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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)mfs_vfsops.c 8.11 (Berkeley) 6/19/95 30 * $FreeBSD: src/sys/ufs/mfs/mfs_vfsops.c,v 1.81.2.3 2001/07/04 17:35:21 tegge Exp $ 31 */ 32 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/conf.h> 37 #include <sys/device.h> 38 #include <sys/kernel.h> 39 #include <sys/proc.h> 40 #include <sys/buf.h> 41 #include <sys/mount.h> 42 #include <sys/signalvar.h> 43 #include <sys/signal2.h> 44 #include <sys/spinlock2.h> 45 #include <sys/vnode.h> 46 #include <sys/malloc.h> 47 #include <sys/sysmsg.h> 48 #include <sys/mman.h> 49 #include <sys/linker.h> 50 #include <sys/fcntl.h> 51 #include <sys/nlookup.h> 52 #include <sys/devfs.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_object.h> 56 #include <vm/vm_page.h> 57 #include <vm/vm_pager.h> 58 #include <vm/vnode_pager.h> 59 #include <vm/vm_extern.h> 60 61 #include <sys/buf2.h> 62 #include <sys/thread2.h> 63 64 #include <vfs/ufs/quota.h> 65 #include <vfs/ufs/inode.h> 66 #include <vfs/ufs/ufsmount.h> 67 #include <vfs/ufs/ufs_extern.h> 68 #include <vfs/ufs/fs.h> 69 #include <vfs/ufs/ffs_extern.h> 70 71 #include "mfsnode.h" 72 #include "mfs_extern.h" 73 74 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); 75 76 static int mfs_mount (struct mount *mp, 77 char *path, caddr_t data, struct ucred *td); 78 static int mfs_start (struct mount *mp, int flags); 79 static int mfs_statfs (struct mount *mp, struct statfs *sbp, 80 struct ucred *cred); 81 static int mfs_init (struct vfsconf *); 82 static void mfs_doio(struct bio *bio, struct mfsnode *mfsp); 83 84 d_open_t mfsopen; 85 d_close_t mfsclose; 86 d_strategy_t mfsstrategy; 87 88 static struct dev_ops mfs_ops = { 89 { "MFS", -1, D_DISK | D_NOEMERGPGR }, 90 .d_open = mfsopen, 91 .d_close = mfsclose, 92 .d_read = physread, 93 .d_write = physwrite, 94 .d_strategy = mfsstrategy, 95 }; 96 97 /* 98 * mfs vfs operations. 99 */ 100 static struct vfsops mfs_vfsops = { 101 .vfs_flags = 0, 102 .vfs_mount = mfs_mount, 103 .vfs_start = mfs_start, 104 .vfs_unmount = ffs_unmount, 105 .vfs_root = ufs_root, 106 .vfs_quotactl = ufs_quotactl, 107 .vfs_statfs = mfs_statfs, 108 .vfs_sync = ffs_sync, 109 .vfs_vget = ffs_vget, 110 .vfs_fhtovp = ffs_fhtovp, 111 .vfs_checkexp = ufs_check_export, 112 .vfs_vptofh = ffs_vptofh, 113 .vfs_init = mfs_init 114 }; 115 116 VFS_SET(mfs_vfsops, mfs, 0); 117 MODULE_VERSION(mfs, 1); 118 119 /* 120 * We allow the underlying MFS block device to be opened and read. 121 */ 122 int 123 mfsopen(struct dev_open_args *ap) 124 { 125 cdev_t dev = ap->a_head.a_dev; 126 127 #if 0 128 if (ap->a_oflags & FWRITE) 129 return(EROFS); 130 #endif 131 if (dev->si_drv1) 132 return(0); 133 return(ENXIO); 134 } 135 136 int 137 mfsclose(struct dev_close_args *ap) 138 { 139 cdev_t dev = ap->a_head.a_dev; 140 struct mfsnode *mfsp; 141 142 if ((mfsp = dev->si_drv1) == NULL) 143 return(0); 144 mfsp->mfs_active = 0; 145 wakeup((caddr_t)mfsp); 146 return(0); 147 } 148 149 int 150 mfsstrategy(struct dev_strategy_args *ap) 151 { 152 cdev_t dev = ap->a_head.a_dev; 153 struct bio *bio = ap->a_bio; 154 struct buf *bp = bio->bio_buf; 155 off_t boff = bio->bio_offset; 156 off_t eoff = boff + bp->b_bcount; 157 struct mfsnode *mfsp; 158 159 if ((mfsp = dev->si_drv1) == NULL) { 160 bp->b_error = ENXIO; 161 goto error; 162 } 163 if (boff < 0) 164 goto bad; 165 if (eoff > mfsp->mfs_size) { 166 if (boff > mfsp->mfs_size || (bp->b_flags & B_BNOCLIP)) 167 goto bad; 168 /* 169 * Return EOF by completing the I/O with 0 bytes transfered. 