1 /* $OpenBSD: tmpfs_vfsops.c,v 1.5 2014/11/02 03:47:28 tedu 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 #if 0 46 #include <sys/cdefs.h> 47 __KERNEL_RCSID(0, "$NetBSD: tmpfs_vfsops.c,v 1.52 2011/09/27 01:10:43 christos Exp $"); 48 #endif 49 50 #include <sys/param.h> 51 #include <sys/types.h> 52 #include <sys/mount.h> 53 #include <sys/stat.h> 54 #include <sys/systm.h> 55 #include <sys/vnode.h> 56 #include <sys/malloc.h> 57 58 #include <tmpfs/tmpfs.h> 59 60 /* MODULE(MODULE_CLASS_VFS, tmpfs, NULL); */ 61 62 struct pool tmpfs_dirent_pool; 63 struct pool tmpfs_node_pool; 64 65 int tmpfs_mount(struct mount *, const char *, void *, struct nameidata *, 66 struct proc *); 67 int tmpfs_start(struct mount *, int, struct proc *); 68 int tmpfs_unmount(struct mount *, int, struct proc *); 69 int tmpfs_root(struct mount *, struct vnode **); 70 int tmpfs_vget(struct mount *, ino_t, struct vnode **); 71 int tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **); 72 int tmpfs_vptofh(struct vnode *, struct fid *); 73 int tmpfs_statfs(struct mount *, struct statfs *, struct proc *); 74 int tmpfs_sync(struct mount *, int, struct ucred *, struct proc *); 75 int tmpfs_init(struct vfsconf *); 76 77 int 78 tmpfs_init(struct vfsconf *vfsp) 79 { 80 81 pool_init(&tmpfs_dirent_pool, sizeof(tmpfs_dirent_t), 0, 0, 0, 82 "tmpfs_dirent", &pool_allocator_nointr); 83 pool_init(&tmpfs_node_pool, sizeof(tmpfs_node_t), 0, 0, 0, 84 "tmpfs_node", &pool_allocator_nointr); 85 86 return 0; 87 } 88 89 int 90 tmpfs_mount(struct mount *mp, const char *path, void *data, 91 struct nameidata *ndp, struct proc *p) 92 { 93 struct tmpfs_args args; 94 tmpfs_mount_t *tmp; 95 tmpfs_node_t *root; 96 uint64_t memlimit; 97 uint64_t nodes; 98 int error; 99 100 #if 0 101 /* Handle retrieval of mount point arguments. */ 102 if (mp->mnt_flag & MNT_GETARGS) { 103 if (mp->mnt_data == NULL) 104 return EIO; 105 tmp = VFS_TO_TMPFS(mp); 106 107 args->ta_version = TMPFS_ARGS_VERSION; 108 args->ta_nodes_max = tmp->tm_nodes_max; 109 args->ta_size_max = tmp->tm_mem_limit; 110 111 root = tmp->tm_root; 112 args->ta_root_uid = root->tn_uid; 113 args->ta_root_gid = root->tn_gid; 114 args->ta_root_mode = root->tn_mode; 115 116 *data_len = sizeof(*args); 117 return 0; 118 } 119 #endif 120 121 if (mp->mnt_flag & MNT_UPDATE) { 122 /* TODO */ 123 return EOPNOTSUPP; 124 } 125 126 /* Prohibit mounts if there is not enough memory. */ 127 if (tmpfs_mem_info(1) < TMPFS_PAGES_RESERVED) 128 return EINVAL; 129 130 error = copyin(data, &args, sizeof(struct tmpfs_args)); 131 if (error) 132 return error; 133 134 /* Get the memory usage limit for this file-system. */ 135 if (args.ta_size_max < PAGE_SIZE) { 136 memlimit = UINT64_MAX; 137 } else { 138 memlimit = args.ta_size_max; 139 } 140 KASSERT(memlimit > 0); 141 142 if (args.ta_nodes_max <= 3) { 143 nodes = 3 + (memlimit / 1024); 144 } else { 145 nodes = args.ta_nodes_max; 146 } 147 nodes = MIN(nodes, INT_MAX); 148 KASSERT(nodes >= 3); 149 150 /* Allocate the tmpfs mount structure and fill it. */ 