mfs_vfsops.c revision 1.51.2.8
1 /* $NetBSD: mfs_vfsops.c,v 1.51.2.8 2005/03/04 16:55:00 skrll Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1990, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)mfs_vfsops.c 8.11 (Berkeley) 6/19/95 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: mfs_vfsops.c,v 1.51.2.8 2005/03/04 16:55:00 skrll Exp $"); 36 37 #if defined(_KERNEL_OPT) 38 #include "opt_compat_netbsd.h" 39 #endif 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/sysctl.h> 44 #include <sys/time.h> 45 #include <sys/kernel.h> 46 #include <sys/proc.h> 47 #include <sys/buf.h> 48 #include <sys/bufq.h> 49 #include <sys/mount.h> 50 #include <sys/signalvar.h> 51 #include <sys/vnode.h> 52 #include <sys/malloc.h> 53 54 #include <miscfs/syncfs/syncfs.h> 55 56 #include <ufs/ufs/quota.h> 57 #include <ufs/ufs/inode.h> 58 #include <ufs/ufs/ufsmount.h> 59 #include <ufs/ufs/ufs_extern.h> 60 61 #include <ufs/ffs/fs.h> 62 #include <ufs/ffs/ffs_extern.h> 63 64 #include <ufs/mfs/mfsnode.h> 65 #include <ufs/mfs/mfs_extern.h> 66 67 caddr_t mfs_rootbase; /* address of mini-root in kernel virtual memory */ 68 u_long mfs_rootsize; /* size of mini-root in bytes */ 69 70 static int mfs_minor; /* used for building internal dev_t */ 71 72 extern int (**mfs_vnodeop_p) __P((void *)); 73 74 MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); 75 76 /* 77 * mfs vfs operations. 78 */ 79 80 extern const struct vnodeopv_desc mfs_vnodeop_opv_desc; 81 82 const struct vnodeopv_desc * const mfs_vnodeopv_descs[] = { 83 &mfs_vnodeop_opv_desc, 84 NULL, 85 }; 86 87 struct vfsops mfs_vfsops = { 88 MOUNT_MFS, 89 mfs_mount, 90 mfs_start, 91 ffs_unmount, 92 ufs_root, 93 ufs_quotactl, 94 mfs_statvfs, 95 ffs_sync, 96 ffs_vget, 97 ffs_fhtovp, 98 ffs_vptofh, 99 mfs_init, 100 mfs_reinit, 101 mfs_done, 102 NULL, 103 NULL, 104 ufs_check_export, 105 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 106 vfs_stdextattrctl, 107 mfs_vnodeopv_descs, 108 }; 109 110 SYSCTL_SETUP(sysctl_vfs_mfs_setup, "sysctl vfs.mfs subtree setup") 111 { 112 113 sysctl_createv(clog, 0, NULL, NULL, 114 CTLFLAG_PERMANENT, 115 CTLTYPE_NODE, "vfs", NULL, 116 NULL, 0, NULL, 0, 117 CTL_VFS, CTL_EOL); 118 sysctl_createv(clog, 0, NULL, NULL, 119 CTLFLAG_PERMANENT|CTLFLAG_ALIAS, 120 CTLTYPE_NODE, "mfs", 121 SYSCTL_DESCR("Memory based file system"), 122 NULL, 1, NULL, 0, 123 CTL_VFS, 3, CTL_EOL); 124 /* 125 * XXX the "1" and the "3" above could be dynamic, thereby 126 * eliminating one more instance of the "number to vfs" 127 * mapping problem, but they are in order as taken from 128 * sys/mount.h 129 */ 130 } 131 132 /* 133 * Memory based filesystem initialization. 134 */ 135 void 136 mfs_init() 137 { 138 #ifdef _LKM 139 malloc_type_attach(M_MFSNODE); 140 #endif 141 /* 142 * ffs_init() ensures to initialize necessary resources 143 * only once. 144 */ 145 ffs_init(); 146 } 147 148 void 149 mfs_reinit() 150 { 151 ffs_reinit(); 152 } 153 154 void 155 mfs_done() 156 { 157 /* 158 * ffs_done() ensures to free necessary resources 159 * only once, when it's no more needed. 