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 * $DragonFly: src/sys/vfs/mfs/mfs_vfsops.c,v 1.41 2008/07/26 22:31:54 mneumann Exp $ 36 */ 37 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/conf.h> 42 #include <sys/device.h> 43 #include <sys/kernel.h> 44 #include <sys/proc.h> 45 #include <sys/buf.h> 46 #include <sys/mount.h> 47 #include <sys/signalvar.h> 48 #include <sys/signal2.h> 49 #include <sys/vnode.h> 50 #include <sys/malloc.h> 51 #include <sys/sysproto.h> 52 #include <sys/mman.h> 53 #include <sys/linker.h> 54 #include <sys/fcntl.h> 55 #include <sys/nlookup.h> 56 #include <sys/devfs.h> 57 58 #include <vm/vm.h> 59 #include <vm/vm_object.h> 60 #include <vm/vm_page.h> 61 #include <vm/vm_pager.h> 62 #include <vm/vnode_pager.h> 63 #include <vm/vm_extern.h> 64 65 #include <sys/buf2.h> 66 #include <sys/thread2.h> 67 68 #include <vfs/ufs/quota.h> 69 #include <vfs/ufs/inode.h> 70 #include <vfs/ufs/ufsmount.h> 71 #include <vfs/ufs/ufs_extern.h> 72 #include <vfs/ufs/fs.h> 73 #include <vfs/ufs/ffs_extern.h> 74 75 #include "mfsnode.h" 76 #include "mfs_extern.h" 77 78 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); 79 80 static int mfs_mount (struct mount *mp, 81 char *path, caddr_t data, struct ucred *td); 82 static int mfs_start (struct mount *mp, int flags); 83 static int mfs_statfs (struct mount *mp, struct statfs *sbp, 84 struct ucred *cred); 85 static int mfs_init (struct vfsconf *); 86 static void mfs_doio(struct bio *bio, struct mfsnode *mfsp); 87 88 d_open_t mfsopen; 89 d_close_t mfsclose; 90 d_strategy_t mfsstrategy; 91 92 static struct dev_ops mfs_ops = { 93 { "MFS", -1, D_DISK }, 94 .d_open = mfsopen, 95 .d_close = mfsclose, 96 .d_read = physread, 97 .d_write = physwrite, 98 .d_strategy = mfsstrategy, 99 }; 100 101 /* 102 * mfs vfs operations. 103 */ 104 static struct vfsops mfs_vfsops = { 105 .vfs_mount = mfs_mount, 106 .vfs_start = mfs_start, 107 .vfs_unmount = ffs_unmount, 108 .vfs_root = ufs_root, 109 .vfs_quotactl = ufs_quotactl, 110 .vfs_statfs = mfs_statfs, 111 .vfs_sync = ffs_sync, 112 .vfs_vget = ffs_vget, 113 .vfs_fhtovp = ffs_fhtovp, 114 .vfs_checkexp = ufs_check_export, 115 .vfs_vptofh = ffs_vptofh, 116 .vfs_init = mfs_init 117 }; 118 119 VFS_SET(mfs_vfsops, mfs, 0); 120 MODULE_VERSION(mfs, 1); 121 122 /* 123 * We allow the underlying MFS block device to be opened and read. 124 */ 125 int 126 mfsopen(struct dev_open_args *ap) 127 { 128 cdev_t dev = ap->a_head.a_dev; 129 130 #if 0 131 if (ap->a_oflags & FWRITE) 132 return(EROFS); 133 #endif 134 if (dev->si_drv1) 135 return(0); 136 return(ENXIO); 137 } 138 139 int 140 mfsclose(struct dev_close_args *ap) 141 { 142 cdev_t dev = ap->a_head.a_dev; 143 struct mfsnode *mfsp; 144 145 if ((mfsp = dev->si_drv1) == NULL) 146 return(0); 147 mfsp->mfs_active = 0; 148 wakeup((caddr_t)mfsp); 149 return(0); 150 } 151 152 int 153 mfsstrategy(struct dev_strategy_args *ap) 154 { 155 cdev_t dev = ap->a_head.a_dev; 156 struct bio *bio = ap->a_bio; 157 struct buf *bp = bio->bio_buf; 158 off_t boff = bio->bio_offset; 159 off_t eoff = boff + bp->b_bcount; 160 struct mfsnode *mfsp; 161 162 if ((mfsp = dev->si_drv1) == NULL) { 163 bp->b_error = ENXIO; 164 goto error; 165 } 166 if (boff < 0) 167 goto bad; 168 if (eoff > mfsp->mfs_size) { 169 if (boff > mfsp->mfs_size || (bp->b_flags & B_BNOCLIP)) 170 goto bad; 171 /* 172 * Return EOF by completing the I/O with 0 bytes transfered. 173 * Set B_INVAL to indicate that any data in the buffer is not 174 * valid. 