| 1 | /* $NetBSD: mfs_vfsops.c,v 1.110 2015/03/17 09:39:29 hannken Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1989, 1990, 1993, 1994 |
| 5 | * The Regents of the University of California. All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * 3. Neither the name of the University nor the names of its contributors |
| 16 | * may be used to endorse or promote products derived from this software |
| 17 | * without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 29 | * SUCH DAMAGE. |
| 30 | * |
| 31 | * @(#)mfs_vfsops.c 8.11 (Berkeley) 6/19/95 |
| 32 | */ |
| 33 | |
| 34 | #include <sys/cdefs.h> |
| 35 | __KERNEL_RCSID(0, "$NetBSD: mfs_vfsops.c,v 1.110 2015/03/17 09:39:29 hannken Exp $" ); |
| 36 | |
| 37 | #if defined(_KERNEL_OPT) |
| 38 | #include "opt_compat_netbsd.h" |
| 39 | #endif |
| 40 | |
| 41 | #include <sys/param.h> |
| 42 | #include <sys/systm.h> |
| 43 | #include <sys/sysctl.h> |
| 44 | #include <sys/time.h> |
| 45 | #include <sys/kernel.h> |
| 46 | #include <sys/proc.h> |
| 47 | #include <sys/buf.h> |
| 48 | #include <sys/bufq.h> |
| 49 | #include <sys/mount.h> |
| 50 | #include <sys/signalvar.h> |
| 51 | #include <sys/vnode.h> |
| 52 | #include <sys/kmem.h> |
| 53 | #include <sys/module.h> |
| 54 | |
| 55 | #include <miscfs/genfs/genfs.h> |
| 56 | #include <miscfs/specfs/specdev.h> |
| 57 | |
| 58 | #include <ufs/ufs/quota.h> |
| 59 | #include <ufs/ufs/inode.h> |
| 60 | #include <ufs/ufs/ufsmount.h> |
| 61 | #include <ufs/ufs/ufs_extern.h> |
| 62 | |
| 63 | #include <ufs/ffs/fs.h> |
| 64 | #include <ufs/ffs/ffs_extern.h> |
| 65 | |
| 66 | #include <ufs/mfs/mfsnode.h> |
| 67 | #include <ufs/mfs/mfs_extern.h> |
| 68 | |
| 69 | MODULE(MODULE_CLASS_VFS, mfs, "ffs" ); |
| 70 | |
| 71 | kmutex_t mfs_lock; /* global lock */ |
| 72 | |
| 73 | /* used for building internal dev_t, minor == 0 reserved for miniroot */ |
| 74 | static devminor_t mfs_minor = 1; |
| 75 | static int mfs_initcnt; |
| 76 | |
| 77 | extern int (**mfs_vnodeop_p)(void *); |
| 78 | |
| 79 | static struct sysctllog *mfs_sysctl_log; |
| 80 | |
| 81 | /* |
| 82 | * mfs vfs operations. |
| 83 | */ |
| 84 | |
| 85 | extern const struct vnodeopv_desc mfs_vnodeop_opv_desc; |
| 86 | |
| 87 | const struct vnodeopv_desc * const mfs_vnodeopv_descs[] = { |
| 88 | &mfs_vnodeop_opv_desc, |
| 89 | NULL, |
| 90 | }; |
| 91 | |
| 92 | struct vfsops mfs_vfsops = { |
| 93 | .vfs_name = MOUNT_MFS, |
| 94 | .vfs_min_mount_data = sizeof (struct mfs_args), |
| 95 | .vfs_mount = mfs_mount, |
| 96 | .vfs_start = mfs_start, |
| 97 | .vfs_unmount = ffs_unmount, |
| 98 | .vfs_root = ufs_root, |
| 99 | .vfs_quotactl = ufs_quotactl, |
| 100 | .vfs_statvfs = mfs_statvfs, |
| 101 | .vfs_sync = ffs_sync, |
| 102 | .vfs_vget = ufs_vget, |
