1 /* $OpenBSD: tmpfs_vfsops.c,v 1.8 2016/01/13 13:01:40 gsoares 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; 128 129 /* Get the memory usage limit for this file-system. */ 130 if (args.ta_size_max < PAGE_SIZE) { 131 memlimit = UINT64_MAX; 132 } else { 133 memlimit = args.ta_size_max; 134 } 135 KASSERT(memlimit > 0); 136 137 if (args.ta_nodes_max <= 3) { 138 nodes = 3 + (memlimit / 1024); 139 } else { 140 nodes = args.ta_nodes_max; 141 } 142 nodes = MIN(nodes, INT_MAX); 143 KASSERT(nodes >= 3); 144 145 /* Allocate the tmpfs mount structure and fill it. */ 146 tmp = malloc(sizeof(tmpfs_mount_t), M_MISCFSMNT, M_WAITOK); 147 148 tmp->tm_nodes_max = (ino_t)nodes; 149 tmp->tm_nodes_cnt = 0; 150 tmp->tm_highest_inode = 1; 151 LIST_INIT(&tmp->tm_nodes); 152 153 rw_init(&tmp->tm_lock, "tmplk"); 154 tmpfs_mntmem_init(tmp, memlimit); 155 156 /* Allocate the root node. */ 157 error = tmpfs_alloc_node(tmp, VDIR, args.ta_root_uid, 158 args.ta_root_gid, args.ta_root_mode & ALLPERMS, NULL, 159 VNOVAL, &root); 160 KASSERT(error == 0 && root != NULL); 161 162 /* 163 * Parent of the root inode is itself. Also, root inode has no 164 * directory entry (i.e. is never attached), thus hold an extra 165 * reference (link) for it. 166 */ 167 root->tn_links++; 168 root->tn_spec.tn_dir.tn_parent = root; 169 tmp->tm_root = root; 170 171 mp->mnt_data = tmp; 172 mp->mnt_flag |= MNT_LOCAL; 173 mp->mnt_stat.f_namemax = TMPFS_MAXNAMLEN; 174 #if 0 175 mp->mnt_fs_bshift = PAGE_SHIFT; 176 mp->mnt_dev_bshift = DEV_BSHIFT; 177 mp->mnt_iflag |= IMNT_MPSAFE; 178 #endif 179 vfs_getnewfsid(mp); 180 181 mp->mnt_stat.mount_info.tmpfs_args = args; 182 183 bzero(&mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname)); 184 bzero(&mp->mnt_stat.f_mntfromname, sizeof(mp->mnt_stat.f_mntfromname)); 185 bzero(&mp->mnt_stat.f_mntfromspec, sizeof(mp->mnt_stat.f_mntfromspec)); 186 187 strlcpy(mp->mnt_stat.f_mntonname, path, 188 sizeof(mp->mnt_stat.f_mntonname) - 1); 189 strlcpy(mp->mnt_stat.f_mntfromname, "tmpfs", 190 sizeof(mp->mnt_stat.f_mntfromname) - 1); 191 strlcpy(mp->mnt_stat.f_mntfromspec, "tmpfs", 192 sizeof(mp->mnt_stat.f_mntfromspec) - 1); 193 194 return error; 195 } 196 197 int 198 tmpfs_start(struct mount *mp, int flags, struct proc *p) 199 { 200 201 return 0; 202 } 203 204 int 205 tmpfs_unmount(struct mount *mp, int mntflags, struct proc *p) 206 { 207 tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp); 208 tmpfs_node_t *node, *cnode; 209 int error, flags = 0; 210 211 /* Handle forced unmounts. */ 212 if (mntflags & MNT_FORCE) 213 flags |= FORCECLOSE; 214 215 /* Finalize all pending I/O. */ 216 error = vflush(mp, NULL, flags); 217 if (error != 0) 218 return error; 219 220 221 /* 222 * First round, detach and destroy all directory entries. 223 * Also, clear the pointers to the vnodes - they are gone. 224 */ 225 LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) { 226 tmpfs_dirent_t *de; 227 228 node->tn_vnode = NULL; 229 if (node->tn_type != VDIR) { 230 continue; 231 } 232 while ((de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir)) != NULL) { 233 cnode = de->td_node; 234 if (cnode) { 235 cnode->tn_vnode = NULL; 236 } 237 tmpfs_dir_detach(node, de); 238 tmpfs_free_dirent(tmp, de); 239 } 240 } 241 242 /* Second round, destroy all inodes. */ 243 