mfs_vfsops.c revision 1.108
1 /* $NetBSD: mfs_vfsops.c,v 1.108 2014/05/08 08:21:53 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 1.108 2014/05/08 08:21:53 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 int 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_fhtovp = ffs_fhtovp, 105 .vfs_vptofh = ffs_vptofh, 106 .vfs_init = mfs_init, 107 .vfs_reinit = mfs_reinit, 108 .vfs_done = mfs_done, 109 .vfs_snapshot = (void *)eopnotsupp, 110 .vfs_extattrctl = vfs_stdextattrctl, 111 .vfs_suspendctl = (void *)eopnotsupp, 112 .vfs_renamelock_enter = genfs_renamelock_enter, 113 .vfs_renamelock_exit = genfs_renamelock_exit, 114 .vfs_fsync = (void *)eopnotsupp, 115 .vfs_opv_descs = mfs_vnodeopv_descs 116 }; 117 118 static int 119 mfs_modcmd(modcmd_t cmd, void *arg) 120 { 121 int error; 122 123 switch (cmd) { 124 case MODULE_CMD_INIT: 125 error = vfs_attach(&mfs_vfsops); 126 if (error != 0) 127 break; 128 sysctl_createv(&mfs_sysctl_log, 0, NULL, NULL, 129 CTLFLAG_PERMANENT|CTLFLAG_ALIAS, 130 CTLTYPE_NODE, "mfs", 131 SYSCTL_DESCR("Memory based file system"), 132 NULL, 1, NULL, 0, 133 CTL_VFS, 3, CTL_EOL); 134 /* 135 * XXX the "1" and the "3" above could be dynamic, thereby 136 * eliminating one more instance of the "number to vfs" 137 * mapping problem, but they are in order as taken from 138 * sys/mount.h 139 */ 140 break; 141 case MODULE_CMD_FINI: 142 error = vfs_detach(&mfs_vfsops); 143 if (error != 0) 144 break; 145 sysctl_teardown(&mfs_sysctl_log); 146 break; 147 default: 148 error = ENOTTY; 149 break; 150 } 151 152 return (error); 153 } 154 155 /* 156 * Memory based filesystem initialization. 157 */ 158 void 159 mfs_init(void) 160 { 161 162 if (mfs_initcnt++ == 0) { 163 mutex_init(&mfs_lock, MUTEX_DEFAULT, IPL_NONE); 164 ffs_init(); 165 } 166 } 167 168 void 169 mfs_reinit(void) 170 { 171 172 ffs_reinit(); 173 } 174 175 void 176 mfs_done(void) 177 { 178 179 if (--mfs_initcnt == 0) { 180 ffs_done(); 181 mutex_destroy(&mfs_lock); 182 } 183 } 184 185 /* 186 * Called by main() when mfs is going to be mounted as root. 187 */ 188 189 int 190 mfs_mountroot(void) 191 { 192 struct fs *fs; 193 struct mount *mp; 194 struct lwp *l = curlwp; /* XXX */ 195 struct ufsmount *ump; 196 struct mfsnode *mfsp; 197 int error = 0; 198 199 if ((error = vfs_rootmountalloc(MOUNT_MFS, "mfs_root", &mp))) { 200 vrele(rootvp); 201 return (error); 202 } 203 204 mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP); 205 rootvp->v_data = mfsp; 206 rootvp->v_op = mfs_vnodeop_p; 207 rootvp->v_tag = VT_MFS; 208 mfsp->mfs_baseoff = mfs_rootbase; 209 mfsp->mfs_size = mfs_rootsize; 210 mfsp->mfs_vnode = rootvp; 211 mfsp->mfs_proc = NULL; /* indicate kernel space */ 212 mfsp->mfs_shutdown = 0; 213 cv_init(&mfsp->mfs_cv, "mfs"); 214 mfsp->mfs_refcnt = 1; 215 bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0); 216 if ((error = ffs_mountfs(rootvp, mp, l)) != 0) { 217 vfs_unbusy(mp, false, NULL); 218 bufq_free(mfsp->mfs_buflist); 219 vfs_destroy(mp); 220 kmem_free(mfsp, sizeof(*mfsp)); 221 return (error); 222 } 223 mountlist_append(mp); 224 mp->mnt_vnodecovered = NULLVP; 225 ump = VFSTOUFS(mp); 226 fs = ump->um_fs; 227 (void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0); 228 (void)ffs_statvfs(mp, &mp->mnt_stat); 229 vfs_unbusy(mp, false, NULL); 230 return (0); 231 } 232 233 /* 234 * VFS Operations. 