mfs_vfsops.c revision 1.100
1 /* $NetBSD: mfs_vfsops.c,v 1.100 2008/12/19 17:11:57 pgoyette 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 1.100 2008/12/19 17:11:57 pgoyette 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 void * mfs_rootbase; /* address of mini-root in kernel virtual memory */ 72 u_long mfs_rootsize; /* size of mini-root in bytes */ 73 kmutex_t mfs_lock; /* global lock */ 74 75 static int mfs_minor; /* used for building internal dev_t */ 76 static int mfs_initcnt; 77 78 extern int (**mfs_vnodeop_p)(void *); 79 80 static struct sysctllog *mfs_sysctl_log; 81 82 /* 83 * mfs vfs operations. 84 */ 85 86 extern const struct vnodeopv_desc mfs_vnodeop_opv_desc; 87 88 const struct vnodeopv_desc * const mfs_vnodeopv_descs[] = { 89 &mfs_vnodeop_opv_desc, 90 NULL, 91 }; 92 93 struct vfsops mfs_vfsops = { 94 MOUNT_MFS, 95 sizeof (struct mfs_args), 96 mfs_mount, 97 mfs_start, 98 ffs_unmount, 99 ufs_root, 100 ufs_quotactl, 101 mfs_statvfs, 102 ffs_sync, 103 ffs_vget, 104 ffs_fhtovp, 105 ffs_vptofh, 106 mfs_init, 107 mfs_reinit, 108 mfs_done, 109 NULL, 110 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 111 vfs_stdextattrctl, 112 (void *)eopnotsupp, /* vfs_suspendctl */ 113 genfs_renamelock_enter, 114 genfs_renamelock_exit, 115 (void *)eopnotsupp, 116 mfs_vnodeopv_descs, 117 0, 118 { NULL, NULL }, 119 }; 120 121 static int 122 mfs_modcmd(modcmd_t cmd, void *arg) 123 { 124 int error; 125 126 switch (cmd) { 127 case MODULE_CMD_INIT: 128 error = vfs_attach(&mfs_vfsops); 129 if (error != 0) 130 break; 131 sysctl_createv(&mfs_sysctl_log, 0, NULL, NULL, 132 CTLFLAG_PERMANENT, 133 CTLTYPE_NODE, "vfs", NULL, 134 NULL, 0, NULL, 0, 135 CTL_VFS, CTL_EOL); 136 sysctl_createv(&mfs_sysctl_log, 0, NULL, NULL, 137 CTLFLAG_PERMANENT|CTLFLAG_ALIAS, 138 CTLTYPE_NODE, "mfs", 139 SYSCTL_DESCR("Memory based file system"), 140 NULL, 1, NULL, 0, 141 CTL_VFS, 3, CTL_EOL); 142 /* 143 * XXX the "1" and the "3" above could be dynamic, thereby 144 * eliminating one more instance of the "number to vfs" 145 * mapping problem, but they are in order as taken from 146 * sys/mount.h 147 */ 148 break; 149 case MODULE_CMD_FINI: 150 error = vfs_detach(&mfs_vfsops); 151 if (error != 0) 152 break; 153 sysctl_teardown(&mfs_sysctl_log); 154 break; 155 default: 156 error = ENOTTY; 157 break; 158 } 159 160 return (error); 161 } 162 163 /* 164 * Memory based filesystem initialization. 165 */ 166 void 167 mfs_init(void) 168 { 169 170 if (mfs_initcnt++ == 0) { 171 mutex_init(&mfs_lock, MUTEX_DEFAULT, IPL_NONE); 172 ffs_init(); 173 } 174 } 175 176 void 177 mfs_reinit(void) 178 { 179 180 ffs_reinit(); 181 } 182 183 void 184 mfs_done(void) 185 { 186 187 if (--mfs_initcnt == 0) { 188 ffs_done(); 189 mutex_destroy(&mfs_lock); 190 } 191 } 192 193 /* 194 * Called by main() when mfs is going to be mounted as root. 195 */ 196 197 int 198 mfs_mountroot(void) 199 { 200 struct fs *fs; 201 struct mount *mp; 202 struct lwp *l = curlwp; /* XXX */ 203 struct ufsmount *ump; 204 struct mfsnode *mfsp; 205 int error = 0; 206 207 if ((error = vfs_rootmountalloc(MOUNT_MFS, "mfs_root", &mp))) { 208 vrele(rootvp); 209 return (error); 210 } 211 212 mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP); 213 rootvp->v_data = mfsp; 214 rootvp->v_op = mfs_vnodeop_p; 215 rootvp->v_tag = VT_MFS; 216 mfsp->mfs_baseoff = mfs_rootbase; 217 mfsp->mfs_size = mfs_rootsize; 218 mfsp->mfs_vnode = rootvp; 219 mfsp->mfs_proc = NULL; /* indicate kernel space */ 220 mfsp->mfs_shutdown = 0; 221 cv_init(&mfsp->mfs_cv, "mfs"); 222 mfsp->mfs_refcnt = 1; 223 bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0); 224 if ((error = ffs_mountfs(rootvp, mp, l)) != 0) { 225 vfs_unbusy(mp, false, NULL); 226 bufq_free(mfsp->mfs_buflist); 227 vfs_destroy(mp); 228 kmem_free(mfsp, sizeof(*mfsp)); 229 return (error); 230 } 231 mutex_enter(&mountlist_lock); 232 CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list); 233 mutex_exit(&mountlist_lock); 234 mp->mnt_vnodecovered = NULLVP; 235 ump = VFSTOUFS(mp); 236 fs = ump->um_fs; 237 (void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0); 238 (void)ffs_statvfs(mp, &mp->mnt_stat); 239 vfs_unbusy(mp, false, NULL); 240 return (0); 241 } 242 243 /* 244 * This is called early in boot to set the base address and size 245 * of the mini-root. 246 */ 247 int 248 mfs_initminiroot(void *base) 249 { 250 struct fs *fs = (struct fs *)((char *)base + SBLOCK_UFS1); 251 252 /* check for valid super block */ 253 if (fs->fs_magic != FS_UFS1_MAGIC || fs->fs_bsize > MAXBSIZE || 254 fs->fs_bsize < sizeof(struct fs)) 255 return (0); 256 rootfstype = MOUNT_MFS; 257 mfs_rootbase = base; 258 mfs_rootsize = fs->fs_fsize * fs->fs_size; 259 rootdev = makedev(255, mfs_minor); 260 mfs_minor++; 261 return (mfs_rootsize); 262 } 263 264 /* 265 * VFS Operations. 266 * 267 * mount system call 268 */ 269 /* ARGSUSED */ 270 int 271 mfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 272 { 273 struct lwp *l = curlwp; 274 struct vnode *devvp; 275 struct mfs_args *args = data; 276 struct ufsmount *ump; 277 struct fs *fs; 278 struct mfsnode *mfsp; 279 struct proc *p; 280 int flags, error = 0; 281 282 if (*data_len < sizeof *args) 283 return EINVAL; 284 285 p = l->l_proc; 286 if (mp->mnt_flag & MNT_GETARGS) { 287 struct vnode *vp; 288 289 ump = VFSTOUFS(mp); 290 if (ump == NULL) 291 return EIO; 292 293 vp = ump->um_devvp; 294 if (vp == NULL) 295 return EIO; 296 297 mfsp = VTOMFS(vp); 298 if (mfsp == NULL) 299 return EIO; 300 301 args->fspec = NULL; 302 args->base = mfsp->mfs_baseoff; 303 args->size = mfsp->mfs_size; 304 *data_len = sizeof *args; 305 return 0; 306 } 307 /* 308 * XXX turn off async to avoid hangs when writing lots of data. 309 * the problem is that MFS needs to allocate pages to clean pages, 310 * so if we wait until the last minute to clean pages then there 311 * may not be any pages available to do the cleaning. 312 * ... and since the default partially-synchronous mode turns out 313 * to not be sufficient under heavy load, make it full synchronous. 314 */ 315 mp->mnt_flag &= ~MNT_ASYNC; 316 mp->mnt_flag |= MNT_SYNCHRONOUS; 317 318 /* 319 * If updating, check whether changing from read-only to 320 * read/write; if there is no device name, that's all we do. 321 */ 322 if (mp->mnt_flag & MNT_UPDATE) { 323 ump = VFSTOUFS(mp); 324 fs = ump->um_fs; 325 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 326 flags = WRITECLOSE; 327 if (mp->mnt_flag & MNT_FORCE) 328 flags |= FORCECLOSE; 329 error = ffs_flushfiles(mp, flags, l); 330 if (error) 331 return (error); 332 } 333 if (fs->fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR)) 334 fs->fs_ronly = 0; 335 if (args->fspec == NULL) 336 return EINVAL; 337 return (0); 338 } 339 error = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp); 340 if (error) 341 return (error); 342 devvp->v_vflag |= VV_MPSAFE; 343 devvp->v_type = VBLK; 344 spec_node_init(devvp, makedev(255, mfs_minor)); 