while ((node = LIST_FIRST(&tmp->tm_nodes)) != NULL) { 244 tmpfs_free_node(tmp, node); 245 } 246 247 /* Throw away the tmpfs_mount structure. */ 248 tmpfs_mntmem_destroy(tmp); 249 /* mutex_destroy(&tmp->tm_lock); */ 250 /* kmem_free(tmp, sizeof(*tmp)); */ 251 free(tmp, M_MISCFSMNT, sizeof(tmpfs_mount_t)); 252 mp->mnt_data = NULL; 253 254 return 0; 255 } 256 257 int 258 tmpfs_root(struct mount *mp, struct vnode **vpp) 259 { 260 tmpfs_node_t *node = VFS_TO_TMPFS(mp)->tm_root; 261 262 rw_enter_write(&node->tn_nlock); 263 return tmpfs_vnode_get(mp, node, vpp); 264 } 265 266 int 267 tmpfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) 268 { 269 270 printf("tmpfs_vget called; need for it unknown yet\n"); 271 return EOPNOTSUPP; 272 } 273 274 int 275 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp) 276 { 277 tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp); 278 tmpfs_node_t *node; 279 tmpfs_fid_t tfh; 280 281 if (fhp->fid_len != sizeof(tmpfs_fid_t)) { 282 return EINVAL; 283 } 284 memcpy(&tfh, fhp, sizeof(tmpfs_fid_t)); 285 286 rw_enter_write(&tmp->tm_lock); 287 LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) { 288 if (node->tn_id != tfh.tf_id) { 289 continue; 290 } 291 if (TMPFS_NODE_GEN(node) != tfh.tf_gen) { 292 continue; 293 } 294 rw_enter_write(&node->tn_nlock); 295 break; 296 } 297 rw_exit_write(&tmp->tm_lock); 298 299 /* Will release the tn_nlock. */ 300 return node ? tmpfs_vnode_get(mp, node, vpp) : ESTALE; 301 } 302 303 int 304 tmpfs_vptofh(struct vnode *vp, struct fid *fhp) 305 { 306 tmpfs_fid_t tfh; 307 tmpfs_node_t *node; 308 309 node = VP_TO_TMPFS_NODE(vp); 310 311 memset(&tfh, 0, sizeof(tfh)); 312 tfh.tf_len = sizeof(tmpfs_fid_t); 313 tfh.tf_gen = TMPFS_NODE_GEN(node); 314 tfh.tf_id = node->tn_id; 315 memcpy(fhp, &tfh, sizeof(tfh)); 316 317 return 0; 318 } 319 320 int 321 tmpfs_statfs(struct mount *mp, struct statfs *sbp, struct proc *p) 322 { 323 tmpfs_mount_t *tmp; 324 fsfilcnt_t freenodes; 325 uint64_t avail; 326 327 tmp = VFS_TO_TMPFS(mp); 328 329 sbp->f_iosize = sbp->f_bsize = PAGE_SIZE; 330 331 rw_enter_write(&tmp->tm_acc_lock); 332 avail = tmpfs_pages_avail(tmp); 333 sbp->f_blocks = (tmpfs_bytes_max(tmp) >> PAGE_SHIFT); 334 sbp->f_bfree = avail; 335 sbp->f_bavail = avail & INT64_MAX; /* f_bavail is int64_t */ 336 337 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_cnt, 338 avail * PAGE_SIZE / sizeof(tmpfs_node_t)); 339 340 sbp->f_files = tmp->tm_nodes_cnt + freenodes; 341 sbp->f_ffree = freenodes; 342 sbp->f_favail = freenodes & INT64_MAX; /* f_favail is int64_t */ 343 rw_exit_write(&tmp->tm_acc_lock); 344 345 copy_statfs_info(sbp, mp); 346 347 return 0; 348 } 349 350 int 351 tmpfs_sync(struct mount *mp, int waitfor, struct ucred *cred, struct proc *p) 352 { 353 354 return 0; 355 } 356 357 /* 358 * tmpfs vfs operations. 359 */ 360 361 struct vfsops tmpfs_vfsops = { 362 tmpfs_mount, /* vfs_mount */ 363 tmpfs_start, /* vfs_start */ 364 tmpfs_unmount, /* vfs_unmount */ 365 tmpfs_root, /* vfs_root */ 366 (void *)eopnotsupp, /* vfs_quotactl */ 367 tmpfs_statfs, /* vfs_statfs */ 368 tmpfs_sync, /* vfs_sync */ 369 tmpfs_vget, /* vfs_vget */ 370 tmpfs_fhtovp, /* vfs_fhtovp */ 371 tmpfs_vptofh, /* vfs_vptofh */ 372 tmpfs_init, /* vfs_init */ 373 NULL, /* vfs_sysctl */ 374 (void *)eopnotsupp, 375 }; 376