FreeBSD/Linux Kernel Cross Reference
sys/fs/fuse/fuse_io.c
1 /*
2 * Copyright (c) 2007-2009 Google Inc.
3 * 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 are
7 * met:
8 *
9 * * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following disclaimer
13 * in the documentation and/or other materials provided with the
14 * distribution.
15 * * Neither the name of Google Inc. nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * Copyright (C) 2005 Csaba Henk.
32 * All rights reserved.
33 *
34 * Redistribution and use in source and binary forms, with or without
35 * modification, are permitted provided that the following conditions
36 * are met:
37 * 1. Redistributions of source code must retain the above copyright
38 * notice, this list of conditions and the following disclaimer.
39 * 2. Redistributions in binary form must reproduce the above copyright
40 * notice, this list of conditions and the following disclaimer in the
41 * documentation and/or other materials provided with the distribution.
42 *
43 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
44 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
47 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * SUCH DAMAGE.
54 */
55
56 #include <sys/cdefs.h>
57 __FBSDID("$FreeBSD: releng/10.4/sys/fs/fuse/fuse_io.c 248084 2013-03-09 02:32:23Z attilio $");
58
59 #include <sys/types.h>
60 #include <sys/module.h>
61 #include <sys/systm.h>
62 #include <sys/errno.h>
63 #include <sys/param.h>
64 #include <sys/kernel.h>
65 #include <sys/conf.h>
66 #include <sys/uio.h>
67 #include <sys/malloc.h>
68 #include <sys/queue.h>
69 #include <sys/lock.h>
70 #include <sys/sx.h>
71 #include <sys/mutex.h>
72 #include <sys/rwlock.h>
73 #include <sys/proc.h>
74 #include <sys/mount.h>
75 #include <sys/vnode.h>
76 #include <sys/stat.h>
77 #include <sys/unistd.h>
78 #include <sys/filedesc.h>
79 #include <sys/file.h>
80 #include <sys/fcntl.h>
81 #include <sys/bio.h>
82 #include <sys/buf.h>
83 #include <sys/sysctl.h>
84
85 #include <vm/vm.h>
86 #include <vm/vm_extern.h>
87 #include <vm/pmap.h>
88 #include <vm/vm_map.h>
89 #include <vm/vm_page.h>
90 #include <vm/vm_object.h>
91
92 #include "fuse.h"
93 #include "fuse_file.h"
94 #include "fuse_node.h"
95 #include "fuse_internal.h"
96 #include "fuse_ipc.h"
97 #include "fuse_io.h"
98
99 #define FUSE_DEBUG_MODULE IO
100 #include "fuse_debug.h"
101
102
103 static int
104 fuse_read_directbackend(struct vnode *vp, struct uio *uio,
105 struct ucred *cred, struct fuse_filehandle *fufh);
106 static int
107 fuse_read_biobackend(struct vnode *vp, struct uio *uio,
108 struct ucred *cred, struct fuse_filehandle *fufh);
109 static int
110 fuse_write_directbackend(struct vnode *vp, struct uio *uio,
111 struct ucred *cred, struct fuse_filehandle *fufh);
112 static int
113 fuse_write_biobackend(struct vnode *vp, struct uio *uio,
114 struct ucred *cred, struct fuse_filehandle *fufh, int ioflag);
115
116 int
117 fuse_io_dispatch(struct vnode *vp, struct uio *uio, int ioflag,
118 struct ucred *cred)
119 {
120 struct fuse_filehandle *fufh;
121 int err, directio;
122
123 MPASS(vp->v_type == VREG || vp->v_type == VDIR);
124
125 err = fuse_filehandle_getrw(vp,
126 (uio->uio_rw == UIO_READ) ? FUFH_RDONLY : FUFH_WRONLY, &fufh);
127 if (err) {
128 printf("FUSE: io dispatch: filehandles are closed\n");
129 return err;
130 }
131 /*
132 * Ideally, when the daemon asks for direct io at open time, the
133 * standard file flag should be set according to this, so that would
134 * just change the default mode, which later on could be changed via
135 * fcntl(2).
