mfs_vfsops.c revision 1.95
1 /* $NetBSD: mfs_vfsops.c,v 1.95 2008/04/30 12:49:17 ad 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 1.95 2008/04/30 12:49:17 ad 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 54 #include <miscfs/genfs/genfs.h> 55 #include <miscfs/specfs/specdev.h> 56 #include <miscfs/syncfs/syncfs.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 void * mfs_rootbase; /* address of mini-root in kernel virtual memory */ 70 u_long mfs_rootsize; /* size of mini-root in bytes */ 71 kmutex_t mfs_lock; /* global lock */ 72 73 static int mfs_minor; /* used for building internal dev_t */ 74 static int mfs_initcnt; 75 76 extern int (**mfs_vnodeop_p)(void *); 77 78 /* 79 * mfs vfs operations. 80 */ 81 82 extern const struct vnodeopv_desc mfs_vnodeop_opv_desc; 83 84 const struct vnodeopv_desc * const mfs_vnodeopv_descs[] = { 85 &mfs_vnodeop_opv_desc, 86 NULL, 87 }; 88 89 struct vfsops mfs_vfsops = { 90 MOUNT_MFS, 91 sizeof (struct mfs_args), 92 mfs_mount, 93 mfs_start, 94 ffs_unmount, 95 ufs_root, 96 ufs_quotactl, 97 mfs_statvfs, 98 ffs_sync, 99 ffs_vget, 100 ffs_fhtovp, 101 ffs_vptofh, 102 mfs_init, 103 mfs_reinit, 104 mfs_done, 105 NULL, 106 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 107 vfs_stdextattrctl, 108 (void *)eopnotsupp, /* vfs_suspendctl */ 109 genfs_renamelock_enter, 110 genfs_renamelock_exit, 111 (void *)eopnotsupp, 112 mfs_vnodeopv_descs, 113 0, 114 { NULL, NULL }, 115 }; 116 VFS_ATTACH(mfs_vfsops); 117 118 SYSCTL_SETUP(sysctl_vfs_mfs_setup, "sysctl vfs.mfs subtree setup") 119 { 120 121 sysctl_createv(clog, 0, NULL, NULL, 122 CTLFLAG_PERMANENT, 123 CTLTYPE_NODE, "vfs", NULL, 124 NULL, 0, NULL, 0, 125 CTL_VFS, CTL_EOL); 126 sysctl_createv(clog, 0, NULL, NULL, 127 CTLFLAG_PERMANENT|CTLFLAG_ALIAS, 128 CTLTYPE_NODE, "mfs", 129 SYSCTL_DESCR("Memory based file system"), 130 NULL, 1, NULL, 0, 131 CTL_VFS, 3, CTL_EOL); 132 /* 133 * XXX the "1" and the "3" above could be dynamic, thereby 134 * eliminating one more instance of the "number to vfs" 135 * mapping problem, but they are in order as taken from 136 * sys/mount.h 137 */ 138 } 139 140 /* 141 * Memory based filesystem initialization. 142 */ 143 void 144 mfs_init(void) 145 { 146 147 if (mfs_initcnt++ == 0) { 148 mutex_init(&mfs_lock, MUTEX_DEFAULT, IPL_NONE); 149 ffs_init(); 150 } 151 } 152 153 void 154 mfs_reinit(void) 155 { 156 157 ffs_reinit(); 158 } 159 160 void 161 mfs_done(void) 162 { 163 164 if (--mfs_initcnt == 0) { 165 ffs_done(); 166 mutex_destroy(&mfs_lock); 167 } 168 } 169 170 /* 171 * Called by main() when mfs is going to be mounted as root. 172 */ 173 174 int 175 mfs_mountroot(void) 176 { 177 struct fs *fs; 178 struct mount *mp; 179 struct lwp *l = curlwp; /* XXX */ 180 struct ufsmount *ump; 181 struct mfsnode *mfsp; 182 int error = 0; 183 184 if ((error = vfs_rootmountalloc(MOUNT_MFS, "mfs_root", &mp))) { 185 vrele(rootvp); 186 return (error); 187 } 188 189 mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP); 190 rootvp->v_data = mfsp; 191 rootvp->v_op = mfs_vnodeop_p; 192 rootvp->v_tag = VT_MFS; 193 mfsp->mfs_baseoff = mfs_rootbase; 194 mfsp->mfs_size = mfs_rootsize; 195 mfsp->mfs_vnode = rootvp; 196 mfsp->mfs_proc = NULL; /* indicate kernel space */ 197 mfsp->mfs_shutdown = 0; 198 cv_init(&mfsp->mfs_cv, "mfs"); 199 mfsp->mfs_refcnt = 1; 200 bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0); 201 if ((error = ffs_mountfs(rootvp, mp, l)) != 0) { 202 vfs_unbusy(mp, false, NULL); 203 