151 tmp = malloc(sizeof(tmpfs_mount_t), M_MISCFSMNT, M_WAITOK); 152 if (tmp == NULL) 153 return ENOMEM; 154 155 tmp->tm_nodes_max = (ino_t)nodes; 156 tmp->tm_nodes_cnt = 0; 157 tmp->tm_highest_inode = 1; 158 LIST_INIT(&tmp->tm_nodes); 159 160 rw_init(&tmp->tm_lock, "tmplk"); 161 tmpfs_mntmem_init(tmp, memlimit); 162 163 /* Allocate the root node. */ 164 error = tmpfs_alloc_node(tmp, VDIR, args.ta_root_uid, 165 args.ta_root_gid, args.ta_root_mode & ALLPERMS, NULL, 166 VNOVAL, &root); 167 KASSERT(error == 0 && root != NULL); 168 169 /* 170 * Parent of the root inode is itself. Also, root inode has no 171 * directory entry (i.e. is never attached), thus hold an extra 172 * reference (link) for it. 173 */ 174 root->tn_links++; 175 root->tn_spec.tn_dir.tn_parent = root; 176 tmp->tm_root = root; 177 178 mp->mnt_data = tmp; 179 mp->mnt_flag |= MNT_LOCAL; 180 mp->mnt_stat.f_namemax = TMPFS_MAXNAMLEN; 181 #if 0 182 mp->mnt_fs_bshift = PAGE_SHIFT; 183 mp->mnt_dev_bshift = DEV_BSHIFT; 184 mp->mnt_iflag |= IMNT_MPSAFE; 185 #endif 186 vfs_getnewfsid(mp); 187 188 mp->mnt_stat.mount_info.tmpfs_args = args; 189 190 bzero(&mp->mnt_stat.f_mntonname, sizeof(mp->mnt_stat.f_mntonname)); 191 bzero(&mp->mnt_stat.f_mntfromname, sizeof(mp->mnt_stat.f_mntfromname)); 192 bzero(&mp->mnt_stat.f_mntfromspec, sizeof(mp->mnt_stat.f_mntfromspec)); 193 194 strlcpy(mp->mnt_stat.f_mntonname, path, 195 sizeof(mp->mnt_stat.f_mntonname) - 1); 196 strlcpy(mp->mnt_stat.f_mntfromname, "tmpfs", 197 sizeof(mp->mnt_stat.f_mntfromname) - 1); 198 strlcpy(mp->mnt_stat.f_mntfromspec, "tmpfs", 199 sizeof(mp->mnt_stat.f_mntfromspec) - 1); 200 201 return error; 202 } 203 204 int 205 tmpfs_start(struct mount *mp, int flags, struct proc *p) 206 { 207 208 return 0; 209 } 210 211 int 212 tmpfs_unmount(struct mount *mp, int mntflags, struct proc *p) 213 { 214 tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp); 215 tmpfs_node_t *node, *cnode; 216 int error, flags = 0; 217 218 /* Handle forced unmounts. */ 219 if (mntflags & MNT_FORCE) 220 flags |= FORCECLOSE; 221 222 /* Finalize all pending I/O. */ 223 error = vflush(mp, NULL, flags); 224 if (error != 0) 225 return error; 226 227 228 /* 229 * First round, detach and destroy all directory entries. 230 * Also, clear the pointers to the vnodes - they are gone. 231 */ 232 LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) { 233 tmpfs_dirent_t *de; 234 235 node->tn_vnode = NULL; 236 if (node->tn_type != VDIR) { 237 continue; 238 } 239 while ((de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir)) != NULL) { 240 cnode = de->td_node; 241 if (cnode) { 242 cnode->tn_vnode = NULL; 243 } 244 tmpfs_dir_detach(node, de); 245 tmpfs_free_dirent(tmp, de); 246 } 247 } 248 249 /* Second round, destroy all inodes. */ 250 while ((node = LIST_FIRST(&tmp->tm_nodes)) != NULL) { 251 tmpfs_free_node(tmp, node); 252 } 253 254 /* Throw away the tmpfs_mount structure. */ 255 tmpfs_mntmem_destroy(tmp); 256 /* mutex_destroy(&tmp->tm_lock); */ 257 /* kmem_free(tmp, sizeof(*tmp)); */ 258 