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 /* 217 * STALE vnode! This probably indicates a buggy 218 * server, but it could also be the result of a race 219 * between FUSE_LOOKUP and another client's 220 * FUSE_UNLINK/FUSE_CREATE 221 */ 222 SDT_PROBE3(fusefs, , node, stale_vnode, *vpp, vtyp, 223 nodeid); 224 fuse_internal_vnode_disappear(*vpp); 225 lockmgr((*vpp)->v_vnlock, LK_RELEASE, NULL); 226 *vpp = NULL; 227 return (EAGAIN); 228 } 229 MPASS((*vpp)->v_data != NULL); 230 MPASS(VTOFUD(*vpp)->nid == nodeid); 231 SDT_PROBE2(fusefs, , node, trace, 1, "vnode taken from hash"); 232 return (0); 233 } 234 fvdat = malloc(sizeof(*fvdat), M_FUSEVN, M_WAITOK | M_ZERO); 235 switch (vtyp) { 236 case VFIFO: 237 err = getnewvnode("fuse", mp, &fuse_fifoops, vpp); 238 break; 239 default: 240 err = getnewvnode("fuse", mp, &fuse_vnops, vpp); 241 break; 242 } 243 if (err) { 244 free(fvdat, M_FUSEVN); 245 return (err); 246 } 247 lockmgr((*vpp)->v_vnlock, LK_EXCLUSIVE, NULL); 248 fuse_vnode_init(*vpp, fvdat, nodeid, vtyp); 249 err = insmntque(*vpp, mp); 250 ASSERT_VOP_ELOCKED(*vpp, "fuse_vnode_alloc"); 251 if (err) { 252 lockmgr((*vpp)->v_vnlock, LK_RELEASE, NULL); 253 free(fvdat, M_FUSEVN); 254 *vpp = NULL; 255 return (err); 256 } 257 /* Disallow async reads for fifos because UFS does. I don't know why */ 258 if (data->dataflags & FSESS_ASYNC_READ && vtyp != VFIFO) 259 VN_LOCK_ASHARE(*vpp); 260 261 err = vfs_hash_insert(*vpp, fuse_vnode_hash(nodeid), LK_EXCLUSIVE, 262 td, &vp2, fuse_vnode_cmp, &nodeid); 263 if (err) { 264 lockmgr((*vpp)->v_vnlock, LK_RELEASE, NULL); 265 free(fvdat, M_FUSEVN); 266 *vpp = NULL; 267 return (err); 268 } 269 if (vp2 != NULL) { 270 *vpp = vp2; 271 return (0); 272 } 273 274 ASSERT_VOP_ELOCKED(*vpp, "fuse_vnode_alloc"); 275 276 return (0); 277 } 278 279 int 280 fuse_vnode_get(struct mount *mp, 281 struct fuse_entry_out *feo, 282 uint64_t nodeid, 283 struct vnode *dvp, 284 struct vnode **vpp, 285 struct componentname *cnp, 286 enum vtype vtyp) 287 { 288 struct thread *td = (cnp != NULL ? cnp->cn_thread : curthread); 289 /* 290 * feo should only be NULL for the root directory, which (when libfuse 291 * is used) always has generation 0 292 */ 293 uint64_t generation = feo ? feo->generation : 0; 294 int err = 0; 295 296 err = fuse_vnode_alloc(mp, td, nodeid, vtyp, vpp); 297 if (err) { 298 return err; 299 } 300 if (dvp != NULL) { 301 MPASS(cnp && (cnp->cn_flags & ISDOTDOT) == 0); 302 MPASS(cnp && 303 !(cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.')); 304 fuse_vnode_setparent(*vpp, dvp); 305 } 306 if (dvp != NULL && cnp != NULL && (cnp->cn_flags & MAKEENTRY) != 0 && 307 feo != NULL && 308 (feo->entry_valid != 0 || feo->entry_valid_nsec != 0)) { 309 struct timespec timeout; 310 311 ASSERT_VOP_LOCKED(*vpp, "fuse_vnode_get"); 312 ASSERT_VOP_LOCKED(dvp, "fuse_vnode_get"); 313 314 fuse_validity_2_timespec(feo, &timeout); 315 cache_enter_time(dvp, *vpp, cnp, &timeout, NULL); 316 } 317 318 VTOFUD(*vpp)->generation = generation; 319 /* 320 * In userland, libfuse uses cached lookups for dot and dotdot entries, 321 * thus it does not really bump the nlookup counter for forget. 