1 | /* $NetBSD: ext2fs_readwrite.c,v 1.75 2016/08/13 07:40:10 christos Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 1993 |
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 | * @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94 |
32 | * Modified for ext2fs by Manuel Bouyer. |
33 | */ |
34 | |
35 | /*- |
36 | * Copyright (c) 1997 Manuel Bouyer. |
37 | * |
38 | * Redistribution and use in source and binary forms, with or without |
39 | * modification, are permitted provided that the following conditions |
40 | * are met: |
41 | * 1. Redistributions of source code must retain the above copyright |
42 | * notice, this list of conditions and the following disclaimer. |
43 | * 2. Redistributions in binary form must reproduce the above copyright |
44 | * notice, this list of conditions and the following disclaimer in the |
45 | * documentation and/or other materials provided with the distribution. |
46 | * |
47 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
48 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
49 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
50 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
51 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
52 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
53 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
54 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
55 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
56 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
57 | * |
58 | * @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94 |
59 | * Modified for ext2fs by Manuel Bouyer. |
60 | */ |
61 | |
62 | #include <sys/cdefs.h> |
63 | __KERNEL_RCSID(0, "$NetBSD: ext2fs_readwrite.c,v 1.75 2016/08/13 07:40:10 christos Exp $" ); |
64 | |
65 | #include <sys/param.h> |
66 | #include <sys/systm.h> |
67 | #include <sys/resourcevar.h> |
68 | #include <sys/kernel.h> |
69 | #include <sys/file.h> |
70 | #include <sys/stat.h> |
71 | #include <sys/buf.h> |
72 | #include <sys/proc.h> |
73 | #include <sys/mount.h> |
74 | #include <sys/vnode.h> |
75 | #include <sys/signalvar.h> |
76 | #include <sys/kauth.h> |
77 | |
78 | #include <ufs/ufs/inode.h> |
79 | #include <ufs/ufs/ufsmount.h> |
80 | #include <ufs/ufs/ufs_extern.h> |
81 | #include <ufs/ext2fs/ext2fs.h> |
82 | #include <ufs/ext2fs/ext2fs_extern.h> |
83 | |
84 | static int ext2fs_post_read_update(struct vnode *, int, int); |
85 | static int ext2fs_post_write_update(struct vnode *, struct uio *, int, |
86 | kauth_cred_t, off_t, int, int, int); |
87 | |
88 | /* |
89 | * Vnode op for reading. |
90 | */ |
91 | /* ARGSUSED */ |
92 | int |
93 | ext2fs_read(void *v) |
94 | { |
95 | struct vop_read_args /* { |
96 | struct vnode *a_vp; |
97 | struct uio *a_uio; |
98 | int a_ioflag; |
99 | kauth_cred_t a_cred; |
100 | } */ *ap = v; |
101 | struct vnode *vp; |
102 | struct inode *ip; |
103 | struct uio *uio; |
104 | struct ufsmount *ump; |
105 | vsize_t bytelen; |
106 | int advice; |
107 | int error; |
108 | |
109 | vp = ap->a_vp; |
110 | ip = VTOI(vp); |
111 | ump = ip->i_ump; |
112 | uio = ap->a_uio; |
113 | error = 0; |
114 | |
115 | KASSERT(uio->uio_rw == UIO_READ); |
116 | KASSERT(vp->v_type == VREG || vp->v_type == VDIR); |
117 | |
118 | /* XXX Eliminate me by refusing directory reads from userland. */ |
119 | if (vp->v_type == VDIR) |
120 | return ext2fs_bufrd(vp, uio, ap->a_ioflag, ap->a_cred); |
121 | |
122 | if ((uint64_t)uio->uio_offset > ump->um_maxfilesize) |
123 | return EFBIG; |
124 | if (uio->uio_resid == 0) |
125 | return 0; |
126 | if (uio->uio_offset >= ext2fs_size(ip)) |
127 | goto out; |
128 | |
129 | KASSERT(vp->v_type == VREG); |
130 | advice = IO_ADV_DECODE(ap->a_ioflag); |
