1 /* 2 * Copyright (c) 1989, 1990, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)mfs_vfsops.c 8.11 (Berkeley) 6/19/95 34 * $FreeBSD: src/sys/ufs/mfs/mfs_vfsops.c,v 1.81.2.3 2001/07/04 17:35:21 tegge Exp $ 35 */ 36 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/conf.h> 41 #include <sys/device.h> 42 #include <sys/kernel.h> 43 #include <sys/proc.h> 44 #include <sys/buf.h> 45 #include <sys/mount.h> 46 #include <sys/signalvar.h> 47 #include <sys/signal2.h> 48 #include <sys/vnode.h> 49 #include <sys/malloc.h> 50 #include <sys/sysproto.h> 51 #include <sys/mman.h> 52 #include <sys/linker.h> 53 #include <sys/fcntl.h> 54 #include <sys/nlookup.h> 55 #include <sys/devfs.h> 56 57 #include <vm/vm.h> 58 #include <vm/vm_object.h> 59 #include <vm/vm_page.h> 60 #include <vm/vm_pager.h> 61 #include <vm/vnode_pager.h> 62 #include <vm/vm_extern.h> 63 64 #include <sys/buf2.h> 65 #include <sys/thread2.h> 66 67 #include <vfs/ufs/quota.h> 68 #include <vfs/ufs/inode.h> 69 #include <vfs/ufs/ufsmount.h> 70 #include <vfs/ufs/ufs_extern.h> 71 #include <vfs/ufs/fs.h> 72 #include <vfs/ufs/ffs_extern.h> 73 74 #include "mfsnode.h" 75 #include "mfs_extern.h" 76 77 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); 78 79 static int mfs_mount (struct mount *mp, 80 char *path, caddr_t data, struct ucred *td); 81 static int mfs_start (struct mount *mp, int flags); 82 static int mfs_statfs (struct mount *mp, struct statfs *sbp, 83 struct ucred *cred); 84 static int mfs_init (struct vfsconf *); 85 static void mfs_doio(struct bio *bio, struct mfsnode *mfsp); 86 87 d_open_t mfsopen; 88 d_close_t mfsclose; 89 d_strategy_t mfsstrategy; 90 91 static struct dev_ops mfs_ops = { 92 { "MFS", -1, D_DISK }, 93 .d_open = mfsopen, 94 .d_close = mfsclose, 95 .d_read = physread, 96 .d_write = physwrite, 97 .d_strategy = mfsstrategy, 98 }; 99 100 /* 101 * mfs vfs operations. 102 */ 103 static struct vfsops mfs_vfsops = { 104 .vfs_mount = mfs_mount, 105 .vfs_start = mfs_start, 106 .vfs_unmount = ffs_unmount, 107 .vfs_root = ufs_root, 108 .vfs_quotactl = ufs_quotactl, 109 .vfs_statfs = mfs_statfs, 110 .vfs_sync = ffs_sync, 111 .vfs_vget = ffs_vget, 112 .vfs_fhtovp = ffs_fhtovp, 113 .vfs_checkexp = ufs_check_export, 114 .vfs_vptofh = ffs_vptofh, 115 .vfs_init = mfs_init 116 }; 117 118 VFS_SET(mfs_vfsops, mfs, 0); 119 MODULE_VERSION(mfs, 1); 120 121 /* 122 * We allow the underlying MFS block device to be opened and read. 123 */ 124 int 125 mfsopen(struct dev_open_args *ap) 126 { 127 cdev_t dev = ap->a_head.a_dev; 128 129 #if 0 130 if (ap->a_oflags & FWRITE) 131 return(EROFS); 132 #endif 133 if (dev->si_drv1) 134 return(0); 135 return(ENXIO); 136 } 137 138 int 139 mfsclose(struct dev_close_args *ap) 140 { 141 cdev_t dev = ap->a_head.a_dev; 142 struct mfsnode *mfsp; 143 144 if ((mfsp = dev->si_drv1) == NULL) 145 return(0); 146 mfsp->mfs_active = 0; 147 wakeup((caddr_t)mfsp); 148 return(0); 149 } 150 151 int 152 mfsstrategy(struct dev_strategy_args *ap) 153 { 154 cdev_t dev = ap->a_head.a_dev; 155 struct bio *bio = ap->a_bio; 156 struct buf *bp = bio->bio_buf; 157 off_t boff = bio->bio_offset; 158 off_t eoff = boff + bp->b_bcount; 159 struct mfsnode *mfsp; 160 161 if ((mfsp = dev->si_drv1) == NULL) { 162 bp->b_error = ENXIO; 163 goto error; 164 } 165 if (boff < 0) 166 goto bad; 167 if (eoff > mfsp->mfs_size) { 168 if (boff > mfsp->mfs_size || (bp->b_flags & B_BNOCLIP)) 169 goto bad; 170 /* 171 * Return EOF by completing the I/O with 0 bytes transfered. 