1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2007-2009 Google Inc. and Amit Singh 5 * 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 are 9 * met: 10 * 11 * * Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * * Redistributions in binary form must reproduce the above 14 * copyright notice, this list of conditions and the following disclaimer 15 * in the documentation and/or other materials provided with the 16 * distribution. 17 * * Neither the name of Google Inc. nor the names of its 18 * contributors may be used to endorse or promote products derived from 19 * this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 * 33 * Copyright (C) 2005 Csaba Henk. 34 * All rights reserved. 35 * 36 * Copyright (c) 2019 The FreeBSD Foundation 37 * 38 * Portions of this software were developed by BFF Storage Systems, LLC under 39 * sponsorship from the FreeBSD Foundation. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 50 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include <sys/types.h> 67 #include <sys/systm.h> 68 #include <sys/counter.h> 69 #include <sys/module.h> 70 #include <sys/errno.h> 71 #include <sys/param.h> 72 #include <sys/kernel.h> 73 #include <sys/conf.h> 74 #include <sys/uio.h> 75 #include <sys/malloc.h> 76 #include <sys/queue.h> 77 #include <sys/lock.h> 78 #include <sys/sx.h> 79 #include <sys/mutex.h> 80 #include <sys/proc.h> 81 #include <sys/vnode.h> 82 #include <sys/namei.h> 83 #include <sys/mount.h> 84 #include <sys/sysctl.h> 85 #include <sys/fcntl.h> 86 #include <sys/priv.h> 87 #include <sys/buf.h> 88 #include <security/mac/mac_framework.h> 89 #include <vm/vm.h> 90 #include <vm/vm_extern.h> 91 92 #include "fuse.h" 93 #include "fuse_node.h" 94 #include "fuse_internal.h" 95 #include "fuse_io.h" 96 #include "fuse_ipc.h" 97 98 SDT_PROVIDER_DECLARE(fusefs); 99 /* 100 * Fuse trace probe: 101 * arg0: verbosity. Higher numbers give more verbose messages 102 * arg1: Textual message 103 */ 104 SDT_PROBE_DEFINE2(fusefs, , node, trace, "int", "char*"); 105 106 MALLOC_DEFINE(M_FUSEVN, "fuse_vnode", "fuse vnode private data"); 107 108 static int sysctl_fuse_cache_mode(SYSCTL_HANDLER_ARGS); 109 110 static counter_u64_t fuse_node_count; 111 112 SYSCTL_COUNTER_U64(_vfs_fusefs_stats, OID_AUTO, node_count, CTLFLAG_RD, 113 &fuse_node_count, "Count of FUSE vnodes"); 114 115 int fuse_data_cache_mode = FUSE_CACHE_WT; 116 117 /* 118 * DEPRECATED 119 * This sysctl is no longer needed as of fuse protocol 7.23. Individual 120 * servers can select the cache behavior they need for each mountpoint: 121 * - writethrough: the default 122 * - writeback: set FUSE_WRITEBACK_CACHE in fuse_init_out.flags 123 * - uncached: set FOPEN_DIRECT_IO for every file 124 * The sysctl is retained primarily for use by jails supporting older FUSE 125 * protocols. It may be removed entirely once FreeBSD 11.3 and 12.0 are EOL. 126 */ 127 SYSCTL_PROC(_vfs_fusefs, OID_AUTO, data_cache_mode, 128 CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 129 &fuse_data_cache_mode, 0, sysctl_fuse_cache_mode, "I", 130 "Zero: disable caching of FUSE file data; One: write-through caching " 131 "(default); Two: write-back caching (generally unsafe)"); 132 133 static int 134 sysctl_fuse_cache_mode(SYSCTL_HANDLER_ARGS) 135 { 136 int val, error; 137 138 val = *(int *)arg1; 139 error = sysctl_handle_int(oidp, &val, 0, req); 140 if (error || !req->newptr) 141 