131 | while (uio->uio_resid > 0) { |
132 | bytelen = MIN(ext2fs_size(ip) - uio->uio_offset, |
133 | uio->uio_resid); |
134 | if (bytelen == 0) |
135 | break; |
136 | |
137 | error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, |
138 | UBC_READ | UBC_PARTIALOK | UBC_UNMAP_FLAG(vp)); |
139 | if (error) |
140 | break; |
141 | } |
142 | |
143 | out: |
144 | error = ext2fs_post_read_update(vp, ap->a_ioflag, error); |
145 | return error; |
146 | } |
147 | |
148 | /* |
149 | * UFS op for reading via the buffer cache |
150 | */ |
151 | int |
152 | ext2fs_bufrd(struct vnode *vp, struct uio *uio, int ioflag, kauth_cred_t cred) |
153 | { |
154 | struct inode *ip; |
155 | struct ufsmount *ump; |
156 | struct m_ext2fs *fs; |
157 | struct buf *bp; |
158 | off_t bytesinfile; |
159 | daddr_t lbn, nextlbn; |
160 | long size, xfersize, blkoffset; |
161 | int error; |
162 | |
163 | KASSERT(uio->uio_rw == UIO_READ); |
164 | KASSERT(VOP_ISLOCKED(vp)); |
165 | KASSERT(vp->v_type == VDIR || vp->v_type == VLNK); |
166 | |
167 | ip = VTOI(vp); |
168 | ump = ip->i_ump; |
169 | fs = ip->i_e2fs; |
170 | error = 0; |
171 | |
172 | KASSERT(vp->v_type != VLNK || |
173 | ext2fs_size(ip) >= ump->um_maxsymlinklen); |
174 | KASSERT(vp->v_type != VLNK || ump->um_maxsymlinklen != 0 || |
175 | ext2fs_nblock(ip) != 0); |
176 | |
177 | if (uio->uio_offset > ump->um_maxfilesize) |
178 | return EFBIG; |
179 | if (uio->uio_resid == 0) |
180 | return 0; |
181 | if (uio->uio_offset >= ext2fs_size(ip)) |
182 | goto out; |
183 | |
184 | for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { |
185 | bytesinfile = ext2fs_size(ip) - uio->uio_offset; |
186 | if (bytesinfile <= 0) |
187 | break; |
188 | lbn = ext2_lblkno(fs, uio->uio_offset); |
189 | nextlbn = lbn + 1; |
190 | size = fs->e2fs_bsize; |
191 | blkoffset = ext2_blkoff(fs, uio->uio_offset); |
192 | xfersize = fs->e2fs_bsize - blkoffset; |
193 | if (uio->uio_resid < xfersize) |
194 | xfersize = uio->uio_resid; |
195 | if (bytesinfile < xfersize) |
196 | xfersize = bytesinfile; |
197 | |
198 | if (ext2_lblktosize(fs, nextlbn) >= ext2fs_size(ip)) |
199 | error = bread(vp, lbn, size, 0, &bp); |
200 | else { |
201 | int nextsize = fs->e2fs_bsize; |
202 | error = breadn(vp, lbn, |
203 | size, &nextlbn, &nextsize, 1, 0, &bp); |
204 | } |
205 | if (error) |
206 | break; |
207 | |
208 | /* |
209 | * We should only get non-zero b_resid when an I/O error |
210 | * has occurred, which should cause us to break above. |
211 | * However, if the short read did not cause an error, |
212 | * then we want to ensure that we do not uiomove bad |
213 | * or uninitialized data. |
214 | */ |
215 | size -= bp->b_resid; |
216 | if (size < xfersize) { |
217 | if (size == 0) |
218 | break; |
219 | xfersize = size; |
220 | } |
221 | error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); |
222 | if (error) |
223 | break; |
224 | brelse(bp, 0); |
225 | } |
226 | if (bp != NULL) |
227 | brelse(bp, 0); |
228 | |
229 | out: |
230 | error = ext2fs_post_read_update(vp, ioflag, error); |
231 | return error; |
232 | } |
233 | |
234 | static int |
235 | ext2fs_post_read_update(struct vnode *vp, int ioflag, int oerror) |
236 | { |
237 | struct inode *ip = VTOI(vp); |
238 | int error = oerror; |
239 | |
240 | if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { |
241 | ip->i_flag |= IN_ACCESS; |
242 | if ((ioflag & IO_SYNC) == IO_SYNC) |
243 | error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); |
244 | } |
245 | |
246 | /* Read error overrides any inode update error. */ |
247 | if (oerror) |
248 | error = oerror; |
249 | return error; |
250 | } |
251 | |
252 | /* |
253 | * Vnode op for writing. |
254 | */ |
255 | int |
256 | ext2fs_write(void *v) |
257 | { |
