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 1.38 2007/02/25 23:17:13 corecode 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/linker.h> 52 #include <sys/fcntl.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 60 #include <sys/buf2.h> 61 #include <sys/thread2.h> 62 63 #include <vfs/ufs/quota.h> 64 #include <vfs/ufs/inode.h> 65 #include <vfs/ufs/ufsmount.h> 66 #include <vfs/ufs/ufs_extern.h> 67 #include <vfs/ufs/fs.h> 68 #include <vfs/ufs/ffs_extern.h> 69 70 #include "mfsnode.h" 71 #include "mfs_extern.h" 72 73 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); 74 75 extern struct vop_ops *mfs_vnode_vops_p; 76 77 static int mfs_mount (struct mount *mp, 78 char *path, caddr_t data, struct ucred *td); 79 static int mfs_start (struct mount *mp, int flags); 80 static int mfs_statfs (struct mount *mp, struct statfs *sbp, 81 struct ucred *cred); 82 static int mfs_init (struct vfsconf *); 83 84 d_open_t mfsopen; 85 d_close_t mfsclose; 86 d_strategy_t mfsstrategy; 87 88 #define MFS_CDEV_MAJOR 253 89 90 static struct dev_ops mfs_ops = { 91 { "MFS", MFS_CDEV_MAJOR, D_DISK }, 92 .d_open = mfsopen, 93 .d_close = mfsclose, 94 .d_read = physread, 95 .d_write = physwrite, 96 .d_strategy = mfsstrategy, 97 }; 98 99 /* 100 * mfs vfs operations. 101 */ 102 static struct vfsops mfs_vfsops = { 103 .vfs_mount = mfs_mount, 104 .vfs_start = mfs_start, 105 .vfs_unmount = ffs_unmount, 106 .vfs_root = ufs_root, 107 .vfs_quotactl = ufs_quotactl, 108 .vfs_statfs = mfs_statfs, 109 .vfs_sync = ffs_sync, 110 .vfs_vget = ffs_vget, 111 .vfs_fhtovp = ffs_fhtovp, 112 .vfs_checkexp = ufs_check_export, 113 .vfs_vptofh = ffs_vptofh, 114 .vfs_init = mfs_init 115 }; 116 117 VFS_SET(mfs_vfsops, mfs, 0); 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 (ap->a_oflags & FWRITE) 128 return(EROFS); 129 if (dev->si_drv1) 130 return(0); 131 return(ENXIO); 132 } 133 134 int 135 mfsclose(struct dev_close_args *ap) 136 { 137 return(0); 138 } 139 140 int 141 mfsstrategy(struct dev_strategy_args *ap) 142 { 143 cdev_t dev = ap->a_head.a_dev; 144 struct bio *bio = ap->a_bio; 145 struct buf *bp = bio->bio_buf; 146 off_t boff = bio->bio_offset; 147 off_t eoff = boff + bp->b_bcount; 148 struct mfsnode *mfsp; 149 150 if ((mfsp = dev->si_drv1) == NULL) { 151 bp->b_error = ENXIO; 152 goto error; 153 } 154 if (boff < 0) 155 goto bad; 156 if (eoff > mfsp->mfs_size) { 157 if (boff > mfsp->mfs_size || (bp->b_flags & B_BNOCLIP)) 158 goto bad; 159 /* 160 * Return EOF by completing the I/O with 0 bytes transfered. 161 * Set B_INVAL to indicate that any data in the buffer is not 162 * valid. 163 */ 164 if (boff == mfsp->mfs_size) { 165 bp->b_resid = bp->b_bcount; 166 bp->b_flags |= B_INVAL; 167 goto done; 168 } 169 bp->b_bcount = mfsp->mfs_size - boff; 170 } 171 172 /* 173 * Initiate I/O 174 */ 175 bioq_insert_tail(&mfsp->bio_queue, bio); 176 wakeup((caddr_t)mfsp); 177 return(0); 178 179 /* 180 * Failure conditions on bio 181 */ 182 bad: 183 bp->b_error = EINVAL; 184 error: 185 bp->b_flags |= B_ERROR | B_INVAL; 186 done: 187 biodone(bio); 188 return(0); 189 } 190 191 /* 192 * mfs_mount 193 * 194 * Called when mounting local physical media 195 * 196 * PARAMETERS: 197 * mountroot 198 * mp mount point structure 199 * path NULL (flag for root mount!!!) 200 * data <unused> 201 * ndp <unused> 202 * p process (user credentials check [statfs]) 203 * 204 * mount 205 * mp mount point structure 206 * path path to mount point 207 * data pointer to argument struct in user space 208 * ndp mount point namei() return (used for 209 * credentials on reload), reused to look 210 * up block device. 