345 mfs_minor++; 346 mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP); 347 devvp->v_data = mfsp; 348 mfsp->mfs_baseoff = args->base; 349 mfsp->mfs_size = args->size; 350 mfsp->mfs_vnode = devvp; 351 mfsp->mfs_proc = p; 352 mfsp->mfs_shutdown = 0; 353 cv_init(&mfsp->mfs_cv, "mfsidl"); 354 mfsp->mfs_refcnt = 1; 355 bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0); 356 if ((error = ffs_mountfs(devvp, mp, l)) != 0) { 357 mfsp->mfs_shutdown = 1; 358 vrele(devvp); 359 return (error); 360 } 361 ump = VFSTOUFS(mp); 362 fs = ump->um_fs; 363 error = set_statvfs_info(path, UIO_USERSPACE, args->fspec, 364 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 365 if (error) 366 return error; 367 (void)strncpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname, 368 sizeof(fs->fs_fsmnt)); 369 fs->fs_fsmnt[sizeof(fs->fs_fsmnt) - 1] = '\0'; 370 /* XXX: cleanup on error */ 371 return 0; 372 } 373 374 /* 375 * Used to grab the process and keep it in the kernel to service 376 * memory filesystem I/O requests. 377 * 378 * Loop servicing I/O requests. 379 * Copy the requested data into or out of the memory filesystem 380 * address space. 381 */ 382 /* ARGSUSED */ 383 int 384 mfs_start(struct mount *mp, int flags) 385 { 386 struct vnode *vp; 387 struct mfsnode *mfsp; 388 struct proc *p; 389 struct buf *bp; 390 void *base; 391 int sleepreturn = 0, refcnt, error; 392 ksiginfoq_t kq; 393 394 /* 395 * Ensure that file system is still mounted when getting mfsnode. 396 * Add a reference to the mfsnode to prevent it disappearing in 397 * this routine. 398 */ 399 if ((error = vfs_busy(mp, NULL)) != 0) 400 return error; 401 vp = VFSTOUFS(mp)->um_devvp; 402 mfsp = VTOMFS(vp); 403 mutex_enter(&mfs_lock); 404 mfsp->mfs_refcnt++; 405 mutex_exit(&mfs_lock); 406 vfs_unbusy(mp, false, NULL); 407 408 base = mfsp->mfs_baseoff; 409 mutex_enter(&mfs_lock); 410 while (mfsp->mfs_shutdown != 1) { 411 while ((bp = BUFQ_GET(mfsp->mfs_buflist)) != NULL) { 412 mutex_exit(&mfs_lock); 413 mfs_doio(bp, base); 414 mutex_enter(&mfs_lock); 415 } 416 /* 417 * If a non-ignored signal is received, try to unmount. 418 * If that fails, or the filesystem is already in the 419 * process of being unmounted, clear the signal (it has been 420 * "processed"), otherwise we will loop here, as tsleep 421 * will always return EINTR/ERESTART. 422 */ 423 if (sleepreturn != 0) { 424 mutex_exit(&mfs_lock); 425 if (dounmount(mp, 0, curlwp) != 0) { 426 p = curproc; 427 ksiginfo_queue_init(&kq); 428 mutex_enter(p->p_lock); 429 sigclearall(p, NULL, &kq); 430 mutex_exit(p->p_lock); 431 ksiginfo_queue_drain(&kq); 432 } 433 sleepreturn = 0; 434 mutex_enter(&mfs_lock); 435 continue; 436 } 437 438 sleepreturn = cv_wait_sig(&mfsp->mfs_cv, &mfs_lock); 439 } 440 KASSERT(BUFQ_PEEK(mfsp->mfs_buflist) == NULL); 441 refcnt = --mfsp->mfs_refcnt; 442 mutex_exit(&mfs_lock); 443 if (refcnt == 0) { 444 bufq_free(mfsp->mfs_buflist); 445 cv_destroy(&mfsp->mfs_cv); 446 kmem_free(mfsp, sizeof(*mfsp)); 447 } 448 return (sleepreturn); 449 } 450 451 /* 452 * Get file system statistics. 453 */ 454 int 455 mfs_statvfs(struct mount *mp, struct statvfs *sbp) 456 { 457 int error; 458 459 error = ffs_statvfs(mp, sbp); 460 if (error) 461 return error; 462 (void)strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, 463 sizeof(sbp->f_fstypename)); 464 sbp->f_fstypename[sizeof(sbp->f_fstypename) - 1] = '\0'; 465 return 0; 466 } 467
Indexes created Sun Sep 28 16:09:52 GMT 2025