136 * But this doesn't work, the O_DIRECT flag gets cleared at some point
137 * (don't know where). So to make any use of the Fuse direct_io option,
138 * we hardwire it into the file's private data (similarly to Linux,
139 * btw.).
140 */
141 directio = (ioflag & IO_DIRECT) || !fsess_opt_datacache(vnode_mount(vp));
142
143 switch (uio->uio_rw) {
144 case UIO_READ:
145 if (directio) {
146 FS_DEBUG("direct read of vnode %ju via file handle %ju\n",
147 (uintmax_t)VTOILLU(vp), (uintmax_t)fufh->fh_id);
148 err = fuse_read_directbackend(vp, uio, cred, fufh);
149 } else {
150 FS_DEBUG("buffered read of vnode %ju\n",
151 (uintmax_t)VTOILLU(vp));
152 err = fuse_read_biobackend(vp, uio, cred, fufh);
153 }
154 break;
155 case UIO_WRITE:
156 if (directio) {
157 FS_DEBUG("direct write of vnode %ju via file handle %ju\n",
158 (uintmax_t)VTOILLU(vp), (uintmax_t)fufh->fh_id);
159 err = fuse_write_directbackend(vp, uio, cred, fufh);
160 } else {
161 FS_DEBUG("buffered write of vnode %ju\n",
162 (uintmax_t)VTOILLU(vp));
163 err = fuse_write_biobackend(vp, uio, cred, fufh, ioflag);
164 }
165 break;
166 default:
167 panic("uninterpreted mode passed to fuse_io_dispatch");
168 }
169
170 return (err);
171 }
172
173 static int
174 fuse_read_biobackend(struct vnode *vp, struct uio *uio,
175 struct ucred *cred, struct fuse_filehandle *fufh)
176 {
177 struct buf *bp;
178 daddr_t lbn;
179 int bcount;
180 int err = 0, n = 0, on = 0;
181 off_t filesize;
182
183 const int biosize = fuse_iosize(vp);
184
185 FS_DEBUG("resid=%zx offset=%jx fsize=%jx\n",
186 uio->uio_resid, uio->uio_offset, VTOFUD(vp)->filesize);
187
188 if (uio->uio_resid == 0)
189 return (0);
190 if (uio->uio_offset < 0)
191 return (EINVAL);
192
193 bcount = MIN(MAXBSIZE, biosize);
194 filesize = VTOFUD(vp)->filesize;
195
196 do {
197 if (fuse_isdeadfs(vp)) {
198 err = ENXIO;
199 break;
200 }
201 lbn = uio->uio_offset / biosize;
202 on = uio->uio_offset & (biosize - 1);
203
204 FS_DEBUG2G("biosize %d, lbn %d, on %d\n", biosize, (int)lbn, on);
205
206 /*
207 * Obtain the buffer cache block. Figure out the buffer size
208 * when we are at EOF. If we are modifying the size of the
209 * buffer based on an EOF condition we need to hold
210 * nfs_rslock() through obtaining the buffer to prevent
211 * a potential writer-appender from messing with n_size.
212 * Otherwise we may accidently truncate the buffer and
213 * lose dirty data.
214 *
215 * Note that bcount is *not* DEV_BSIZE aligned.
216 */
217 if ((off_t)lbn * biosize >= filesize) {
218 bcount = 0;
219 } else if ((off_t)(lbn + 1) * biosize > filesize) {
220 bcount = filesize - (off_t)lbn *biosize;
221 }
222 bp = getblk(vp, lbn, bcount, PCATCH, 0, 0);
223
224 if (!bp)
225 return (EINTR);
226
227 /*
228 * If B_CACHE is not set, we must issue the read. If this
229 * fails, we return an error.
230 */
231
232 if ((bp->b_flags & B_CACHE) == 0) {
233 bp->b_iocmd = BIO_READ;
234 vfs_busy_pages(bp, 0);
235 err = fuse_io_strategy(vp, bp);
236 if (err) {
237 brelse(bp);
238 return (err);
239 }
240 }
241 /*
242 * on is the offset into the current bp. Figure out how many
243 * bytes we can copy out of the bp. Note that bcount is
244 * NOT DEV_BSIZE aligned.
245 *
246 * Then figure out how many bytes we can copy into the uio.
