ext2fs_readwrite.c revision 1.38.2.5
1 /* $NetBSD: ext2fs_readwrite.c,v 1.38.2.5 2005/11/19 17:37:00 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 1.38.2.5 2005/11/19 17:37:00 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 83 #include <ufs/ufs/inode.h> 84 #include <ufs/ufs/ufsmount.h> 85 #include <ufs/ufs/ufs_extern.h> 86 #include <ufs/ext2fs/ext2fs.h> 87 #include <ufs/ext2fs/ext2fs_extern.h> 88 89 #define doclusterread 0 /* XXX underway */ 90 #define doclusterwrite 0 91 92 /* 93 * Vnode op for reading. 94 */ 95 /* ARGSUSED */ 96 int 97 ext2fs_read(void *v) 98 { 99 struct vop_read_args /* { 100 struct vnode *a_vp; 101 struct uio *a_uio; 102 int a_ioflag; 103 struct ucred *a_cred; 104 } */ *ap = v; 105 struct vnode *vp; 106 struct inode *ip; 107 struct uio *uio; 108 struct m_ext2fs *fs; 109 struct buf *bp; 110 struct ufsmount *ump; 111 void *win; 112 vsize_t bytelen; 113 daddr_t lbn, nextlbn; 114 off_t bytesinfile; 115 long size, xfersize, blkoffset; 116 int error, flags; 117 118 vp = ap->a_vp; 119 ip = VTOI(vp); 120 ump = ip->i_ump; 121 uio = ap->a_uio; 122 error = 0; 123 124 #ifdef DIAGNOSTIC 125 if (uio->uio_rw != UIO_READ) 126 panic("%s: mode", "ext2fs_read"); 127 128 if (vp->v_type == VLNK) { 129 if (ext2fs_size(ip) < ump->um_maxsymlinklen || 130 (ump->um_maxsymlinklen == 0 && ip->i_e2fs_nblock == 0)) 131 panic("%s: short symlink", "ext2fs_read"); 132 } else if (vp->v_type != VREG && vp->v_type != VDIR) 133 panic("%s: type %d", "ext2fs_read", vp->v_type); 134 #endif 135 fs = ip->i_e2fs; 136 if ((u_int64_t)uio->uio_offset > ump->um_maxfilesize) 137 return (EFBIG); 138 if (uio->uio_resid == 0) 139 return (0); 140 if (uio->uio_offset >= ext2fs_size(ip)) 141 goto out; 142 143 if (vp->v_type == VREG) { 144 const int advice = IO_ADV_DECODE(ap->a_ioflag); 145 146 while (uio->uio_resid > 0) { 147 bytelen = MIN(ext2fs_size(ip) - uio->uio_offset, 148 uio->uio_resid); 149 if (bytelen == 0) 150 break; 151 152 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 153 &bytelen, advice, UBC_READ); 154 error = uiomove(win, bytelen, uio); 155 flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0; 156 ubc_release(win, flags); 157 if (error) 158 break; 159 } 160 goto out; 161 } 162 163 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 164 bytesinfile = ext2fs_size(ip) - uio->uio_offset; 165 if (bytesinfile <= 0) 166 break; 167 lbn = lblkno(fs, uio->uio_offset); 168 nextlbn = lbn + 1; 169 size = fs->e2fs_bsize; 170 blkoffset = blkoff(fs, uio->uio_offset); 171 xfersize = fs->e2fs_bsize - blkoffset; 172 if (uio->uio_resid < xfersize) 173 xfersize = uio->uio_resid; 174 if (bytesinfile < xfersize) 175 xfersize = bytesinfile; 176 177 if (lblktosize(fs, nextlbn) >= ext2fs_size(ip)) 178 error = bread(vp, lbn, size, NOCRED, &bp); 179 else { 180 int nextsize = fs->e2fs_bsize; 181 error = breadn(vp, lbn, 182 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 183 } 184 if (error) 185 break; 186 187 /* 188 * We should only get non-zero b_resid when an I/O error 189 * has occurred, which should cause us to break above. 190 * However, if the short read did not cause an error, 191 * then we want to ensure that we do not uiomove bad 192 * or uninitialized data. 193 */ 194 size -= bp->b_resid; 195 if (size < xfersize) { 196 if (size == 0) 197 break; 198 xfersize = size; 199 } 200 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 201 if (error) 202 break; 203 brelse(bp); 204 } 205 if (bp != NULL) 206 brelse(bp); 207 208 out: 209 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 210 ip->i_flag |= IN_ACCESS; 211 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) 212 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 213 } 214 return (error); 215 } 216 217 /* 218 * Vnode op for writing. 219 */ 220 int 221 ext2fs_write(void *v) 222 { 223 struct vop_write_args /* { 224 struct vnode *a_vp; 225 struct uio *a_uio; 226 int a_ioflag; 227 struct ucred *a_cred; 228 } */ *ap = v; 229 struct vnode *vp; 230 struct uio *uio; 231 struct inode *ip; 232 struct m_ext2fs *fs; 233 struct buf *bp; 234 struct proc *p; 235 struct ufsmount *ump; 236 daddr_t lbn; 237 off_t osize; 238 int blkoffset, error, flags, ioflag, resid, xfersize; 239 vsize_t bytelen; 240 void *win; 241 off_t oldoff = 0; /* XXX */ 242 boolean_t async; 243 int extended = 0; 244 245 ioflag = ap->a_ioflag; 246 uio = ap->a_uio; 247 vp = ap->a_vp; 248 ip = VTOI(vp); 249 ump = ip->i_ump; 250 error = 0; 251 252 #ifdef