322 * Follow the same semantic and avoid the bump in order to keep 323 * nlookup counters consistent. 324 */ 325 if (cnp == NULL || ((cnp->cn_flags & ISDOTDOT) == 0 && 326 (cnp->cn_namelen != 1 || cnp->cn_nameptr[0] != '.'))) 327 VTOFUD(*vpp)->nlookup++; 328 329 return 0; 330 } 331 332 /* 333 * Called for every fusefs vnode open to initialize the vnode (not 334 * fuse_filehandle) for use 335 */ 336 void 337 fuse_vnode_open(struct vnode *vp, int32_t fuse_open_flags, struct thread *td) 338 { 339 if (vnode_vtype(vp) == VREG) 340 vnode_create_vobject(vp, 0, td); 341 } 342 343 int 344 fuse_vnode_savesize(struct vnode *vp, struct ucred *cred, pid_t pid) 345 { 346 struct fuse_vnode_data *fvdat = VTOFUD(vp); 347 struct thread *td = curthread; 348 struct fuse_filehandle *fufh = NULL; 349 struct fuse_dispatcher fdi; 350 struct fuse_setattr_in *fsai; 351 int err = 0; 352 353 ASSERT_VOP_ELOCKED(vp, "fuse_io_extend"); 354 355 if (fuse_isdeadfs(vp)) { 356 return EBADF; 357 } 358 if (vnode_vtype(vp) == VDIR) { 359 return EISDIR; 360 } 361 if (vfs_isrdonly(vnode_mount(vp))) { 362 return EROFS; 363 } 364 if (cred == NULL) { 365 cred = td->td_ucred; 366 } 367 fdisp_init(&fdi, sizeof(*fsai)); 368 fdisp_make_vp(&fdi, FUSE_SETATTR, vp, td, cred); 369 fsai = fdi.indata; 370 fsai->valid = 0; 371 372 /* Truncate to a new value. */ 373 MPASS((fvdat->flag & FN_SIZECHANGE) != 0); 374 fsai->size = fvdat->cached_attrs.va_size; 375 fsai->valid |= FATTR_SIZE; 376 377 fuse_filehandle_getrw(vp, FWRITE, &fufh, cred, pid); 378 if (fufh) { 379 fsai->fh = fufh->fh_id; 380 fsai->valid |= FATTR_FH; 381 } 382 err = fdisp_wait_answ(&fdi); 383 fdisp_destroy(&fdi); 384 if (err == 0) 385 fvdat->flag &= ~FN_SIZECHANGE; 386 387 return err; 388 } 389 390 /* 391 * Adjust the vnode's size to a new value. 392 * 393 * If the new value came from the server, such as from a FUSE_GETATTR 394 * operation, set `from_server` true. But if it came from a local operation, 395 * such as write(2) or truncate(2), set `from_server` false. 396 */ 397 int 398 fuse_vnode_setsize(struct vnode *vp, off_t newsize, bool from_server) 399 { 400 struct fuse_vnode_data *fvdat = VTOFUD(vp); 401 struct vattr *attrs; 402 off_t oldsize; 403 size_t iosize; 404 struct buf *bp = NULL; 405 int err = 0; 406 407 ASSERT_VOP_ELOCKED(vp, "fuse_vnode_setsize"); 408 409 iosize = fuse_iosize(vp); 410 oldsize = fvdat->cached_attrs.va_size; 411 fvdat->cached_attrs.va_size = newsize; 412 if ((attrs = VTOVA(vp)) != NULL) 413 attrs->va_size = newsize; 414 415 if (newsize < oldsize) { 416 daddr_t lbn; 417 418 err = vtruncbuf(vp, newsize, fuse_iosize(vp)); 419 if (err) 420 goto out; 421 if (newsize % iosize == 0) 422 goto out; 423 /* 424 * Zero the contents of the last partial block. 