ext2fs_readwrite.c revision 1.46
1 /* $NetBSD: ext2fs_readwrite.c,v 1.46 2007/04/19 11:05:14 yamt 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 * 3. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by Manuel Bouyer. 49 * 4. The name of the author may not be used to endorse or promote products 50 * derived from this software without specific prior written permission. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 53 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 54 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 55 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 56 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 57 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 58 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 59 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 60 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 61 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 62 * 63 * @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94 64 * Modified for ext2fs by Manuel Bouyer. 65 */ 66 67 #include <sys/cdefs.h> 68 __KERNEL_RCSID(0, "$NetBSD: ext2fs_readwrite.c,v 1.46 2007/04/19 11:05:14 yamt Exp $"); 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/resourcevar.h> 73 #include <sys/kernel.h> 74 #include <sys/file.h> 75 #include <sys/stat.h> 76 #include <sys/buf.h> 77 #include <sys/proc.h> 78 #include <sys/mount.h> 79 #include <sys/vnode.h> 80 #include <sys/malloc.h> 81 #include <sys/signalvar.h> 82 #include <sys/kauth.h> 83 84 #include <ufs/ufs/inode.h> 85 #include <ufs/ufs/ufsmount.h> 86 #include <ufs/ufs/ufs_extern.h> 87 #include <ufs/ext2fs/ext2fs.h> 88 #include <ufs/ext2fs/ext2fs_extern.h> 89 90 91 #define doclusterread 0 /* XXX underway */ 92 #define doclusterwrite 0 93 94 /* 95 * Vnode op for reading. 96 */ 97 /* ARGSUSED */ 98 int 99 ext2fs_read(void *v) 100 { 101 struct vop_read_args /* { 102 struct vnode *a_vp; 103 struct uio *a_uio; 104 int a_ioflag; 105 kauth_cred_t a_cred; 106 } */ *ap = v; 107 struct vnode *vp; 108 struct inode *ip; 109 struct uio *uio; 110 struct m_ext2fs *fs; 111 struct buf *bp; 112 struct ufsmount *ump; 113 void *win; 114 vsize_t bytelen; 115 daddr_t lbn, nextlbn; 116 off_t bytesinfile; 117 long size, xfersize, blkoffset; 118 int error, flags; 119 120 vp = ap->a_vp; 121 ip = VTOI(vp); 122 ump = ip->i_ump; 123 uio = ap->a_uio; 124 error = 0; 125 126 #ifdef DIAGNOSTIC 127 if (uio->uio_rw != UIO_READ) 128 panic("%s: mode", "ext2fs_read"); 129 130 if (vp->v_type == VLNK) { 131 if (ext2fs_size(ip) < ump->um_maxsymlinklen || 132 (ump->um_maxsymlinklen == 0 && ip->i_e2fs_nblock == 0)) 133 panic("%s: short symlink", "ext2fs_read"); 134 } else if (vp->v_type != VREG && vp->v_type != VDIR) 135 panic("%s: type %d", "ext2fs_read", vp->v_type); 136 #endif 137 fs = ip->i_e2fs; 138 if ((u_int64_t)uio->uio_offset > ump->um_maxfilesize) 139 return (EFBIG); 140 if (uio->uio_resid == 0) 141 return (0); 142 if (uio->uio_offset >= ext2fs_size(ip)) 143 goto out; 144 145 if (vp->v_type == VREG) { 146 const int advice = IO_ADV_DECODE(ap->a_ioflag); 147 148 while (uio->uio_resid > 0) { 149 bytelen = MIN(ext2fs_size(ip) - uio->uio_offset, 150 uio->uio_resid); 151 if (bytelen == 0) 152 break; 153 154 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 155 &bytelen, advice, UBC_READ); 156 error = uiomove(win, bytelen, uio); 157 flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0; 158 