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 1.12 2003/12/01 04:38:26 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 53 #include <sys/buf2.h> 54 55 #include <vfs/ufs/quota.h> 56 #include <vfs/ufs/inode.h> 57 #include <vfs/ufs/ufsmount.h> 58 #include <vfs/ufs/ufs_extern.h> 59 #include <vfs/ufs/fs.h> 60 #include <vfs/ufs/ffs_extern.h> 61 62 #include "mfsnode.h" 63 #include "mfs_extern.h" 64 65 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); 66 67 68 static int mfs_minor; /* used for building internal dev_t */ 69 70 extern vop_t **mfs_vnodeop_p; 71 72 static int mfs_mount (struct mount *mp, 73 char *path, caddr_t data, struct nameidata *ndp, 74 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 #define MFS_CDEV_MAJOR 253 81 82 static struct cdevsw mfs_cdevsw = { 83 /* name */ "MFS", 84 /* maj */ MFS_CDEV_MAJOR, 85 /* flags */ D_DISK, 86 /* port */ NULL, 87 /* autoq */ 0, 88 89 /* open */ noopen, 90 /* close */ noclose, 91 /* read */ physread, 92 /* write */ physwrite, 93 /* ioctl */ noioctl, 94 /* poll */ nopoll, 95 /* mmap */ nommap, 96 /* strategy */ nostrategy, 97 /* dump */ nodump, 98 /* psize */ nopsize 99 }; 100 101 /* 102 * mfs vfs operations. 103 */ 104 static struct vfsops mfs_vfsops = { 105 mfs_mount, 106 mfs_start, 107 ffs_unmount, 108 ufs_root, 109 ufs_quotactl, 110 mfs_statfs, 111 ffs_sync, 112 ffs_vget, 113 ffs_fhtovp, 114 ufs_check_export, 115 ffs_vptofh, 116 mfs_init, 117 vfs_stduninit, 118 vfs_stdextattrctl, 119 }; 120 121 VFS_SET(mfs_vfsops, mfs, 0); 122 123 124 /* 125 * mfs_mount 126 * 127 * Called when mounting local physical media 128 * 129 * PARAMETERS: 130 * mountroot 131 * mp mount point structure 132 * path NULL (flag for root mount!!!) 133 * data <unused> 134 * ndp <unused> 135 * p process (user credentials check [statfs]) 136 * 137 * mount 138 * mp mount point structure 139 * path path to mount point 140 * data pointer to argument struct in user space 141 * ndp mount point namei() return (used for 142 * credentials on reload), reused to look 143 * up block device. 144 * p process (user credentials check) 145 * 146 * RETURNS: 0 Success 147 * !0 error number (errno.h) 148 * 149 * LOCK STATE: 150 * 151 * ENTRY 152 * mount point is locked 153 * EXIT 154 * mount point is locked 155 * 156 * NOTES: 157 * A NULL path can be used for a flag since the mount 158 * system call will fail with EFAULT in copyinstr in 159 * namei() if it is a genuine NULL from the user. 160 */ 161 /* ARGSUSED */ 162 static int 163 mfs_mount(mp, path, data, ndp, td) 164 struct mount *mp; 165 char *path; 166 caddr_t data; 167 struct nameidata *ndp; 168 struct thread *td; 169 { 170 struct vnode *devvp; 171 struct mfs_args args; 172 struct ufsmount *ump; 173 struct fs *fs; 174 struct mfsnode *mfsp; 175 size_t size; 176 int flags, err; 177 dev_t dev; 178 179 /* 180 * Use NULL path to flag a root mount 181 */ 182 if( path == NULL) { 183 /* 184 *** 185 * Mounting root file system 186 *** 187 */ 188 189 /* you lose */ 190 panic("mfs_mount: mount MFS as root: not configured!"); 191 } 192 193 /* 194 *** 195 * Mounting non-root file system or updating a file system 196 *** 197 */ 198 199 /* copy in user arguments*/ 200 if ((err = copyin(data, (caddr_t)&args, sizeof (struct mfs_args))) != 0) 201 goto error_1; 202 203 /* 204 * If updating, check whether changing from read-only to 205 * read/write; if there is no device name, that's all we do. 206 */ 207 if (mp->mnt_flag & MNT_UPDATE) { 208 /* 209 ******************** 210 * UPDATE 211 ******************** 212 */ 213 ump = VFSTOUFS(mp); 214 fs = ump->um_fs; 215 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 216 flags = WRITECLOSE; 217 if (mp->mnt_flag & MNT_FORCE) 218 flags |= FORCECLOSE; 219 err = ffs_flushfiles(mp, flags, td); 220 if (err) 221 goto error_1; 222 } 223 if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) 224 fs->fs_ronly = 0; 225 /* if not updating name...*/ 226 if (args.fspec == 0) { 227 /* 228 * Process export requests. Jumping to "success" 229 * will return the vfs_export() error code. 230 */ 231 err = vfs_export(mp, &ump->um_export, &args.export); 232 goto success; 233 } 234 235 /* XXX MFS does not support name updating*/ 236 goto success; 237 } 238 /* 239 * Do the MALLOC before the getnewvnode since doing so afterward 240 * might cause a bogus v_data pointer to get dereferenced 241 * elsewhere if MALLOC should block. 