160 */ 161 ffs_done(); 162 #ifdef _LKM 163 malloc_type_detach(M_MFSNODE); 164 #endif 165 } 166 167 /* 168 * Called by main() when mfs is going to be mounted as root. 169 */ 170 171 int 172 mfs_mountroot() 173 { 174 struct fs *fs; 175 struct mount *mp; 176 struct lwp *l = curlwp; /* XXX */ 177 struct ufsmount *ump; 178 struct mfsnode *mfsp; 179 int error = 0; 180 181 if ((error = vfs_rootmountalloc(MOUNT_MFS, "mfs_root", &mp))) { 182 vrele(rootvp); 183 return (error); 184 } 185 186 mfsp = malloc(sizeof *mfsp, M_MFSNODE, M_WAITOK); 187 rootvp->v_data = mfsp; 188 rootvp->v_op = mfs_vnodeop_p; 189 rootvp->v_tag = VT_MFS; 190 mfsp->mfs_baseoff = mfs_rootbase; 191 mfsp->mfs_size = mfs_rootsize; 192 mfsp->mfs_vnode = rootvp; 193 mfsp->mfs_proc = NULL; /* indicate kernel space */ 194 mfsp->mfs_shutdown = 0; 195 bufq_alloc(&mfsp->mfs_buflist, BUFQ_FCFS); 196 if ((error = ffs_mountfs(rootvp, mp, l)) != 0) { 197 mp->mnt_op->vfs_refcount--; 198 vfs_unbusy(mp); 199 bufq_free(&mfsp->mfs_buflist); 200 free(mp, M_MOUNT); 201 free(mfsp, M_MFSNODE); 202 return (error); 203 } 204 simple_lock(&mountlist_slock); 205 CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list); 206 simple_unlock(&mountlist_slock); 207 mp->mnt_vnodecovered = NULLVP; 208 ump = VFSTOUFS(mp); 209 fs = ump->um_fs; 210 (void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0); 211 (void)ffs_statvfs(mp, &mp->mnt_stat, l); 212 vfs_unbusy(mp); 213 return (0); 214 } 215 216 /* 217 * This is called early in boot to set the base address and size 218 * of the mini-root. 219 */ 220 int 221 mfs_initminiroot(base) 222 caddr_t base; 223 { 224 struct fs *fs = (struct fs *)(base + SBLOCK_UFS1); 225 226 /* check for valid super block */ 227 if (fs->fs_magic != FS_UFS1_MAGIC || fs->fs_bsize > MAXBSIZE || 228 fs->fs_bsize < sizeof(struct fs)) 229 return (0); 230 mountroot = mfs_mountroot; 231 mfs_rootbase = base; 232 mfs_rootsize = fs->fs_fsize * fs->fs_size; 233 rootdev = makedev(255, mfs_minor); 234 mfs_minor++; 235 return (mfs_rootsize); 236 } 237 238 /* 239 * VFS Operations. 240 * 241 * mount system call 242 */ 243 /* ARGSUSED */ 244 int 245 mfs_mount(mp, path, data, ndp, l) 246 struct mount *mp; 247 const char *path; 248 void *data; 249 struct nameidata *ndp; 250 struct lwp *l; 251 { 252 struct vnode *devvp; 253 struct mfs_args args; 254 struct ufsmount *ump; 255 struct fs *fs; 256 struct mfsnode *mfsp; 257 struct proc *p; 258 int flags, error; 259 260 p = l->l_proc; 261 if (mp->mnt_flag & MNT_GETARGS) { 262 struct vnode *vp; 263 struct mfsnode *mfsp; 264 265 ump = VFSTOUFS(mp); 266 if (ump == NULL) 267 return EIO; 268 269 vp = ump->um_devvp; 270 if (vp == NULL) 271 return EIO; 272 273 mfsp = VTOMFS(vp); 274 if (mfsp == NULL) 275 return EIO; 276 277 args.fspec = NULL; 278 vfs_showexport(mp, &args.export, &ump->um_export); 279 args.base = mfsp->mfs_baseoff; 280 args.size = mfsp->mfs_size; 281 return copyout(&args, data, sizeof(args)); 282 } 283 /* 284 * XXX turn off async to avoid hangs when writing lots of data. 285 * the problem is that MFS needs to allocate pages to clean pages, 286 * so if we wait until the last minute to clean pages then there 287 * may not be any pages available to do the cleaning. 288 * ... and since the default partially-synchronous mode turns out 289 * to not be sufficient under heavy load, make it full synchronous. 