ubc_release(win, flags); 159 if (error) 160 break; 161 } 162 goto out; 163 } 164 165 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 166 bytesinfile = ext2fs_size(ip) - uio->uio_offset; 167 if (bytesinfile <= 0) 168 break; 169 lbn = lblkno(fs, uio->uio_offset); 170 nextlbn = lbn + 1; 171 size = fs->e2fs_bsize; 172 blkoffset = blkoff(fs, uio->uio_offset); 173 xfersize = fs->e2fs_bsize - blkoffset; 174 if (uio->uio_resid < xfersize) 175 xfersize = uio->uio_resid; 176 if (bytesinfile < xfersize) 177 xfersize = bytesinfile; 178 179 if (lblktosize(fs, nextlbn) >= ext2fs_size(ip)) 180 error = bread(vp, lbn, size, NOCRED, &bp); 181 else { 182 int nextsize = fs->e2fs_bsize; 183 error = breadn(vp, lbn, 184 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 185 } 186 if (error) 187 break; 188 189 /* 190 * We should only get non-zero b_resid when an I/O error 191 * has occurred, which should cause us to break above. 192 * However, if the short read did not cause an error, 193 * then we want to ensure that we do not uiomove bad 194 * or uninitialized data. 195 */ 196 size -= bp->b_resid; 197 if (size < xfersize) { 198 if (size == 0) 199 break; 200 xfersize = size; 201 } 202 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 203 if (error) 204 break; 205 brelse(bp); 206 } 207 if (bp != NULL) 208 brelse(bp); 209 210 out: 211 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 212 ip->i_flag |= IN_ACCESS; 213 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) 214 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 215 } 216 return (error); 217 } 218 219 /* 220 * Vnode op for writing. 221 */ 222 int 223 ext2fs_write(void *v) 224 { 225 struct vop_write_args /* { 226 struct vnode *a_vp; 227 struct uio *a_uio; 228 int a_ioflag; 229 kauth_cred_t a_cred; 230 } */ *ap = v; 231 struct vnode *vp; 232 struct uio *uio; 233 struct inode *ip; 234 struct m_ext2fs *fs; 235 struct buf *bp; 236 struct proc *p; 237 struct ufsmount *ump; 238 daddr_t lbn; 239 off_t osize; 240 int blkoffset, error, flags, ioflag, resid, xfersize; 241 vsize_t bytelen; 242 void *win; 243 off_t oldoff = 0; /* XXX */ 244 bool async; 245 int extended = 0; 246 247 ioflag = ap->a_ioflag; 248 uio = ap->a_uio; 249 vp = ap->a_vp; 250 ip = VTOI(vp); 251 ump = ip->i_ump; 252 error = 0; 253 254 #ifdef DIAGNOSTIC 255 if (uio->uio_rw != UIO_WRITE) 256 panic("%s: mode", "ext2fs_write"); 257 #endif 258 259 switch (vp->v_type) { 260 case VREG: 261 if (ioflag & IO_APPEND) 262 uio->uio_offset = ext2fs_size(ip); 263 if ((ip->i_e2fs_flags & EXT2_APPEND) && 264 uio->uio_offset != ext2fs_size(ip)) 265 return (EPERM); 266 /* FALLTHROUGH */ 267 case VLNK: 268 break; 269 case VDIR: 270 if ((ioflag & IO_SYNC) == 0) 271 panic("%s: nonsync dir write", "ext2fs_write"); 272 break; 273 default: 274 panic("%s: type", "ext2fs_write"); 275 } 276 277 fs = ip->i_e2fs; 278 if (uio->uio_offset < 0 || 279 (u_int64_t)uio->uio_offset + uio->uio_resid > ump->um_maxfilesize) 280 return (EFBIG); 281 /* 282 * Maybe this should be above the vnode op call, but so long as 283 * file servers have no limits, I don't think it matters. 