ext2fs_readwrite.c revision 1.38.2.3
1 /* $NetBSD: ext2fs_readwrite.c,v 1.38.2.3 2005/11/18 08:44:55 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 1.38.2.3 2005/11/18 08:44:55 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 #include <uvm/uvm_readahead.h> 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 struct ucred *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 struct uvm_ractx *ra; 120 121 vp = ap->a_vp; 122 ip = VTOI(vp); 123 ump = ip->i_ump; 124 uio = ap->a_uio; 125 error = 0; 126 127 #ifdef DIAGNOSTIC 128 if (uio->uio_rw != UIO_READ) 129 panic("%s: mode", "ext2fs_read"); 130 131 if (vp->v_type == VLNK) { 132 if (ext2fs_size(ip) < ump->um_maxsymlinklen || 133 (ump->um_maxsymlinklen == 0 && ip->i_e2fs_nblock == 0)) 134 panic("%s: short symlink", "ext2fs_read"); 135 } else if (vp->v_type != VREG && vp->v_type != VDIR) 136 panic("%s: type %d", "ext2fs_read", vp->v_type); 137 #endif 138 fs = ip->i_e2fs; 139 if ((u_int64_t)uio->uio_offset > ump->um_maxfilesize) 140 return (EFBIG); 141 if (uio->uio_resid == 0) 142 return (0); 143 if (uio->uio_offset >= ext2fs_size(ip)) 144 goto out; 145 146 if (vp->v_type == VREG) { 147 const int advice = IO_ADV_DECODE(ap->a_ioflag); 148 149 while (uio->uio_resid > 0) { 150 bytelen = MIN(ext2fs_size(ip) - uio->uio_offset, 151 uio->uio_resid); 152 if (bytelen == 0) 153 break; 154 155 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 156 &bytelen, UBC_READ); 157 uvm_ra_request(vp->v_ractx, advice, &vp->v_uobj, 158 uio->uio_offset, bytelen); 159 error = uiomove(win, bytelen, uio); 160 flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0; 161 ubc_release(win, flags); 162 if (error) 163 break; 164 } 165 goto out; 166 } 167 168 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 169 bytesinfile = ext2fs_size(ip) - uio->uio_offset; 170 if (bytesinfile <= 0) 171 break; 172 lbn = lblkno(fs, uio->uio_offset); 173 nextlbn = lbn + 1; 174 size = fs->e2fs_bsize; 175 blkoffset = blkoff(fs, uio->uio_offset); 176 xfersize = fs->e2fs_bsize - blkoffset; 177 if (uio->uio_resid < xfersize) 178 xfersize = uio->uio_resid; 179 if (bytesinfile < xfersize) 180 xfersize = bytesinfile; 181 182 if (lblktosize(fs, nextlbn) >= ext2fs_size(ip)) 183 error = bread(vp, lbn, size, NOCRED, &bp); 184 else { 185 int nextsize = fs->e2fs_bsize; 186 error = breadn(vp, lbn, 187 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 188 } 189 if (error) 190 break; 191 192 /* 193 * We should only get non-zero b_resid when an I/O error 194 * has occurred, which should cause us to break above. 195 * However, if the short read did not cause an error, 196 * then we want to ensure that we do not uiomove bad 197 * or uninitialized data. 198 */ 199 size -= bp->b_resid; 200 if (size < xfersize) { 201 if (size == 0) 202 break; 203 xfersize = size; 204 } 205 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 206 if (error) 207 break; 208 brelse(bp); 209 } 210 if (bp != NULL) 211 brelse(bp); 212 213 out: 214 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 215 ip->i_flag |= IN_ACCESS; 216 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) 217 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 218 } 219 return (error); 220 } 221 222 /* 223 * Vnode op for writing. 224 */ 225 int 226 ext2fs_write(void *v) 227 { 228 struct vop_write_args /* { 229 struct vnode *a_vp; 230 struct uio *a_uio; 231 int a_ioflag; 232 struct ucred *a_cred; 233 } */ *ap = v; 234 struct vnode *vp; 235 struct uio *uio; 236 struct inode *ip; 237 struct m_ext2fs *fs; 238 struct buf *bp; 239 struct proc *p; 240 struct ufsmount *ump; 241 daddr_t lbn; 242 off_t osize; 243 int blkoffset, error, flags, ioflag, resid, xfersize; 244 vsize_t bytelen; 245 void *win; 246 off_t oldoff = 0; /* XXX */ 247 boolean_t async; 248 int extended = 0; 249 250 ioflag = ap->a_ioflag; 251 uio = ap->a_uio; 252 vp = ap->a_vp; 253 ip = VTOI(vp); 254 ump = ip->i_ump; 255 error = 0; 256 257 #ifdef DIAGNOSTIC 258 if (uio->uio_rw != UIO_WRITE) 259 panic("%s: