ext2fs_readwrite.c revision 1.64.8.2
1 /* $NetBSD: ext2fs_readwrite.c,v 1.64.8.2 2015/01/17 12:10:55 martin 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 1.64.8.2 2015/01/17 12:10:55 martin 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 /* 85 * Vnode op for reading. 86 */ 87 /* ARGSUSED */ 88 int 89 ext2fs_read(void *v) 90 { 91 struct vop_read_args /* { 92 struct vnode *a_vp; 93 struct uio *a_uio; 94 int a_ioflag; 95 kauth_cred_t a_cred; 96 } */ *ap = v; 97 struct vnode *vp; 98 struct inode *ip; 99 struct uio *uio; 100 struct m_ext2fs *fs; 101 struct buf *bp; 102 struct ufsmount *ump; 103 vsize_t bytelen; 104 daddr_t lbn, nextlbn; 105 off_t bytesinfile; 106 long size, xfersize, blkoffset; 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 #ifdef DIAGNOSTIC 116 if (uio->uio_rw != UIO_READ) 117 panic("%s: mode", "ext2fs_read"); 118 119 if (vp->v_type == VLNK) { 120 if (ext2fs_size(ip) < ump->um_maxsymlinklen || 121 (ump->um_maxsymlinklen == 0 && ext2fs_nblock(ip) == 0)) 122 panic("%s: short symlink", "ext2fs_read"); 123 } else if (vp->v_type != VREG && vp->v_type != VDIR) 124 panic("%s: type %d", "ext2fs_read", vp->v_type); 125 #endif 126 fs = ip->i_e2fs; 127 if ((uint64_t)uio->uio_offset > ump->um_maxfilesize) 128 return (EFBIG); 129 if (uio->uio_resid == 0) 130 return (0); 131 if (uio->uio_offset >= ext2fs_size(ip)) 132 goto out; 133 134 if (vp->v_type == VREG) { 135 const int advice = IO_ADV_DECODE(ap->a_ioflag); 136 137 while (uio->uio_resid > 0) { 138 bytelen = MIN(ext2fs_size(ip) - uio->uio_offset, 139 uio->uio_resid); 140 if (bytelen == 0) 141 break; 142 143 error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, 144 UBC_READ | UBC_PARTIALOK | UBC_UNMAP_FLAG(vp)); 145 if (error) 146 break; 147 } 148 goto out; 149 } 150 151 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 152 bytesinfile = ext2fs_size(ip) - uio->uio_offset; 153 if (bytesinfile <= 0) 154 break; 155 lbn = ext2_lblkno(fs, uio->uio_offset); 156 nextlbn = lbn + 1; 157 size = fs->e2fs_bsize; 158 blkoffset = ext2_blkoff(fs, uio->uio_offset); 159 xfersize = fs->e2fs_bsize - blkoffset; 160 if (uio->uio_resid < xfersize) 161 xfersize = uio->uio_resid; 162 if (bytesinfile < xfersize) 163 xfersize = bytesinfile; 164 165 if (ext2_lblktosize(fs, nextlbn) >= ext2fs_size(ip)) 166 error = bread(vp, lbn, size, NOCRED, 0, &bp); 167 else { 168 int nextsize = fs->e2fs_bsize; 169 error = breadn(vp, lbn, 170 size, &nextlbn, &nextsize, 1, NOCRED, 0, &bp); 171 } 172 if (error) 173 break; 174 175 /* 176 * We should only get non-zero b_resid when an I/O error 177 * has occurred, which should cause us to break above. 178 * However, if the short read did not cause an error, 179 * then we want to ensure that we do not uiomove bad 180 * or uninitialized data. 181 */ 182 size -= bp->b_resid; 183 if (size < xfersize) { 184 if (size == 0) 185 break; 186 xfersize = size; 187 } 188 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 189 if (error) 190 break; 191 brelse(bp, 0); 192 } 193 if (bp != NULL) 194 brelse(bp, 0); 195 196 out: 197 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 198 ip->i_flag |= IN_ACCESS; 199 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) 200 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 201 } 202 return (error); 203 } 204 205 /* 206 * Vnode op for writing. 207 */ 208 int 209 ext2fs_write(void *v) 210 { 211 struct vop_write_args /* { 212 struct vnode *a_vp; 213 struct uio *a_uio; 214 int a_ioflag; 215 kauth_cred_t a_cred; 216 } */ *ap = v; 217 struct vnode *vp; 218 struct uio *uio; 219 struct inode *ip; 220 struct m_ext2fs *fs; 221 struct buf *bp; 222 struct ufsmount *ump; 223 daddr_t lbn; 224 off_t osize; 225 int blkoffset, error, flags, ioflag, resid, xfersize; 226 vsize_t bytelen; 227 off_t oldoff = 0; /* XXX */ 228 bool async; 229 int extended = 0; 230 int advice; 231 232 ioflag = ap->a_ioflag; 233 advice = IO_ADV_DECODE(ioflag); 234 uio = ap->a_uio; 235 vp = ap->a_vp; 236 ip = VTOI(vp); 237 ump = ip->i_ump; 238 error = 0; 239 240 #ifdef DIAGNOSTIC 241 if (uio->uio_rw != UIO_WRITE) 242 panic("%s: mode", "ext2fs_write"); 243 #endif 244 245 switch (vp->v_type) { 246 case VREG: 247 if (ioflag & IO_APPEND) 248 uio->uio_offset = ext2fs_size(ip); 