bufq_free(mfsp->mfs_buflist); 204 vfs_destroy(mp, false); 205 kmem_free(mfsp, sizeof(*mfsp)); 206 return (error); 207 } 208 mutex_enter(&mountlist_lock); 209 CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list); 210 mp->mnt_iflag |= IMNT_ONLIST; 211 mutex_exit(&mountlist_lock); 212 mp->mnt_vnodecovered = NULLVP; 213 ump = VFSTOUFS(mp); 214 fs = ump->um_fs; 215 (void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0); 216 (void)ffs_statvfs(mp, &mp->mnt_stat); 217 vfs_unbusy(mp, false, NULL); 218 return (0); 219 } 220 221 /* 222 * This is called early in boot to set the base address and size 223 * of the mini-root. 224 */ 225 int 226 mfs_initminiroot(void *base) 227 { 228 struct fs *fs = (struct fs *)((char *)base + SBLOCK_UFS1); 229 230 /* check for valid super block */ 231 if (fs->fs_magic != FS_UFS1_MAGIC || fs->fs_bsize > MAXBSIZE || 232 fs->fs_bsize < sizeof(struct fs)) 233 return (0); 234 mountroot = mfs_mountroot; 235 mfs_rootbase = base; 236 mfs_rootsize = fs->fs_fsize * fs->fs_size; 237 rootdev = makedev(255, mfs_minor); 238 mfs_minor++; 239 return (mfs_rootsize); 240 } 241 242 /* 243 * VFS Operations. 244 * 245 * mount system call 246 */ 247 /* ARGSUSED */ 248 int 249 mfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 250 { 251 struct lwp *l = curlwp; 252 struct vnode *devvp; 253 struct mfs_args *args = data; 254 struct ufsmount *ump; 255 struct fs *fs; 256 struct mfsnode *mfsp; 257 struct proc *p; 258 int flags, error = 0; 259 260 if (*data_len < sizeof *args) 261 return EINVAL; 262 263 p = l->l_proc; 264 if (mp->mnt_flag & MNT_GETARGS) { 265 struct vnode *vp; 266 267 ump = VFSTOUFS(mp); 268 if (ump == NULL) 269 return EIO; 270 271 vp = ump->um_devvp; 272 if (vp == NULL) 273 return EIO; 274 275 mfsp = VTOMFS(vp); 276 if (mfsp == NULL) 277 return EIO; 278 279 args->fspec = NULL; 280 args->base = mfsp->mfs_baseoff; 281 args->size = mfsp->mfs_size; 282 *data_len = sizeof *args; 283 return 0; 284 } 285 /* 286 * XXX turn off async to avoid hangs when writing lots of data. 287 * the problem is that MFS needs to allocate pages to clean pages, 288 * so if we wait until the last minute to clean pages then there 289 * may not be any pages available to do the cleaning. 290 * ... and since the default partially-synchronous mode turns out 291 * to not be sufficient under heavy load, make it full synchronous. 292 */ 293 mp->mnt_flag &= ~MNT_ASYNC; 294 mp->mnt_flag |= MNT_SYNCHRONOUS; 295 296 /* 297 * If updating, check whether changing from read-only to 298 * read/write; if there is no device name, that's all we do. 299 */ 300 if (mp->mnt_flag & MNT_UPDATE) { 301 ump = VFSTOUFS(mp); 302 fs = ump->um_fs; 303 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 304 flags = WRITECLOSE; 305 if (mp->mnt_flag & MNT_FORCE) 306 flags |= FORCECLOSE; 307 error = ffs_flushfiles(mp, flags, l); 308 if (error) 309 return (error); 310 } 311 if (fs->fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR)) 312 fs->fs_ronly = 0; 313 if (args->fspec == NULL) 314 return EINVAL; 315 return (0); 316 } 317 error = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp); 318 if (error) 319 return (error); 320 devvp->v_vflag |= VV_MPSAFE; 321 devvp->v_type = VBLK; 322 spec_node_init(devvp, makedev(255, mfs_minor)); 323 mfs_minor++; 324 mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP); 325 devvp->v_data = mfsp; 326 mfsp->mfs_baseoff = args->base; 327 mfsp->mfs_size = args->size; 328 mfsp->mfs_vnode = devvp; 329 mfsp->mfs_proc = p; 330 mfsp->mfs_shutdown = 0; 331 cv_init(&mfsp->mfs_cv, "mfsidl"); 332 mfsp->mfs_refcnt = 1; 333 bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0); 334 if ((error = ffs_mountfs(devvp, mp, l)) != 0) { 335 mfsp->mfs_shutdown = 1; 336 vrele(devvp); 337 return (error); 338 } 339 ump = VFSTOUFS(mp); 340 fs = ump->um_fs; 341 error = set_statvfs_info(path, UIO_USERSPACE, args->fspec, 342 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 343 if (error) 344 return error; 345 (void)strncpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname, 346 sizeof(fs->fs_fsmnt)); 347 fs->fs_fsmnt[sizeof(fs->fs_fsmnt) - 1] = '\0'; 348 /* XXX: cleanup on error */ 349 return 0; 350 } 351 352 /* 353 * Used to grab the process and keep it in the kernel to service 354 * memory filesystem I/O requests. 355 * 356 * Loop servicing I/O requests. 357 * Copy the requested data into or out of the memory filesystem 358 * address space. 359 */ 360 /* ARGSUSED */ 361 int 362 mfs_start(struct mount *mp, int flags) 363 { 364 struct vnode *vp; 365 struct mfsnode *mfsp; 366 struct proc *p; 367 struct buf *bp; 368 void *base; 369 int sleepreturn = 0, refcnt, error; 370 ksiginfoq_t kq; 371 372 /* 373 * Ensure that file system is still mounted when getting mfsnode. 374 * Add a reference to the mfsnode to prevent it disappearing in 375 * this routine. 376 */ 377 if ((error = vfs_busy(mp, RW_READER)) != 0) 378 return error; 379 vp = VFSTOUFS(mp)->um_devvp; 380 mfsp = VTOMFS(vp); 381 mutex_enter(&mfs_lock); 382 mfsp->mfs_refcnt++; 383 mutex_exit(&mfs_lock); 384 vfs_unbusy(mp, false, NULL); 385 386 base = mfsp->mfs_baseoff; 387 mutex_enter(&mfs_lock); 388 while (mfsp->mfs_shutdown != 1) { 389 while ((bp = BUFQ_GET(mfsp->mfs_buflist)) != NULL) { 390 mutex_exit(&mfs_lock); 391 mfs_doio(bp, base); 392 mutex_enter(&mfs_lock); 393 } 394 /* 395 * If a non-ignored signal is received, try to unmount. 396 * If that fails, or the filesystem is already in the 397 * process of being unmounted, clear the signal (it has been 398 * "processed"), otherwise we will loop here, as tsleep 399 * will always return EINTR/ERESTART. 400 */ 401 if (sleepreturn != 0) { 402 mutex_exit(&mfs_lock); 403 /* 404 * XXX Freeze syncer. Must do this before locking 405 * the mount point. See dounmount() for details. 406 */ 407 mutex_enter(&syncer_mutex); 408 if (vfs_trybusy(mp, RW_WRITER, NULL) != 0) 409 mutex_exit(&syncer_mutex); 410 else if (dounmount(mp, 0, curlwp) != 0) { 411 p = curproc; 412 ksiginfo_queue_init(&kq); 413 mutex_enter(p->p_lock); 414 sigclearall(p, NULL, &kq); 415 mutex_exit(p->p_lock); 416 ksiginfo_queue_drain(&kq); 417 } 418 sleepreturn = 0; 419 mutex_enter(&mfs_lock); 420 continue; 421 } 422 423 sleepreturn = cv_wait_sig(&mfsp->mfs_cv, &mfs_lock); 424 } 425 KASSERT(BUFQ_PEEK(mfsp->mfs_buflist) == NULL); 426 refcnt = --mfsp->mfs_refcnt; 427 mutex_exit(&mfs_lock); 428 if (refcnt == 0) { 429 bufq_free(mfsp->mfs_buflist); 430 cv_destroy(&mfsp->mfs_cv); 431 kmem_free(mfsp, sizeof(*mfsp)); 432 } 433 return (sleepreturn); 434 } 435 436 /* 437 * Get file system statistics. 438 */ 439 int 440 mfs_statvfs(struct mount *mp, struct statvfs *sbp) 441 { 442 int error; 443 444 error = ffs_statvfs(mp, sbp); 445 if (error) 446 return error; 447 (void)strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, 448 sizeof(sbp->f_fstypename)); 449 sbp->f_fstypename[sizeof(sbp->f_fstypename) - 1] = '\0'; 450 return 0; 451 } 452
Indexes created Sun Sep 28 16:09:52 GMT 2025