1 /* $OpenBSD: tmpfs_vfsops.c,v 1.14 2017/12/11 05:27:40 deraadt Exp $ */ 2 /* $NetBSD: tmpfs_vfsops.c,v 1.52 2011/09/27 01:10:43 christos Exp $ */ 3 4 /* 5 * Copyright (c) 2005, 2006, 2007 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Julio M. Merino Vidal, developed as part of Google's Summer of Code 10 * 2005 program. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* 35 * Efficient memory file system. 36 * 37 * tmpfs is a file system that uses NetBSD's virtual memory sub-system 38 * (the well-known UVM) to store file data and metadata in an efficient 39 * way. This means that it does not follow the structure of an on-disk 40 * file system because it simply does not need to. Instead, it uses 41 * memory-specific data structures and algorithms to automatically 42 * allocate and release resources. 43 */ 44 45 #include <sys/param.h> 46 #include <sys/mount.h> 47 #include <sys/stat.h> 48 #include <sys/systm.h> 49 #include <sys/vnode.h> 50 #include <sys/malloc.h> 51 52 #include <tmpfs/tmpfs.h> 53 54 /* MODULE(MODULE_CLASS_VFS, tmpfs, NULL); */ 55 56 struct pool tmpfs_dirent_pool; 57 struct pool tmpfs_node_pool; 58 59 int tmpfs_mount(struct mount *, const char *, void *, struct nameidata *, 60 struct proc *); 61 int tmpfs_start(struct mount *, int, struct proc *); 62 int tmpfs_unmount(struct mount *, int, struct proc *); 63 int tmpfs_root(struct mount *, struct vnode **); 64 int tmpfs_vget(struct mount *, ino_t, struct vnode **); 65 int tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **); 66 int tmpfs_vptofh(struct vnode *, struct fid *); 67 int tmpfs_statfs(struct mount *, struct statfs *, struct proc *); 68 int tmpfs_sync(struct mount *, int, struct ucred *, struct proc *); 69 int tmpfs_init(struct vfsconf *); 70 71 int 72 tmpfs_init(struct vfsconf *vfsp) 73 { 74 75 pool_init(&tmpfs_dirent_pool, sizeof(tmpfs_dirent_t), 0, IPL_NONE, 76 PR_WAITOK, "tmpfs_dirent", NULL); 77 pool_init(&tmpfs_node_pool, sizeof(tmpfs_node_t), 0, IPL_NONE, 78 PR_WAITOK, "tmpfs_node", NULL); 79 80 return 0; 81 } 82 83 int 84 tmpfs_mount(struct mount *mp, const char *path, void *data, 85 struct nameidata *ndp, struct proc *p) 86 { 87 struct tmpfs_args *args = data; 88 tmpfs_mount_t *tmp; 89 tmpfs_node_t *root; 90 uint64_t memlimit; 91 uint64_t nodes; 92 int error; 93 94 #if 0 95 /* Handle retrieval of mount point arguments. */ 96 if (mp->mnt_flag & MNT_GETARGS) { 97 if (mp->mnt_data == NULL) 98 return EIO; 99 tmp = VFS_TO_TMPFS(mp); 100 101 args->ta_version = TMPFS_ARGS_VERSION; 102 args->ta_nodes_max = tmp->tm_nodes_max; 103 args->ta_size_max = tmp->tm_mem_limit; 104 105 root = tmp->tm_root; 106 args->ta_root_uid = root->tn_uid; 107 args->ta_root_gid = root->tn_gid; 108 args->ta_root_mode = root->tn_mode; 109 110 *data_len = sizeof(*args); 111 return 0; 112 } 113 #endif 114 115 if (mp->mnt_flag & MNT_UPDATE) { 116 /* TODO */ 117 return EOPNOTSUPP; 118 } 119 120 /* Prohibit mounts if there is not enough memory. */ 121 if (tmpfs_mem_info(1) < TMPFS_PAGES_RESERVED) 122 return EINVAL; 123 124 error = copyin(data, args, sizeof(struct tmpfs_args)); 125 if (error) 126 return error; 127 if (args->ta_root_uid == VNOVAL || args->ta_root_gid == VNOVAL || 128 args->ta_root_mode == VNOVAL) 129 return EINVAL; 