| 103 | .vfs_loadvnode = ffs_loadvnode, |
| 104 | .vfs_newvnode = ffs_newvnode, |
| 105 | .vfs_fhtovp = ffs_fhtovp, |
| 106 | .vfs_vptofh = ffs_vptofh, |
| 107 | .vfs_init = mfs_init, |
| 108 | .vfs_reinit = mfs_reinit, |
| 109 | .vfs_done = mfs_done, |
| 110 | .vfs_snapshot = (void *)eopnotsupp, |
| 111 | .vfs_extattrctl = vfs_stdextattrctl, |
| 112 | .vfs_suspendctl = (void *)eopnotsupp, |
| 113 | .vfs_renamelock_enter = genfs_renamelock_enter, |
| 114 | .vfs_renamelock_exit = genfs_renamelock_exit, |
| 115 | .vfs_fsync = (void *)eopnotsupp, |
| 116 | .vfs_opv_descs = mfs_vnodeopv_descs |
| 117 | }; |
| 118 | |
| 119 | static int |
| 120 | mfs_modcmd(modcmd_t cmd, void *arg) |
| 121 | { |
| 122 | int error; |
| 123 | |
| 124 | switch (cmd) { |
| 125 | case MODULE_CMD_INIT: |
| 126 | error = vfs_attach(&mfs_vfsops); |
| 127 | if (error != 0) |
| 128 | break; |
| 129 | sysctl_createv(&mfs_sysctl_log, 0, NULL, NULL, |
| 130 | CTLFLAG_PERMANENT|CTLFLAG_ALIAS, |
| 131 | CTLTYPE_NODE, "mfs" , |
| 132 | SYSCTL_DESCR("Memory based file system" ), |
| 133 | NULL, 1, NULL, 0, |
| 134 | CTL_VFS, 3, CTL_EOL); |
| 135 | /* |
| 136 | * XXX the "1" and the "3" above could be dynamic, thereby |
| 137 | * eliminating one more instance of the "number to vfs" |
| 138 | * mapping problem, but they are in order as taken from |
| 139 | * sys/mount.h |
| 140 | */ |
| 141 | break; |
| 142 | case MODULE_CMD_FINI: |
| 143 | error = vfs_detach(&mfs_vfsops); |
| 144 | if (error != 0) |
| 145 | break; |
| 146 | sysctl_teardown(&mfs_sysctl_log); |
| 147 | break; |
| 148 | default: |
| 149 | error = ENOTTY; |
| 150 | break; |
| 151 | } |
| 152 | |
| 153 | return (error); |
| 154 | } |
| 155 | |
| 156 | /* |
| 157 | * Memory based filesystem initialization. |
| 158 | */ |
| 159 | void |
| 160 | mfs_init(void) |
| 161 | { |
| 162 | |
| 163 | if (mfs_initcnt++ == 0) { |
| 164 | mutex_init(&mfs_lock, MUTEX_DEFAULT, IPL_NONE); |
| 165 | ffs_init(); |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | void |
| 170 | mfs_reinit(void) |
| 171 | { |
| 172 | |
| 173 | ffs_reinit(); |
| 174 | } |
| 175 | |
| 176 | void |
| 177 | mfs_done(void) |
| 178 | { |
| 179 | |
| 180 | if (--mfs_initcnt == 0) { |
| 181 | ffs_done(); |
| 182 | mutex_destroy(&mfs_lock); |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | /* |
| 187 | * Called by main() when mfs is going to be mounted as root. |
| 188 | */ |
| 189 | |
| 190 | int |
| 191 | mfs_mountroot(void) |
| 192 | { |
| 193 | struct fs *fs; |
| 194 | struct mount *mp; |
| 195 | struct lwp *l = curlwp; /* XXX */ |
| 196 | struct ufsmount *ump; |
| 197 | struct mfsnode *mfsp; |
| 198 | int error = 0; |
| 199 | |
| 200 | if ((error = vfs_rootmountalloc(MOUNT_MFS, "mfs_root" , &mp))) { |