235 * 236 * mount system call 237 */ 238 /* ARGSUSED */ 239 int 240 mfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 241 { 242 struct lwp *l = curlwp; 243 struct vnode *devvp; 244 struct mfs_args *args = data; 245 struct ufsmount *ump; 246 struct fs *fs; 247 struct mfsnode *mfsp; 248 struct proc *p; 249 int flags, error = 0; 250 251 if (args == NULL) 252 return EINVAL; 253 if (*data_len < sizeof *args) 254 return EINVAL; 255 256 p = l->l_proc; 257 if (mp->mnt_flag & MNT_GETARGS) { 258 struct vnode *vp; 259 260 ump = VFSTOUFS(mp); 261 if (ump == NULL) 262 return EIO; 263 264 vp = ump->um_devvp; 265 if (vp == NULL) 266 return EIO; 267 268 mfsp = VTOMFS(vp); 269 if (mfsp == NULL) 270 return EIO; 271 272 args->fspec = NULL; 273 args->base = mfsp->mfs_baseoff; 274 args->size = mfsp->mfs_size; 275 *data_len = sizeof *args; 276 return 0; 277 } 278 /* 279 * XXX turn off async to avoid hangs when writing lots of data. 280 * the problem is that MFS needs to allocate pages to clean pages, 281 * so if we wait until the last minute to clean pages then there 282 * may not be any pages available to do the cleaning. 283 * ... and since the default partially-synchronous mode turns out 284 * to not be sufficient under heavy load, make it full synchronous. 285 */ 286 mp->mnt_flag &= ~MNT_ASYNC; 287 mp->mnt_flag |= MNT_SYNCHRONOUS; 288 289 /* 290 * If updating, check whether changing from read-only to 291 * read/write; if there is no device name, that's all we do. 292 */ 293 if (mp->mnt_flag & MNT_UPDATE) { 294 ump = VFSTOUFS(mp); 295 fs = ump->um_fs; 296 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 297 flags = WRITECLOSE; 298 if (mp->mnt_flag & MNT_FORCE) 299 flags |= FORCECLOSE; 300 error = ffs_flushfiles(mp, flags, l); 301 if (error) 302 return (error); 303 } 304 if (fs->fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR)) 305 fs->fs_ronly = 0; 306 if (args->fspec == NULL) 307 return EINVAL; 308 return (0); 309 } 310 error = getnewvnode(VT_MFS, NULL, mfs_vnodeop_p, NULL, &devvp); 311 if (error) 312 return (error); 313 devvp->v_vflag |= VV_MPSAFE; 314 devvp->v_type = VBLK; 315 spec_node_init(devvp, makedev(255, mfs_minor)); 316 mfs_minor++; 317 mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP); 318 devvp->v_data = mfsp; 319 mfsp->mfs_baseoff = args->base; 320 mfsp->mfs_size = args->size; 321 mfsp->mfs_vnode = devvp; 322 mfsp->mfs_proc = p; 323 mfsp->mfs_shutdown = 0; 324 cv_init(&mfsp->mfs_cv, "mfsidl"); 325 mfsp->mfs_refcnt = 1; 326 bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0); 327 if ((error = ffs_mountfs(devvp, mp, l)) != 0) { 328 mfsp->mfs_shutdown = 1; 329 