284 */ 285 p = curproc; 286 if (vp->v_type == VREG && p && 287 uio->uio_offset + uio->uio_resid > 288 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 289 mutex_enter(&proclist_mutex); 290 psignal(p, SIGXFSZ); 291 mutex_exit(&proclist_mutex); 292 return (EFBIG); 293 } 294 if (uio->uio_resid == 0) 295 return (0); 296 297 async = vp->v_mount->mnt_flag & MNT_ASYNC; 298 resid = uio->uio_resid; 299 osize = ext2fs_size(ip); 300 301 if (vp->v_type == VREG) { 302 while (uio->uio_resid > 0) { 303 oldoff = uio->uio_offset; 304 blkoffset = blkoff(fs, uio->uio_offset); 305 bytelen = MIN(fs->e2fs_bsize - blkoffset, 306 uio->uio_resid); 307 308 error = ufs_balloc_range(vp, uio->uio_offset, 309 bytelen, ap->a_cred, 0); 310 if (error) 311 break; 312 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 313 &bytelen, UVM_ADV_NORMAL, UBC_WRITE); 314 error = uiomove(win, bytelen, uio); 315 flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0; 316 ubc_release(win, flags); 317 if (error) 318 break; 319 320 /* 321 * update UVM's notion of the size now that we've 322 * copied the data into the vnode's pages. 323 */ 324 325 if (vp->v_size < uio->uio_offset) { 326 uvm_vnp_setsize(vp, uio->uio_offset); 327 extended = 1; 328 } 329 330 /* 331 * flush what we just wrote if necessary. 332 * XXXUBC simplistic async flushing. 333 */ 334 335 if (!async && oldoff >> 16 != uio->uio_offset >> 16) { 336 simple_lock(&vp->v_interlock); 337 error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16, 338 (uio->uio_offset >> 16) << 16, PGO_CLEANIT); 339 } 340 } 341 if (error == 0 && ioflag & IO_SYNC) { 342 simple_lock(&vp->v_interlock); 343 error = VOP_PUTPAGES(vp, trunc_page(oldoff), 344 round_page(blkroundup(fs, uio->uio_offset)), 345 PGO_CLEANIT | PGO_SYNCIO); 346 } 347 348 goto out; 349 } 350 351 flags = ioflag & IO_SYNC ? B_SYNC : 0; 352 for (error = 0; uio->uio_resid > 0;) { 353 lbn = lblkno(fs, uio->uio_offset); 354 blkoffset = blkoff(fs, uio->uio_offset); 355 xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); 356 if (xfersize < fs->e2fs_bsize) 357 flags |= B_CLRBUF; 358 else 359 flags &= ~B_CLRBUF; 360 error = ext2fs_balloc(ip, 361 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 362 if (error) 363 break; 364 if (ext2fs_size(ip) < uio->uio_offset + xfersize) { 365 error = ext2fs_setsize(ip, uio->uio_offset + xfersize); 366 if (error) 367 break; 368 } 369 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 370 371 /* 372 * update UVM's notion of the size now that we've 373 * copied the data into the vnode's pages. 374 */ 375 376 if (vp->v_size < uio->uio_offset) { 377 uvm_vnp_setsize(vp, uio->uio_offset); 378 extended = 1; 379 } 380 381 if (ioflag & IO_SYNC) 382 (void)bwrite(bp); 383 else if (xfersize + blkoffset == fs->e2fs_bsize) 384 bawrite(bp); 385 else 386 bdwrite(bp); 387 if (error || xfersize == 0) 388 break; 389 } 390 391 /* 392 * If we successfully wrote any data, and we are not the superuser 393 * we clear the setuid and setgid bits as a precaution against 394 * tampering. 395 */ 396 397 out: 398 ip->i_flag |= IN_CHANGE | IN_UPDATE; 399 if (resid > uio->uio_resid && ap->a_cred && 400 kauth_authorize_generic(ap->a_cred, KAUTH_GENERIC_ISSUSER, NULL)) 401 ip->i_e2fs_mode &= ~(ISUID | ISGID); 402 if (resid > uio->uio_resid) 403 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); 404 if (error) { 405 (void) ext2fs_truncate(vp, osize, ioflag & IO_SYNC, ap->a_cred, 406 p); 407 uio->uio_offset -= resid - uio->uio_resid; 408 uio->uio_resid = resid; 409 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) 410 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 411 KASSERT(vp->v_size == ext2fs_size(ip)); 412 return (error); 413 } 414
Indexes created Tue Sep 30 20:09:53 GMT 2025