| 201 | vrele(rootvp); |
| 202 | return (error); |
| 203 | } |
| 204 | |
| 205 | mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP); |
| 206 | rootvp->v_data = mfsp; |
| 207 | rootvp->v_op = mfs_vnodeop_p; |
| 208 | rootvp->v_tag = VT_MFS; |
| 209 | mfsp->mfs_baseoff = mfs_rootbase; |
| 210 | mfsp->mfs_size = mfs_rootsize; |
| 211 | mfsp->mfs_vnode = rootvp; |
| 212 | mfsp->mfs_proc = NULL; /* indicate kernel space */ |
| 213 | mfsp->mfs_shutdown = 0; |
| 214 | cv_init(&mfsp->mfs_cv, "mfs" ); |
| 215 | mfsp->mfs_refcnt = 1; |
| 216 | bufq_alloc(&mfsp->mfs_buflist, "fcfs" , 0); |
| 217 | if ((error = ffs_mountfs(rootvp, mp, l)) != 0) { |
| 218 | vfs_unbusy(mp, false, NULL); |
| 219 | bufq_free(mfsp->mfs_buflist); |
| 220 | vfs_destroy(mp); |
| 221 | kmem_free(mfsp, sizeof(*mfsp)); |
| 222 | return (error); |
| 223 | } |
| 224 | mountlist_append(mp); |
| 225 | mp->mnt_vnodecovered = NULLVP; |
| 226 | ump = VFSTOUFS(mp); |
| 227 | fs = ump->um_fs; |
| 228 | (void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0); |
| 229 | (void)ffs_statvfs(mp, &mp->mnt_stat); |
| 230 | vfs_unbusy(mp, false, NULL); |
| 231 | return (0); |
| 232 | } |
| 233 | |
| 234 | /* |
| 235 | * VFS Operations. |
| 236 | * |
| 237 | * mount system call |
| 238 | */ |
| 239 | /* ARGSUSED */ |
| 240 | int |
| 241 | mfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) |
| 242 | { |
| 243 | struct lwp *l = curlwp; |
| 244 | struct vnode *devvp; |
| 245 | struct mfs_args *args = data; |
| 246 | struct ufsmount *ump; |
| 247 | struct fs *fs; |
| 248 | struct mfsnode *mfsp; |
| 249 | struct proc *p; |
| 250 | devminor_t minor; |
| 251 | int flags, error = 0; |
| 252 | |
| 253 | if (args == NULL) |
| 254 | return EINVAL; |
| 255 | if (*data_len < sizeof *args) |
| 256 | return EINVAL; |
| 257 | |
| 258 | p = l->l_proc; |
| 259 | if (mp->mnt_flag & MNT_GETARGS) { |
| 260 | struct vnode *vp; |
| 261 | |
| 262 | ump = VFSTOUFS(mp); |
| 263 | if (ump == NULL) |
| 264 | return EIO; |
| 265 | |
| 266 | vp = ump->um_devvp; |
| 267 | if (vp == NULL) |
| 268 | return EIO; |
| 269 | |
| 270 | mfsp = VTOMFS(vp); |
| 271 | if (mfsp == NULL) |
| 272 | return EIO; |
| 273 | |
| 274 | args->fspec = NULL; |
| 275 | args->base = mfsp->mfs_baseoff; |
| 276 | args->size = mfsp->mfs_size; |
| 277 | *data_len = sizeof *args; |
| 278 | return 0; |
| 279 | } |
| 280 | /* |
| 281 | * XXX turn off async to avoid hangs when writing lots of data. |
| 282 | * the problem is that MFS needs to allocate pages to clean pages, |
| 283 | * so if we wait until the last minute to clean pages then there |
| 284 | * may not be any pages available to do the cleaning. |
| 285 | * ... and since the default partially-synchronous mode turns out |
