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 1.34 2006/07/28 02:17:41 dillon 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/vnode.h> 49 #include <sys/malloc.h> 50 #include <sys/linker.h> 51 #include <sys/fcntl.h> 52 53 #include <vm/vm.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_page.h> 56 #include <vm/vm_pager.h> 57 #include <vm/vnode_pager.h> 58 59 #include <sys/buf2.h> 60 #include <sys/thread2.h> 61 62 #include <vfs/ufs/quota.h> 63 #include <vfs/ufs/inode.h> 64 #include <vfs/ufs/ufsmount.h> 65 #include <vfs/ufs/ufs_extern.h> 66 #include <vfs/ufs/fs.h> 67 #include <vfs/ufs/ffs_extern.h> 68 69 #include "mfsnode.h" 70 #include "mfs_extern.h" 71 72 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); 73 74 extern struct vop_ops *mfs_vnode_vops_p; 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 83 d_open_t mfsopen; 84 d_close_t mfsclose; 85 d_strategy_t mfsstrategy; 86 87 #define MFS_CDEV_MAJOR 253 88 89 static struct dev_ops mfs_ops = { 90 { "MFS", MFS_CDEV_MAJOR, D_DISK }, 91 .d_open = mfsopen, 92 .d_close = mfsclose, 93 .d_read = physread, 94 .d_write = physwrite, 95 .d_strategy = mfsstrategy, 96 }; 97 98 /* 99 * mfs vfs operations. 100 */ 101 static struct vfsops mfs_vfsops = { 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); 117 118 /* 119 * We allow the underlying MFS block device to be opened and read. 120 */ 121 int 122 mfsopen(struct dev_open_args *ap) 123 { 124 dev_t dev = ap->a_head.a_dev; 125 126 if (ap->a_oflags & FWRITE) 127 return(EROFS); 128 if (dev->si_drv1) 129 return(0); 130 return(ENXIO); 131 } 132 133 int 134 mfsclose(struct dev_close_args *ap) 135 { 136 return(0); 137 } 138 139 int 140 mfsstrategy(struct dev_strategy_args *ap) 141 { 142 dev_t dev = ap->a_head.a_dev; 143 struct bio *bio = ap->a_bio; 144 struct buf *bp = bio->bio_buf; 145 off_t boff = bio->bio_offset; 146 off_t eoff = boff + bp->b_bcount; 147 struct mfsnode *mfsp; 148 149 if ((mfsp = dev->si_drv1) == NULL) { 150 bp->b_error = ENXIO; 151 goto error; 152 } 153 if (boff < 0) 154 goto bad; 155 if (eoff > mfsp->mfs_size) { 156 if (boff > mfsp->mfs_size || (bp->b_flags & B_BNOCLIP)) 157 goto bad; 158 /* 159 * Return EOF by completing the I/O with 0 bytes transfered. 160 * Set B_INVAL to indicate that any data in the buffer is not 161 * valid. 162 */ 163 if (boff == mfsp->mfs_size) { 164 bp->b_resid = bp->b_bcount; 165 bp->b_flags |= B_INVAL; 166 goto done; 167 } 168 bp->b_bcount = mfsp->mfs_size - boff; 169 } 170 171 /* 172 * Initiate I/O 173 */ 174 bioq_insert_tail(&mfsp->bio_queue, bio); 175 wakeup((caddr_t)mfsp); 176 return(0); 177 178 /* 179 * Failure conditions on bio 180 */ 181 bad: 182 bp->b_error = EINVAL; 183 error: 184 bp->b_flags |= B_ERROR | B_INVAL; 185 done: 186 biodone(bio); 187 return(0); 188 } 189 190 /* 191 * mfs_mount 192 * 193 * Called when mounting local physical media 194 * 195 * PARAMETERS: 196 * mountroot 197 * mp mount point structure 198 * path NULL (flag for root mount!!!) 199 * data <unused> 200 * ndp <unused> 201 * p process (user credentials check [statfs]) 202 * 203 * mount 204 * mp mount point structure 205 * path path to mount point 206 * data pointer to argument struct in user space 207 * ndp mount point namei() return (used for 208 * credentials on reload), reused to look 209 * up block device. 