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 1.19 2004/10/12 19:20:59 dillon Exp $ 36 */ 37 38 39 #include "opt_mfs.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/conf.h> 44 #include <sys/kernel.h> 45 #include <sys/proc.h> 46 #include <sys/buf.h> 47 #include <sys/mount.h> 48 #include <sys/signalvar.h> 49 #include <sys/vnode.h> 50 #include <sys/malloc.h> 51 #include <sys/linker.h> 52 #include <sys/fcntl.h> 53 54 #include <sys/buf2.h> 55 56 #include <vfs/ufs/quota.h> 57 #include <vfs/ufs/inode.h> 58 #include <vfs/ufs/ufsmount.h> 59 #include <vfs/ufs/ufs_extern.h> 60 #include <vfs/ufs/fs.h> 61 #include <vfs/ufs/ffs_extern.h> 62 63 #include "mfsnode.h" 64 #include "mfs_extern.h" 65 66 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); 67 68 69 extern struct vop_ops *mfs_vnode_vops; 70 71 static int mfs_mount (struct mount *mp, 72 char *path, caddr_t data, struct thread *td); 73 static int mfs_start (struct mount *mp, int flags, struct thread *td); 74 static int mfs_statfs (struct mount *mp, struct statfs *sbp, 75 struct thread *td); 76 static int mfs_init (struct vfsconf *); 77 78 d_open_t mfsopen; 79 d_close_t mfsclose; 80 d_strategy_t mfsstrategy; 81 82 #define MFS_CDEV_MAJOR 253 83 84 static struct cdevsw mfs_cdevsw = { 85 /* name */ "MFS", 86 /* maj */ MFS_CDEV_MAJOR, 87 /* flags */ D_DISK, 88 /* port */ NULL, 89 /* clone */ NULL, 90 91 /* open */ mfsopen, 92 /* close */ mfsclose, 93 /* read */ physread, 94 /* write */ physwrite, 95 /* ioctl */ noioctl, 96 /* poll */ nopoll, 97 /* mmap */ nommap, 98 /* strategy */ mfsstrategy, 99 /* dump */ nodump, 100 /* psize */ nopsize 101 }; 102 103 /* 104 * mfs vfs operations. 105 */ 106 static struct vfsops mfs_vfsops = { 107 mfs_mount, 108 mfs_start, 109 ffs_unmount, 110 ufs_root, 111 ufs_quotactl, 112 mfs_statfs, 113 ffs_sync, 114 ffs_vget, 115 ffs_fhtovp, 116 ufs_check_export, 117 ffs_vptofh, 118 mfs_init, 119 vfs_stduninit, 120 vfs_stdextattrctl, 121 }; 122 123 VFS_SET(mfs_vfsops, mfs, 0); 124 125 /* 126 * We allow the underlying MFS block device to be opened and read. 127 */ 128 int 129 mfsopen(dev_t dev, int flags, int mode, struct thread *td) 130 { 131 if (flags & FWRITE) 132 return(EROFS); 133 if (dev->si_drv1) 134 return(0); 135 return(ENXIO); 136 } 137 138 int 139 mfsclose(dev_t dev, int flags, int mode, struct thread *td) 140 { 141 return(0); 142 } 143 144 void 145 mfsstrategy(struct buf *bp) 146 { 147 struct mfsnode *mfsp; 148 149 if ((mfsp = bp->b_dev->si_drv1) != NULL) { 150 off_t boff = (off_t)bp->b_blkno << DEV_BSHIFT; 151 off_t eoff = boff + bp->b_bcount; 152 153 if (eoff <= mfsp->mfs_size) { 154 bufq_insert_tail(&mfsp->buf_queue, bp); 155 wakeup((caddr_t)mfsp); 156 } else if (boff < mfsp->mfs_size) { 157 bp->b_bcount = mfsp->mfs_size - boff; 158 bufq_insert_tail(&mfsp->buf_queue, bp); 159 wakeup((caddr_t)mfsp); 160 } else if (boff == mfsp->mfs_size) { 161 bp->b_resid = bp->b_bcount; 162 biodone(bp); 163 } else { 164 bp->b_error = EINVAL; 165 biodone(bp); 166 } 167 } else { 168 bp->b_error = ENXIO; 169 bp->b_flags |= B_ERROR; 170 biodone(bp); 171 } 172 } 173 174 /* 175 * mfs_mount 176 * 177 * Called when mounting local physical media 178 * 179 * PARAMETERS: 180 * mountroot 181 * mp mount point structure 182 * path NULL (flag for root mount!!!) 183 * data <unused> 184 * ndp <unused> 185 * p process (user credentials check [statfs]) 186 * 187 * mount 188 * mp mount point structure 189 * path path to mount point 190 * data pointer to argument struct in user space 191 * ndp mount point namei() return (used for 192 * credentials on reload), reused to look 193 * up block device. 