1 /* $OpenBSD: tmpfs_vfsops.c,v 1.10 2016/07/22 13:11:01 kettenis 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/types.h> 47 #include <sys/mount.h> 48 #include <sys/stat.h> 49 #include <sys/systm.h> 50 #include <sys/vnode.h> 51 #include <sys/malloc.h> 52 53 #include <tmpfs/tmpfs.h> 54 55 /* MODULE(MODULE_CLASS_VFS, tmpfs, NULL); */ 56 57 struct pool tmpfs_dirent_pool; 58 struct pool tmpfs_node_pool; 59 60 int tmpfs_mount(struct mount *, const char *, void *, struct nameidata *, 61 struct proc *); 62 int tmpfs_start(struct mount *, int, struct proc *); 63 int tmpfs_unmount(struct mount *, int, struct proc *); 64 int tmpfs_root(struct mount *, struct vnode **); 65 int tmpfs_vget(struct mount *, ino_t, struct vnode **); 66 int tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **); 67 int tmpfs_vptofh(struct vnode *, struct fid *); 68 int tmpfs_statfs(struct mount *, struct statfs *, struct proc *); 69 int tmpfs_sync(struct mount *, int, struct ucred *, struct proc *); 70 int tmpfs_init(struct vfsconf *); 71 72 int 73 tmpfs_init(struct vfsconf *vfsp) 74 { 75 76 pool_init(&tmpfs_dirent_pool, sizeof(tmpfs_dirent_t), 0, 0, PR_WAITOK, 77 "tmpfs_dirent", NULL); 78 pool_init(&tmpfs_node_pool, sizeof(tmpfs_node_t), 0, 0, PR_WAITOK, 79 "tmpfs_node", NULL); 80 81 return 0; 82 } 83 84 int 85 tmpfs_mount(struct mount *mp, const char *path, void *data, 86 struct nameidata *ndp, struct proc *p) 87 { 88 struct tmpfs_args args; 89 tmpfs_mount_t *tmp; 90 tmpfs_node_t *root; 91 uint64_t memlimit; 92 uint64_t nodes; 93 int error; 94 95 #if 0 96 /* Handle retrieval of mount point arguments. */ 97 if (mp->mnt_flag & MNT_GETARGS) { 98 if (mp->mnt_data == NULL) 99 return EIO; 100 tmp = VFS_TO_TMPFS(mp); 101 102 args->ta_version = TMPFS_ARGS_VERSION; 103 args->ta_nodes_max = tmp->tm_nodes_max; 104 args->ta_size_max = tmp->tm_mem_limit; 105 106 root = tmp->tm_root; 107 args->ta_root_uid = root->tn_uid; 108 args->ta_root_gid = root->tn_gid; 109 args->ta_root_mode = root->tn_mode; 110 111 *data_len = sizeof(*args); 112 return 0; 113 } 114 #endif 115 116 if (mp->mnt_flag & MNT_UPDATE) { 117 /* TODO */ 118 return EOPNOTSUPP; 119 } 120 121 /* Prohibit mounts if there is not enough memory. */ 122 if (tmpfs_mem_info(1) < TMPFS_PAGES_RESERVED) 123 return EINVAL; 124 125 error = copyin(data, &args, sizeof(struct tmpfs_args)); 126 if (error) 127 return error; 128 if (args.ta_root_uid == VNOVAL || args.ta_root_gid == VNOVAL || 129 args.ta_root_mode == VNOVAL) 130 return EINVAL; 131 132 /* Get the memory usage limit for this file-system. */ 133 if (args.ta_size_max < PAGE_SIZE) { 134 memlimit = UINT64_MAX; 135 } else { 136 memlimit = args.ta_size_max; 137 } 138 KASSERT(memlimit > 0); 139 140 if (args.ta_nodes_max <= 3) { 141 nodes = 3 + (memlimit / 1024); 142 } else { 143 nodes = args.ta_nodes_max; 144 } 145 nodes = MIN(nodes, INT_MAX); 146 KASSERT(nodes >= 3); 147 148 /* Allocate the tmpfs mount structure and fill it. */ 149 tmp = malloc(sizeof(tmpfs_mount_t), M_MISCFSMNT, M_WAITOK); 