free(tmp, M_MISCFSMNT, sizeof(tmpfs_mount_t)); 259 mp->mnt_data = NULL; 260 261 return 0; 262 } 263 264 int 265 tmpfs_root(struct mount *mp, struct vnode **vpp) 266 { 267 tmpfs_node_t *node = VFS_TO_TMPFS(mp)->tm_root; 268 269 rw_enter_write(&node->tn_nlock); 270 return tmpfs_vnode_get(mp, node, vpp); 271 } 272 273 int 274 tmpfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) 275 { 276 277 printf("tmpfs_vget called; need for it unknown yet\n"); 278 return EOPNOTSUPP; 279 } 280 281 int 282 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp) 283 { 284 tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp); 285 tmpfs_node_t *node; 286 tmpfs_fid_t tfh; 287 288 if (fhp->fid_len != sizeof(tmpfs_fid_t)) { 289 return EINVAL; 290 } 291 memcpy(&tfh, fhp, sizeof(tmpfs_fid_t)); 292 293 rw_enter_write(&tmp->tm_lock); 294 LIST_FOREACH(node, &tmp->tm_nodes, tn_entries) { 295 if (node->tn_id != tfh.tf_id) { 296 continue; 297 } 298 if (TMPFS_NODE_GEN(node) != tfh.tf_gen) { 299 continue; 300 } 301 rw_enter_write(&node->tn_nlock); 302 break; 303 } 304 rw_exit_write(&tmp->tm_lock); 305 306 /* Will release the tn_nlock. */ 307 return node ? tmpfs_vnode_get(mp, node, vpp) : ESTALE; 308 } 309 310 int 311 tmpfs_vptofh(struct vnode *vp, struct fid *fhp) 312 { 313 tmpfs_fid_t tfh; 314 tmpfs_node_t *node; 315 316 node = VP_TO_TMPFS_NODE(vp); 317 318 memset(&tfh, 0, sizeof(tfh)); 319 tfh.tf_len = sizeof(tmpfs_fid_t); 320 tfh.tf_gen = TMPFS_NODE_GEN(node); 321 tfh.tf_id = node->tn_id; 322 memcpy(fhp, &tfh, sizeof(tfh)); 323 324 return 0; 325 } 326 327 int 328 tmpfs_statfs(struct mount *mp, struct statfs *sbp, struct proc *p) 329 { 330 tmpfs_mount_t *tmp; 331 fsfilcnt_t freenodes; 332 uint64_t avail; 333 334 tmp = VFS_TO_TMPFS(mp); 335 336 sbp->f_iosize = sbp->f_bsize = PAGE_SIZE; 337 338 rw_enter_write(&tmp->tm_acc_lock); 339 avail = tmpfs_pages_avail(tmp); 340 sbp->f_blocks = (tmpfs_bytes_max(tmp) >> PAGE_SHIFT); 341 sbp->f_bfree = avail; 342 sbp->f_bavail = avail & INT64_MAX; /* f_bavail is int64_t */ 343 344 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_cnt, 345 avail * PAGE_SIZE / sizeof(tmpfs_node_t)); 346 347 sbp->f_files = tmp->tm_nodes_cnt + freenodes; 348 sbp->f_ffree = freenodes; 349 sbp->f_favail = freenodes & INT64_MAX; /* f_favail is int64_t */ 350 rw_exit_write(&tmp->tm_acc_lock); 351 352 copy_statfs_info(sbp, mp); 353 354 return 0; 355 } 356 357 int 358 tmpfs_sync(struct mount *mp, int waitfor, struct ucred *cred, struct proc *p) 359 { 360 361 return 0; 362 } 363 364 /* 365 * tmpfs vfs operations. 366 */ 367 368 struct vfsops tmpfs_vfsops = { 369 tmpfs_mount, /* vfs_mount */ 370 tmpfs_start, /* vfs_start */ 371 tmpfs_unmount, /* vfs_unmount */ 372 tmpfs_root, /* vfs_root */ 373 (void *)eopnotsupp, /* vfs_quotactl */ 374 tmpfs_statfs, /* vfs_statfs */ 375 tmpfs_sync, /* vfs_sync */ 376 tmpfs_vget, /* vfs_vget */ 377 tmpfs_fhtovp, /* vfs_fhtovp */ 378 tmpfs_vptofh, /* vfs_vptofh */ 379 tmpfs_init, /* vfs_init */ 380 NULL, /* vfs_sysctl */ 381 (void *)eopnotsupp, 382 }; 383