258 | struct vop_write_args /* { |
259 | struct vnode *a_vp; |
260 | struct uio *a_uio; |
261 | int a_ioflag; |
262 | kauth_cred_t a_cred; |
263 | } */ *ap = v; |
264 | struct vnode *vp; |
265 | struct uio *uio; |
266 | struct inode *ip; |
267 | struct m_ext2fs *fs; |
268 | struct ufsmount *ump; |
269 | off_t osize; |
270 | int blkoffset, error, ioflag, resid; |
271 | vsize_t bytelen; |
272 | off_t oldoff = 0; /* XXX */ |
273 | bool async; |
274 | int extended = 0; |
275 | int advice; |
276 | |
277 | ioflag = ap->a_ioflag; |
278 | advice = IO_ADV_DECODE(ioflag); |
279 | uio = ap->a_uio; |
280 | vp = ap->a_vp; |
281 | ip = VTOI(vp); |
282 | ump = ip->i_ump; |
283 | error = 0; |
284 | |
285 | KASSERT(uio->uio_rw == UIO_WRITE); |
286 | KASSERT(vp->v_type == VREG); |
287 | |
288 | if (ioflag & IO_APPEND) |
289 | uio->uio_offset = ext2fs_size(ip); |
290 | if ((ip->i_e2fs_flags & EXT2_APPEND) && |
291 | uio->uio_offset != ext2fs_size(ip)) |
292 | return EPERM; |
293 | |
294 | fs = ip->i_e2fs; |
295 | if (uio->uio_offset < 0 || |
296 | (uint64_t)uio->uio_offset + uio->uio_resid > ump->um_maxfilesize) |
297 | return EFBIG; |
298 | if (uio->uio_resid == 0) |
299 | return 0; |
300 | |
301 | async = vp->v_mount->mnt_flag & MNT_ASYNC; |
302 | resid = uio->uio_resid; |
303 | osize = ext2fs_size(ip); |
304 | |
305 | KASSERT(vp->v_type == VREG); |
306 | while (uio->uio_resid > 0) { |
307 | oldoff = uio->uio_offset; |
308 | blkoffset = ext2_blkoff(fs, uio->uio_offset); |
309 | bytelen = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); |
310 | |
311 | if (vp->v_size < oldoff + bytelen) { |
312 | uvm_vnp_setwritesize(vp, oldoff + bytelen); |
313 | } |
314 | error = ufs_balloc_range(vp, uio->uio_offset, bytelen, |
315 | ap->a_cred, 0); |
316 | if (error) |
317 | break; |
318 | error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, |
319 | UBC_WRITE | UBC_UNMAP_FLAG(vp)); |
320 | if (error) |
321 | break; |
322 | |
323 | /* |
324 | * update UVM's notion of the size now that we've |
325 | * copied the data into the vnode's pages. |
326 | */ |
327 | |
328 | if (vp->v_size < uio->uio_offset) { |
329 | uvm_vnp_setsize(vp, uio->uio_offset); |
330 | extended = 1; |
331 | } |
332 | |
333 | /* |
334 | * flush what we just wrote if necessary. |
335 | * XXXUBC simplistic async flushing. |
336 | */ |
337 | |
338 | if (!async && oldoff >> 16 != uio->uio_offset >> 16) { |
339 | mutex_enter(vp->v_interlock); |
340 | error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16, |
341 | (uio->uio_offset >> 16) << 16, |
342 | PGO_CLEANIT | PGO_LAZY); |
343 | } |
344 | } |
345 | if (error == 0 && ioflag & IO_SYNC) { |
346 | mutex_enter(vp->v_interlock); |
347 | error = VOP_PUTPAGES(vp, trunc_page(oldoff), |
348 | round_page(ext2_blkroundup(fs, uio->uio_offset)), |
349 | PGO_CLEANIT | PGO_SYNCIO); |
350 | } |
351 | |
352 | error = ext2fs_post_write_update(vp, uio, ioflag, ap->a_cred, osize, |
353 | resid, extended, error); |
354 | return error; |
355 | } |
356 | |
357 | /* |
358 | * UFS op for writing via the buffer cache |
359 | */ |
360 | int |
361 | ext2fs_bufwr(struct vnode *vp, struct uio *uio, int ioflag, kauth_cred_t cred) |
362 | { |
363 | struct inode *ip; |
364 | struct ufsmount *ump; |
365 | struct m_ext2fs *fs; |
366 | struct buf *bp; |
367 | int flags; |
368 | off_t osize; |
369 | daddr_t lbn; |
370 | int resid, blkoffset, xfersize; |
371 | int extended = 0; |
372 | int error; |
373 | |
374 | KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); |
375 | KASSERT(vp->v_type == VDIR || vp->v_type == VLNK); |
376 | KASSERT(vp->v_type != VDIR || ISSET(ioflag, IO_SYNC)); |
377 | KASSERT(uio->uio_rw == UIO_WRITE); |
378 | |
379 | ip = VTOI(vp); |
380 | ump = ip->i_ump; |