150 151 tmp->tm_nodes_max = (ino_t)nodes; 152 tmp->tm_nodes_cnt = 0; 153 tmp->tm_highest_inode = 1; 154 LIST_INIT(&tmp->tm_nodes); 155 156 rw_init(&tmp->tm_lock, "tmplk"); 157 tmpfs_mntmem_init(tmp, memlimit); 158 159 /* Allocate the root node. */ 160 error = tmpfs_alloc_node(tmp, VDIR, args.ta_root_uid, 161 args.ta_root_gid, args.ta_root_mode & ALLPERMS, NULL, 162 VNOVAL, &root); 163 KASSERT(error == 0 && root != NULL); 164 165 /* 166 * Parent of the root inode is itself. Also, root inode has no 167 * directory entry (i.e. is never attached), thus hold an extra 168 * reference (link) for it. 169 */ 170 root->tn_links++; 171 root->tn_spec.tn_dir.tn_parent = root; 172 tmp->tm_root = root; 173 174 mp->mnt_data = tmp; 175 mp->mnt_flag |= MNT_LOCAL; 176 mp->mnt_stat.f_namemax = TMPFS_MAXNAMLEN; 177 #if 0 178 mp->mnt_fs_bshift = PAGE_SHIFT; 179 mp->mnt_dev_bshift = DEV_BSHIFT; 180 mp->mnt_iflag |= IMNT_MPSAFE; 181 #endif 182 vfs_getnewfsid(mp); 183 184 mp->mnt_stat.mount_info.tmpfs_args = args; 185 186 bzero(&mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname)); 187 bzero(&mp->mnt_stat.f_mntfromname, sizeof(mp->mnt_stat.f_mntfromname)); 188 bzero(&mp->mnt_stat.f_mntfromspec, sizeof(mp->mnt_stat.f_mntfromspec)); 189 190 strlcpy(mp->mnt_stat.f_mntonname, path, 191 sizeof(mp->mnt_stat.f_mntonname) - 1); 192 strlcpy(mp->mnt_stat.f_mntfromname, "tmpfs", 193 sizeof(mp->mnt_stat.f_mntfromname) - 1); 194 strlcpy(mp->mnt_stat.f_mntfromspec, "tmpfs", 195 sizeof(mp->mnt_stat.f_mntfromspec) - 1); 196 197 return error; 198 } 199 200 int 201 tmpfs_start(struct mount *mp, int flags, struct proc *p) 202 { 203 204 return 0; 205 } 206 207 int 208 tmpfs_unmount(struct mount *mp, int mntflags, struct proc *p) 209 { 210 tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp); 211 tmpfs_node_t *node, *cnode; 212 int error, flags = 0; 213 214 /* Handle forced unmounts. */ 215 if (mntflags & MNT_FORCE) 216 flags |= FORCECLOSE; 217 218 /* Finalize all pending I/O. */ 219 error = vflush(mp, NULL, flags); 220 if (error != 0) 221 return error; 222 223 224 /* 225 * First round, detach and destroy all directory entries. 226 * Also, clear the pointers to the vnodes - they are gone. 227 */ 228 LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) { 229 tmpfs_dirent_t *de; 230 231 node->tn_vnode = NULL; 232 if (node->tn_type != VDIR) { 233 continue; 234 } 235 while ((de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir)) != NULL) { 236 cnode = de->td_node; 237 if (cnode) { 238 cnode->tn_vnode = NULL; 239 } 240 tmpfs_dir_detach(node, de); 241 tmpfs_free_dirent(tmp, de); 242 } 243 } 244 245 /* Second round, destroy all inodes. */ 246 while ((node = LIST_FIRST(&tmp->tm_nodes)) != NULL) { 247 tmpfs_free_node(tmp, node); 248 } 249 250 /* Throw away the tmpfs_mount structure. */ 251 tmpfs_mntmem_destroy(tmp); 252 /* mutex_destroy(&tmp->tm_lock); */ 253 /* kmem_free(tmp, sizeof(*tmp)); */ 254 free(tmp, M_MISCFSMNT, sizeof(tmpfs_mount_t)); 255 mp->mnt_data = NULL; 256 257 return 0; 258 } 259 260 int 261 tmpfs_root(struct mount *mp, struct vnode **vpp) 262 { 263 tmpfs_node_t *node = VFS_TO_TMPFS(mp)->tm_root; 264 265 rw_enter_write(&node->tn_nlock); 266 return tmpfs_vnode_get(mp, node, vpp); 267 } 268 269 int 270 tmpfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) 271 { 272 273 printf("tmpfs_vget called; need for it unknown yet\n"); 274 return EOPNOTSUPP; 275 } 276 277 int 278 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp) 279 { 280 tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp); 281 tmpfs_node_t *node; 282 tmpfs_fid_t tfh; 283 284 if (fhp->fid_len != sizeof(tmpfs_fid_t)) { 285 return EINVAL; 286 } 287 memcpy(&tfh, fhp, sizeof(tmpfs_fid_t)); 288 289 rw_enter_write(&tmp->tm_lock); 290 LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) { 291 if (node->tn_id != tfh.tf_id) { 292 continue; 293 } 294 if (TMPFS_NODE_GEN(node) != tfh.tf_gen) { 295 continue; 296 } 297 rw_enter_write(&node->tn_nlock); 298 break; 299 } 300 rw_exit_write(&tmp->tm_lock); 301 302 /* Will release the tn_nlock. */ 303 return node ? tmpfs_vnode_get(mp, node, vpp) : ESTALE; 304 } 305 306 int 307 tmpfs_vptofh(struct vnode *vp, struct fid *fhp) 308 { 309 tmpfs_fid_t tfh; 310 tmpfs_node_t *node; 311 312 node = VP_TO_TMPFS_NODE(vp); 313 314 memset(&tfh, 0, sizeof(tfh)); 315 tfh.tf_len = sizeof(tmpfs_fid_t); 316 tfh.tf_gen = TMPFS_NODE_GEN(node); 317 tfh.tf_id = node->tn_id; 318 memcpy(fhp, &tfh, sizeof(tfh)); 319 320 return 0; 321 } 322 323 int 324 tmpfs_statfs(struct mount *mp, struct statfs *sbp, struct proc *p) 325 { 326 tmpfs_mount_t *tmp; 327 fsfilcnt_t freenodes; 328 uint64_t avail; 329 330 tmp = VFS_TO_TMPFS(mp); 331 332 sbp->f_iosize = sbp->f_bsize = PAGE_SIZE; 333 334 rw_enter_write(&tmp->tm_acc_lock); 335 avail = tmpfs_pages_avail(tmp); 336 sbp->f_blocks = (tmpfs_bytes_max(tmp) >> PAGE_SHIFT); 337 sbp->f_bfree = avail; 338 sbp->f_bavail = avail & INT64_MAX; /* f_bavail is int64_t */ 339 340 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_cnt, 341 avail * PAGE_SIZE / sizeof(tmpfs_node_t)); 342 343 sbp->f_files = tmp->tm_nodes_cnt + freenodes; 344 sbp->f_ffree = freenodes; 345 sbp->f_favail = freenodes & INT64_MAX; /* f_favail is int64_t */ 346 rw_exit_write(&tmp->tm_acc_lock); 347 348 copy_statfs_info(sbp, mp); 349 350 return 0; 351 } 352 353 int 354 tmpfs_sync(struct mount *mp, int waitfor, struct ucred *cred, struct proc *p) 355 { 356 357 return 0; 358 } 359 360 /* 361 * tmpfs vfs operations. 362 */ 363 364 struct vfsops tmpfs_vfsops = { 365 tmpfs_mount, /* vfs_mount */ 366 tmpfs_start, /* vfs_start */ 367 tmpfs_unmount, /* vfs_unmount */ 368 tmpfs_root, /* vfs_root */ 369 (void *)eopnotsupp, /* vfs_quotactl */ 370 tmpfs_statfs, /* vfs_statfs */ 371 tmpfs_sync, /* vfs_sync */ 372 tmpfs_vget, /* vfs_vget */ 373 tmpfs_fhtovp, /* vfs_fhtovp */ 374 tmpfs_vptofh, /* vfs_vptofh */ 375 tmpfs_init, /* vfs_init */ 376 (void *)eopnotsupp, /* vfs_sysctl */ 377 (void *)eopnotsupp, 378 }; 379