mode", "ext2fs_write"); 260 #endif 261 262 switch (vp->v_type) { 263 case VREG: 264 if (ioflag & IO_APPEND) 265 uio->uio_offset = ext2fs_size(ip); 266 if ((ip->i_e2fs_flags & EXT2_APPEND) && 267 uio->uio_offset != ext2fs_size(ip)) 268 return (EPERM); 269 /* FALLTHROUGH */ 270 case VLNK: 271 break; 272 case VDIR: 273 if ((ioflag & IO_SYNC) == 0) 274 panic("%s: nonsync dir write", "ext2fs_write"); 275 break; 276 default: 277 panic("%s: type", "ext2fs_write"); 278 } 279 280 fs = ip->i_e2fs; 281 if (uio->uio_offset < 0 || 282 (u_int64_t)uio->uio_offset + uio->uio_resid > ump->um_maxfilesize) 283 return (EFBIG); 284 /* 285 * Maybe this should be above the vnode op call, but so long as 286 * file servers have no limits, I don't think it matters. 287 */ 288 p = uio->uio_procp; 289 if (vp->v_type == VREG && p && 290 uio->uio_offset + uio->uio_resid > 291 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 292 psignal(p, SIGXFSZ); 293 return (EFBIG); 294 } 295 if (uio->uio_resid == 0) 296 return (0); 297 298 async = vp->v_mount->mnt_flag & MNT_ASYNC; 299 resid = uio->uio_resid; 300 osize = ext2fs_size(ip); 301 302 if (vp->v_type == VREG) { 303 while (uio->uio_resid > 0) { 304 oldoff = uio->uio_offset; 305 blkoffset = blkoff(fs, uio->uio_offset); 306 bytelen = MIN(fs->e2fs_bsize - blkoffset, 307 uio->uio_resid); 308 309 error = ufs_balloc_range(vp, uio->uio_offset, 310 bytelen, ap->a_cred, 0); 311 if (error) 312 break; 313 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 314 &bytelen, UBC_WRITE); 315 error = uiomove(win, bytelen, uio); 316 flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0; 317 ubc_release(win, flags); 318 if (error) 319 break; 320 321 /* 322 * update UVM's notion of the size now that we've 323 * copied the data into the vnode's pages. 324 */ 325 326 if (vp->v_size < uio->uio_offset) { 327 uvm_vnp_setsize(vp, uio->uio_offset); 328 extended = 1; 329 } 330 331 /* 332 * flush what we just wrote if necessary. 333 * XXXUBC simplistic async flushing. 334 */ 335 336 if (!async && oldoff >> 16 != uio->uio_offset >> 16) { 337 simple_lock(&vp->v_interlock); 338 error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16, 339 (uio->uio_offset >> 16) << 16, PGO_CLEANIT); 340 } 341 } 342 if (error == 0 && ioflag & IO_SYNC) { 343 simple_lock(&vp->v_interlock); 344 error = VOP_PUTPAGES(vp, trunc_page(oldoff), 345 round_page(blkroundup(fs, uio->uio_offset)), 346 PGO_CLEANIT | PGO_SYNCIO); 347 } 348 349 goto out; 350 } 351 352 flags = ioflag & IO_SYNC ? B_SYNC : 0; 353 for (error = 0; uio->uio_resid > 0;) { 354 lbn = lblkno(fs, uio->uio_offset); 355 blkoffset = blkoff(fs, uio->uio_offset); 356 xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); 357 if (xfersize < fs->e2fs_bsize) 358 flags |= B_CLRBUF; 359 else 360 flags &= ~B_CLRBUF; 361 error = ext2fs_balloc(ip, 362 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 363 if (error) 364 break; 365 if (ext2fs_size(ip) < uio->uio_offset + xfersize) { 366 error = ext2fs_setsize(ip, uio->uio_offset + xfersize); 367 if (error) 368 break; 369 } 370 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 371 372 /* 373 * update UVM's notion of the size now that we've 374 * copied the data into the vnode's pages. 375 */ 376 377 if (vp->v_size < uio->uio_offset) { 378 uvm_vnp_setsize(vp, uio->uio_offset); 379 extended = 1; 380 } 381 382 if (ioflag & IO_SYNC) 383 (void)bwrite(bp); 384 else if (xfersize + blkoffset == fs->e2fs_bsize) 385 bawrite(bp); 386 else 387 bdwrite(bp); 388 if (error || xfersize == 0) 389 break; 390 } 391 392 /* 393 * If we successfully wrote any data, and we are not the superuser 394 * we clear the setuid and setgid bits as a precaution against 395 * tampering. 396 */ 397 398 out: 399 ip->i_flag |= IN_CHANGE | IN_UPDATE; 400 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 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 uio->uio_procp); 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
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