247 */
248
249 n = 0;
250 if (on < bcount)
251 n = MIN((unsigned)(bcount - on), uio->uio_resid);
252 if (n > 0) {
253 FS_DEBUG2G("feeding buffeater with %d bytes of buffer %p,"
254 " saying %d was asked for\n",
255 n, bp->b_data + on, n + (int)bp->b_resid);
256 err = uiomove(bp->b_data + on, n, uio);
257 }
258 brelse(bp);
259 FS_DEBUG2G("end of turn, err %d, uio->uio_resid %zd, n %d\n",
260 err, uio->uio_resid, n);
261 } while (err == 0 && uio->uio_resid > 0 && n > 0);
262
263 return (err);
264 }
265
266 static int
267 fuse_read_directbackend(struct vnode *vp, struct uio *uio,
268 struct ucred *cred, struct fuse_filehandle *fufh)
269 {
270 struct fuse_dispatcher fdi;
271 struct fuse_read_in *fri;
272 int err = 0;
273
274 if (uio->uio_resid == 0)
275 return (0);
276
277 fdisp_init(&fdi, 0);
278
279 /*
280 * XXX In "normal" case we use an intermediate kernel buffer for
281 * transmitting data from daemon's context to ours. Eventually, we should
282 * get rid of this. Anyway, if the target uio lives in sysspace (we are
283 * called from pageops), and the input data doesn't need kernel-side
284 * processing (we are not called from readdir) we can already invoke
285 * an optimized, "peer-to-peer" I/O routine.
286 */
287 while (uio->uio_resid > 0) {
288 fdi.iosize = sizeof(*fri);
289 fdisp_make_vp(&fdi, FUSE_READ, vp, uio->uio_td, cred);
290 fri = fdi.indata;
291 fri->fh = fufh->fh_id;
292 fri->offset = uio->uio_offset;
293 fri->size = MIN(uio->uio_resid,
294 fuse_get_mpdata(vp->v_mount)->max_read);
295
296 FS_DEBUG2G("fri->fh %ju, fri->offset %ju, fri->size %ju\n",
297 (uintmax_t)fri->fh, (uintmax_t)fri->offset,
298 (uintmax_t)fri->size);
299
300 if ((err = fdisp_wait_answ(&fdi)))
301 goto out;
302
303 FS_DEBUG2G("complete: got iosize=%d, requested fri.size=%zd; "
304 "resid=%zd offset=%ju\n",
305 fri->size, fdi.iosize, uio->uio_resid,
306 (uintmax_t)uio->uio_offset);
307
308 if ((err = uiomove(fdi.answ, MIN(fri->size, fdi.iosize), uio)))
309 break;
310 if (fdi.iosize < fri->size)
311 break;
312 }
313
314 out:
315 fdisp_destroy(&fdi);
316 return (err);
317 }
318
319 static int
320 fuse_write_directbackend(struct vnode *vp, struct uio *uio,
321 struct ucred *cred, struct fuse_filehandle *fufh)
322 {
323 struct fuse_vnode_data *fvdat = VTOFUD(vp);
324 struct fuse_write_in *fwi;
325 struct fuse_dispatcher fdi;
326 size_t chunksize;
327 int diff;
328 int err = 0;
329
330 if (!uio->uio_resid)
331 return (0);
332
333 fdisp_init(&fdi, 0);
334
335 while (uio->uio_resid > 0) {
336 chunksize = MIN(uio->uio_resid,
337 fuse_get_mpdata(vp->v_mount)->max_write);
338
339 fdi.iosize = sizeof(*fwi) + chunksize;
340 fdisp_make_vp(&fdi, FUSE_WRITE, vp, uio->uio_td, cred);
341
342 fwi = fdi.indata;
343 fwi->fh = fufh->fh_id;
344 fwi->offset = uio->uio_offset;
345 fwi->size = chunksize;
346
347 if ((err = uiomove((char *)fdi.indata + sizeof(*fwi),
348 chunksize, uio)))
349 break;
350
351 if ((err = fdisp_wait_answ(&fdi)))
352 break;
353
354 diff = chunksize - ((struct fuse_write_out *)fdi.answ)->size;
355 if (diff < 0) {
356 err = EINVAL;
357 break;
358 }
359 uio->uio_resid += diff;
360 uio->uio_offset -= diff;
361 if (uio->uio_offset > fvdat->filesize)
362 fuse_vnode_setsize(vp, cred, uio->uio_offset);
363 }
364
365 fdisp_destroy(&fdi);
366
367 return (err);
368 }
369
370 static int