175 */ 176 if (boff == mfsp->mfs_size) { 177 bp->b_resid = bp->b_bcount; 178 bp->b_flags |= B_INVAL; 179 goto done; 180 } 181 bp->b_bcount = mfsp->mfs_size - boff; 182 } 183 184 /* 185 * Initiate I/O 186 */ 187 if (mfsp->mfs_td == curthread) { 188 mfs_doio(bio, mfsp); 189 } else { 190 bioq_insert_tail(&mfsp->bio_queue, bio); 191 wakeup((caddr_t)mfsp); 192 } 193 return(0); 194 195 /* 196 * Failure conditions on bio 197 */ 198 bad: 199 bp->b_error = EINVAL; 200 error: 201 bp->b_flags |= B_ERROR | B_INVAL; 202 done: 203 biodone(bio); 204 return(0); 205 } 206 207 /* 208 * mfs_mount 209 * 210 * Called when mounting local physical media 211 * 212 * PARAMETERS: 213 * mountroot 214 * mp mount point structure 215 * path NULL (flag for root mount!!!) 216 * data <unused> 217 * ndp <unused> 218 * p process (user credentials check [statfs]) 219 * 220 * mount 221 * mp mount point structure 222 * path path to mount point 223 * data pointer to argument struct in user space 224 * ndp mount point namei() return (used for 225 * credentials on reload), reused to look 226 * up block device. 227 * p process (user credentials check) 228 * 229 * RETURNS: 0 Success 230 * !0 error number (errno.h) 231 * 232 * LOCK STATE: 233 * 234 * ENTRY 235 * mount point is locked 236 * EXIT 237 * mount point is locked 238 * 239 * NOTES: 240 * A NULL path can be used for a flag since the mount 241 * system call will fail with EFAULT in copyinstr in 242 * namei() if it is a genuine NULL from the user. 243 */ 244 /* ARGSUSED */ 245 static int 246 mfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred) 247 { 248 struct vnode *devvp; 249 struct mfs_args args; 250 struct ufsmount *ump; 251 struct fs *fs; 252 struct mfsnode *mfsp; 253 struct nlookupdata nd; 254 size_t size; 255 char devname[16]; 256 int flags; 257 int minnum; 258 int error; 259 cdev_t dev; 260 261 /* 262 * Use NULL path to flag a root mount 263 */ 264 if (path == NULL) { 265 /* 266 *** 267 * Mounting root file system 268 *** 269 */ 270 271 /* you lose */ 272 panic("mfs_mount: mount MFS as root: not configured!"); 273 } 274 275 mfsp = NULL; 276 277 /* 278 *** 279 * Mounting non-root file system or updating a file system 280 *** 281 */ 282 283 /* copy in user arguments*/ 284 error = copyin(data, (caddr_t)&args, sizeof (struct mfs_args)); 285 if (error) 286 goto error_1; 287 288 /* 289 * If updating, check whether changing from read-only to 290 * read/write; if there is no device name, that's all we do. 291 */ 292 if (mp->mnt_flag & MNT_UPDATE) { 293 /* 294 ******************** 295 * UPDATE 296 ******************** 297 */ 298 ump = VFSTOUFS(mp); 299 fs = ump->um_fs; 300 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 301 flags = WRITECLOSE; 302 if (mp->mnt_flag & MNT_FORCE) 303 flags |= FORCECLOSE; 304 error = ffs_flushfiles(mp, flags); 305 if (error) 306 goto error_1; 307 } 308 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) { 309 /* XXX reopen the device vnode read-write */ 310 fs->fs_ronly = 0; 311 } 312 /* if not updating name...*/ 313 if (args.fspec == 0) { 314 /* 315 * Process export requests. Jumping to "success" 316 * will return the vfs_export() error code. 317 */ 318 error = vfs_export(mp, &ump->um_export, &args.export); 319 goto success; 320 } 321 322 /* XXX MFS does not support name updating*/ 323 goto success; 324 } 325 326 /* 327 * Do the MALLOC before the make_dev since doing so afterward 328 * might cause a bogus v_data pointer to get dereferenced 329 * elsewhere if MALLOC should block. 