210 * p process (user credentials check) 211 * 212 * RETURNS: 0 Success 213 * !0 error number (errno.h) 214 * 215 * LOCK STATE: 216 * 217 * ENTRY 218 * mount point is locked 219 * EXIT 220 * mount point is locked 221 * 222 * NOTES: 223 * A NULL path can be used for a flag since the mount 224 * system call will fail with EFAULT in copyinstr in 225 * namei() if it is a genuine NULL from the user. 226 */ 227 /* ARGSUSED */ 228 static int 229 mfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred) 230 { 231 struct vnode *devvp; 232 struct mfs_args args; 233 struct ufsmount *ump; 234 struct fs *fs; 235 struct mfsnode *mfsp; 236 size_t size; 237 int flags, err; 238 int minnum; 239 dev_t dev; 240 241 /* 242 * Use NULL path to flag a root mount 243 */ 244 if( path == NULL) { 245 /* 246 *** 247 * Mounting root file system 248 *** 249 */ 250 251 /* you lose */ 252 panic("mfs_mount: mount MFS as root: not configured!"); 253 } 254 255 /* 256 *** 257 * Mounting non-root file system or updating a file system 258 *** 259 */ 260 261 /* copy in user arguments*/ 262 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0) 263 goto error_1; 264 265 /* 266 * If updating, check whether changing from read-only to 267 * read/write; if there is no device name, that's all we do. 268 */ 269 if (mp->mnt_flag & MNT_UPDATE) { 270 /* 271 ******************** 272 * UPDATE 273 ******************** 274 */ 275 ump = VFSTOUFS(mp); 276 fs = ump->um_fs; 277 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 278 flags = WRITECLOSE; 279 if (mp->mnt_flag & MNT_FORCE) 280 flags |= FORCECLOSE; 281 err = ffs_flushfiles(mp, flags); 282 if (err) 283 goto error_1; 284 } 285 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) { 286 /* XXX reopen the device vnode read-write */ 287 fs->fs_ronly = 0; 288 } 289 /* if not updating name...*/ 290 if (args.fspec == 0) { 291 /* 292 * Process export requests. Jumping to "success" 293 * will return the vfs_export() error code. 294 */ 295 err = vfs_export(mp, &ump->um_export, &args.export); 296 goto success; 297 } 298 299 /* XXX MFS does not support name updating*/ 300 goto success; 301 } 302 /* 303 * Do the MALLOC before the getnewvnode since doing so afterward 304 * might cause a bogus v_data pointer to get dereferenced 305 * elsewhere if MALLOC should block. 306 */ 307 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK); 308 309 err = getspecialvnode(VT_MFS, NULL, &mfs_vnode_vops_p, &devvp, 0, 0); 310 if (err) { 311 FREE(mfsp, M_MFSNODE); 312 goto error_1; 313 } 314 315 minnum = (curproc->p_pid & 0xFF) | 316 ((curproc->p_pid & ~0xFF) << 8); 317 318 devvp->v_type = VCHR; 319 dev = make_dev(&mfs_ops, minnum, UID_ROOT, GID_WHEEL, 0600, 320 "MFS%d", minnum >> 16); 321 /* It is not clear that these will get initialized otherwise */ 322 dev->si_bsize_phys = DEV_BSIZE; 323 dev->si_iosize_max = DFLTPHYS; 324 dev->si_drv1 = mfsp; 325 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum)); 326 devvp->v_data = mfsp; 327 mfsp->mfs_baseoff = args.base; 328 mfsp->mfs_size = args.size; 329 mfsp->mfs_vnode = devvp; 330 mfsp->mfs_dev = reference_dev(dev); 331 mfsp->mfs_td = curthread; 332 mfsp->mfs_active = 1; 333 bioq_init(&mfsp->bio_queue); 334 335 /* 336 * Our 'block' device must be backed by a VM object. Theoretically 337 * we could use the anonymous memory VM object supplied by userland, 338 * but it would be somewhat of a complex task to deal with it 339 * that way since it would result in I/O requests which supply 340 * the VM pages from our own object. 341 * 342 * vnode_pager_alloc() is typically called when a VM object is 343 * being referenced externally. We have to undo the refs for 344 * the self reference between vnode and object. 