vrele(devvp); 330 return (error); 331 } 332 ump = VFSTOUFS(mp); 333 fs = ump->um_fs; 334 error = set_statvfs_info(path, UIO_USERSPACE, args->fspec, 335 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 336 if (error) 337 return error; 338 (void)strncpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname, 339 sizeof(fs->fs_fsmnt)); 340 fs->fs_fsmnt[sizeof(fs->fs_fsmnt) - 1] = '\0'; 341 /* XXX: cleanup on error */ 342 return 0; 343 } 344 345 /* 346 * Used to grab the process and keep it in the kernel to service 347 * memory filesystem I/O requests. 348 * 349 * Loop servicing I/O requests. 350 * Copy the requested data into or out of the memory filesystem 351 * address space. 352 */ 353 /* ARGSUSED */ 354 int 355 mfs_start(struct mount *mp, int flags) 356 { 357 struct vnode *vp; 358 struct mfsnode *mfsp; 359 struct proc *p; 360 struct buf *bp; 361 void *base; 362 int sleepreturn = 0, refcnt, error; 363 ksiginfoq_t kq; 364 365 /* 366 * Ensure that file system is still mounted when getting mfsnode. 367 * Add a reference to the mfsnode to prevent it disappearing in 368 * this routine. 369 */ 370 if ((error = vfs_busy(mp, NULL)) != 0) 371 return error; 372 vp = VFSTOUFS(mp)->um_devvp; 373 mfsp = VTOMFS(vp); 374 mutex_enter(&mfs_lock); 375 mfsp->mfs_refcnt++; 376 mutex_exit(&mfs_lock); 377 vfs_unbusy(mp, false, NULL); 378 379 base = mfsp->mfs_baseoff; 380 mutex_enter(&mfs_lock); 381 while (mfsp->mfs_shutdown != 1) { 382 while ((bp = bufq_get(mfsp->mfs_buflist)) != NULL) { 383 mutex_exit(&mfs_lock); 384 mfs_doio(bp, base); 385 mutex_enter(&mfs_lock); 386 } 387 /* 388 * If a non-ignored signal is received, try to unmount. 389 * If that fails, or the filesystem is already in the 390 * process of being unmounted, clear the signal (it has been 391 * "processed"), otherwise we will loop here, as tsleep 392 * will always return EINTR/ERESTART. 393 */ 394 if (sleepreturn != 0) { 395 mutex_exit(&mfs_lock); 396 if (dounmount(mp, 0, curlwp) != 0) { 397 p = curproc; 398 ksiginfo_queue_init(&kq); 399 mutex_enter(p->p_lock); 400 sigclearall(p, NULL, &kq); 401 mutex_exit(p->p_lock); 402 ksiginfo_queue_drain(&kq); 403 } 404 sleepreturn = 0; 405 mutex_enter(&mfs_lock); 406 continue; 407 } 408 409 sleepreturn = cv_wait_sig(&mfsp->mfs_cv, &mfs_lock); 410 } 411 KASSERT(bufq_peek(mfsp->mfs_buflist) == NULL); 412 refcnt = --mfsp->mfs_refcnt; 413 mutex_exit(&mfs_lock); 414 if (refcnt == 0) { 415 bufq_free(mfsp->mfs_buflist); 416 cv_destroy(&mfsp->mfs_cv); 417 kmem_free(mfsp, sizeof(*mfsp)); 418 } 419 return (sleepreturn); 420 } 421 422 /* 423 * Get file system statistics. 424 */ 425 int 426 mfs_statvfs(struct mount *mp, struct statvfs *sbp) 427 { 428 int error; 429 430 error = ffs_statvfs(mp, sbp); 431 if (error) 432 return error; 433 (void)strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, 434 sizeof(sbp->f_fstypename)); 435 sbp->f_fstypename[sizeof(sbp->f_fstypename) - 1] = '\0'; 436 return 0; 437 } 438
Indexes created Sat Sep 27 22:09:54 GMT 2025