330 */ 331 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, 332 M_WAITOK|M_ZERO); 333 334 minnum = (int)curproc->p_pid; 335 336 dev = make_dev(&mfs_ops, minnum, UID_ROOT, GID_WHEEL, 0600, 337 "mfs%d", minnum); 338 /* It is not clear that these will get initialized otherwise */ 339 dev->si_bsize_phys = DEV_BSIZE; 340 dev->si_iosize_max = DFLTPHYS; 341 dev->si_drv1 = mfsp; 342 mfsp->mfs_baseoff = args.base; 343 mfsp->mfs_size = args.size; 344 mfsp->mfs_dev = dev; 345 mfsp->mfs_td = curthread; 346 mfsp->mfs_active = 1; 347 bioq_init(&mfsp->bio_queue); 348 349 devfs_config(); /* sync devfs work */ 350 ksnprintf(devname, sizeof(devname), "/dev/mfs%d", minnum); 351 nlookup_init(&nd, devname, UIO_SYSSPACE, 0); 352 devvp = NULL; 353 error = nlookup(&nd); 354 if (error == 0) { 355 devvp = nd.nl_nch.ncp->nc_vp; 356 if (devvp == NULL) 357 error = ENOENT; 358 error = vget(devvp, LK_SHARED); 359 } 360 nlookup_done(&nd); 361 362 if (error) 363 goto error_1; 364 vn_unlock(devvp); 365 366 /* 367 * Our 'block' device must be backed by a VM object. Theoretically 368 * we could use the anonymous memory VM object supplied by userland, 369 * but it would be somewhat of a complex task to deal with it 370 * that way since it would result in I/O requests which supply 371 * the VM pages from our own object. 372 * 373 * vnode_pager_alloc() is typically called when a VM object is 374 * being referenced externally. We have to undo the refs for 375 * the self reference between vnode and object. 376 */ 377 vnode_pager_setsize(devvp, args.size); 378 379 /* Save "mounted from" info for mount point (NULL pad)*/ 380 copyinstr(args.fspec, /* device name*/ 381 mp->mnt_stat.f_mntfromname, /* save area*/ 382 MNAMELEN - 1, /* max size*/ 383 &size); /* real size*/ 384 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 385 /* vref is eaten by mount? */ 386 387 error = ffs_mountfs(devvp, mp, M_MFSNODE); 388 if (error) { 389 mfsp->mfs_active = 0; 390 goto error_2; 391 } 392 393 /* 394 * Initialize FS stat information in mount struct; uses 395 * mp->mnt_stat.f_mntfromname. 396 * 397 * This code is common to root and non-root mounts 398 */ 399 VFS_STATFS(mp, &mp->mnt_stat, cred); 400 401 goto success; 402 403 error_2: /* error with devvp held*/ 404 vrele(devvp); 405 406 error_1: /* no state to back out*/ 407 if (mfsp) { 408 if (mfsp->mfs_dev) { 409 destroy_dev(mfsp->mfs_dev); 410 mfsp->mfs_dev = NULL; 411 } 412 FREE(mfsp, M_MFSNODE); 413 } 414 415 success: 416 return(error); 417 } 418 419 /* 420 * Used to grab the process and keep it in the kernel to service 421 * memory filesystem I/O requests. 422 * 423 * Loop servicing I/O requests. 424 * Copy the requested data into or out of the memory filesystem 425 * address space. 426 */ 427 /* ARGSUSED */ 428 static int 429 mfs_start(struct mount *mp, int flags) 430 { 431 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 432 struct mfsnode *mfsp = vp->v_rdev->si_drv1; 433 struct bio *bio; 434 struct buf *bp; 435 int gotsig = 0, sig; 436 thread_t td = curthread; 437 438 /* 439 * We must prevent the system from trying to swap 440 * out or kill ( when swap space is low, see vm/pageout.c ) the 441 * process. A deadlock can occur if the process is swapped out, 442 * and the system can loop trying to kill the unkillable ( while 443 * references exist ) MFS process when swap space is low. 444 */ 445 KKASSERT(curproc); 446 PHOLD(curproc); 447 448 mfsp->mfs_td = td; 449 450 while (mfsp->mfs_active) { 451 crit_enter(); 452 453 while ((bio = bioq_first(&mfsp->bio_queue)) != NULL) { 454 bioq_remove(&mfsp->bio_queue, bio); 455 crit_exit(); 456 bp = bio->bio_buf; 457 mfs_doio(bio, mfsp); 458 wakeup(bp); 459 crit_enter(); 460 } 461 462 crit_exit(); 463 464 /* 465 * If a non-ignored signal is received, try to unmount. 