| 286 | * to not be sufficient under heavy load, make it full synchronous. |
| 287 | */ |
| 288 | mp->mnt_flag &= ~MNT_ASYNC; |
| 289 | mp->mnt_flag |= MNT_SYNCHRONOUS; |
| 290 | |
| 291 | /* |
| 292 | * If updating, check whether changing from read-only to |
| 293 | * read/write; if there is no device name, that's all we do. |
| 294 | */ |
| 295 | if (mp->mnt_flag & MNT_UPDATE) { |
| 296 | ump = VFSTOUFS(mp); |
| 297 | fs = ump->um_fs; |
| 298 | if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { |
| 299 | flags = WRITECLOSE; |
| 300 | if (mp->mnt_flag & MNT_FORCE) |
| 301 | flags |= FORCECLOSE; |
| 302 | error = ffs_flushfiles(mp, flags, l); |
| 303 | if (error) |
| 304 | return (error); |
| 305 | } |
| 306 | if (fs->fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR)) |
| 307 | fs->fs_ronly = 0; |
| 308 | if (args->fspec == NULL) |
| 309 | return EINVAL; |
| 310 | return (0); |
| 311 | } |
| 312 | mutex_enter(&mfs_lock); |
| 313 | minor = mfs_minor++; |
| 314 | mutex_exit(&mfs_lock); |
| 315 | error = bdevvp(makedev(255, minor), &devvp); |
| 316 | if (error) |
| 317 | return (error); |
| 318 | mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP); |
| 319 | /* |
| 320 | * Changing v_op and v_data here is safe as we are |
| 321 | * the exclusive owner of this device node. |
| 322 | */ |
| 323 | KASSERT(devvp->v_op == spec_vnodeop_p); |
| 324 | KASSERT(devvp->v_data == NULL); |
| 325 | devvp->v_op = mfs_vnodeop_p; |
| 326 | devvp->v_data = mfsp; |
| 327 | mfsp->mfs_baseoff = args->base; |
| 328 | mfsp->mfs_size = args->size; |
| 329 | mfsp->mfs_vnode = devvp; |
| 330 | mfsp->mfs_proc = p; |
| 331 | mfsp->mfs_shutdown = 0; |
| 332 | cv_init(&mfsp->mfs_cv, "mfsidl" ); |
| 333 | mfsp->mfs_refcnt = 1; |
| 334 | bufq_alloc(&mfsp->mfs_buflist, "fcfs" , 0); |
| 335 | if ((error = ffs_mountfs(devvp, mp, l)) != 0) { |
| 336 | mfsp->mfs_shutdown = 1; |
| 337 | vrele(devvp); |
| 338 | return (error); |
| 339 | } |
| 340 | ump = VFSTOUFS(mp); |
| 341 | fs = ump->um_fs; |
| 342 | error = set_statvfs_info(path, UIO_USERSPACE, args->fspec, |
| 343 | UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); |
| 344 | if (error) |
| 345 | return error; |
| 346 | (void)strncpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname, |
| 347 | sizeof(fs->fs_fsmnt)); |
| 348 | fs->fs_fsmnt[sizeof(fs->fs_fsmnt) - 1] = '\0'; |
| 349 | /* XXX: cleanup on error */ |
| 350 | return 0; |
| 351 | } |
| 352 | |
| 353 | /* |
| 354 | * Used to grab the process and keep it in the kernel to service |
| 355 | * memory filesystem I/O requests. |
| 356 | * |
| 357 | * Loop servicing I/O requests. |
| 358 | * Copy the requested data into or out of the memory filesystem |
| 359 | * address space. |
| 360 | */ |
| 361 | /* ARGSUSED */ |