249 if ((ip->i_e2fs_flags & EXT2_APPEND) && 250 uio->uio_offset != ext2fs_size(ip)) 251 return (EPERM); 252 /* FALLTHROUGH */ 253 case VLNK: 254 break; 255 case VDIR: 256 if ((ioflag & IO_SYNC) == 0) 257 panic("%s: nonsync dir write", "ext2fs_write"); 258 break; 259 default: 260 panic("%s: type", "ext2fs_write"); 261 } 262 263 fs = ip->i_e2fs; 264 if (uio->uio_offset < 0 || 265 (uint64_t)uio->uio_offset + uio->uio_resid > ump->um_maxfilesize) 266 return (EFBIG); 267 if (uio->uio_resid == 0) 268 return (0); 269 270 async = vp->v_mount->mnt_flag & MNT_ASYNC; 271 resid = uio->uio_resid; 272 osize = ext2fs_size(ip); 273 274 if (vp->v_type == VREG) { 275 while (uio->uio_resid > 0) { 276 oldoff = uio->uio_offset; 277 blkoffset = ext2_blkoff(fs, uio->uio_offset); 278 bytelen = MIN(fs->e2fs_bsize - blkoffset, 279 uio->uio_resid); 280 281 if (vp->v_size < oldoff + bytelen) { 282 uvm_vnp_setwritesize(vp, oldoff + bytelen); 283 } 284 error = ufs_balloc_range(vp, uio->uio_offset, 285 bytelen, ap->a_cred, 0); 286 if (error) 287 break; 288 error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, 289 UBC_WRITE | UBC_UNMAP_FLAG(vp)); 290 if (error) 291 break; 292 293 /* 294 * update UVM's notion of the size now that we've 295 * copied the data into the vnode's pages. 296 */ 297 298 if (vp->v_size < uio->uio_offset) { 299 uvm_vnp_setsize(vp, uio->uio_offset); 300 extended = 1; 301 } 302 303 /* 304 * flush what we just wrote if necessary. 305 * XXXUBC simplistic async flushing. 306 */ 307 308 if (!async && oldoff >> 16 != uio->uio_offset >> 16) { 309 mutex_enter(vp->v_interlock); 310 error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16, 311 (uio->uio_offset >> 16) << 16, 312 PGO_CLEANIT | PGO_LAZY); 313 } 314 } 315 if (error == 0 && ioflag & IO_SYNC) { 316 mutex_enter(vp->v_interlock); 317 error = VOP_PUTPAGES(vp, trunc_page(oldoff), 318 round_page(ext2_blkroundup(fs, uio->uio_offset)), 319 PGO_CLEANIT | PGO_SYNCIO); 320 } 321 322 goto out; 323 } 324 325 flags = ioflag & IO_SYNC ? B_SYNC : 0; 326 for (error = 0; uio->uio_resid > 0;) { 327 lbn = ext2_lblkno(fs, uio->uio_offset); 328 blkoffset = ext2_blkoff(fs, uio->uio_offset); 329 xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); 330 if (xfersize < fs->e2fs_bsize) 331 flags |= B_CLRBUF; 332 else 333 flags &= ~B_CLRBUF; 334 error = ext2fs_balloc(ip, 335 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 336 if (error) 337 break; 338 if (ext2fs_size(ip) < uio->uio_offset + xfersize) { 339 error = ext2fs_setsize(ip, uio->uio_offset + xfersize); 340 if (error) 341 break; 342 } 343 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 344 345 /* 346 * update UVM's notion of the size now that we've 347 * copied the data into the vnode's pages. 348 */ 349 350 if (vp->v_size < uio->uio_offset) { 351 uvm_vnp_setsize(vp, uio->uio_offset); 352 extended = 1; 353 } 354 355 if (ioflag & IO_SYNC) 356 (void)bwrite(bp); 357 else if (xfersize + blkoffset == fs->e2fs_bsize) 358 bawrite(bp); 359 else 360 bdwrite(bp); 361 if (error || xfersize == 0) 362 break; 363 } 364 365 /* 366 * If we successfully wrote any data, and we are not the superuser 367 * we clear the setuid and setgid bits as a precaution against 368 * tampering. 369 */ 370 371 out: 372 ip->i_flag |= IN_CHANGE | IN_UPDATE; 373 if (vp->v_mount->mnt_flag & MNT_RELATIME) 374 ip->i_flag |= IN_ACCESS; 375 if (resid > uio->uio_resid && ap->a_cred) { 376 if (ip->i_e2fs_mode & ISUID) { 377 if (kauth_authorize_vnode(ap->a_cred, 378 KAUTH_VNODE_RETAIN_SUID, vp, NULL, EPERM) != 0) 379 ip->i_e2fs_mode &= ISUID; 380 } 381 382 if (ip->i_e2fs_mode & ISGID) { 383 if (kauth_authorize_vnode(ap->a_cred, 384 KAUTH_VNODE_RETAIN_SGID, vp, NULL, EPERM) != 0) 385 ip->i_e2fs_mode &= ~ISGID; 386 } 387 } 388 if (resid > uio->uio_resid) 389 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); 390 if (error) { 391 (void) ext2fs_truncate(vp, osize, ioflag & IO_SYNC, ap->a_cred); 392 uio->uio_offset -= resid - uio->uio_resid; 393 uio->uio_resid = resid; 394 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) 395 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 396 KASSERT(vp->v_size == ext2fs_size(ip)); 397 return (error); 398 } 399
Indexes created Tue Sep 30 20:09:53 GMT 2025