170 * Set B_INVAL to indicate that any data in the buffer is not 171 * valid. 172 */ 173 if (boff == mfsp->mfs_size) { 174 bp->b_resid = bp->b_bcount; 175 bp->b_flags |= B_INVAL; 176 goto done; 177 } 178 bp->b_bcount = mfsp->mfs_size - boff; 179 } 180 181 /* 182 * Initiate I/O 183 */ 184 if (mfsp->mfs_td == curthread) { 185 mfs_doio(bio, mfsp); 186 } else { 187 bioq_insert_tail(&mfsp->bio_queue, bio); 188 wakeup((caddr_t)mfsp); 189 } 190 return(0); 191 192 /* 193 * Failure conditions on bio 194 */ 195 bad: 196 bp->b_error = EINVAL; 197 error: 198 bp->b_flags |= B_ERROR | B_INVAL; 199 done: 200 biodone(bio); 201 return(0); 202 } 203 204 /* 205 * mfs_mount 206 * 207 * Called when mounting local physical media 208 * 209 * PARAMETERS: 210 * mountroot 211 * mp mount point structure 212 * path NULL (flag for root mount!!!) 213 * data <unused> 214 * ndp <unused> 215 * p process (user credentials check [statfs]) 216 * 217 * mount 218 * mp mount point structure 219 * path path to mount point 220 * data pointer to argument struct in user space 221 * ndp mount point namei() return (used for 222 * credentials on reload), reused to look 223 * up block device. 224 * p process (user credentials check) 225 * 226 * RETURNS: 0 Success 227 * !0 error number (errno.h) 228 * 229 * LOCK STATE: 230 * 231 * ENTRY 232 * mount point is locked 233 * EXIT 234 * mount point is locked 235 * 236 * NOTES: 237 * A NULL path can be used for a flag since the mount 238 * system call will fail with EFAULT in copyinstr in 239 * namei() if it is a genuine NULL from the user. 240 */ 241 /* ARGSUSED */ 242 static int 243 mfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred) 244 { 245 struct vnode *devvp; 246 struct mfs_args args; 247 struct ufsmount *ump; 248 struct fs *fs; 249 struct mfsnode *mfsp; 250 struct nlookupdata nd; 251 size_t size; 252 char devname[16]; 253 int flags; 254 int minnum; 255 int error; 256 cdev_t dev; 257 258 /* 259 * Use NULL path to flag a root mount 260 */ 261 if (path == NULL) { 262 /* 263 *** 264 * Mounting root file system 265 *** 266 */ 267 268 /* you lose */ 269 panic("mfs_mount: mount MFS as root: not configured!"); 270 } 271 272 mfsp = NULL; 273 274 /* 275 *** 276 * Mounting non-root file system or updating a file system 277 *** 278 */ 279 280 /* copy in user arguments*/ 281 error = copyin(data, (caddr_t)&args, sizeof (struct mfs_args)); 282 if (error) 283 goto error_1; 284 285 /* 286 * If updating, check whether changing from read-only to 287 * read/write; if there is no device name, that's all we do. 288 */ 289 if (mp->mnt_flag & MNT_UPDATE) { 290 /* 291 ******************** 292 * UPDATE 293 ******************** 294 */ 295 ump = VFSTOUFS(mp); 296 fs = ump->um_fs; 297 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 298 flags = WRITECLOSE; 299 if (mp->mnt_flag & MNT_FORCE) 300 flags |= FORCECLOSE; 301 error = ffs_flushfiles(mp, flags); 302 if (error) 303 goto error_1; 304 } 305 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) { 306 /* XXX reopen the device vnode read-write */ 307 fs->fs_ronly = 0; 308 } 309 /* if not updating name...*/ 310 if (args.fspec == 0) { 311 /* 312 * Process export requests. Jumping to "success" 313 * will return the vfs_export() error code. 314 */ 315 error = vfs_export(mp, &ump->um_export, &args.export); 316 goto success; 317 } 318 319 /* XXX MFS does not support name updating*/ 320 goto success; 321 } 322 323 /* 324 * Do the MALLOC before the make_dev since doing so afterward 325 * might cause a bogus v_data pointer to get dereferenced 326 * elsewhere if MALLOC should block. 