1 /* $OpenBSD: tmpfs_mem.c,v 1.5 2014/11/02 03:47:28 tedu 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 #if 0 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: tmpfs_mem.c,v 1.4 2011/05/24 01:09:47 rmind Exp $"); 41 #endif 42 43 #include <sys/param.h> 44 #include <sys/namei.h> 45 #include <sys/pool.h> 46 #include <sys/vnode.h> 47 #include <sys/sysctl.h> 48 #include <sys/malloc.h> 49 50 #include <tmpfs/tmpfs.h> 51 52 extern struct pool tmpfs_dirent_pool; 53 extern struct pool tmpfs_node_pool; 54 55 void 56 tmpfs_mntmem_init(struct tmpfs_mount *mp, uint64_t memlimit) 57 { 58 59 rw_init(&mp->tm_acc_lock, "tacclk"); 60 mp->tm_mem_limit = memlimit; 61 mp->tm_bytes_used = 0; 62 } 63 64 void 65 tmpfs_mntmem_destroy(struct tmpfs_mount *mp) 66 { 67 68 KASSERT(mp->tm_bytes_used == 0); 69 /* mutex_destroy(&mp->tm_acc_lock); */ 70 } 71 72 /* 73 * tmpfs_mem_info: return the number of available memory pages. 74 * 75 * => If 'total' is true, then return _total_ amount of pages. 76 * => If false, then return the amount of _free_ memory pages. 77 * 78 * Remember to remove TMPFS_PAGES_RESERVED from the returned value to avoid 79 * excessive memory usage. 80 */ 81 size_t 82 tmpfs_mem_info(int total) 83 { 84 int size = 0; 85 86 /* XXX: unlocked */ 87 size += uvmexp.swpages; 88 if (!total) { 89 size -= uvmexp.swpgonly; 90 } 91 92 size += uvmexp.free; 93 /* size += uvmexp.filepages; */ 94 if (size > uvmexp.wired) { 95 size -= uvmexp.wired; 96 } else { 97 size = 0; 98 } 99 100 KASSERT(size >= 0); 101 102 return (size_t)size; 103 } 104 105 uint64_t 106 tmpfs_bytes_max(struct tmpfs_mount *mp) 107 { 108 size_t freepages = tmpfs_mem_info(0); 109 uint64_t avail_mem; 110 111 if (freepages < TMPFS_PAGES_RESERVED) { 112 freepages = 0; 113 } else { 114 freepages -= TMPFS_PAGES_RESERVED; 115 } 116 avail_mem = round_page(mp->tm_bytes_used) + (freepages << PAGE_SHIFT); 117 return MIN(mp->tm_mem_limit, avail_mem); 118 } 119 120 uint64_t 121 tmpfs_pages_avail(struct tmpfs_mount *mp) 122 { 123 124 return (tmpfs_bytes_max(mp) - mp->tm_bytes_used) >> PAGE_SHIFT; 125 } 126 127 int 128 tmpfs_mem_incr(struct tmpfs_mount *mp, size_t sz) 129 { 130 uint64_t lim; 131 132 rw_enter_write(&mp->tm_acc_lock); 133 lim = tmpfs_bytes_max(mp); 134 if (mp->tm_bytes_used + sz >= lim) { 135 rw_exit_write(&mp->tm_acc_lock); 136 return 0; 137 } 138 mp->tm_bytes_used += sz; 139 rw_exit_write(&mp->tm_acc_lock); 140 return 1; 141 } 142 143 void 144 tmpfs_mem_decr(struct tmpfs_mount *mp, size_t sz) 145 { 146 147 rw_enter_write(&mp->tm_acc_lock); 148 KASSERT(mp->tm_bytes_used >= sz); 149 mp->tm_bytes_used -= sz; 150 rw_exit_write(&mp->tm_acc_lock); 151 } 152 153 struct tmpfs_dirent * 154 tmpfs_dirent_get(struct tmpfs_mount *mp) 155 { 156 157 if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_dirent))) { 158 return NULL; 159 } 160 return pool_get(&tmpfs_dirent_pool, PR_WAITOK); 161 } 162 163 void 164 tmpfs_dirent_put(struct tmpfs_mount *mp, struct tmpfs_dirent *de) 165 { 166 167 tmpfs_mem_decr(mp, sizeof(struct tmpfs_dirent)); 168 pool_put(&tmpfs_dirent_pool, de); 169 } 170 171 struct tmpfs_node * 172 tmpfs_node_get(struct tmpfs_mount *mp) 173 { 174 175 mp->tm_nodes_cnt++; 176 if (mp->tm_nodes_cnt > mp->tm_nodes_max) { 177 mp->tm_nodes_cnt--; 178 return NULL; 179 } 180 if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_node))) { 181 return NULL; 182 } 183 return pool_get(&tmpfs_node_pool, PR_WAITOK); 184 } 185 186 void 187 tmpfs_node_put(struct tmpfs_mount *mp, struct tmpfs_node *tn) 188 { 189 190 mp->tm_nodes_cnt--; 191 tmpfs_mem_decr(mp, sizeof(struct tmpfs_node)); 192 pool_put(&tmpfs_node_pool, tn); 193 } 194 195 /* 196 * Quantum size to round-up the tmpfs names in order to reduce re-allocations. 197 */ 198 199 #define TMPFS_NAME_QUANTUM (32) 200 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ 201 202 char * 203 tmpfs_strname_alloc(struct tmpfs_mount *mp, size_t len) 204 { 205 const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); 206 207 KASSERT(sz > 0 && sz <= 1024); 208 if (!tmpfs_mem_incr(mp, sz)) { 209 return NULL; 210 } 211 return malloc(sz, M_TEMP, M_WAITOK); /* XXX */ 212 } 213 214 void 215 tmpfs_strname_free(struct tmpfs_mount *mp, char *str, size_t len) 216 { 217 const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); 218 219 KASSERT(sz > 0 && sz <= 1024); 220 tmpfs_mem_decr(mp, sz); 221 free(str, M_TEMP, sz); 222 } 223 224 int 225 tmpfs_strname_neqlen(struct componentname *fcnp, struct componentname *tcnp) 226 { 227 const size_t fln = roundup2(fcnp->cn_namelen, TMPFS_NAME_QUANTUM); 228 const size_t tln = roundup2(tcnp->cn_namelen, TMPFS_NAME_QUANTUM); 229 230 return (fln != tln) || memcmp(fcnp->cn_nameptr, tcnp->cn_nameptr, fln); 231 } 232