130 131 /* Get the memory usage limit for this file-system. */ 132 if (args->ta_size_max < PAGE_SIZE) { 133 memlimit = UINT64_MAX; 134 } else { 135 memlimit = args->ta_size_max; 136 } 137 KASSERT(memlimit > 0); 138 139 if (args->ta_nodes_max <= 3) { 140 nodes = 3 + (memlimit / 1024); 141 } else { 142 nodes = args->ta_nodes_max; 143 } 144 nodes = MIN(nodes, INT_MAX); 145 KASSERT(nodes >= 3); 146 147 /* Allocate the tmpfs mount structure and fill it. */ 148 tmp = malloc(sizeof(tmpfs_mount_t), M_MISCFSMNT, M_WAITOK); 149 150 tmp->tm_nodes_max = (ino_t)nodes; 151 tmp->tm_nodes_cnt = 0; 152 tmp->tm_highest_inode = 1; 153 LIST_INIT(&tmp->tm_nodes); 154 155 rw_init(&tmp->tm_lock, "tmplk"); 156 tmpfs_mntmem_init(tmp, memlimit); 157 158 /* Allocate the root node. */ 159 error = tmpfs_alloc_node(tmp, VDIR, args->ta_root_uid, 160 args->ta_root_gid, args->ta_root_mode & ALLPERMS, NULL, 161 VNOVAL, &root); 162 KASSERT(error == 0 && root != NULL); 163 164 /* 165 * Parent of the root inode is itself. Also, root inode has no 166 * directory entry (i.e. is never attached), thus hold an extra 167 * reference (link) for it. 168 */ 169 root->tn_links++; 170 root->tn_spec.tn_dir.tn_parent = root; 171 tmp->tm_root = root; 172 173 mp->mnt_data = tmp; 174 mp->mnt_flag |= MNT_LOCAL; 175 mp->mnt_stat.f_namemax = TMPFS_MAXNAMLEN; 176 #if 0 177 mp->mnt_fs_bshift = PAGE_SHIFT; 178 mp->mnt_dev_bshift = DEV_BSHIFT; 179 mp->mnt_iflag |= IMNT_MPSAFE; 180 #endif 181 vfs_getnewfsid(mp); 182 183 mp->mnt_stat.mount_info.tmpfs_args = *args; 184 185 bzero(&mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname)); 186 bzero(&mp->mnt_stat.f_mntfromname, sizeof(mp->mnt_stat.f_mntfromname)); 187 bzero(&mp->mnt_stat.f_mntfromspec, sizeof(mp->mnt_stat.f_mntfromspec)); 188 189 strlcpy(mp->mnt_stat.f_mntonname, path, 190 sizeof(mp->mnt_stat.f_mntonname) - 1); 191 strlcpy(mp->mnt_stat.f_mntfromname, "tmpfs", 192 sizeof(mp->mnt_stat.f_mntfromname) - 1); 193 strlcpy(mp->mnt_stat.f_mntfromspec, "tmpfs", 194 sizeof(mp->mnt_stat.f_mntfromspec) - 1); 195 196 return error; 197 } 198 199 int 200 tmpfs_start(struct mount *mp, int flags, struct proc *p) 201 { 202 203 return 0; 204 } 205 206 int 207 tmpfs_unmount(struct mount *mp, int mntflags, struct proc *p) 208 { 209 tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp); 210 tmpfs_node_t *node, *cnode; 211 int error, flags = 0; 212 213 /* Handle forced unmounts. */ 214 if (mntflags & MNT_FORCE) 215 flags |= FORCECLOSE; 216 217 /* Finalize all pending I/O. */ 218 error = vflush(mp, NULL, flags); 219 if (error != 0) 220 return error; 221 222 223 /* 224 * First round, detach and destroy all directory entries. 225 * Also, clear the pointers to the vnodes - they are gone. 226 */ 227 LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) { 228 tmpfs_dirent_t *de; 229 230 node->tn_vnode = NULL; 231 if (node->tn_type != VDIR) { 232 continue; 233 } 234 while ((de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir)) != NULL) { 235 cnode = de->td_node; 236 if (cnode) { 237 cnode->tn_vnode = NULL; 238 } 239 tmpfs_dir_detach(node, de); 240 tmpfs_free_dirent(tmp, de); 241 } 242 } 243 244 /* Second round, destroy all inodes. */ 245 while ((node = LIST_FIRST(&tmp->tm_nodes)) != NULL) { 246 