371 fuse_write_biobackend(struct vnode *vp, struct uio *uio,
372 struct ucred *cred, struct fuse_filehandle *fufh, int ioflag)
373 {
374 struct fuse_vnode_data *fvdat = VTOFUD(vp);
375 struct buf *bp;
376 daddr_t lbn;
377 int bcount;
378 int n, on, err = 0;
379
380 const int biosize = fuse_iosize(vp);
381
382 KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode"));
383 FS_DEBUG("resid=%zx offset=%jx fsize=%jx\n",
384 uio->uio_resid, uio->uio_offset, fvdat->filesize);
385 if (vp->v_type != VREG)
386 return (EIO);
387 if (uio->uio_offset < 0)
388 return (EINVAL);
389 if (uio->uio_resid == 0)
390 return (0);
391 if (ioflag & IO_APPEND)
392 uio_setoffset(uio, fvdat->filesize);
393
394 /*
395 * Find all of this file's B_NEEDCOMMIT buffers. If our writes
396 * would exceed the local maximum per-file write commit size when
397 * combined with those, we must decide whether to flush,
398 * go synchronous, or return err. We don't bother checking
399 * IO_UNIT -- we just make all writes atomic anyway, as there's
400 * no point optimizing for something that really won't ever happen.
401 */
402 do {
403 if (fuse_isdeadfs(vp)) {
404 err = ENXIO;
405 break;
406 }
407 lbn = uio->uio_offset / biosize;
408 on = uio->uio_offset & (biosize - 1);
409 n = MIN((unsigned)(biosize - on), uio->uio_resid);
410
411 FS_DEBUG2G("lbn %ju, on %d, n %d, uio offset %ju, uio resid %zd\n",
412 (uintmax_t)lbn, on, n,
413 (uintmax_t)uio->uio_offset, uio->uio_resid);
414
415 again:
416 /*
417 * Handle direct append and file extension cases, calculate
418 * unaligned buffer size.
419 */
420 if (uio->uio_offset == fvdat->filesize && n) {
421 /*
422 * Get the buffer (in its pre-append state to maintain
423 * B_CACHE if it was previously set). Resize the
424 * nfsnode after we have locked the buffer to prevent
425 * readers from reading garbage.
426 */
427 bcount = on;
428 FS_DEBUG("getting block from OS, bcount %d\n", bcount);
429 bp = getblk(vp, lbn, bcount, PCATCH, 0, 0);
430
431 if (bp != NULL) {
432 long save;
433
434 err = fuse_vnode_setsize(vp, cred,
435 uio->uio_offset + n);
436 if (err) {
437 brelse(bp);
438 break;
439 }
440 save = bp->b_flags & B_CACHE;
441 bcount += n;
442 allocbuf(bp, bcount);
443 bp->b_flags |= save;
444 }
445 } else {
446 /*
447 * Obtain the locked cache block first, and then
448 * adjust the file's size as appropriate.
449 */
450 bcount = on + n;
451 if ((off_t)lbn * biosize + bcount < fvdat->filesize) {
452 if ((off_t)(lbn + 1) * biosize < fvdat->filesize)
453 bcount = biosize;
454 else
455 bcount = fvdat->filesize -
456 (off_t)lbn *biosize;
457 }
458 FS_DEBUG("getting block from OS, bcount %d\n", bcount);
459 bp = getblk(vp, lbn, bcount, PCATCH, 0, 0);
460 if (bp && uio->uio_offset + n > fvdat->filesize) {
461 err = fuse_vnode_setsize(vp, cred,
462 uio->uio_offset + n);
463 if (err) {
464 brelse(bp);
465 break;
466 }
467 }
468 }
469
470 if (!bp) {
471 err = EINTR;
472 break;
473 }
474 /*
475 * Issue a READ if B_CACHE is not set. In special-append
476 * mode, B_CACHE is based on the buffer prior to the write
477 * op and is typically set, avoiding the read. If a read
478 * is required in special append mode, the server will
479 * probably send us a short-read since we extended the file
480 * on our end, resulting in b_resid == 0 and, thusly,
481 * B_CACHE getting set.
