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 1.16 2004/08/13 17:51:11 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 nameidata *ndp, 73 struct thread *td); 74 static int mfs_start (struct mount *mp, int flags, struct thread *td); 75 static int mfs_statfs (struct mount *mp, struct statfs *sbp, 76 struct thread *td); 77 static int mfs_init (struct vfsconf *); 78 79 d_open_t mfsopen; 80 d_close_t mfsclose; 81 d_strategy_t mfsstrategy; 82 83 #define MFS_CDEV_MAJOR 253 84 85 static struct cdevsw mfs_cdevsw = { 86 /* name */ "MFS", 87 /* maj */ MFS_CDEV_MAJOR, 88 /* flags */ D_DISK, 89 /* port */ NULL, 90 /* clone */ NULL, 91 92 /* open */ mfsopen, 93 /* close */ mfsclose, 94 /* read */ physread, 95 /* write */ physwrite, 96 /* ioctl */ noioctl, 97 /* poll */ nopoll, 98 /* mmap */ nommap, 99 /* strategy */ mfsstrategy, 100 /* dump */ nodump, 101 /* psize */ nopsize 102 }; 103 104 /* 105 * mfs vfs operations. 106 */ 107 static struct vfsops mfs_vfsops = { 108 mfs_mount, 109 mfs_start, 110 ffs_unmount, 111 ufs_root, 112 ufs_quotactl, 113 mfs_statfs, 114 ffs_sync, 115 ffs_vget, 116 ffs_fhtovp, 117 ufs_check_export, 118 ffs_vptofh, 119 mfs_init, 120 vfs_stduninit, 121 vfs_stdextattrctl, 122 }; 123 124 VFS_SET(mfs_vfsops, mfs, 0); 125 126 /* 127 * We allow the underlying MFS block device to be opened and read. 128 */ 129 int 130 mfsopen(dev_t dev, int flags, int mode, struct thread *td) 131 { 132 if (flags & FWRITE) 133 return(EROFS); 134 if (dev->si_drv1) 135 return(0); 136 return(ENXIO); 137 } 138 139 int 140 mfsclose(dev_t dev, int flags, int mode, struct thread *td) 141 { 142 return(0); 143 } 144 145 void 146 mfsstrategy(struct buf *bp) 147 { 148 struct mfsnode *mfsp; 149 150 if ((mfsp = bp->b_dev->si_drv1) != NULL) { 151 off_t boff = (off_t)bp->b_blkno << DEV_BSHIFT; 152 off_t eoff = boff + bp->b_bcount; 153 154 if (eoff <= mfsp->mfs_size) { 155 bufq_insert_tail(&mfsp->buf_queue, bp); 156 wakeup((caddr_t)mfsp); 157 } else if (boff < mfsp->mfs_size) { 158 bp->b_bcount = mfsp->mfs_size - boff; 159 bufq_insert_tail(&mfsp->buf_queue, bp); 160 wakeup((caddr_t)mfsp); 161 } else if (boff == mfsp->mfs_size) { 162 bp->b_resid = bp->b_bcount; 163 biodone(bp); 164 } else { 165 bp->b_error = EINVAL; 166 biodone(bp); 167 } 168 } else { 169 bp->b_error = ENXIO; 170 bp->b_flags |= B_ERROR; 171 biodone(bp); 172 } 173 } 174 175 /* 176 * mfs_mount 177 * 178 * Called when mounting local physical media 179 * 180 * PARAMETERS: 181 * mountroot 182 * mp mount point structure 183 * path NULL (flag for root mount!!!) 184 * data <unused> 185 * ndp <unused> 186 * p process (user credentials check [statfs]) 187 * 188 * mount 189 * mp mount point structure 190 * path path to mount point 191 * data pointer to argument struct in user space 192 * ndp mount point namei() return (used for 193 * credentials on reload), reused to look 194 * up block device. 