return (error); 142 143 switch (val) { 144 case FUSE_CACHE_UC: 145 case FUSE_CACHE_WT: 146 case FUSE_CACHE_WB: 147 *(int *)arg1 = val; 148 break; 149 default: 150 return (EDOM); 151 } 152 return (0); 153 } 154 155 static void 156 fuse_vnode_init(struct vnode *vp, struct fuse_vnode_data *fvdat, 157 uint64_t nodeid, enum vtype vtyp) 158 { 159 fvdat->nid = nodeid; 160 LIST_INIT(&fvdat->handles); 161 vattr_null(&fvdat->cached_attrs); 162 if (nodeid == FUSE_ROOT_ID) { 163 vp->v_vflag |= VV_ROOT; 164 } 165 vp->v_type = vtyp; 166 vp->v_data = fvdat; 167 168 counter_u64_add(fuse_node_count, 1); 169 } 170 171 void 172 fuse_vnode_destroy(struct vnode *vp) 173 { 174 struct fuse_vnode_data *fvdat = vp->v_data; 175 176 vp->v_data = NULL; 177 KASSERT(LIST_EMPTY(&fvdat->handles), 178 ("Destroying fuse vnode with open files!")); 179 free(fvdat, M_FUSEVN); 180 181 counter_u64_add(fuse_node_count, -1); 182 } 183 184 int 185 fuse_vnode_cmp(struct vnode *vp, void *nidp) 186 { 187 return (VTOI(vp) != *((uint64_t *)nidp)); 188 } 189 190 SDT_PROBE_DEFINE3(fusefs, , node, stale_vnode, "struct vnode*", "enum vtype", 191 "uint64_t"); 192 static int 193 fuse_vnode_alloc(struct mount *mp, 194 struct thread *td, 195 uint64_t nodeid, 196 enum vtype vtyp, 197 struct vnode **vpp) 198 { 199 struct fuse_data *data; 200 struct fuse_vnode_data *fvdat; 201 struct vnode *vp2; 202 int err = 0; 203 204 data = fuse_get_mpdata(mp); 205 if (vtyp == VNON) { 206 return EINVAL; 207 } 208 *vpp = NULL; 209 err = vfs_hash_get(mp, fuse_vnode_hash(nodeid), LK_EXCLUSIVE, td, vpp, 210 fuse_vnode_cmp, &nodeid); 211 if (err) 212 return (err); 213 214 if (*vpp) { 215 if ((*vpp)->v_type == vtyp) { 216 /* Reuse a vnode that hasn't yet been reclaimed */ 217 MPASS((*vpp)->v_data != NULL); 218 MPASS(VTOFUD(*vpp)->nid == nodeid); 219 SDT_PROBE2(fusefs, , node, trace, 1, 220 "vnode taken from hash"); 221 return (0); 222 } else { 223 /* 224 * The inode changed types! If we get here, we can't 225 * tell whether the inode's entry cache had expired 226 * yet. So this could be the result of a buggy server, 227 * but more likely the server just reused an inode 228 * number following an entry cache expiration. 229 */ 230 SDT_PROBE3(fusefs, , node, stale_vnode, *vpp, vtyp, 231 nodeid); 232 fuse_internal_vnode_disappear(*vpp); 233 vgone(*vpp); 234 lockmgr((*vpp)->v_vnlock, LK_RELEASE, NULL); 235 } 236 } 237 fvdat = malloc(sizeof(*fvdat), M_FUSEVN, M_WAITOK | M_ZERO); 238 switch (vtyp) { 239 case VFIFO: 240 err = getnewvnode("fuse", mp, &fuse_fifoops, vpp); 241 break; 242 default: 243 err = getnewvnode("fuse", mp, &fuse_vnops, vpp); 244 break; 245 } 246 if (err) { 247 free(fvdat, M_FUSEVN); 248 return (err); 249 } 250 lockmgr((*vpp)->v_vnlock, LK_EXCLUSIVE, NULL); 251 fuse_vnode_init(*vpp, fvdat, nodeid, vtyp); 252 err = insmntque(*vpp, mp); 253 ASSERT_VOP_ELOCKED(*vpp, "fuse_vnode_alloc"); 254 if (err) { 255 lockmgr((*vpp)->v_vnlock, LK_RELEASE, NULL); 256 free(fvdat, M_FUSEVN); 257 *vpp = NULL; 258 return (err); 259 } 260 /* Disallow async reads for fifos because UFS does. I don't know why */ 261 if (data->dataflags & FSESS_ASYNC_READ && vtyp != VFIFO) 262 VN_LOCK_ASHARE(*vpp); 263 264 err = vfs_hash_insert(*vpp, fuse_vnode_hash(nodeid), LK_EXCLUSIVE, 265 td, &vp2, fuse_vnode_cmp, &nodeid); 266 if (err) { 267 lockmgr((*vpp)->v_vnlock, LK_RELEASE, NULL); 268 free(fvdat, M_FUSEVN); 269 *vpp = NULL; 270 