211 * p process (user credentials check) 212 * 213 * RETURNS: 0 Success 214 * !0 error number (errno.h) 215 * 216 * LOCK STATE: 217 * 218 * ENTRY 219 * mount point is locked 220 * EXIT 221 * mount point is locked 222 * 223 * NOTES: 224 * A NULL path can be used for a flag since the mount 225 * system call will fail with EFAULT in copyinstr in 226 * namei() if it is a genuine NULL from the user. 227 */ 228 /* ARGSUSED */ 229 static int 230 mfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred) 231 { 232 struct vnode *devvp; 233 struct mfs_args args; 234 struct ufsmount *ump; 235 struct fs *fs; 236 struct mfsnode *mfsp; 237 size_t size; 238 int flags, err; 239 int minnum; 240 cdev_t dev; 241 242 /* 243 * Use NULL path to flag a root mount 244 */ 245 if( path == NULL) { 246 /* 247 *** 248 * Mounting root file system 249 *** 250 */ 251 252 /* you lose */ 253 panic("mfs_mount: mount MFS as root: not configured!"); 254 } 255 256 /* 257 *** 258 * Mounting non-root file system or updating a file system 259 *** 260 */ 261 262 /* copy in user arguments*/ 263 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0) 264 goto error_1; 265 266 /* 267 * If updating, check whether changing from read-only to 268 * read/write; if there is no device name, that's all we do. 269 */ 270 if (mp->mnt_flag & MNT_UPDATE) { 271 /* 272 ******************** 273 * UPDATE 274 ******************** 275 */ 276 ump = VFSTOUFS(mp); 277 fs = ump->um_fs; 278 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 279 flags = WRITECLOSE; 280 if (mp->mnt_flag & MNT_FORCE) 281 flags |= FORCECLOSE; 282 err = ffs_flushfiles(mp, flags); 283 if (err) 284 goto error_1; 285 } 286 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) { 287 /* XXX reopen the device vnode read-write */ 288 fs->fs_ronly = 0; 289 } 290 /* if not updating name...*/ 291 if (args.fspec == 0) { 292 /* 293 * Process export requests. Jumping to "success" 294 * will return the vfs_export() error code. 295 */ 296 err = vfs_export(mp, &ump->um_export, &args.export); 297 goto success; 298 } 299 300 /* XXX MFS does not support name updating*/ 301 goto success; 302 } 303 /* 304 * Do the MALLOC before the getnewvnode since doing so afterward 305 * might cause a bogus v_data pointer to get dereferenced 306 * elsewhere if MALLOC should block. 307 */ 308 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK); 309 310 err = getspecialvnode(VT_MFS, NULL, &mfs_vnode_vops_p, &devvp, 0, 0); 311 if (err) { 312 FREE(mfsp, M_MFSNODE); 313 goto error_1; 314 } 315 316 minnum = (curproc->p_pid & 0xFF) | 317 ((curproc->p_pid & ~0xFF) << 8); 318 319 devvp->v_type = VCHR; 320 dev = make_dev(&mfs_ops, minnum, UID_ROOT, GID_WHEEL, 0600, 321 "MFS%d", minnum >> 16); 322 /* It is not clear that these will get initialized otherwise */ 323 dev->si_bsize_phys = DEV_BSIZE; 324 dev->si_iosize_max = DFLTPHYS; 325 dev->si_drv1 = mfsp; 326 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum)); 327 devvp->v_data = mfsp; 328 mfsp->mfs_baseoff = args.base; 329 mfsp->mfs_size = args.size; 330 mfsp->mfs_vnode = devvp; 331 mfsp->mfs_dev = reference_dev(dev); 332 mfsp->mfs_td = curthread; 333 mfsp->mfs_active = 1; 334 bioq_init(&mfsp->bio_queue); 335 336 /* 337 * Our 'block' device must be backed by a VM object. Theoretically 338 * we could use the anonymous memory VM object supplied by userland, 339 * but it would be somewhat of a complex task to deal with it 340 * that way since it would result in I/O requests which supply 341 * the VM pages from our own object. 