DIAGNOSTIC 253 if (uio->uio_rw != UIO_WRITE) 254 panic("%s: mode", "ext2fs_write"); 255 #endif 256 257 switch (vp->v_type) { 258 case VREG: 259 if (ioflag & IO_APPEND) 260 uio->uio_offset = ext2fs_size(ip); 261 if ((ip->i_e2fs_flags & EXT2_APPEND) && 262 uio->uio_offset != ext2fs_size(ip)) 263 return (EPERM); 264 /* FALLTHROUGH */ 265 case VLNK: 266 break; 267 case VDIR: 268 if ((ioflag & IO_SYNC) == 0) 269 panic("%s: nonsync dir write", "ext2fs_write"); 270 break; 271 default: 272 panic("%s: type", "ext2fs_write"); 273 } 274 275 fs = ip->i_e2fs; 276 if (uio->uio_offset < 0 || 277 (u_int64_t)uio->uio_offset + uio->uio_resid > ump->um_maxfilesize) 278 return (EFBIG); 279 /* 280 * Maybe this should be above the vnode op call, but so long as 281 * file servers have no limits, I don't think it matters. 282 */ 283 p = uio->uio_procp; 284 if (vp->v_type == VREG && p && 285 uio->uio_offset + uio->uio_resid > 286 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 287 psignal(p, SIGXFSZ); 288 return (EFBIG); 289 } 290 if (uio->uio_resid == 0) 291 return (0); 292 293 async = vp->v_mount->mnt_flag & MNT_ASYNC; 294 resid = uio->uio_resid; 295 osize = ext2fs_size(ip); 296 297 if (vp->v_type == VREG) { 298 while (uio->uio_resid > 0) { 299 oldoff = uio->uio_offset; 300 blkoffset = blkoff(fs, uio->uio_offset); 301 bytelen = MIN(fs->e2fs_bsize - blkoffset, 302 uio->uio_resid); 303 304 error = ufs_balloc_range(vp, uio->uio_offset, 305 bytelen, ap->a_cred, 0); 306 if (error) 307 break; 308 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 309 &bytelen, UVM_ADV_NORMAL, UBC_WRITE); 310 error = uiomove(win, bytelen, uio); 311 flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0; 312 ubc_release(win, flags); 313 if (error) 314 break; 315 316 /* 317 * update UVM's notion of the size now that we've 318 * copied the data into the vnode's pages. 319 */ 320 321 if (vp->v_size < uio->uio_offset) { 322 uvm_vnp_setsize(vp, uio->uio_offset); 323 extended = 1; 324 } 325 326 /* 327 * flush what we just wrote if necessary. 328 * XXXUBC simplistic async flushing. 329 */ 330 331 if (!async && oldoff >> 16 != uio->uio_offset >> 16) { 332 simple_lock(&vp->v_interlock); 333 error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16, 334 (uio->uio_offset >> 16) << 16, PGO_CLEANIT); 335 } 336 } 337 if (error == 0 && ioflag & IO_SYNC) { 338 simple_lock(&vp->v_interlock); 339 error = VOP_PUTPAGES(vp, trunc_page(oldoff), 340 round_page(blkroundup(fs, uio->uio_offset)), 341 PGO_CLEANIT | PGO_SYNCIO); 342 } 343 344 goto out; 345 } 346 347 flags = ioflag & IO_SYNC ? B_SYNC : 0; 348 for (error = 0; uio->uio_resid > 0;) { 349 lbn = lblkno(fs, uio->uio_offset); 350 blkoffset = blkoff(fs, uio->uio_offset); 351 xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); 352 if (xfersize < fs->e2fs_bsize) 353 flags |= B_CLRBUF; 354 else 355 flags &= ~B_CLRBUF; 356 error = ext2fs_balloc(ip, 357 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 358 if (error) 359 break; 360 if (ext2fs_size(ip) < uio->uio_offset + xfersize) { 361 error = ext2fs_setsize(ip, uio->uio_offset + xfersize); 362 if (error) 363 break; 364 } 365 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 366 367 /* 368 * update UVM's notion of the size now that we've 369 * copied the data into the vnode's pages. 370 */ 371 372 if (vp->v_size < uio->uio_offset) { 373 uvm_vnp_setsize(vp, uio->uio_offset); 374 extended = 1; 375 } 376 377 if (ioflag & IO_SYNC) 378 (void)bwrite(bp); 379 else if (xfersize + blkoffset == fs->e2fs_bsize) 380 bawrite(bp); 381 else 382 bdwrite(bp); 383 if (error || xfersize == 0) 384 break; 385 } 386 387 /* 388 * If we successfully wrote any data, and we are not the superuser 389 * we clear the setuid and setgid bits as a precaution against 390 * tampering. 391 */ 392 393 out: 394 ip->i_flag |= IN_CHANGE | IN_UPDATE; 395 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 396 ip->i_e2fs_mode &= ~(ISUID | ISGID); 397 if (resid > uio->uio_resid) 398 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); 399 if (error) { 400 (void) ext2fs_truncate(vp, osize, ioflag & IO_SYNC, ap->a_cred, 401 uio->uio_procp); 402 uio->uio_offset -= resid - uio->uio_resid; 403 uio->uio_resid = resid; 404 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) 405 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 406 KASSERT(vp->v_size == ext2fs_size(ip)); 407 return (error); 408 } 409
Indexes created Tue Sep 30 20:09:53 GMT 2025