tmpfs_free_node(tmp, node); 247 } 248 249 /* Throw away the tmpfs_mount structure. */ 250 tmpfs_mntmem_destroy(tmp); 251 /* mutex_destroy(&tmp->tm_lock); */ 252 /* kmem_free(tmp, sizeof(*tmp)); */ 253 free(tmp, M_MISCFSMNT, sizeof(tmpfs_mount_t)); 254 mp->mnt_data = NULL; 255 256 return 0; 257 } 258 259 int 260 tmpfs_root(struct mount *mp, struct vnode **vpp) 261 { 262 tmpfs_node_t *node = VFS_TO_TMPFS(mp)->tm_root; 263 264 rw_enter_write(&node->tn_nlock); 265 return tmpfs_vnode_get(mp, node, vpp); 266 } 267 268 int 269 tmpfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) 270 { 271 272 printf("tmpfs_vget called; need for it unknown yet\n"); 273 return EOPNOTSUPP; 274 } 275 276 int 277 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp) 278 { 279 tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp); 280 tmpfs_node_t *node; 281 tmpfs_fid_t tfh; 282 283 if (fhp->fid_len != sizeof(tmpfs_fid_t)) { 284 return EINVAL; 285 } 286 memcpy(&tfh, fhp, sizeof(tmpfs_fid_t)); 287 288 rw_enter_write(&tmp->tm_lock); 289 LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) { 290 if (node->tn_id != tfh.tf_id) { 291 continue; 292 } 293 if (TMPFS_NODE_GEN(node) != tfh.tf_gen) { 294 continue; 295 } 296 rw_enter_write(&node->tn_nlock); 297 break; 298 } 299 rw_exit_write(&tmp->tm_lock); 300 301 /* Will release the tn_nlock. */ 302 return node ? tmpfs_vnode_get(mp, node, vpp) : ESTALE; 303 } 304 305 int 306 tmpfs_vptofh(struct vnode *vp, struct fid *fhp) 307 { 308 tmpfs_fid_t tfh; 309 tmpfs_node_t *node; 310 311 node = VP_TO_TMPFS_NODE(vp); 312 313 memset(&tfh, 0, sizeof(tfh)); 314 tfh.tf_len = sizeof(tmpfs_fid_t); 315 tfh.tf_gen = TMPFS_NODE_GEN(node); 316 tfh.tf_id = node->tn_id; 317 memcpy(fhp, &tfh, sizeof(tfh)); 318 319 return 0; 320 } 321 322 int 323 tmpfs_statfs(struct mount *mp, struct statfs *sbp, struct proc *p) 324 { 325 tmpfs_mount_t *tmp; 326 fsfilcnt_t freenodes; 327 uint64_t avail; 328 329 tmp = VFS_TO_TMPFS(mp); 330 331 sbp->f_iosize = sbp->f_bsize = PAGE_SIZE; 332 333 rw_enter_write(&tmp->tm_acc_lock); 334 avail = tmpfs_pages_avail(tmp); 335 sbp->f_blocks = (tmpfs_bytes_max(tmp) >> PAGE_SHIFT); 336 sbp->f_bfree = avail; 337 sbp->f_bavail = avail & INT64_MAX; /* f_bavail is int64_t */ 338 339 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_cnt, 340 avail * PAGE_SIZE / sizeof(tmpfs_node_t)); 341 342 sbp->f_files = tmp->tm_nodes_cnt + freenodes; 343 sbp->f_ffree = freenodes; 344 sbp->f_favail = freenodes & INT64_MAX; /* f_favail is int64_t */ 345 rw_exit_write(&tmp->tm_acc_lock); 346 347 copy_statfs_info(sbp, mp); 348 349 return 0; 350 } 351 352 int 353 tmpfs_sync(struct mount *mp, int waitfor, struct ucred *cred, struct proc *p) 354 { 355 356 return 0; 357 } 358 359 /* 360 * tmpfs vfs operations. 361 */ 362 363 struct vfsops tmpfs_vfsops = { 364 tmpfs_mount, /* vfs_mount */ 365 tmpfs_start, /* vfs_start */ 366 tmpfs_unmount, /* vfs_unmount */ 367 tmpfs_root, /* vfs_root */ 368 (void *)eopnotsupp, /* vfs_quotactl */ 369 tmpfs_statfs, /* vfs_statfs */ 370 tmpfs_sync, /* vfs_sync */ 371 tmpfs_vget, /* vfs_vget */ 372 tmpfs_fhtovp, /* vfs_fhtovp */ 373 tmpfs_vptofh, /* vfs_vptofh */ 374 tmpfs_init, /* vfs_init */ 375 (void *)eopnotsupp, /* vfs_sysctl */ 376 (void *)eopnotsupp, 377 }; 378