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 1.25 2006/02/17 19:18:07 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 <sys/thread2.h> 57 58 #include <vfs/ufs/quota.h> 59 #include <vfs/ufs/inode.h> 60 #include <vfs/ufs/ufsmount.h> 61 #include <vfs/ufs/ufs_extern.h> 62 #include <vfs/ufs/fs.h> 63 #include <vfs/ufs/ffs_extern.h> 64 65 #include "mfsnode.h" 66 #include "mfs_extern.h" 67 68 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); 69 70 71 extern struct vop_ops *mfs_vnode_vops; 72 73 static int mfs_mount (struct mount *mp, 74 char *path, caddr_t data, struct thread *td); 75 static int mfs_start (struct mount *mp, int flags, struct thread *td); 76 static int mfs_statfs (struct mount *mp, struct statfs *sbp, 77 struct thread *td); 78 static int mfs_init (struct vfsconf *); 79 80 d_open_t mfsopen; 81 d_close_t mfsclose; 82 d_strategy_t mfsstrategy; 83 84 #define MFS_CDEV_MAJOR 253 85 86 static struct cdevsw mfs_cdevsw = { 87 /* name */ "MFS", 88 /* maj */ MFS_CDEV_MAJOR, 89 /* flags */ D_DISK, 90 /* port */ NULL, 91 /* clone */ NULL, 92 93 /* open */ mfsopen, 94 /* close */ mfsclose, 95 /* read */ physread, 96 /* write */ physwrite, 97 /* ioctl */ noioctl, 98 /* poll */ nopoll, 99 /* mmap */ nommap, 100 /* strategy */ mfsstrategy, 101 /* dump */ nodump, 102 /* psize */ nopsize 103 }; 104 105 /* 106 * mfs vfs operations. 107 */ 108 static struct vfsops mfs_vfsops = { 109 .vfs_mount = mfs_mount, 110 .vfs_start = mfs_start, 111 .vfs_unmount = ffs_unmount, 112 .vfs_root = ufs_root, 113 .vfs_quotactl = ufs_quotactl, 114 .vfs_statfs = mfs_statfs, 115 .vfs_sync = ffs_sync, 116 .vfs_vget = ffs_vget, 117 .vfs_fhtovp = ffs_fhtovp, 118 .vfs_checkexp = ufs_check_export, 119 .vfs_vptofh = ffs_vptofh, 120 .vfs_init = mfs_init 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(dev_t dev, struct bio *bio) 146 { 147 struct buf *bp = bio->bio_buf; 148 struct mfsnode *mfsp; 149 150 if ((mfsp = dev->si_drv1) != NULL) { 151 off_t boff = (off_t)bio->bio_blkno << DEV_BSHIFT; 152 off_t eoff = boff + bp->b_bcount; 153 154 if (eoff <= mfsp->mfs_size) { 155 bioq_insert_tail(&mfsp->bio_queue, bio); 156 wakeup((caddr_t)mfsp); 157 } else if (boff < mfsp->mfs_size) { 158 bp->b_bcount = mfsp->mfs_size - boff; 159 bioq_insert_tail(&mfsp->bio_queue, bio); 160 wakeup((caddr_t)mfsp); 161 } else if (boff == mfsp->mfs_size) { 162 bp->b_resid = bp->b_bcount; 163 biodone(bio); 164 } else { 165 bp->b_error = EINVAL; 166 biodone(bio); 167 } 168 } else { 169 bp->b_error = ENXIO; 170 bp->b_flags |= B_ERROR; 171 biodone(bio); 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 thread *td) 215 { 216 struct vnode *devvp; 217 struct mfs_args args; 218 struct ufsmount *ump; 219 struct fs *fs; 220 struct mfsnode *mfsp; 221 size_t size; 222 int flags, err; 223 int minnum; 224 dev_t dev; 225 226 /* 227 * Use NULL path to flag a root mount 228 */ 229 if( path == NULL) { 230 /* 231 *** 232 * Mounting root file system 233 *** 234 */ 235 236 /* you lose */ 237 panic("mfs_mount: mount MFS as root: not configured!"); 238 } 239 240 /* 241 *** 242 * Mounting non-root file system or updating a file system 243 *** 244 */ 245 246 /* copy in user arguments*/ 247 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0) 248 goto error_1; 249 250 /* 251 * If updating, check whether changing from read-only to 252 * read/write; if there is no device name, that's all we do. 253 */ 254 if (mp->mnt_flag & MNT_UPDATE) { 255 /* 256 ******************** 257 * UPDATE 258 ******************** 259 */ 260 ump = VFSTOUFS(mp); 261 fs = ump->um_fs; 262 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 263 flags = WRITECLOSE; 264 if (mp->mnt_flag & MNT_FORCE) 265 flags |= FORCECLOSE; 266 err = ffs_flushfiles(mp, flags, td); 267 if (err) 268 goto error_1; 269 } 270 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) 271 fs->fs_ronly = 0; 272 /* if not updating name...*/ 273 if (args.fspec == 0) { 274 /* 275 * Process export requests. Jumping to "success" 276 * will return the vfs_export() error code. 277 */ 278 err = vfs_export(mp, &ump->um_export, &args.export); 279 goto success; 280 } 281 282 /* XXX MFS does not support name updating*/ 283 goto success; 284 } 285 /* 286 * Do the MALLOC before the getnewvnode since doing so afterward 287 * might cause a bogus v_data pointer to get dereferenced 288 * elsewhere if MALLOC should block. 