482 *
483 * We can also avoid issuing the read if the write covers
484 * the entire buffer. We have to make sure the buffer state
485 * is reasonable in this case since we will not be initiating
486 * I/O. See the comments in kern/vfs_bio.c's getblk() for
487 * more information.
488 *
489 * B_CACHE may also be set due to the buffer being cached
490 * normally.
491 */
492
493 if (on == 0 && n == bcount) {
494 bp->b_flags |= B_CACHE;
495 bp->b_flags &= ~B_INVAL;
496 bp->b_ioflags &= ~BIO_ERROR;
497 }
498 if ((bp->b_flags & B_CACHE) == 0) {
499 bp->b_iocmd = BIO_READ;
500 vfs_busy_pages(bp, 0);
501 fuse_io_strategy(vp, bp);
502 if ((err = bp->b_error)) {
503 brelse(bp);
504 break;
505 }
506 }
507 if (bp->b_wcred == NOCRED)
508 bp->b_wcred = crhold(cred);
509
510 /*
511 * If dirtyend exceeds file size, chop it down. This should
512 * not normally occur but there is an append race where it
513 * might occur XXX, so we log it.
514 *
515 * If the chopping creates a reverse-indexed or degenerate
516 * situation with dirtyoff/end, we 0 both of them.
517 */
518
519 if (bp->b_dirtyend > bcount) {
520 FS_DEBUG("FUSE append race @%lx:%d\n",
521 (long)bp->b_blkno * biosize,
522 bp->b_dirtyend - bcount);
523 bp->b_dirtyend = bcount;
524 }
525 if (bp->b_dirtyoff >= bp->b_dirtyend)
526 bp->b_dirtyoff = bp->b_dirtyend = 0;
527
528 /*
529 * If the new write will leave a contiguous dirty
530 * area, just update the b_dirtyoff and b_dirtyend,
531 * otherwise force a write rpc of the old dirty area.
532 *
533 * While it is possible to merge discontiguous writes due to
534 * our having a B_CACHE buffer ( and thus valid read data
535 * for the hole), we don't because it could lead to
536 * significant cache coherency problems with multiple clients,
537 * especially if locking is implemented later on.
538 *
539 * as an optimization we could theoretically maintain
540 * a linked list of discontinuous areas, but we would still
541 * have to commit them separately so there isn't much
542 * advantage to it except perhaps a bit of asynchronization.
543 */
544
545 if (bp->b_dirtyend > 0 &&
546 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
547 /*
548 * Yes, we mean it. Write out everything to "storage"
549 * immediatly, without hesitation. (Apart from other
550 * reasons: the only way to know if a write is valid
551 * if its actually written out.)
552 */
553 bwrite(bp);
554 if (bp->b_error == EINTR) {
555 err = EINTR;
556 break;
557 }
558 goto again;
559 }
560 err = uiomove((char *)bp->b_data + on, n, uio);
561
562 /*
563 * Since this block is being modified, it must be written
564 * again and not just committed. Since write clustering does
565 * not work for the stage 1 data write, only the stage 2
566 * commit rpc, we have to clear B_CLUSTEROK as well.
567 */
568 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
569
570 if (err) {
571 bp->b_ioflags |= BIO_ERROR;
572 bp->b_error = err;
573 brelse(bp);
574 break;
575 }
576 /*
577 * Only update dirtyoff/dirtyend if not a degenerate
578 * condition.
