1 /* $OpenBSD: tmpfs_mem.c,v 1.2 2013/06/03 10:37:02 espie 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/malloc.h> 48 49 #include <tmpfs/tmpfs.h> 50 51 extern struct pool tmpfs_dirent_pool; 52 extern struct pool tmpfs_node_pool; 53 54 void 55 tmpfs_mntmem_init(struct tmpfs_mount *mp, uint64_t memlimit) 56 { 57 58 rw_init(&mp->tm_acc_lock, "tacclk"); 59 mp->tm_mem_limit = memlimit; 60 mp->tm_bytes_used = 0; 61 } 62 63 void 64 tmpfs_mntmem_destroy(struct tmpfs_mount *mp) 65 { 66 67 KASSERT(mp->tm_bytes_used == 0); 68 /* mutex_destroy(&mp->tm_acc_lock); */ 69 } 70 71 /* 72 * tmpfs_mem_info: return the number of available memory pages. 73 * 74 * => If 'total' is true, then return _total_ amount of pages. 75 * => If false, then return the amount of _free_ memory pages. 76 * 77 * Remember to remove TMPFS_PAGES_RESERVED from the returned value to avoid 78 * excessive memory usage. 79 */ 80 size_t 81 tmpfs_mem_info(int total) 82 { 83 int size = 0; 84 85 /* XXX: unlocked */ 86 size += uvmexp.swpages; 87 if (!total) { 88 size -= uvmexp.swpgonly; 89 } 90 91 size += uvmexp.free; 92 /* size += uvmexp.filepages; */ 93 if (size > uvmexp.wired) { 94 size -= uvmexp.wired; 95 } else { 96 size = 0; 97 } 98 99 KASSERT(size >= 0); 100 101 return (size_t)size; 102 } 103 104 uint64_t 105 tmpfs_bytes_max(struct tmpfs_mount *mp) 106 { 107 size_t freepages = tmpfs_mem_info(0); 108 uint64_t avail_mem; 109 110 if (freepages < TMPFS_PAGES_RESERVED) { 111 freepages = 0; 112 } else { 113 freepages -= TMPFS_PAGES_RESERVED; 114 } 115 avail_mem = round_page(mp->tm_bytes_used) + (freepages << PAGE_SHIFT); 116 return MIN(mp->tm_mem_limit, avail_mem); 117 } 118 119 uint64_t 120 tmpfs_pages_avail(struct tmpfs_mount *mp) 121 { 122 123 return (tmpfs_bytes_max(mp) - mp->tm_bytes_used) >> PAGE_SHIFT; 124 } 125 126 int 127 tmpfs_mem_incr(struct tmpfs_mount *mp, size_t sz) 128 { 129 uint64_t lim; 130 131 rw_enter_write(&mp->tm_acc_lock); 132 lim = tmpfs_bytes_max(mp); 133 if (mp->tm_bytes_used + sz >= lim) { 134 rw_exit_write(&mp->tm_acc_lock); 135 return 0; 136 } 137 mp->tm_bytes_used += sz; 138 rw_exit_write(&mp->tm_acc_lock); 139 return 1; 140 } 141 142 void 143 tmpfs_mem_decr(struct tmpfs_mount *mp, size_t sz) 144 { 145 146 rw_enter_write(&mp->tm_acc_lock); 147 KASSERT(mp->tm_bytes_used >= sz); 148 mp->tm_bytes_used -= sz; 149 rw_exit_write(&mp->tm_acc_lock); 150 } 151 152 struct tmpfs_dirent * 153 tmpfs_dirent_get(struct tmpfs_mount *mp) 154 { 155 156 if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_dirent))) { 157 return NULL; 158 } 159 return pool_get(&tmpfs_dirent_pool, PR_WAITOK); 160 } 161 162 void 163 tmpfs_dirent_put(struct tmpfs_mount *mp, struct tmpfs_dirent *de) 164 { 165 166 tmpfs_mem_decr(mp, sizeof(struct tmpfs_dirent)); 167 pool_put(&tmpfs_dirent_pool, de); 168 } 169 170 struct tmpfs_node * 171 tmpfs_node_get(struct tmpfs_mount *mp) 172 { 173 174 mp->tm_nodes_cnt++; 175 if (mp->tm_nodes_cnt > mp->tm_nodes_max) { 176 mp->tm_nodes_cnt--; 177 return NULL; 178 } 179 if (!tmpfs_mem_incr(mp, sizeof(struct tmpfs_node))) { 180 return NULL; 181 } 182 return pool_get(&tmpfs_node_pool, PR_WAITOK); 183 } 184 185 void 186 tmpfs_node_put(struct tmpfs_mount *mp, struct tmpfs_node *tn) 187 { 188 189 mp->tm_nodes_cnt--; 190 tmpfs_mem_decr(mp, sizeof(struct tmpfs_node)); 191 pool_put(&tmpfs_node_pool, tn); 192 } 193 194 /* 195 * Quantum size to round-up the tmpfs names in order to reduce re-allocations. 196 */ 197 198 #define TMPFS_NAME_QUANTUM (32) 199 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */ 200 201 char * 202 tmpfs_strname_alloc(struct tmpfs_mount *mp, size_t len) 203 { 204 const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); 205 206 KASSERT(sz > 0 && sz <= 1024); 207 if (!tmpfs_mem_incr(mp, sz)) { 208 return NULL; 209 } 210 return malloc(sz, M_TEMP, M_WAITOK); /* XXX */ 211 } 212 213 void 214 tmpfs_strname_free(struct tmpfs_mount *mp, char *str, size_t len) 215 { 216 const size_t sz = roundup2(len, TMPFS_NAME_QUANTUM); 217 218 KASSERT(sz > 0 && sz <= 1024); 219 tmpfs_mem_decr(mp, sz); 220 free(str, M_TEMP); 221 } 222 223 int 224 tmpfs_strname_neqlen(struct componentname *fcnp, struct componentname *tcnp) 225 { 226 const size_t fln = roundup2(fcnp->cn_namelen, TMPFS_NAME_QUANTUM); 227 const size_t tln = roundup2(tcnp->cn_namelen, TMPFS_NAME_QUANTUM); 228 229 return (fln != tln) || memcmp(fcnp->cn_nameptr, tcnp->cn_nameptr, fln); 230 } 231