345 */ 346 vnode_pager_alloc(devvp, args.size, 0, 0); 347 --devvp->v_usecount; 348 --devvp->v_object->ref_count; 349 350 /* Save "mounted from" info for mount point (NULL pad)*/ 351 copyinstr( args.fspec, /* device name*/ 352 mp->mnt_stat.f_mntfromname, /* save area*/ 353 MNAMELEN - 1, /* max size*/ 354 &size); /* real size*/ 355 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 356 357 vx_unlock(devvp); 358 if ((err = ffs_mountfs(devvp, mp, M_MFSNODE)) != 0) { 359 mfsp->mfs_active = 0; 360 goto error_2; 361 } 362 363 /* 364 * Initialize FS stat information in mount struct; uses 365 * mp->mnt_stat.f_mntfromname. 366 * 367 * This code is common to root and non-root mounts 368 */ 369 VFS_STATFS(mp, &mp->mnt_stat, cred); 370 371 goto success; 372 373 error_2: /* error with devvp held*/ 374 375 /* release devvp before failing*/ 376 vrele(devvp); 377 378 error_1: /* no state to back out*/ 379 380 success: 381 return( err); 382 } 383 384 /* 385 * Used to grab the process and keep it in the kernel to service 386 * memory filesystem I/O requests. 387 * 388 * Loop servicing I/O requests. 389 * Copy the requested data into or out of the memory filesystem 390 * address space. 391 */ 392 /* ARGSUSED */ 393 static int 394 mfs_start(struct mount *mp, int flags) 395 { 396 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 397 struct mfsnode *mfsp = VTOMFS(vp); 398 struct bio *bio; 399 struct buf *bp; 400 int gotsig = 0, sig; 401 thread_t td = curthread; 402 403 /* 404 * We must prevent the system from trying to swap 405 * out or kill ( when swap space is low, see vm/pageout.c ) the 406 * process. A deadlock can occur if the process is swapped out, 407 * and the system can loop trying to kill the unkillable ( while 408 * references exist ) MFS process when swap space is low. 409 */ 410 KKASSERT(curproc); 411 PHOLD(curproc); 412 413 mfsp->mfs_td = td; 414 415 while (mfsp->mfs_active) { 416 crit_enter(); 417 418 while ((bio = bioq_first(&mfsp->bio_queue)) != NULL) { 419 bioq_remove(&mfsp->bio_queue, bio); 420 crit_exit(); 421 bp = bio->bio_buf; 422 mfs_doio(bio, mfsp); 423 wakeup(bp); 424 crit_enter(); 425 } 426 427 crit_exit(); 428 429 /* 430 * If a non-ignored signal is received, try to unmount. 431 * If that fails, clear the signal (it has been "processed"), 432 * otherwise we will loop here, as tsleep will always return 433 * EINTR/ERESTART. 434 */ 435 /* 436 * Note that dounmount() may fail if work was queued after 437 * we slept. We have to jump hoops here to make sure that we 438 * process any buffers after the sleep, before we dounmount() 439 */ 440 if (gotsig) { 441 gotsig = 0; 442 if (dounmount(mp, 0) != 0) { 443 KKASSERT(td->td_proc); 444 sig = CURSIG(td->td_proc); 445 if (sig) 446 SIGDELSET(td->td_proc->p_siglist, sig); 447 } 448 } 449 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0)) 450 gotsig++; /* try to unmount in next pass */ 451 } 452 PRELE(curproc); 453 v_release_rdev(vp); /* hack because we do not implement CLOSE */ 454 /* XXX destroy/release devvp */ 455 return (0); 456 } 457 458 /* 459 * Get file system statistics. 460 */ 461 static int 462 mfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred) 463 { 464 int error; 465 466 error = ffs_statfs(mp, sbp, cred); 467 sbp->f_type = mp->mnt_vfc->vfc_typenum; 468 return (error); 469 } 470 471 /* 472 * Memory based filesystem initialization. 473 */ 474 static int 475 mfs_init(struct vfsconf *vfsp) 476 { 477 dev_ops_add(&mfs_ops, 0, 0); 478 return (0); 479 } 480