172 * Set B_INVAL to indicate that any data in the buffer is not 173 * valid. 174 */ 175 if (boff == mfsp->mfs_size) { 176 bp->b_resid = bp->b_bcount; 177 bp->b_flags |= B_INVAL; 178 goto done; 179 } 180 bp->b_bcount = mfsp->mfs_size - boff; 181 } 182 183 /* 184 * Initiate I/O 185 */ 186 if (mfsp->mfs_td == curthread) { 187 mfs_doio(bio, mfsp); 188 } else { 189 bioq_insert_tail(&mfsp->bio_queue, bio); 190 wakeup((caddr_t)mfsp); 191 } 192 return(0); 193 194 /* 195 * Failure conditions on bio 196 */ 197 bad: 198 bp->b_error = EINVAL; 199 error: 200 bp->b_flags |= B_ERROR | B_INVAL; 201 done: 202 biodone(bio); 203 return(0); 204 } 205 206 /* 207 * mfs_mount 208 * 209 * Called when mounting local physical media 210 * 211 * PARAMETERS: 212 * mountroot 213 * mp mount point structure 214 * path NULL (flag for root mount!!!) 215 * data <unused> 216 * ndp <unused> 217 * p process (user credentials check [statfs]) 218 * 219 * mount 220 * mp mount point structure 221 * path path to mount point 222 * data pointer to argument struct in user space 223 * ndp mount point namei() return (used for 224 * credentials on reload), reused to look 225 * up block device. 226 * p process (user credentials check) 227 * 228 * RETURNS: 0 Success 229 * !0 error number (errno.h) 230 * 231 * LOCK STATE: 232 * 233 * ENTRY 234 * mount point is locked 235 * EXIT 236 * mount point is locked 237 * 238 * NOTES: 239 * A NULL path can be used for a flag since the mount 240 * system call will fail with EFAULT in copyinstr in 241 * namei() if it is a genuine NULL from the user. 242 */ 243 /* ARGSUSED */ 244 static int 245 mfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred) 246 { 247 struct vnode *devvp; 248 struct mfs_args args; 249 struct ufsmount *ump; 250 struct fs *fs; 251 struct mfsnode *mfsp; 252 struct nlookupdata nd; 253 size_t size; 254 char devname[16]; 255 int flags; 256 int minnum; 257 int error; 258 cdev_t dev; 259 260 /* 261 * Use NULL path to flag a root mount 262 */ 263 if (path == NULL) { 264 /* 265 *** 266 * Mounting root file system 267 *** 268 */ 269 270 /* you lose */ 271 panic("mfs_mount: mount MFS as root: not configured!"); 272 } 273 274 mfsp = NULL; 275 276 /* 277 *** 278 * Mounting non-root file system or updating a file system 279 *** 280 */ 281 282 /* copy in user arguments*/ 283 error = copyin(data, (caddr_t)&args, sizeof (struct mfs_args)); 284 if (error) 285 goto error_1; 286 287 /* 288 * If updating, check whether changing from read-only to 289 * read/write; if there is no device name, that's all we do. 290 */ 291 if (mp->mnt_flag & MNT_UPDATE) { 292 /* 293 ******************** 294 * UPDATE 295 ******************** 296 */ 297 ump = VFSTOUFS(mp); 298 fs = ump->um_fs; 299 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 300 flags = WRITECLOSE; 301 if (mp->mnt_flag & MNT_FORCE) 302 flags |= FORCECLOSE; 303 error = ffs_flushfiles(mp, flags); 304 if (error) 305 goto error_1; 306 } 307 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) { 308 /* XXX reopen the device vnode read-write */ 309 fs->fs_ronly = 0; 310 } 311 /* if not updating name...*/ 312 if (args.fspec == 0) { 313 /* 314 * Process export requests. Jumping to "success" 315 * will return the vfs_export() error code. 316 */ 317 error = vfs_export(mp, &ump->um_export, &args.export); 318 goto success; 319 } 320 321 /* XXX MFS does not support name updating*/ 322 goto success; 323 } 324 325 /* 326 * Do the MALLOC before the make_dev since doing so afterward 327 * might cause a bogus v_data pointer to get dereferenced 328 * elsewhere if MALLOC should block. 