342 * 343 * vnode_pager_alloc() is typically called when a VM object is 344 * being referenced externally. We have to undo the refs for 345 * the self reference between vnode and object. 346 */ 347 vnode_pager_alloc(devvp, args.size, 0, 0); 348 --devvp->v_usecount; 349 --devvp->v_object->ref_count; 350 351 /* Save "mounted from" info for mount point (NULL pad)*/ 352 copyinstr( args.fspec, /* device name*/ 353 mp->mnt_stat.f_mntfromname, /* save area*/ 354 MNAMELEN - 1, /* max size*/ 355 &size); /* real size*/ 356 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 357 358 vx_unlock(devvp); 359 if ((err = ffs_mountfs(devvp, mp, M_MFSNODE)) != 0) { 360 mfsp->mfs_active = 0; 361 goto error_2; 362 } 363 364 /* 365 * Initialize FS stat information in mount struct; uses 366 * mp->mnt_stat.f_mntfromname. 367 * 368 * This code is common to root and non-root mounts 369 */ 370 VFS_STATFS(mp, &mp->mnt_stat, cred); 371 372 goto success; 373 374 error_2: /* error with devvp held*/ 375 376 /* release devvp before failing*/ 377 vrele(devvp); 378 379 error_1: /* no state to back out*/ 380 381 success: 382 return( err); 383 } 384 385 /* 386 * Used to grab the process and keep it in the kernel to service 387 * memory filesystem I/O requests. 388 * 389 * Loop servicing I/O requests. 390 * Copy the requested data into or out of the memory filesystem 391 * address space. 392 */ 393 /* ARGSUSED */ 394 static int 395 mfs_start(struct mount *mp, int flags) 396 { 397 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 398 struct mfsnode *mfsp = VTOMFS(vp); 399 struct bio *bio; 400 struct buf *bp; 401 int gotsig = 0, sig; 402 thread_t td = curthread; 403 404 /* 405 * We must prevent the system from trying to swap 406 * out or kill ( when swap space is low, see vm/pageout.c ) the 407 * process. A deadlock can occur if the process is swapped out, 408 * and the system can loop trying to kill the unkillable ( while 409 * references exist ) MFS process when swap space is low. 410 */ 411 KKASSERT(curproc); 412 PHOLD(curproc); 413 414 mfsp->mfs_td = td; 415 416 while (mfsp->mfs_active) { 417 crit_enter(); 418 419 while ((bio = bioq_first(&mfsp->bio_queue)) != NULL) { 420 bioq_remove(&mfsp->bio_queue, bio); 421 crit_exit(); 422 bp = bio->bio_buf; 423 mfs_doio(bio, mfsp); 424 wakeup(bp); 425 crit_enter(); 426 } 427 428 crit_exit(); 429 430 /* 431 * If a non-ignored signal is received, try to unmount. 432 * If that fails, clear the signal (it has been "processed"), 433 * otherwise we will loop here, as tsleep will always return 434 * EINTR/ERESTART. 435 */ 436 /* 437 * Note that dounmount() may fail if work was queued after 438 * we slept. We have to jump hoops here to make sure that we 439 * process any buffers after the sleep, before we dounmount() 440 */ 441 if (gotsig) { 442 gotsig = 0; 443 if (dounmount(mp, 0) != 0) { 444 KKASSERT(td->td_proc); 445 sig = CURSIG(td->td_lwp); 446 if (sig) 447 lwp_delsig(td->td_lwp, sig); 448 } 449 } 450 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0)) 451 gotsig++; /* try to unmount in next pass */ 452 } 453 PRELE(curproc); 454 v_release_rdev(vp); /* hack because we do not implement CLOSE */ 455 /* XXX destroy/release devvp */ 456 return (0); 457 } 458 459 /* 460 * Get file system statistics. 461 */ 462 static int 463 mfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred) 464 { 465 int error; 466 467 error = ffs_statfs(mp, sbp, cred); 468 sbp->f_type = mp->mnt_vfc->vfc_typenum; 469 return (error); 470 } 471 472 /* 473 * Memory based filesystem initialization. 474 */ 475 static int 476 mfs_init(struct vfsconf *vfsp) 477 { 478 dev_ops_add(&mfs_ops, 0, 0); 479 return (0); 480 } 481