| 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 | |