289 */ 290 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK); 291 292 err = getspecialvnode(VT_MFS, NULL, &mfs_vnode_vops, &devvp, 0, 0); 293 if (err) { 294 FREE(mfsp, M_MFSNODE); 295 goto error_1; 296 } 297 298 minnum = (curproc->p_pid & 0xFF) | 299 ((curproc->p_pid & ~0xFF) << 8); 300 301 devvp->v_type = VCHR; 302 dev = make_dev(&mfs_cdevsw, minnum, UID_ROOT, GID_WHEEL, 0600, 303 "MFS%d", minnum >> 16); 304 /* It is not clear that these will get initialized otherwise */ 305 dev->si_bsize_phys = DEV_BSIZE; 306 dev->si_iosize_max = DFLTPHYS; 307 dev->si_drv1 = mfsp; 308 addaliasu(devvp, makeudev(MFS_CDEV_MAJOR, minnum)); 309 devvp->v_data = mfsp; 310 mfsp->mfs_baseoff = args.base; 311 mfsp->mfs_size = args.size; 312 mfsp->mfs_vnode = devvp; 313 mfsp->mfs_dev = reference_dev(dev); 314 mfsp->mfs_td = td; 315 mfsp->mfs_active = 1; 316 bioq_init(&mfsp->bio_queue); 317 318 /* Save "mounted from" info for mount point (NULL pad)*/ 319 copyinstr( args.fspec, /* device name*/ 320 mp->mnt_stat.f_mntfromname, /* save area*/ 321 MNAMELEN - 1, /* max size*/ 322 &size); /* real size*/ 323 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 324 325 vx_unlock(devvp); 326 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) { 327 mfsp->mfs_active = 0; 328 goto error_2; 329 } 330 331 /* 332 * Initialize FS stat information in mount struct; uses 333 * mp->mnt_stat.f_mntfromname. 334 * 335 * This code is common to root and non-root mounts 336 */ 337 VFS_STATFS(mp, &mp->mnt_stat, td); 338 339 goto success; 340 341 error_2: /* error with devvp held*/ 342 343 /* release devvp before failing*/ 344 vrele(devvp); 345 346 error_1: /* no state to back out*/ 347 348 success: 349 return( err); 350 } 351 352 /* 353 * Used to grab the process and keep it in the kernel to service 354 * memory filesystem I/O requests. 355 * 356 * Loop servicing I/O requests. 357 * Copy the requested data into or out of the memory filesystem 358 * address space. 359 */ 360 /* ARGSUSED */ 361 static int 362 mfs_start(struct mount *mp, int flags, struct thread *td) 363 { 364 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 365 struct mfsnode *mfsp = VTOMFS(vp); 366 struct bio *bio; 367 int gotsig = 0, sig; 368 369 /* 370 * We must prevent the system from trying to swap 371 * out or kill ( when swap space is low, see vm/pageout.c ) the 372 * process. A deadlock can occur if the process is swapped out, 373 * and the system can loop trying to kill the unkillable ( while 374 * references exist ) MFS process when swap space is low. 375 */ 376 KKASSERT(curproc); 377 PHOLD(curproc); 378 379 while (mfsp->mfs_active) { 380 crit_enter(); 381 382 while ((bio = bioq_first(&mfsp->bio_queue)) != NULL) { 383 bioq_remove(&mfsp->bio_queue, bio); 384 crit_exit(); 385 mfs_doio(bio, mfsp); 386 wakeup((caddr_t)bio->bio_buf); 387 crit_enter(); 388 } 389 390 crit_exit(); 391 392 /* 393 * If a non-ignored signal is received, try to unmount. 394 * If that fails, clear the signal (it has been "processed"), 395 * otherwise we will loop here, as tsleep will always return 396 * EINTR/ERESTART. 397 */ 398 /* 399 * Note that dounmount() may fail if work was queued after 400 * we slept. We have to jump hoops here to make sure that we 401 * process any buffers after the sleep, before we dounmount() 402 */ 403 if (gotsig) { 404 gotsig = 0; 405 if (dounmount(mp, 0, td) != 0) { 406 KKASSERT(td->td_proc); 407 sig = CURSIG(td->td_proc); 408 if (sig) 409 SIGDELSET(td->td_proc->p_siglist, sig); 410 } 411 } 412 else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0)) 413 gotsig++; /* try to unmount in next pass */ 414 } 415 PRELE(curproc); 416 v_release_rdev(vp); /* hack because we do not implement CLOSE */ 417 /* XXX destroy/release devvp */ 418 return (0); 419 } 420 421 /* 422 * Get file system statistics. 423 */ 424 static int 425 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 426 { 427 int error; 428 429 error = ffs_statfs(mp, sbp, td); 430 sbp->f_type = mp->mnt_vfc->vfc_typenum; 431 return (error); 432 } 433 434 /* 435 * Memory based filesystem initialization. 436 */ 437 static int 438 mfs_init(struct vfsconf *vfsp) 439 { 440 cdevsw_add(&mfs_cdevsw, 0, 0); 441 return (0); 442 } 443