381 | fs = ip->i_e2fs; |
382 | error = 0; |
383 | |
384 | if (uio->uio_offset < 0 || |
385 | uio->uio_resid > ump->um_maxfilesize || |
386 | uio->uio_offset > (ump->um_maxfilesize - uio->uio_resid)) |
387 | return EFBIG; |
388 | if (uio->uio_resid == 0) |
389 | return 0; |
390 | |
391 | flags = ioflag & IO_SYNC ? B_SYNC : 0; |
392 | resid = uio->uio_resid; |
393 | osize = ext2fs_size(ip); |
394 | |
395 | for (error = 0; uio->uio_resid > 0;) { |
396 | lbn = ext2_lblkno(fs, uio->uio_offset); |
397 | blkoffset = ext2_blkoff(fs, uio->uio_offset); |
398 | xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); |
399 | if (xfersize < fs->e2fs_bsize) |
400 | flags |= B_CLRBUF; |
401 | else |
402 | flags &= ~B_CLRBUF; |
403 | error = ext2fs_balloc(ip, lbn, blkoffset + xfersize, cred, &bp, |
404 | flags); |
405 | if (error) |
406 | break; |
407 | if (ext2fs_size(ip) < uio->uio_offset + xfersize) { |
408 | error = ext2fs_setsize(ip, uio->uio_offset + xfersize); |
409 | if (error) |
410 | break; |
411 | } |
412 | error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); |
413 | |
414 | /* |
415 | * update UVM's notion of the size now that we've |
416 | * copied the data into the vnode's pages. |
417 | */ |
418 | |
419 | if (vp->v_size < uio->uio_offset) { |
420 | uvm_vnp_setsize(vp, uio->uio_offset); |
421 | extended = 1; |
422 | } |
423 | |
424 | if (ioflag & IO_SYNC) |
425 | (void)bwrite(bp); |
426 | else if (xfersize + blkoffset == fs->e2fs_bsize) |
427 | bawrite(bp); |
428 | else |
429 | bdwrite(bp); |
430 | if (error || xfersize == 0) |
431 | break; |
432 | } |
433 | |
434 | error = ext2fs_post_write_update(vp, uio, ioflag, cred, osize, resid, |
435 | extended, error); |
436 | return error; |
437 | } |
438 | |
439 | static int |
440 | ext2fs_post_write_update(struct vnode *vp, struct uio *uio, int ioflag, |
441 | kauth_cred_t cred, off_t osize, int resid, int extended, int oerror) |
442 | { |
443 | struct inode *ip = VTOI(vp); |
444 | int error = oerror; |
445 | |
446 | /* Trigger ctime and mtime updates, and atime if MNT_RELATIME. */ |
447 | ip->i_flag |= IN_CHANGE | IN_UPDATE; |
448 | if (vp->v_mount->mnt_flag & MNT_RELATIME) |
449 | ip->i_flag |= IN_ACCESS; |
450 | |
451 | /* |
452 | * If we successfully wrote any data and we are not the superuser, |
453 | * we clear the setuid and setgid bits as a precaution against |
454 | * tampering. |
455 | */ |
456 | if (resid > uio->uio_resid && cred) { |
457 | if (ip->i_e2fs_mode & ISUID) { |
458 | if (kauth_authorize_vnode(cred, |
459 | KAUTH_VNODE_RETAIN_SUID, vp, NULL, EPERM) != 0) |
460 | ip->i_e2fs_mode &= ISUID; |
461 | } |
462 | |
463 | if (ip->i_e2fs_mode & ISGID) { |
464 | if (kauth_authorize_vnode(cred, |
465 | KAUTH_VNODE_RETAIN_SGID, vp, NULL, EPERM) != 0) |
466 | ip->i_e2fs_mode &= ~ISGID; |
467 | } |
468 | } |
469 | |
470 | /* If we successfully wrote anything, notify kevent listeners. */ |
471 | if (resid > uio->uio_resid) |
472 | VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); |
473 | |
474 | /* |
475 | * Update the size on disk: truncate back to original size on |
476 | * error, or reflect the new size on success. |
477 | */ |
478 | if (error) { |
479 | (void) ext2fs_truncate(vp, osize, ioflag & IO_SYNC, cred); |
480 | uio->uio_offset -= resid - uio->uio_resid; |
481 | uio->uio_resid = resid; |
482 | } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) |
483 | error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); |
484 | |
485 | /* Make sure the vnode uvm size matches the inode file size. */ |
486 | KASSERT(vp->v_size == ext2fs_size(ip)); |
487 | |
488 | /* Write error overrides any inode update error. */ |
489 | if (oerror) |
490 | error = oerror; |
491 | return error; |
492 | } |
493 | |