329 */ 330 mfsp = kmalloc(sizeof *mfsp, M_MFSNODE, M_WAITOK | M_ZERO); 331 332 minnum = (int)curproc->p_pid; 333 334 dev = make_dev(&mfs_ops, minnum, UID_ROOT, GID_WHEEL, 0600, 335 "mfs%d", minnum); 336 /* It is not clear that these will get initialized otherwise */ 337 dev->si_bsize_phys = DEV_BSIZE; 338 dev->si_iosize_max = DFLTPHYS; 339 dev->si_drv1 = mfsp; 340 mfsp->mfs_baseoff = args.base; 341 mfsp->mfs_size = args.size; 342 mfsp->mfs_dev = dev; 343 mfsp->mfs_td = curthread; 344 mfsp->mfs_active = 1; 345 bioq_init(&mfsp->bio_queue); 346 347 devfs_config(); /* sync devfs work */ 348 ksnprintf(devname, sizeof(devname), "/dev/mfs%d", minnum); 349 nlookup_init(&nd, devname, UIO_SYSSPACE, 0); 350 devvp = NULL; 351 error = nlookup(&nd); 352 if (error == 0) { 353 devvp = nd.nl_nch.ncp->nc_vp; 354 if (devvp == NULL) 355 error = ENOENT; 356 error = vget(devvp, LK_SHARED); 357 } 358 nlookup_done(&nd); 359 360 if (error) 361 goto error_1; 362 vn_unlock(devvp); 363 364 /* 365 * Our 'block' device must be backed by a VM object. Theoretically 366 * we could use the anonymous memory VM object supplied by userland, 367 * but it would be somewhat of a complex task to deal with it 368 * that way since it would result in I/O requests which supply 369 * the VM pages from our own object. 370 * 371 * vnode_pager_alloc() is typically called when a VM object is 372 * being referenced externally. We have to undo the refs for 373 * the self reference between vnode and object. 374 */ 375 vnode_pager_setsize(devvp, args.size); 376 377 /* Save "mounted from" info for mount point (NULL pad)*/ 378 copyinstr(args.fspec, /* device name*/ 379 mp->mnt_stat.f_mntfromname, /* save area*/ 380 MNAMELEN - 1, /* max size*/ 381 &size); /* real size*/ 382 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 383 /* vref is eaten by mount? */ 384 385 error = ffs_mountfs(devvp, mp, M_MFSNODE); 386 if (error) { 387 mfsp->mfs_active = 0; 388 goto error_2; 389 } 390 391 /* 392 * Initialize FS stat information in mount struct; uses 393 * mp->mnt_stat.f_mntfromname. 394 * 395 * This code is common to root and non-root mounts 396 */ 397 VFS_STATFS(mp, &mp->mnt_stat, cred); 398 399 goto success; 400 401 error_2: /* error with devvp held*/ 402 vrele(devvp); 403 404 error_1: /* no state to back out*/ 405 if (mfsp) { 406 if (mfsp->mfs_dev) { 407 destroy_dev(mfsp->mfs_dev); 408 mfsp->mfs_dev = NULL; 409 } 410 kfree(mfsp, M_MFSNODE); 411 } 412 413 success: 414 return(error); 415 } 416 417 /* 418 * Used to grab the process and keep it in the kernel to service 419 * memory filesystem I/O requests. 420 * 421 * Loop servicing I/O requests. 422 * Copy the requested data into or out of the memory filesystem 423 * address space. 424 */ 425 /* ARGSUSED */ 426 static int 427 mfs_start(struct mount *mp, int flags) 428 { 429 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 430 struct mfsnode *mfsp = vp->v_rdev->si_drv1; 431 struct bio *bio; 432 struct buf *bp; 433 int gotsig = 0, sig; 434 thread_t td = curthread; 435 436 /* 437 * We must prevent the system from trying to swap 438 * out or kill ( when swap space is low, see vm/pageout.c ) the 439 * process. A deadlock can occur if the process is swapped out, 440 * and the system can loop trying to kill the unkillable ( while 441 * references exist ) MFS process when swap space is low. 442 */ 443 KKASSERT(curproc); 444 PHOLD(curproc); 445 446 mfsp->mfs_td = td; 447 448 while (mfsp->mfs_active) { 449 crit_enter(); 450 451 while ((bio = bioq_takefirst(&mfsp->bio_queue)) != NULL) { 452 crit_exit(); 453 bp = bio->bio_buf; 454 mfs_doio(bio, mfsp); 455 wakeup(bp); 456 crit_enter(); 457 } 458 459 crit_exit(); 460 461 /* 462 * If a non-ignored signal is received, try to unmount. 