327 */ 328 mfsp = kmalloc(sizeof *mfsp, M_MFSNODE, M_WAITOK | M_ZERO); 329 330 minnum = (int)curproc->p_pid; 331 332 dev = make_dev(&mfs_ops, minnum, UID_ROOT, GID_WHEEL, 0600, 333 "mfs%d", minnum); 334 /* It is not clear that these will get initialized otherwise */ 335 dev->si_bsize_phys = DEV_BSIZE; 336 dev->si_iosize_max = MAXPHYS; 337 dev->si_drv1 = mfsp; 338 mfsp->mfs_baseoff = args.base; 339 mfsp->mfs_size = args.size; 340 mfsp->mfs_dev = dev; 341 mfsp->mfs_td = curthread; 342 mfsp->mfs_active = 1; 343 bioq_init(&mfsp->bio_queue); 344 345 devfs_config(); /* sync devfs work */ 346 ksnprintf(devname, sizeof(devname), "/dev/mfs%d", minnum); 347 nlookup_init(&nd, devname, UIO_SYSSPACE, 0); 348 devvp = NULL; 349 error = nlookup(&nd); 350 if (error == 0) { 351 devvp = nd.nl_nch.ncp->nc_vp; 352 if (devvp == NULL) 353 error = ENOENT; 354 error = vget(devvp, LK_SHARED); 355 } 356 nlookup_done(&nd); 357 358 if (error) 359 goto error_1; 360 vn_unlock(devvp); 361 362 /* 363 * Our 'block' device must be backed by a VM object. Theoretically 364 * we could use the anonymous memory VM object supplied by userland, 365 * but it would be somewhat of a complex task to deal with it 366 * that way since it would result in I/O requests which supply 367 * the VM pages from our own object. 368 * 369 * vnode_pager_alloc() is typically called when a VM object is 370 * being referenced externally. We have to undo the refs for 371 * the self reference between vnode and object. 372 */ 373 vnode_pager_setsize(devvp, args.size); 374 375 /* Save "mounted from" info for mount point (NULL pad)*/ 376 copyinstr(args.fspec, /* device name*/ 377 mp->mnt_stat.f_mntfromname, /* save area*/ 378 MNAMELEN - 1, /* max size*/ 379 &size); /* real size*/ 380 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 381 /* vref is eaten by mount? */ 382 383 error = ffs_mountfs(devvp, mp, M_MFSNODE); 384 if (error) { 385 mfsp->mfs_active = 0; 386 goto error_2; 387 } 388 389 /* 390 * Initialize FS stat information in mount struct; uses 391 * mp->mnt_stat.f_mntfromname. 392 * 393 * This code is common to root and non-root mounts 394 */ 395 VFS_STATFS(mp, &mp->mnt_stat, cred); 396 397 /* 398 * Mark VFS_START MPSAFE; this is to avoid accessing 399 * per-mount token after VFS_START exits 400 */ 401 mp->mnt_kern_flag |= MNTK_ST_MPSAFE; 402 403 goto success; 404 405 error_2: /* error with devvp held*/ 406 vrele(devvp); 407 408 error_1: /* no state to back out*/ 409 if (mfsp) { 410 if (mfsp->mfs_dev) { 411 destroy_dev(mfsp->mfs_dev); 412 mfsp->mfs_dev = NULL; 413 } 414 kfree(mfsp, M_MFSNODE); 415 } 416 417 success: 418 return(error); 419 } 420 421 /* 422 * Used to grab the process and keep it in the kernel to service 423 * memory filesystem I/O requests. 424 * 425 * Loop servicing I/O requests. 426 * Copy the requested data into or out of the memory filesystem 427 * address space. 428 */ 429 /* ARGSUSED */ 430 static int 431 mfs_start(struct mount *mp, int flags) 432 { 433 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 434 struct mfsnode *mfsp = vp->v_rdev->si_drv1; 435 struct bio *bio; 436 struct buf *bp; 437 int gotsig = 0, sig; 438 thread_t td = curthread; 439 440 /* 441 * We must prevent the system from trying to swap 442 * out or kill ( when swap space is low, see vm/pageout.c ) the 443 * process. A deadlock can occur if the process is swapped out, 444 * and the system can loop trying to kill the unkillable ( while 445 * references exist ) MFS process when swap space is low. 446 */ 447 KKASSERT(curproc); 448 PHOLD(curproc); 449 450 mfsp->mfs_td = td; 451 452 while (mfsp->mfs_active) { 453 crit_enter(); 454 455 while ((bio = bioq_takefirst(&mfsp->bio_queue)) != NULL) { 456 crit_exit(); 457 bp = bio->bio_buf; 458 mfs_doio(bio, mfsp); 459 wakeup(bp); 460 crit_enter(); 461 } 462 463 crit_exit(); 464 465 /* 466 * If a non-ignored signal is received, try to unmount. 