425 * Sure seems like vtruncbuf should do this for us. 426 */ 427 428 lbn = newsize / iosize; 429 bp = getblk(vp, lbn, iosize, PCATCH, 0, 0); 430 if (!bp) { 431 err = EINTR; 432 goto out; 433 } 434 if (!(bp->b_flags & B_CACHE)) 435 goto out; /* Nothing to do */ 436 MPASS(bp->b_flags & B_VMIO); 437 vfs_bio_clrbuf(bp); 438 bp->b_dirtyend = MIN(bp->b_dirtyend, newsize - lbn * iosize); 439 } else if (from_server && newsize > oldsize && oldsize != VNOVAL) { 440 /* 441 * The FUSE server changed the file size behind our back. We 442 * should invalidate the entire cache. 443 */ 444 daddr_t left_lbn, end_lbn; 445 446 left_lbn = oldsize / iosize; 447 end_lbn = howmany(newsize, iosize); 448 v_inval_buf_range(vp, 0, end_lbn, iosize); 449 } 450 out: 451 if (bp) 452 brelse(bp); 453 vnode_pager_setsize(vp, newsize); 454 return err; 455 } 456 457 /* Get the current, possibly dirty, size of the file */ 458 int 459 fuse_vnode_size(struct vnode *vp, off_t *filesize, struct ucred *cred, 460 struct thread *td) 461 { 462 struct fuse_vnode_data *fvdat = VTOFUD(vp); 463 int error = 0; 464 465 if (!(fvdat->flag & FN_SIZECHANGE) && 466 (!fuse_vnode_attr_cache_valid(vp) || 467 fvdat->cached_attrs.va_size == VNOVAL)) 468 error = fuse_internal_do_getattr(vp, NULL, cred, td); 469 470 if (!error) 471 *filesize = fvdat->cached_attrs.va_size; 472 473 return error; 474 } 475 476 void 477 fuse_vnode_undirty_cached_timestamps(struct vnode *vp, bool atime) 478 { 479 struct fuse_vnode_data *fvdat = VTOFUD(vp); 480 481 fvdat->flag &= ~(FN_MTIMECHANGE | FN_CTIMECHANGE); 482 if (atime) 483 fvdat->flag &= ~FN_ATIMECHANGE; 484 } 485 486 /* Update a fuse file's cached timestamps */ 487 void 488 fuse_vnode_update(struct vnode *vp, int flags) 489 { 490 struct fuse_vnode_data *fvdat = VTOFUD(vp); 491 struct mount *mp = vnode_mount(vp); 492 struct fuse_data *data = fuse_get_mpdata(mp); 493 struct timespec ts; 494 495 vfs_timestamp(&ts); 496 497 if (data->time_gran > 1) 498 ts.tv_nsec = rounddown(ts.tv_nsec, data->time_gran); 499 500 if (mp->mnt_flag & MNT_NOATIME) 501 flags &= ~FN_ATIMECHANGE; 502 503 if (flags & FN_ATIMECHANGE) 504 fvdat->cached_attrs.va_atime = ts; 505 if (flags & FN_MTIMECHANGE) 506 fvdat->cached_attrs.va_mtime = ts; 507 if (flags & FN_CTIMECHANGE) 508 fvdat->cached_attrs.va_ctime = ts; 509 510 fvdat->flag |= flags; 511 } 512 513 void 514 fuse_node_init(void) 515 { 516 fuse_node_count = counter_u64_alloc(M_WAITOK); 517 } 518 519 void 520 fuse_node_destroy(void) 521 { 522 counter_u64_free(fuse_node_count); 523 } 524