579 */
580 if (n) {
581 if (bp->b_dirtyend > 0) {
582 bp->b_dirtyoff = MIN(on, bp->b_dirtyoff);
583 bp->b_dirtyend = MAX((on + n), bp->b_dirtyend);
584 } else {
585 bp->b_dirtyoff = on;
586 bp->b_dirtyend = on + n;
587 }
588 vfs_bio_set_valid(bp, on, n);
589 }
590 err = bwrite(bp);
591 if (err)
592 break;
593 } while (uio->uio_resid > 0 && n > 0);
594
595 if (fuse_sync_resize && (fvdat->flag & FN_SIZECHANGE) != 0)
596 fuse_vnode_savesize(vp, cred);
597
598 return (err);
599 }
600
601 int
602 fuse_io_strategy(struct vnode *vp, struct buf *bp)
603 {
604 struct fuse_filehandle *fufh;
605 struct fuse_vnode_data *fvdat = VTOFUD(vp);
606 struct ucred *cred;
607 struct uio *uiop;
608 struct uio uio;
609 struct iovec io;
610 int error = 0;
611
612 const int biosize = fuse_iosize(vp);
613
614 MPASS(vp->v_type == VREG || vp->v_type == VDIR);
615 MPASS(bp->b_iocmd == BIO_READ || bp->b_iocmd == BIO_WRITE);
616 FS_DEBUG("inode=%ju offset=%jd resid=%ld\n",
617 (uintmax_t)VTOI(vp), (intmax_t)(((off_t)bp->b_blkno) * biosize),
618 bp->b_bcount);
619
620 error = fuse_filehandle_getrw(vp,
621 (bp->b_iocmd == BIO_READ) ? FUFH_RDONLY : FUFH_WRONLY, &fufh);
622 if (error) {
623 printf("FUSE: strategy: filehandles are closed\n");
624 bp->b_ioflags |= BIO_ERROR;
625 bp->b_error = error;
626 return (error);
627 }
628 cred = bp->b_iocmd == BIO_READ ? bp->b_rcred : bp->b_wcred;
629
630 uiop = &uio;
631 uiop->uio_iov = &io;
632 uiop->uio_iovcnt = 1;
633 uiop->uio_segflg = UIO_SYSSPACE;
634 uiop->uio_td = curthread;
635
636 /*
637 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
638 * do this here so we do not have to do it in all the code that
639 * calls us.
640 */
641 bp->b_flags &= ~B_INVAL;
642 bp->b_ioflags &= ~BIO_ERROR;
643
644 KASSERT(!(bp->b_flags & B_DONE),
645 ("fuse_io_strategy: bp %p already marked done", bp));
646 if (bp->b_iocmd == BIO_READ) {
647 io.iov_len = uiop->uio_resid = bp->b_bcount;
648 io.iov_base = bp->b_data;
649 uiop->uio_rw = UIO_READ;
650
651 uiop->uio_offset = ((off_t)bp->b_blkno) * biosize;
652 error = fuse_read_directbackend(vp, uiop, cred, fufh);
653
654 if ((!error && uiop->uio_resid) ||
655 (fsess_opt_brokenio(vnode_mount(vp)) && error == EIO &&
656 uiop->uio_offset < fvdat->filesize && fvdat->filesize > 0 &&
657 uiop->uio_offset >= fvdat->cached_attrs.va_size)) {
658 /*
659 * If we had a short read with no error, we must have
660 * hit a file hole. We should zero-fill the remainder.
661 * This can also occur if the server hits the file EOF.
662 *
663 * Holes used to be able to occur due to pending
664 * writes, but that is not possible any longer.
