mount *mp, size_t len) 198 { 199 const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); 200 201 KASSERT(sz > 0 && sz <= 1024); 202 if (!tmpfs_mem_incr(mp, sz)) { 203 return NULL; 204 } 205 return malloc(sz, M_TEMP, M_WAITOK); /* XXX */ 206 } 207 208 void 209 tmpfs_strname_free(struct tmpfs_mount *mp, char *str, size_t len) 210 { 211 const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); 212 213 KASSERT(sz > 0 && sz <= 1024); 214 tmpfs_mem_decr(mp, sz); 215 free(str, M_TEMP, sz); 216 } 217 218 int 219 tmpfs_strname_neqlen(struct componentname *fcnp, struct componentname *tcnp) 220 { 221 const size_t fln = roundup2(fcnp->cn_namelen, TMPFS_NAME_QUANTUM); 222 const size_t tln = roundup2(tcnp->cn_namelen, TMPFS_NAME_QUANTUM); 223 224 return (fln != tln) || memcmp(fcnp->cn_nameptr, tcnp->cn_nameptr, fln); 225 } 226