195 * p process (user credentials check) 196 * 197 * RETURNS: 0 Success 198 * !0 error number (errno.h) 199 * 200 * LOCK STATE: 201 * 202 * ENTRY 203 * mount point is locked 204 * EXIT 205 * mount point is locked 206 * 207 * NOTES: 208 * A NULL path can be used for a flag since the mount 209 * system call will fail with EFAULT in copyinstr in 210 * namei() if it is a genuine NULL from the user. 211 */ 212 /* ARGSUSED */ 213 static int 214 mfs_mount(struct mount *mp, char *path, caddr_t data, struct nameidata *ndp, 215 struct thread *td) 216 { 217 struct vnode *devvp; 218 struct mfs_args args; 219 struct ufsmount *ump; 220 struct fs *fs; 221 struct mfsnode *mfsp; 222 size_t size; 223 int flags, err; 224 int minnum; 225 dev_t dev; 226 227 /* 228 * Use NULL path to flag a root mount 229 */ 230 if( path == NULL) { 231 /* 232 *** 233 * Mounting root file system 234 *** 235 */ 236 237 /* you lose */ 238 panic("mfs_mount: mount MFS as root: not configured!"); 239 } 240 241 /* 242 *** 243 * Mounting non-root file system or updating a file system 244 *** 245 */ 246 247 /* copy in user arguments*/ 248 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0) 249 goto error_1; 250 251 /* 252 * If updating, check whether changing from read-only to 253 * read/write; if there is no device name, that's all we do. 254 */ 255 if (mp->mnt_flag & MNT_UPDATE) { 256 /* 257 ******************** 258 * UPDATE 259 ******************** 260 */ 261 ump = VFSTOUFS(mp); 262 fs = ump->um_fs; 263 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 264 flags = WRITECLOSE; 265 if (mp->mnt_flag & MNT_FORCE) 266 flags |= FORCECLOSE; 267 err = ffs_flushfiles(mp, flags, td); 268 if (err) 269 goto error_1; 270 } 271 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) 272 fs->fs_ronly = 0; 273 /* if not updating name...*/ 274 if (args.fspec == 0) { 275 /* 276 * Process export requests. Jumping to "success" 277 * will return the vfs_export() error code. 278 */ 279 err = vfs_export(mp, &ump->um_export, &args.export); 280 goto success; 281 } 282 283 /* XXX MFS does not support name updating*/ 284 goto success; 285 } 286 /* 287 * Do the MALLOC before the getnewvnode since doing so afterward 288 * might cause a bogus v_data pointer to get dereferenced 289 * elsewhere if MALLOC should block. 290 */ 291 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK); 292 293 err = getnewvnode(VT_MFS, NULL, mfs_vnode_vops, &devvp); 294 if (err) { 295 FREE(mfsp, M_MFSNODE); 296 goto error_1; 297 } 298 299 minnum = (curproc->p_pid & 0xFF) | 300 ((curproc->p_pid & ~0xFF) << 8); 301 302 devvp->v_type = VCHR; 303 dev = make_dev(&mfs_cdevsw, minnum, UID_ROOT, GID_WHEEL, 0600, 304 "MFS%d", minnum >> 16); 305 /* It is not clear that these will get initialized otherwise */ 306 dev->si_bsize_phys = DEV_BSIZE; 307 dev->si_iosize_max = DFLTPHYS; 308 dev->si_drv1 = mfsp; 309 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum)); 310 devvp->v_data = mfsp; 311 mfsp->mfs_baseoff = args.base; 312 mfsp->mfs_size = args.size; 313 mfsp->mfs_vnode = devvp; 314 mfsp->mfs_dev = reference_dev(dev); 315 mfsp->mfs_td = td; 316 mfsp->mfs_active = 1; 317 bufq_init(&mfsp->buf_queue); 318 319 /* 320 * Since this is a new mount, we want the names for 321 * the device and the mount point copied in. If an 322 * error occurs, the mountpoint is discarded by the 323 * upper level code. 324 */ 325 /* Save "last mounted on" info for mount point (NULL pad)*/ 326 copyinstr( path, /* mount point*/ 327 mp->mnt_stat.f_mntonname, /* save area*/ 328 MNAMELEN - 1, /* max size*/ 329 &size); /* real size*/ 330 bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 331 332 /* Save "mounted from" info for mount