194 * p process (user credentials check) 195 * 196 * RETURNS: 0 Success 197 * !0 error number (errno.h) 198 * 199 * LOCK STATE: 200 * 201 * ENTRY 202 * mount point is locked 203 * EXIT 204 * mount point is locked 205 * 206 * NOTES: 207 * A NULL path can be used for a flag since the mount 208 * system call will fail with EFAULT in copyinstr in 209 * namei() if it is a genuine NULL from the user. 210 */ 211 /* ARGSUSED */ 212 static int 213 mfs_mount(struct mount *mp, char *path, caddr_t data, struct thread *td) 214 { 215 struct vnode *devvp; 216 struct mfs_args args; 217 struct ufsmount *ump; 218 struct fs *fs; 219 struct mfsnode *mfsp; 220 size_t size; 221 int flags, err; 222 int minnum; 223 dev_t dev; 224 225 /* 226 * Use NULL path to flag a root mount 227 */ 228 if( path == NULL) { 229 /* 230 *** 231 * Mounting root file system 232 *** 233 */ 234 235 /* you lose */ 236 panic("mfs_mount: mount MFS as root: not configured!"); 237 } 238 239 /* 240 *** 241 * Mounting non-root file system or updating a file system 242 *** 243 */ 244 245 /* copy in user arguments*/ 246 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0) 247 goto error_1; 248 249 /* 250 * If updating, check whether changing from read-only to 251 * read/write; if there is no device name, that's all we do. 252 */ 253 if (mp->mnt_flag & MNT_UPDATE) { 254 /* 255 ******************** 256 * UPDATE 257 ******************** 258 */ 259 ump = VFSTOUFS(mp); 260 fs = ump->um_fs; 261 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 262 flags = WRITECLOSE; 263 if (mp->mnt_flag & MNT_FORCE) 264 flags |= FORCECLOSE; 265 err = ffs_flushfiles(mp, flags, td); 266 if (err) 267 goto error_1; 268 } 269 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) 270 fs->fs_ronly = 0; 271 /* if not updating name...*/ 272 if (args.fspec == 0) { 273 /* 274 * Process export requests. Jumping to "success" 275 * will return the vfs_export() error code. 276 */ 277 err = vfs_export(mp, &ump->um_export, &args.export); 278 goto success; 279 } 280 281 /* XXX MFS does not support name updating*/ 282 goto success; 283 } 284 /* 285 * Do the MALLOC before the getnewvnode since doing so afterward 286 * might cause a bogus v_data pointer to get dereferenced 287 * elsewhere if MALLOC should block. 288 */ 289 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK); 290 291 err = getnewvnode(VT_MFS, NULL, mfs_vnode_vops, &devvp, 0, 0); 292 if (err) { 293 FREE(mfsp, M_MFSNODE); 294 goto error_1; 295 } 296 297 minnum = (curproc->p_pid & 0xFF) | 298 ((curproc->p_pid & ~0xFF) << 8); 299 300 devvp->v_type = VCHR; 301 dev = make_dev(&mfs_cdevsw, minnum, UID_ROOT, GID_WHEEL, 0600, 302 "MFS%d", minnum >> 16); 303 /* It is not clear that these will get initialized otherwise */ 304 dev->si_bsize_phys = DEV_BSIZE; 305 dev->si_iosize_max = DFLTPHYS; 306 dev->si_drv1 = mfsp; 307 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum)); 308 devvp->v_data = mfsp; 309 mfsp->mfs_baseoff = args.base; 310 mfsp->mfs_size = args.size; 311 mfsp->mfs_vnode = devvp; 312 mfsp->mfs_dev = reference_dev(dev); 313 mfsp->mfs_td = td; 314 mfsp->mfs_active = 1; 315 bufq_init(&mfsp->buf_queue); 316 317 /* 318 * Since this is a new mount, we want the names for 319 * the device and the mount point copied in. If an 320 * error occurs, the mountpoint is discarded by the 321 * upper level code. 322 */ 323 /* Save "last mounted on" info for mount point (NULL pad)*/ 324 copyinstr( path, /* mount