463 * If that fails, clear the signal (it has been "processed"), 464 * otherwise we will loop here, as tsleep will always return 465 * EINTR/ERESTART. 466 */ 467 /* 468 * Note that dounmount() may fail if work was queued after 469 * we slept. We have to jump hoops here to make sure that we 470 * process any buffers after the sleep, before we dounmount() 471 */ 472 if (gotsig) { 473 gotsig = 0; 474 if (dounmount(mp, 0) != 0) { 475 KKASSERT(td->td_proc); 476 sig = CURSIG(td->td_lwp); 477 if (sig) { 478 spin_lock(&td->td_lwp->lwp_spin); 479 lwp_delsig(td->td_lwp, sig); 480 spin_unlock(&td->td_lwp->lwp_spin); 481 } 482 } 483 } 484 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0)) 485 gotsig++; /* try to unmount in next pass */ 486 } 487 PRELE(curproc); 488 if (mfsp->mfs_dev) { 489 destroy_dev(mfsp->mfs_dev); 490 mfsp->mfs_dev = NULL; 491 } 492 kfree(mfsp, M_MFSNODE); 493 return (0); 494 } 495 496 /* 497 * Get file system statistics. 498 */ 499 static int 500 mfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred) 501 { 502 int error; 503 504 error = ffs_statfs(mp, sbp, cred); 505 sbp->f_type = mp->mnt_vfc->vfc_typenum; 506 return (error); 507 } 508 509 /* 510 * Memory based filesystem initialization. 511 */ 512 static int 513 mfs_init(struct vfsconf *vfsp) 514 { 515 return (0); 516 } 517 518 /* 519 * Memory file system I/O. 520 * 521 * Trivial on the HP since buffer has already been mapping into KVA space. 522 * 523 * Read and Write are handled with a simple copyin and copyout. 524 * 525 * We also partially support VOP_FREEBLKS(). We can't implement 526 * completely -- for example, on fragments or inode metadata, but we can 527 * implement it for page-aligned requests. 528 */ 529 static void 530 mfs_doio(struct bio *bio, struct mfsnode *mfsp) 531 { 532 struct buf *bp = bio->bio_buf; 533 caddr_t base = mfsp->mfs_baseoff + bio->bio_offset; 534 int bytes; 535 536 switch(bp->b_cmd) { 537 case BUF_CMD_FREEBLKS: 538 /* 539 * Implement FREEBLKS, which allows the filesystem to tell 540 * a block device when blocks are no longer needed (like when 541 * a file is deleted). We use the hook to MADV_FREE the VM. 542 * This makes an MFS filesystem work as well or better then 543 * a sun-style swap-mounted filesystem. 544 */ 545 bytes = bp->b_bcount; 546 547 if ((vm_offset_t)base & PAGE_MASK) { 548 int n = PAGE_SIZE - ((vm_offset_t)base & PAGE_MASK); 549 bytes -= n; 550 base += n; 551 } 552 if (bytes > 0) { 553 struct madvise_args uap; 554 555 bytes &= ~PAGE_MASK; 556 if (bytes != 0) { 557 bzero(&uap, sizeof(uap)); 558 uap.addr = base; 559 uap.len = bytes; 560 uap.behav = MADV_FREE; 561 sys_madvise(&uap); 562 } 563 } 564 bp->b_error = 0; 565 break; 566 case BUF_CMD_READ: 567 /* 568 * Read data from our 'memory' disk 569 */ 570 bp->b_error = copyin(base, bp->b_data, bp->b_bcount); 571 break; 572 case BUF_CMD_WRITE: 573 /* 574 * Write data to our 'memory' disk 575 */ 576 bp->b_error = copyout(bp->b_data, base, bp->b_bcount); 577 break; 578 default: 579 panic("mfs: bad b_cmd %d\n", bp->b_cmd); 580 } 581 if (bp->b_error) 582 bp->b_flags |= B_ERROR; 583 biodone(bio); 584 } 585