point (NULL pad)*/ 333 copyinstr( args.fspec, /* device name*/ 334 mp->mnt_stat.f_mntfromname, /* save area*/ 335 MNAMELEN - 1, /* max size*/ 336 &size); /* real size*/ 337 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 338 339 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) { 340 mfsp->mfs_active = 0; 341 goto error_2; 342 } 343 344 /* 345 * Initialize FS stat information in mount struct; uses both 346 * mp->mnt_stat.f_mntonname and mp->mnt_stat.f_mntfromname 347 * 348 * This code is common to root and non-root mounts 349 */ 350 (void) VFS_STATFS(mp, &mp->mnt_stat, td); 351 352 goto success; 353 354 error_2: /* error with devvp held*/ 355 356 /* release devvp before failing*/ 357 vrele(devvp); 358 359 error_1: /* no state to back out*/ 360 361 success: 362 return( err); 363 } 364 365 /* 366 * Used to grab the process and keep it in the kernel to service 367 * memory filesystem I/O requests. 368 * 369 * Loop servicing I/O requests. 370 * Copy the requested data into or out of the memory filesystem 371 * address space. 372 */ 373 /* ARGSUSED */ 374 static int 375 mfs_start(struct mount *mp, int flags, struct thread *td) 376 { 377 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 378 struct mfsnode *mfsp = VTOMFS(vp); 379 struct buf *bp; 380 int gotsig = 0, sig; 381 382 /* 383 * We must prevent the system from trying to swap 384 * out or kill ( when swap space is low, see vm/pageout.c ) the 385 * process. A deadlock can occur if the process is swapped out, 386 * and the system can loop trying to kill the unkillable ( while 387 * references exist ) MFS process when swap space is low. 388 */ 389 KKASSERT(curproc); 390 PHOLD(curproc); 391 392 while (mfsp->mfs_active) { 393 int s; 394 395 s = splbio(); 396 397 while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) { 398 bufq_remove(&mfsp->buf_queue, bp); 399 splx(s); 400 mfs_doio(bp, mfsp); 401 wakeup((caddr_t)bp); 402 s = splbio(); 403 } 404 405 splx(s); 406 407 /* 408 * If a non-ignored signal is received, try to unmount. 409 * If that fails, clear the signal (it has been "processed"), 410 * otherwise we will loop here, as tsleep will always return 411 * EINTR/ERESTART. 412 */ 413 /* 414 * Note that dounmount() may fail if work was queued after 415 * we slept. We have to jump hoops here to make sure that we 416 * process any buffers after the sleep, before we dounmount() 417 */ 418 if (gotsig) { 419 gotsig = 0; 420 if (dounmount(mp, 0, td) != 0) { 421 KKASSERT(td->td_proc); 422 sig = CURSIG(td->td_proc); 423 if (sig) 424 SIGDELSET(td->td_proc->p_siglist, sig); 425 } 426 } 427 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0)) 428 gotsig++; /* try to unmount in next pass */ 429 } 430 PRELE(curproc); 431 v_release_rdev(vp); /* hack because we do not implement CLOSE */ 432 /* XXX destroy/release devvp */ 433 return (0); 434 } 435 436 /* 437 * Get file system statistics. 438 */ 439 static int 440 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 441 { 442 int error; 443 444 error = ffs_statfs(mp, sbp, td); 445 sbp->f_type = mp->mnt_vfc->vfc_typenum; 446 return (error); 447 } 448 449 /* 450 * Memory based filesystem initialization. 451 */ 452 static int 453 mfs_init(struct vfsconf *vfsp) 454 { 455 cdevsw_add(&mfs_cdevsw, 0, 0); 456 return (0); 457 } 458