466 * If that fails, clear the signal (it has been "processed"), 467 * otherwise we will loop here, as tsleep will always return 468 * EINTR/ERESTART. 469 */ 470 /* 471 * Note that dounmount() may fail if work was queued after 472 * we slept. We have to jump hoops here to make sure that we 473 * process any buffers after the sleep, before we dounmount() 474 */ 475 if (gotsig) { 476 gotsig = 0; 477 if (dounmount(mp, 0) != 0) { 478 KKASSERT(td->td_proc); 479 sig = CURSIG(td->td_lwp); 480 if (sig) { 481 spin_lock(&td->td_lwp->lwp_spin); 482 lwp_delsig(td->td_lwp, sig); 483 spin_unlock(&td->td_lwp->lwp_spin); 484 } 485 } 486 } 487 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0)) 488 gotsig++; /* try to unmount in next pass */ 489 } 490 PRELE(curproc); 491 if (mfsp->mfs_dev) { 492 destroy_dev(mfsp->mfs_dev); 493 mfsp->mfs_dev = NULL; 494 } 495 FREE(mfsp, M_MFSNODE); 496 return (0); 497 } 498 499 /* 500 * Get file system statistics. 501 */ 502 static int 503 mfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred) 504 { 505 int error; 506 507 error = ffs_statfs(mp, sbp, cred); 508 sbp->f_type = mp->mnt_vfc->vfc_typenum; 509 return (error); 510 } 511 512 /* 513 * Memory based filesystem initialization. 514 */ 515 static int 516 mfs_init(struct vfsconf *vfsp) 517 { 518 return (0); 519 } 520 521 /* 522 * Memory file system I/O. 523 * 524 * Trivial on the HP since buffer has already been mapping into KVA space. 525 * 526 * Read and Write are handled with a simple copyin and copyout. 527 * 528 * We also partially support VOP_FREEBLKS(). We can't implement 529 * completely -- for example, on fragments or inode metadata, but we can 530 * implement it for page-aligned requests. 531 */ 532 static void 533 mfs_doio(struct bio *bio, struct mfsnode *mfsp) 534 { 535 struct buf *bp = bio->bio_buf; 536 caddr_t base = mfsp->mfs_baseoff + bio->bio_offset; 537 int bytes; 538 539 switch(bp->b_cmd) { 540 case BUF_CMD_FREEBLKS: 541 /* 542 * Implement FREEBLKS, which allows the filesystem to tell 543 * a block device when blocks are no longer needed (like when 544 * a file is deleted). We use the hook to MADV_FREE the VM. 545 * This makes an MFS filesystem work as well or better then 546 * a sun-style swap-mounted filesystem. 547 */ 548 bytes = bp->b_bcount; 549 550 if ((vm_offset_t)base & PAGE_MASK) { 551 int n = PAGE_SIZE - ((vm_offset_t)base & PAGE_MASK); 552 bytes -= n; 553 base += n; 554 } 555 if (bytes > 0) { 556 struct madvise_args uap; 557 558 bytes &= ~PAGE_MASK; 559 if (bytes != 0) { 560 bzero(&uap, sizeof(uap)); 561 uap.addr = base; 562 uap.len = bytes; 563 uap.behav = MADV_FREE; 564 sys_madvise(&uap); 565 } 566 } 567 bp->b_error = 0; 568 break; 569 case BUF_CMD_READ: 570 /* 571 * Read data from our 'memory' disk 572 */ 573 bp->b_error = copyin(base, bp->b_data, bp->b_bcount); 574 break; 575 case BUF_CMD_WRITE: 576 /* 577 * Write data to our 'memory' disk 578 */ 579 bp->b_error = copyout(bp->b_data, base, bp->b_bcount); 580 break; 581 default: 582 panic("mfs: bad b_cmd %d\n", bp->b_cmd); 583 } 584 if (bp->b_error) 585 bp->b_flags |= B_ERROR; 586 biodone(bio); 587 } 588