ext2fs_readwrite.c revision 1.30
1 /* $NetBSD: ext2fs_readwrite.c,v 1.30 2003/08/07 16:34:26 agc 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 the University of 49 * California, Berkeley and its contributors. 50 * 4. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * 66 * @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94 67 * Modified for ext2fs by Manuel Bouyer. 68 */ 69 70 #include <sys/cdefs.h> 71 __KERNEL_RCSID(0, "$NetBSD: ext2fs_readwrite.c,v 1.30 2003/08/07 16:34:26 agc Exp $"); 72 73 #include <sys/param.h> 74 #include <sys/systm.h> 75 #include <sys/resourcevar.h> 76 #include <sys/kernel.h> 77 #include <sys/file.h> 78 #include <sys/stat.h> 79 #include <sys/buf.h> 80 #include <sys/proc.h> 81 #include <sys/mount.h> 82 #include <sys/vnode.h> 83 #include <sys/malloc.h> 84 #include <sys/signalvar.h> 85 86 #include <ufs/ufs/inode.h> 87 #include <ufs/ufs/ufs_extern.h> 88 #include <ufs/ext2fs/ext2fs.h> 89 #include <ufs/ext2fs/ext2fs_extern.h> 90 91 92 #define doclusterread 0 /* XXX underway */ 93 #define doclusterwrite 0 94 95 /* 96 * Vnode op for reading. 97 */ 98 /* ARGSUSED */ 99 int 100 ext2fs_read(v) 101 void *v; 102 { 103 struct vop_read_args /* { 104 struct vnode *a_vp; 105 struct uio *a_uio; 106 int a_ioflag; 107 struct ucred *a_cred; 108 } */ *ap = v; 109 struct vnode *vp; 110 struct inode *ip; 111 struct uio *uio; 112 struct m_ext2fs *fs; 113 struct buf *bp; 114 void *win; 115 vsize_t bytelen; 116 daddr_t lbn, nextlbn; 117 off_t bytesinfile; 118 long size, xfersize, blkoffset; 119 int error; 120 121 vp = ap->a_vp; 122 ip = VTOI(vp); 123 uio = ap->a_uio; 124 125 #ifdef DIAGNOSTIC 126 if (uio->uio_rw != UIO_READ) 127 panic("%s: mode", "ext2fs_read"); 128 129 if (vp->v_type == VLNK) { 130 if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen || 131 (vp->v_mount->mnt_maxsymlinklen == 0 && 132 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 > 139 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 140 return (EFBIG); 141 if (uio->uio_resid == 0) 142 return (0); 143 if (uio->uio_offset >= ip->i_e2fs_size) 144 return (0); 145 146 if (vp->v_type == VREG) { 147 error = 0; 148 while (uio->uio_resid > 0) { 149 bytelen = MIN(ip->i_e2fs_size - uio->uio_offset, 150 uio->uio_resid); 151 152 if (bytelen == 0) { 153 break; 154 } 155 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 156 &bytelen, UBC_READ); 157 error = uiomove(win, bytelen, uio); 158 ubc_release(win, 0); 159 if (error) { 160 break; 161 } 162 } 163 goto out; 164 } 165 166 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 167 if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 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) >= ip->i_e2fs_size) 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 = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT); 215 } 216 return (error); 217 } 218 219 /* 220 * Vnode op for writing. 221 */ 222 int 223 ext2fs_write(v) 224 void *v; 225 { 226 struct vop_write_args /* { 227 struct vnode *a_vp; 228 struct uio *a_uio; 229 int a_ioflag; 230 struct ucred *a_cred; 231 } */ *ap = v; 232 struct vnode *vp; 233 struct uio *uio; 234 struct inode *ip; 235 struct m_ext2fs *fs; 236 struct buf *bp; 237 struct proc *p; 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; 244 boolean_t 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 error = 0; 252 253 #ifdef DIAGNOSTIC 254 if (uio->uio_rw != UIO_WRITE) 255 panic("%s: mode", "ext2fs_write"); 256 #endif 257 258 switch (vp->v_type) { 259 case VREG: 260 if (ioflag & IO_APPEND) 261 uio->uio_offset = ip->i_e2fs_size; 262 if ((ip->i_e2fs_flags & EXT2_APPEND) && 263 uio->uio_offset != ip->i_e2fs_size) 264 return (EPERM); 265 /* FALLTHROUGH */ 266 case VLNK: 267 break; 268 case VDIR: 269 if ((ioflag & IO_SYNC) == 0) 270 panic("%s: nonsync dir write", "ext2fs_write"); 