290 */ 291 mp->mnt_flag &= ~MNT_ASYNC; 292 mp->mnt_flag |= MNT_SYNCHRONOUS; 293 294 error = copyin(data, (caddr_t)&args, sizeof (struct mfs_args)); 295 if (error) 296 return (error); 297 298 /* 299 * If updating, check whether changing from read-only to 300 * read/write; if there is no device name, that's all we do. 301 */ 302 if (mp->mnt_flag & MNT_UPDATE) { 303 ump = VFSTOUFS(mp); 304 fs = ump->um_fs; 305 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { 306 flags = WRITECLOSE; 307 if (mp->mnt_flag & MNT_FORCE) 308 flags |= FORCECLOSE; 309 error = ffs_flushfiles(mp, flags, l); 310 if (error) 311 return (error); 312 } 313 if (fs->fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR)) 314 fs->fs_ronly = 0; 315 if (args.fspec == 0) 316 return (vfs_export(mp, &ump->um_export, &args.export)); 317 return (0); 318 } 319 error = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp); 320 if (error) 321 return (error); 322 devvp->v_type = VBLK; 323 if (checkalias(devvp, makedev(255, mfs_minor), (struct mount *)0)) 324 panic("mfs_mount: dup dev"); 325 mfs_minor++; 326 mfsp = (struct mfsnode *)malloc(sizeof *mfsp, M_MFSNODE, M_WAITOK); 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_proc = p; 332 mfsp->mfs_shutdown = 0; 333 bufq_alloc(&mfsp->mfs_buflist, BUFQ_FCFS); 334 if ((error = ffs_mountfs(devvp, mp, l)) != 0) { 335 mfsp->mfs_shutdown = 1; 336 vrele(devvp); 337 return (error); 338 } 339 ump = VFSTOUFS(mp); 340 fs = ump->um_fs; 341 error = set_statvfs_info(path, UIO_USERSPACE, args.fspec, 342 UIO_USERSPACE, mp, l); 343 if (error) 344 return error; 345 (void)strncpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname, 346 sizeof(fs->fs_fsmnt)); 347 fs->fs_fsmnt[sizeof(fs->fs_fsmnt) - 1] = '\0'; 348 /* XXX: cleanup on error */ 349 return 0; 350 } 351 352 int mfs_pri = PWAIT | PCATCH; /* XXX prob. temp */ 353 354 /* 355 * Used to grab the process and keep it in the kernel to service 356 * memory filesystem I/O requests. 357 * 358 * Loop servicing I/O requests. 359 * Copy the requested data into or out of the memory filesystem 360 * address space. 361 */ 362 /* ARGSUSED */ 363 int 364 mfs_start(mp, flags, l) 365 struct mount *mp; 366 int flags; 367 struct lwp *l; 368 { 369 struct vnode *vp = VFSTOUFS(mp)->um_devvp; 370 struct mfsnode *mfsp = VTOMFS(vp); 371 struct buf *bp; 372 caddr_t base; 373 int sleepreturn = 0; 374 375 base = mfsp->mfs_baseoff; 376 while (mfsp->mfs_shutdown != 1) { 377 while ((bp = BUFQ_GET(&mfsp->mfs_buflist)) != NULL) { 378 mfs_doio(bp, base); 379 wakeup((caddr_t)bp); 380 } 381 /* 382 * If a non-ignored signal is received, try to unmount. 383 * If that fails, or the filesystem is already in the 384 * process of being unmounted, clear the signal (it has been 385 * "processed"), otherwise we will loop here, as tsleep 386 * will always return EINTR/ERESTART. 387 */ 388 if (sleepreturn != 0) { 389 /* 390 * XXX Freeze syncer. Must do this before locking 391 * the mount point. See dounmount() for details. 392 */ 393 lockmgr(&syncer_lock, LK_EXCLUSIVE, NULL); 394 if (vfs_busy(mp, LK_NOWAIT, 0) != 0) 395 lockmgr(&syncer_lock, LK_RELEASE, NULL); 396 else if (dounmount(mp, 0, l) != 0) 397 CLRSIG(l->l_proc, CURSIG(l)); 398 sleepreturn = 0; 399 continue; 400 } 401 402 sleepreturn = tsleep(vp, mfs_pri, "mfsidl", 0); 403 } 404 KASSERT(BUFQ_PEEK(&mfsp->mfs_buflist) == NULL); 405 bufq_free(&mfsp->mfs_buflist); 406 return (sleepreturn); 407 } 408 409 /* 410 * Get file system statistics. 411 */ 412 int 413 mfs_statvfs(mp, sbp, l) 414 struct mount *mp; 415 struct statvfs *sbp; 416 struct lwp *l; 417 { 418 int error; 419 420 error = ffs_statvfs(mp, sbp, l); 421 if (error) 422 return error; 423 (void)strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, 424 sizeof(sbp->f_fstypename)); 425 sbp->f_fstypename[sizeof(sbp->f_fstypename) - 1] = '\0'; 426 return 0; 427 } 428
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