| 362 | int |
| 363 | mfs_start(struct mount *mp, int flags) |
| 364 | { |
| 365 | struct vnode *vp; |
| 366 | struct mfsnode *mfsp; |
| 367 | struct proc *p; |
| 368 | struct buf *bp; |
| 369 | void *base; |
| 370 | int sleepreturn = 0, refcnt, error; |
| 371 | ksiginfoq_t kq; |
| 372 | |
| 373 | /* |
| 374 | * Ensure that file system is still mounted when getting mfsnode. |
| 375 | * Add a reference to the mfsnode to prevent it disappearing in |
| 376 | * this routine. |
| 377 | */ |
| 378 | if ((error = vfs_busy(mp, NULL)) != 0) |
| 379 | return error; |
| 380 | vp = VFSTOUFS(mp)->um_devvp; |
| 381 | mfsp = VTOMFS(vp); |
| 382 | mutex_enter(&mfs_lock); |
| 383 | mfsp->mfs_refcnt++; |
| 384 | mutex_exit(&mfs_lock); |
| 385 | vfs_unbusy(mp, false, NULL); |
| 386 | |
| 387 | base = mfsp->mfs_baseoff; |
| 388 | mutex_enter(&mfs_lock); |
| 389 | while (mfsp->mfs_shutdown != 1) { |
| 390 | while ((bp = bufq_get(mfsp->mfs_buflist)) != NULL) { |
| 391 | mutex_exit(&mfs_lock); |
| 392 | mfs_doio(bp, base); |
| 393 | mutex_enter(&mfs_lock); |
| 394 | } |
| 395 | /* |
| 396 | * If a non-ignored signal is received, try to unmount. |
| 397 | * If that fails, or the filesystem is already in the |
| 398 | * process of being unmounted, clear the signal (it has been |
| 399 | * "processed"), otherwise we will loop here, as tsleep |
| 400 | * will always return EINTR/ERESTART. |
| 401 | */ |
| 402 | if (sleepreturn != 0) { |
| 403 | mutex_exit(&mfs_lock); |
| 404 | if (dounmount(mp, 0, curlwp) != 0) { |
| 405 | p = curproc; |
| 406 | ksiginfo_queue_init(&kq); |
| 407 | mutex_enter(p->p_lock); |
| 408 | sigclearall(p, NULL, &kq); |
| 409 | mutex_exit(p->p_lock); |
| 410 | ksiginfo_queue_drain(&kq); |
| 411 | } |
| 412 | sleepreturn = 0; |
| 413 | mutex_enter(&mfs_lock); |
| 414 | continue; |
| 415 | } |
| 416 | |
| 417 | sleepreturn = cv_wait_sig(&mfsp->mfs_cv, &mfs_lock); |
| 418 | } |
| 419 | KASSERT(bufq_peek(mfsp->mfs_buflist) == NULL); |
| 420 | refcnt = --mfsp->mfs_refcnt; |
| 421 | mutex_exit(&mfs_lock); |
| 422 | if (refcnt == 0) { |
| 423 | bufq_free(mfsp->mfs_buflist); |
| 424 | cv_destroy(&mfsp->mfs_cv); |
| 425 | kmem_free(mfsp, sizeof(*mfsp)); |
| 426 | } |
| 427 | return (sleepreturn); |
| 428 | } |
| 429 | |
| 430 | /* |
| 431 | * Get file system statistics. |
| 432 | */ |
| 433 | int |
| 434 | mfs_statvfs(struct mount *mp, struct statvfs *sbp) |
| 435 | { |
| 436 | int error; |
| 437 | |
| 438 | error = ffs_statvfs(mp, sbp); |
| 439 | if (error) |
| 440 | return error; |
| 441 | (void)strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, |
| 442 | sizeof(sbp->f_fstypename)); |
| 443 | sbp->f_fstypename[sizeof(sbp->f_fstypename) - 1] = '\0'; |
| 444 | return 0; |
| 445 | } |
| 446 | |