return (err); 271 } 272 if (vp2 != NULL) { 273 *vpp = vp2; 274 return (0); 275 } 276 277 ASSERT_VOP_ELOCKED(*vpp, "fuse_vnode_alloc"); 278 279 return (0); 280 } 281 282 int 283 fuse_vnode_get(struct mount *mp, 284 struct fuse_entry_out *feo, 285 uint64_t nodeid, 286 struct vnode *dvp, 287 struct vnode **vpp, 288 struct componentname *cnp, 289 enum vtype vtyp) 290 { 291 struct thread *td = (cnp != NULL ? cnp->cn_thread : curthread); 292 /* 293 * feo should only be NULL for the root directory, which (when libfuse 294 * is used) always has generation 0 295 */ 296 uint64_t generation = feo ? feo->generation : 0; 297 int err = 0; 298 299 err = fuse_vnode_alloc(mp, td, nodeid, vtyp, vpp); 300 if (err) { 301 return err; 302 } 303 if (dvp != NULL) { 304 MPASS(cnp && (cnp->cn_flags & ISDOTDOT) == 0); 305 MPASS(cnp && 306 !(cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.')); 307 fuse_vnode_setparent(*vpp, dvp); 308 } 309 if (dvp != NULL && cnp != NULL && (cnp->cn_flags & MAKEENTRY) != 0 && 310 feo != NULL && 311 (feo->entry_valid != 0 || feo->entry_valid_nsec != 0)) { 312 struct timespec timeout; 313 314 ASSERT_VOP_LOCKED(*vpp, "fuse_vnode_get"); 315 ASSERT_VOP_LOCKED(dvp, "fuse_vnode_get"); 316 317 fuse_validity_2_timespec(feo, &timeout); 318 cache_enter_time(dvp, *vpp, cnp, &timeout, NULL); 319 } 320 321 VTOFUD(*vpp)->generation = generation; 322 /* 323 * In userland, libfuse uses cached lookups for dot and dotdot entries, 324 * thus it does not really bump the nlookup counter for forget. 325 * Follow the same semantic and avoid the bump in order to keep 326 * nlookup counters consistent. 327 */ 328 if (cnp == NULL || ((cnp->cn_flags & ISDOTDOT) == 0 && 329 (cnp->cn_namelen != 1 || cnp->cn_nameptr[0] != '.'))) 330 VTOFUD(*vpp)->nlookup++; 331 332 return 0; 333 } 334 335 /* 336 * Called for every fusefs vnode open to initialize the vnode (not 337 * fuse_filehandle) for use 338 */ 339 void 340 fuse_vnode_open(struct vnode *vp, int32_t fuse_open_flags, struct thread *td) 341 { 342 if (vnode_vtype(vp) == VREG) 343 vnode_create_vobject(vp, 0, td); 344 } 345 346 int 347 fuse_vnode_savesize(struct vnode *vp, struct ucred *cred, pid_t pid) 348 { 349 struct fuse_vnode_data *fvdat = VTOFUD(vp); 350 struct thread *td = curthread; 351 struct fuse_filehandle *fufh = NULL; 352 struct fuse_dispatcher fdi; 353 struct fuse_setattr_in *fsai; 354 int err = 0; 355 356 ASSERT_VOP_ELOCKED(vp, "fuse_io_extend"); 357 358 if (fuse_isdeadfs(vp)) { 359 return EBADF; 360 } 361 if (vnode_vtype(vp) == VDIR) { 362 return EISDIR; 363 } 364 if (vfs_isrdonly(vnode_mount(vp))) { 365 return EROFS; 366 } 367 if (cred == NULL) { 368 cred = td->td_ucred; 369 } 370 fdisp_init(&fdi, sizeof(*fsai)); 371 fdisp_make_vp(&fdi, FUSE_SETATTR, vp, td, cred); 372 fsai = fdi.indata; 373 fsai->valid = 0; 374 375 /* Truncate to a new value. */ 376 MPASS((fvdat->flag & FN_SIZECHANGE) != 0); 377 fsai->size = fvdat->cached_attrs.va_size; 378 fsai->valid |= FATTR_SIZE; 379 380 fuse_filehandle_getrw(vp, FWRITE, &fufh, cred, pid); 381 if (fufh) { 382 fsai->fh = fufh->fh_id; 383 fsai->valid |= FATTR_FH; 384 } 385 err = fdisp_wait_answ(&fdi); 386 fdisp_destroy(&fdi); 387 if (err == 0) 388 fvdat->flag &= ~FN_SIZECHANGE; 389 390 return err; 391 } 392 393 /* 394 * Adjust the vnode's size to a new value. 