1 /* $NetBSD: ext2fs_readwrite.c,v 1.77 2020/04/23 21:47:08 ad 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 1.77 2020/04/23 21:47:08 ad 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_VNODE_FLAGS(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_VNODE_FLAGS(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 rw_enter(vp->v_uobj.vmobjlock, RW_WRITER); 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 rw_enter(vp->v_uobj.vmobjlock, RW_WRITER); 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