point*/ 325 mp->mnt_stat.f_mntonname, /* save area*/ 326 MNAMELEN - 1, /* max size*/ 327 &size); /* real size*/ 328 bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 329 330 /* Save "mounted from" info for mount point (NULL pad)*/ 331 copyinstr( args.fspec, /* device name*/ 332 mp->mnt_stat.f_mntfromname, /* save area*/ 333 MNAMELEN - 1, /* max size*/ 334 &size); /* real size*/ 335 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 336 337 vx_unlock(devvp); 338 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) { 339 mfsp->mfs_active = 0; 340 goto error_2; 341 } 342 343 /* 344 * Initialize FS stat information in mount struct; uses both 345 * mp->mnt_stat.f_mntonname and mp->mnt_stat.f_mntfromname 346 * 347 * This code is common to root and non-root mounts 348 */ 349 (void) VFS_STATFS(mp, &mp->mnt_stat, td); 350 351 goto success; 352 353 error_2: /* error with devvp held*/ 354 355 /* release devvp before failing*/ 356 vrele(devvp); 357 358 error_1: /* no state to back out*/ 359 360 success: 361 return( err); 362 } 363 364 /* 365 * Used to grab the process and keep it in the kernel to service 366 * memory filesystem I/O requests. 367 * 368 * Loop servicing I/O requests. 369 * Copy the requested data into or out of the memory filesystem 370 * address space. 371 */ 372 /* ARGSUSED */ 373 static int 374 mfs_start(struct mount *mp, int flags, struct thread *td) 375 { 376 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 377 struct mfsnode *mfsp = VTOMFS(vp); 378 struct buf *bp; 379 int gotsig = 0, sig; 380 381 /* 382 * We must prevent the system from trying to swap 383 * out or kill ( when swap space is low, see vm/pageout.c ) the 384 * process. A deadlock can occur if the process is swapped out, 385 * and the system can loop trying to kill the unkillable ( while 386 * references exist ) MFS process when swap space is low. 387 */ 388 KKASSERT(curproc); 389 PHOLD(curproc); 390 391 while (mfsp->mfs_active) { 392 int s; 393 394 s = splbio(); 395 396 while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) { 397 bufq_remove(&mfsp->buf_queue, bp); 398 splx(s); 399 mfs_doio(bp, mfsp); 400 wakeup((caddr_t)bp); 401 s = splbio(); 402 } 403 404 splx(s); 405 406 /* 407 * If a non-ignored signal is received, try to unmount. 408 * If that fails, clear the signal (it has been "processed"), 409 * otherwise we will loop here, as tsleep will always return 410 * EINTR/ERESTART. 411 */ 412 /* 413 * Note that dounmount() may fail if work was queued after 414 * we slept. We have to jump hoops here to make sure that we 415 * process any buffers after the sleep, before we dounmount() 416 */ 417 if (gotsig) { 418 gotsig = 0; 419 if (dounmount(mp, 0, td) != 0) { 420 KKASSERT(td->td_proc); 421 sig = CURSIG(td->td_proc); 422 if (sig) 423 SIGDELSET(td->td_proc->p_siglist, sig); 424 } 425 } 426 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0)) 427 gotsig++; /* try to unmount in next pass */ 428 } 429 PRELE(curproc); 430 v_release_rdev(vp); /* hack because we do not implement CLOSE */ 431 /* XXX destroy/release devvp */ 432 return (0); 433 } 434 435 /* 436 * Get file system statistics. 437 */ 438 static int 439 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 440 { 441 int error; 442 443 error = ffs_statfs(mp, sbp, td); 444 sbp->f_type = mp->mnt_vfc->vfc_typenum; 445 return (error); 446 } 447 448 /* 449 * Memory based filesystem initialization. 450 */ 451 static int 452 mfs_init(struct vfsconf *vfsp) 453 { 454 cdevsw_add(&mfs_cdevsw, 0, 0); 455 return (0); 456 } 457