395 * 396 * If the new value came from the server, such as from a FUSE_GETATTR 397 * operation, set `from_server` true. But if it came from a local operation, 398 * such as write(2) or truncate(2), set `from_server` false. 399 */ 400 int 401 fuse_vnode_setsize(struct vnode *vp, off_t newsize, bool from_server) 402 { 403 struct fuse_vnode_data *fvdat = VTOFUD(vp); 404 struct vattr *attrs; 405 off_t oldsize; 406 size_t iosize; 407 struct buf *bp = NULL; 408 int err = 0; 409 410 ASSERT_VOP_ELOCKED(vp, "fuse_vnode_setsize"); 411 412 iosize = fuse_iosize(vp); 413 oldsize = fvdat->cached_attrs.va_size; 414 fvdat->cached_attrs.va_size = newsize; 415 if ((attrs = VTOVA(vp)) != NULL) 416 attrs->va_size = newsize; 417 418 if (newsize < oldsize) { 419 daddr_t lbn; 420 421 err = vtruncbuf(vp, newsize, fuse_iosize(vp)); 422 if (err) 423 goto out; 424 if (newsize % iosize == 0) 425 goto out; 426 /* 427 * Zero the contents of the last partial block. 428 * Sure seems like vtruncbuf should do this for us. 429 */ 430 431 lbn = newsize / iosize; 432 bp = getblk(vp, lbn, iosize, PCATCH, 0, 0); 433 if (!bp) { 434 err = EINTR; 435 goto out; 436 } 437 if (!(bp->b_flags & B_CACHE)) 438 goto out; /* Nothing to do */ 439 MPASS(bp->b_flags & B_VMIO); 440 vfs_bio_clrbuf(bp); 441 bp->b_dirtyend = MIN(bp->b_dirtyend, newsize - lbn * iosize); 442 } else if (from_server && newsize > oldsize && oldsize != VNOVAL) { 443 /* 444 * The FUSE server changed the file size behind our back. We 445 * should invalidate the entire cache. 446 */ 447 daddr_t left_lbn, end_lbn; 448 449 left_lbn = oldsize / iosize; 450 end_lbn = howmany(newsize, iosize); 451 v_inval_buf_range(vp, 0, end_lbn, iosize); 452 } 453 out: 454 if (bp) 455 brelse(bp); 456 vnode_pager_setsize(vp, newsize); 457 return err; 458 } 459 460 /* Get the current, possibly dirty, size of the file */ 461 int 462 fuse_vnode_size(struct vnode *vp, off_t *filesize, struct ucred *cred, 463 struct thread *td) 464 { 465 struct fuse_vnode_data *fvdat = VTOFUD(vp); 466 int error = 0; 467 468 if (!(fvdat->flag & FN_SIZECHANGE) && 469 (!fuse_vnode_attr_cache_valid(vp) || 470 fvdat->cached_attrs.va_size == VNOVAL)) 471 error = fuse_internal_do_getattr(vp, NULL, cred, td); 472 473 if (!error) 474 *filesize = fvdat->cached_attrs.va_size; 475 476 return error; 477 } 478 479 void 480 fuse_vnode_undirty_cached_timestamps(struct vnode *vp, bool atime) 481 { 482 struct fuse_vnode_data *fvdat = VTOFUD(vp); 483 484 fvdat->flag &= ~(FN_MTIMECHANGE | FN_CTIMECHANGE); 485 if (atime) 486 fvdat->flag &= ~FN_ATIMECHANGE; 487 } 488 489 /* Update a fuse file's cached timestamps */ 490 void 491 fuse_vnode_update(struct vnode *vp, int flags) 492 { 493 struct fuse_vnode_data *fvdat = VTOFUD(vp); 494 struct mount *mp = vnode_mount(vp); 495 struct fuse_data *data = fuse_get_mpdata(mp); 496 struct timespec ts; 497 498 vfs_timestamp(&ts); 499 500 if (data->time_gran > 1) 501 ts.tv_nsec = rounddown(ts.tv_nsec, data->time_gran); 502 503 if (mp->mnt_flag & MNT_NOATIME) 504 flags &= ~FN_ATIMECHANGE; 505 506 if (flags & FN_ATIMECHANGE) 507 fvdat->cached_attrs.va_atime = ts; 508 if (flags & FN_MTIMECHANGE) 509 fvdat->cached_attrs.va_mtime = ts; 510 if (flags & FN_CTIMECHANGE) 511 fvdat->cached_attrs.va_ctime = ts; 512 513 fvdat->flag |= flags; 514 } 515 516 void 517 fuse_node_init(void) 518 { 519 fuse_node_count = counter_u64_alloc(M_WAITOK); 520 } 521 522 void 523 fuse_node_destroy(void) 524 { 525 counter_u64_free(fuse_node_count); 526 } 527