665 */
666 int nread = bp->b_bcount - uiop->uio_resid;
667 int left = uiop->uio_resid;
668
669 if (error != 0) {
670 printf("FUSE: Fix broken io: offset %ju, "
671 " resid %zd, file size %ju/%ju\n",
672 (uintmax_t)uiop->uio_offset,
673 uiop->uio_resid, fvdat->filesize,
674 fvdat->cached_attrs.va_size);
675 error = 0;
676 }
677 if (left > 0)
678 bzero((char *)bp->b_data + nread, left);
679 uiop->uio_resid = 0;
680 }
681 if (error) {
682 bp->b_ioflags |= BIO_ERROR;
683 bp->b_error = error;
684 }
685 } else {
686 /*
687 * If we only need to commit, try to commit
688 */
689 if (bp->b_flags & B_NEEDCOMMIT) {
690 FS_DEBUG("write: B_NEEDCOMMIT flags set\n");
691 }
692 /*
693 * Setup for actual write
694 */
695 if ((off_t)bp->b_blkno * biosize + bp->b_dirtyend >
696 fvdat->filesize)
697 bp->b_dirtyend = fvdat->filesize -
698 (off_t)bp->b_blkno * biosize;
699
700 if (bp->b_dirtyend > bp->b_dirtyoff) {
701 io.iov_len = uiop->uio_resid = bp->b_dirtyend
702 - bp->b_dirtyoff;
703 uiop->uio_offset = (off_t)bp->b_blkno * biosize
704 + bp->b_dirtyoff;
705 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
706 uiop->uio_rw = UIO_WRITE;
707
708 error = fuse_write_directbackend(vp, uiop, cred, fufh);
709
710 if (error == EINTR || error == ETIMEDOUT
711 || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
712
713 bp->b_flags &= ~(B_INVAL | B_NOCACHE);
714 if ((bp->b_flags & B_PAGING) == 0) {
715 bdirty(bp);
716 bp->b_flags &= ~B_DONE;
717 }
718 if ((error == EINTR || error == ETIMEDOUT) &&
719 (bp->b_flags & B_ASYNC) == 0)
720 bp->b_flags |= B_EINTR;
721 } else {
722 if (error) {
723 bp->b_ioflags |= BIO_ERROR;
724 bp->b_flags |= B_INVAL;
725 bp->b_error = error;
726 }
727 bp->b_dirtyoff = bp->b_dirtyend = 0;
728 }
729 } else {
730 bp->b_resid = 0;
731 bufdone(bp);
732 return (0);
733 }
734 }
735 bp->b_resid = uiop->uio_resid;
736 bufdone(bp);
737 return (error);
738 }
739
740 int
741 fuse_io_flushbuf(struct vnode *vp, int waitfor, struct thread *td)
742 {
743 struct vop_fsync_args a = {
744 .a_vp = vp,
745 .a_waitfor = waitfor,
746 .a_td = td,
747 };
748
749 return (vop_stdfsync(&a));
750 }
751
752 /*
753 * Flush and invalidate all dirty buffers. If another process is already
754 * doing the flush, just wait for completion.
755 */
756 int
757 fuse_io_invalbuf(struct vnode *vp, struct thread *td)
758 {
759 struct fuse_vnode_data *fvdat = VTOFUD(vp);
760 int error = 0;
761
762 if (vp->v_iflag & VI_DOOMED)
763 return 0;
764
765 ASSERT_VOP_ELOCKED(vp, "fuse_io_invalbuf");
766
767 while (fvdat->flag & FN_FLUSHINPROG) {
768 struct proc *p = td->td_proc;
769
770 if (vp->v_mount->mnt_kern_flag & MNTK_UNMOUNTF)
771 return EIO;
772 fvdat->flag |= FN_FLUSHWANT;
773 tsleep(&fvdat->flag, PRIBIO + 2, "fusevinv", 2 * hz);
774 error = 0;
775 if (p != NULL) {
776 PROC_LOCK(p);
777 if (SIGNOTEMPTY(p->p_siglist) ||
778 SIGNOTEMPTY(td->td_siglist))
779 error = EINTR;
780 PROC_UNLOCK(p);
781 }
782 if (error == EINTR)
783 return EINTR;
784 }
785 fvdat->flag |= FN_FLUSHINPROG;
786
787 if (vp->v_bufobj.bo_object != NULL) {
788 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object);
789 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
790 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object);
791 }
792 error = vinvalbuf(vp, V_SAVE, PCATCH, 0);
793 while (error) {
794 if (error == ERESTART || error == EINTR) {
795 fvdat->flag &= ~FN_FLUSHINPROG;
796 if (fvdat->flag & FN_FLUSHWANT) {
797 fvdat->flag &= ~FN_FLUSHWANT;
798 wakeup(&fvdat->flag);
799 }
800 return EINTR;
801 }
802 error = vinvalbuf(vp, V_SAVE, PCATCH, 0);
803 }
804 fvdat->flag &= ~FN_FLUSHINPROG;
805 if (fvdat->flag & FN_FLUSHWANT) {
806 fvdat->flag &= ~FN_FLUSHWANT;
807 wakeup(&fvdat->flag);
808 }
809 return (error);
810 }
Cache object: 6849ea5160971e364d6e65c7d425f15d
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