242 */ 243 MALLOC(mfsp, struct mfsnode *, sizeof *mfsp, M_MFSNODE, M_WAITOK); 244 245 err = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp); 246 if (err) { 247 FREE(mfsp, M_MFSNODE); 248 goto error_1; 249 } 250 devvp->v_type = VCHR; 251 dev = make_dev(&mfs_cdevsw, mfs_minor, 0, 0, 0, "MFS%d", mfs_minor); 252 /* It is not clear that these will get initialized otherwise */ 253 dev->si_bsize_phys = DEV_BSIZE; 254 dev->si_iosize_max = DFLTPHYS; 255 addaliasu(devvp, makeudev(253, mfs_minor++)); 256 devvp->v_data = mfsp; 257 mfsp->mfs_baseoff = args.base; 258 mfsp->mfs_size = args.size; 259 mfsp->mfs_vnode = devvp; 260 mfsp->mfs_td = td; 261 mfsp->mfs_active = 1; 262 bufq_init(&mfsp->buf_queue); 263 264 /* 265 * Since this is a new mount, we want the names for 266 * the device and the mount point copied in. If an 267 * error occurs, the mountpoint is discarded by the 268 * upper level code. 269 */ 270 /* Save "last mounted on" info for mount point (NULL pad)*/ 271 copyinstr( path, /* mount point*/ 272 mp->mnt_stat.f_mntonname, /* save area*/ 273 MNAMELEN - 1, /* max size*/ 274 &size); /* real size*/ 275 bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 276 277 /* Save "mounted from" info for mount point (NULL pad)*/ 278 copyinstr( args.fspec, /* device name*/ 279 mp->mnt_stat.f_mntfromname, /* save area*/ 280 MNAMELEN - 1, /* max size*/ 281 &size); /* real size*/ 282 bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 283 284 if ((err = ffs_mountfs(devvp, mp, td, M_MFSNODE)) != 0) { 285 mfsp->mfs_active = 0; 286 goto error_2; 287 } 288 289 /* 290 * Initialize FS stat information in mount struct; uses both 291 * mp->mnt_stat.f_mntonname and mp->mnt_stat.f_mntfromname 292 * 293 * This code is common to root and non-root mounts 294 */ 295 (void) VFS_STATFS(mp, &mp->mnt_stat, td); 296 297 goto success; 298 299 error_2: /* error with devvp held*/ 300 301 /* release devvp before failing*/ 302 vrele(devvp); 303 304 error_1: /* no state to back out*/ 305 306 success: 307 return( err); 308 } 309 310 /* 311 * Used to grab the process and keep it in the kernel to service 312 * memory filesystem I/O requests. 313 * 314 * Loop servicing I/O requests. 315 * Copy the requested data into or out of the memory filesystem 316 * address space. 317 */ 318 /* ARGSUSED */ 319 static int 320 mfs_start(struct mount *mp, int flags, struct thread *td) 321 { 322 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 323 struct mfsnode *mfsp = VTOMFS(vp); 324 struct buf *bp; 325 int gotsig = 0, sig; 326 327 /* 328 * We must prevent the system from trying to swap 329 * out or kill ( when swap space is low, see vm/pageout.c ) the 330 * process. A deadlock can occur if the process is swapped out, 331 * and the system can loop trying to kill the unkillable ( while 332 * references exist ) MFS process when swap space is low. 333 */ 334 KKASSERT(curproc); 335 PHOLD(curproc); 336 337 while (mfsp->mfs_active) { 338 int s; 339 340 s = splbio(); 341 342 while ((bp = bufq_first(&mfsp->buf_queue)) != NULL) { 343 bufq_remove(&mfsp->buf_queue, bp); 344 splx(s); 345 mfs_doio(bp, mfsp); 346 wakeup((caddr_t)bp); 347 s = splbio(); 348 } 349 350 splx(s); 351 352 /* 353 * If a non-ignored signal is received, try to unmount. 354 * If that fails, clear the signal (it has been "processed"), 355 * otherwise we will loop here, as tsleep will always return 356 * EINTR/ERESTART. 357 */ 358 /* 359 * Note that dounmount() may fail if work was queued after 360 * we slept. We have to jump hoops here to make sure that we 361 * process any buffers after the sleep, before we dounmount() 362 */ 363 if (gotsig) { 364 gotsig = 0; 365 if (dounmount(mp, 0, td) != 0) { 366 KKASSERT(td->td_proc); 367 sig = CURSIG(td->td_proc); 368 if (sig) 369 SIGDELSET(td->td_proc->p_siglist, sig); 370 } 371 } 372 else if (tsleep((caddr_t)vp, PCATCH, "mfsidl", 0)) 373 gotsig++; /* try to unmount in next pass */ 374 } 375 PRELE(curproc); 376 return (0); 377 } 378 379 /* 380 * Get file system statistics. 381 */ 382 static int 383 mfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 384 { 385 int error; 386 387 error = ffs_statfs(mp, sbp, td); 388 sbp->f_type = mp->mnt_vfc->vfc_typenum; 389 return (error); 390 } 391 392 /* 393 * Memory based filesystem initialization. 394 */ 395 static int 396 mfs_init(vfsp) 397 struct vfsconf *vfsp; 398 { 399 400 cdevsw_add(&mfs_cdevsw); 401 return (0); 402 } 403 404