467 * If that fails, clear the signal (it has been "processed"), 468 * otherwise we will loop here, as tsleep will always return 469 * EINTR/ERESTART. 470 */ 471 /* 472 * Note that dounmount() may fail if work was queued after 473 * we slept. We have to jump hoops here to make sure that we 474 * process any buffers after the sleep, before we dounmount() 475 */ 476 if (gotsig) { 477 gotsig = 0; 478 if (dounmount(mp, 0, 0) != 0) { 479 KKASSERT(td->td_proc); 480 lwkt_gettoken(&td->td_proc->p_token); 481 sig = CURSIG(td->td_lwp); 482 if (sig) { 483 spin_lock(&td->td_lwp->lwp_spin); 484 lwp_delsig(td->td_lwp, sig, 1); 485 spin_unlock(&td->td_lwp->lwp_spin); 486 } 487 lwkt_reltoken(&td->td_proc->p_token); 488 } 489 } 490 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0)) 491 gotsig++; /* try to unmount in next pass */ 492 } 493 PRELE(curproc); 494 if (mfsp->mfs_dev) { 495 destroy_dev(mfsp->mfs_dev); 496 mfsp->mfs_dev = NULL; 497 } 498 kfree(mfsp, M_MFSNODE); 499 return (EMOUNTEXIT); 500 } 501 502 /* 503 * Get file system statistics. 504 */ 505 static int 506 mfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred) 507 { 508 int error; 509 510 error = ffs_statfs(mp, sbp, cred); 511 sbp->f_type = mp->mnt_vfc->vfc_typenum; 512 return (error); 513 } 514 515 /* 516 * Memory based filesystem initialization. 517 */ 518 static int 519 mfs_init(struct vfsconf *vfsp) 520 { 521 return (0); 522 } 523 524 /* 525 * Memory file system I/O. 526 * 527 * Trivial on the HP since buffer has already been mapping into KVA space. 528 * 529 * Read and Write are handled with a simple copyin and copyout. 530 * 531 * We also partially support VOP_FREEBLKS(). We can't implement 532 * completely -- for example, on fragments or inode metadata, but we can 533 * implement it for page-aligned requests. 534 */ 535 static void 536 mfs_doio(struct bio *bio, struct mfsnode *mfsp) 537 { 538 struct buf *bp = bio->bio_buf; 539 caddr_t base = mfsp->mfs_baseoff + bio->bio_offset; 540 int bytes; 541 542 switch(bp->b_cmd) { 543 case BUF_CMD_FREEBLKS: 544 /* 545 * Implement FREEBLKS, which allows the filesystem to tell 546 * a block device when blocks are no longer needed (like when 547 * a file is deleted). We use the hook to MADV_FREE the VM. 548 * This makes an MFS filesystem work as well or better then 549 * a sun-style swap-mounted filesystem. 550 */ 551 bytes = bp->b_bcount; 552 553 if ((vm_offset_t)base & PAGE_MASK) { 554 int n = PAGE_SIZE - ((vm_offset_t)base & PAGE_MASK); 555 bytes -= n; 556 base += n; 557 } 558 if (bytes > 0) { 559 struct madvise_args uap; 560 561 bytes &= ~PAGE_MASK; 562 if (bytes != 0) { 563 struct sysmsg sysmsg; 564 565 bzero(&sysmsg, sizeof(sysmsg)); 566 bzero(&uap, sizeof(uap)); 567 uap.addr = base; 568 uap.len = bytes; 569 uap.behav = MADV_FREE; 570 sys_madvise(&sysmsg, &uap); 571 } 572 } 573 bp->b_error = 0; 574 break; 575 case BUF_CMD_READ: 576 /* 577 * Read data from our 'memory' disk 578 */ 579 bp->b_error = copyin(base, bp->b_data, bp->b_bcount); 580 break; 581 case BUF_CMD_WRITE: 582 /* 583 * Write data to our 'memory' disk 584 */ 585 bp->b_error = copyout(bp->b_data, base, bp->b_bcount); 586 break; 587 default: 588 panic("mfs: bad b_cmd %d", bp->b_cmd); 589 } 590 if (bp->b_error) 591 bp->b_flags |= B_ERROR; 592 biodone(bio); 593 } 594