271 break; 272 default: 273 panic("%s: type", "ext2fs_write"); 274 } 275 276 fs = ip->i_e2fs; 277 if (uio->uio_offset < 0 || 278 (u_int64_t)uio->uio_offset + uio->uio_resid > 279 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 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 = uio->uio_procp; 286 if (vp->v_type == VREG && p && 287 uio->uio_offset + uio->uio_resid > 288 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 289 psignal(p, SIGXFSZ); 290 return (EFBIG); 291 } 292 if (uio->uio_resid == 0) 293 return (0); 294 295 async = vp->v_mount->mnt_flag & MNT_ASYNC; 296 resid = uio->uio_resid; 297 osize = ip->i_e2fs_size; 298 299 if (vp->v_type == VREG) { 300 while (uio->uio_resid > 0) { 301 oldoff = uio->uio_offset; 302 blkoffset = blkoff(fs, uio->uio_offset); 303 bytelen = MIN(fs->e2fs_bsize - blkoffset, 304 uio->uio_resid); 305 306 error = ufs_balloc_range(vp, uio->uio_offset, 307 bytelen, ap->a_cred, 0); 308 if (error) { 309 break; 310 } 311 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 312 &bytelen, UBC_WRITE); 313 error = uiomove(win, bytelen, uio); 314 ubc_release(win, 0); 315 if (error) { 316 break; 317 } 318 319 /* 320 * update UVM's notion of the size now that we've 321 * copied the data into the vnode's pages. 322 */ 323 324 if (vp->v_size < uio->uio_offset) { 325 uvm_vnp_setsize(vp, uio->uio_offset); 326 extended = 1; 327 } 328 329 /* 330 * flush what we just wrote if necessary. 331 * XXXUBC simplistic async flushing. 332 */ 333 334 if (!async && oldoff >> 16 != uio->uio_offset >> 16) { 335 simple_lock(&vp->v_interlock); 336 error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16, 337 (uio->uio_offset >> 16) << 16, PGO_CLEANIT); 338 } 339 } 340 if (error == 0 && ioflag & IO_SYNC) { 341 simple_lock(&vp->v_interlock); 342 error = VOP_PUTPAGES(vp, trunc_page(oldoff), 343 round_page(blkroundup(fs, uio->uio_offset)), 344 PGO_CLEANIT | PGO_SYNCIO); 345 } 346 347 goto out; 348 } 349 350 flags = ioflag & IO_SYNC ? B_SYNC : 0; 351 for (error = 0; uio->uio_resid > 0;) { 352 lbn = lblkno(fs, uio->uio_offset); 353 blkoffset = blkoff(fs, uio->uio_offset); 354 xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); 355 if (xfersize < fs->e2fs_bsize) 356 flags |= B_CLRBUF; 357 else 358 flags &= ~B_CLRBUF; 359 error = ext2fs_balloc(ip, 360 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 361 if (error) 362 break; 363 if (ip->i_e2fs_size < uio->uio_offset + xfersize) { 364 ip->i_e2fs_size = uio->uio_offset + xfersize; 365 } 366 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 367 368 /* 369 * update UVM's notion of the size now that we've 370 * copied the data into the vnode's pages. 371 */ 372 373 if (vp->v_size < uio->uio_offset) { 374 uvm_vnp_setsize(vp, uio->uio_offset); 375 extended = 1; 376 } 377 378 if (ioflag & IO_SYNC) 379 (void)bwrite(bp); 380 else if (xfersize + blkoffset == fs->e2fs_bsize) 381 bawrite(bp); 382 else 383 bdwrite(bp); 384 if (error || xfersize == 0) 385 break; 386 } 387 388 /* 389 * If we successfully wrote any data, and we are not the superuser 390 * we clear the setuid and setgid bits as a precaution against 391 * tampering. 392 */ 393 394 out: 395 ip->i_flag |= IN_CHANGE | IN_UPDATE; 396 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 397 ip->i_e2fs_mode &= ~(ISUID | ISGID); 398 if (resid > uio->uio_resid) 399 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); 400 if (error) { 401 (void) VOP_TRUNCATE(vp, osize, ioflag & IO_SYNC, ap->a_cred, 402 uio->uio_procp); 403 uio->uio_offset -= resid - uio->uio_resid; 404 uio->uio_resid = resid; 405 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) 406 error = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT); 407 KASSERT(vp->v_size == ip->i_e2fs_size); 408 return (error); 409 } 410
Indexes created Tue Sep 30 20:09:53 GMT 2025