ext2fs_readwrite.c revision 1.52.6.1
1 /* $NetBSD: ext2fs_readwrite.c,v 1.52.6.1 2009/01/19 13:20:31 skrll 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 1.52.6.1 2009/01/19 13:20:31 skrll 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 vsize_t bytelen; 114 daddr_t lbn, nextlbn; 115 off_t bytesinfile; 116 long size, xfersize, blkoffset; 117 int error; 118 119 vp = ap->a_vp; 120 ip = VTOI(vp); 121 ump = ip->i_ump; 122 uio = ap->a_uio; 123 error = 0; 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 (ext2fs_size(ip) < ump->um_maxsymlinklen || 131 (ump->um_maxsymlinklen == 0 && ip->i_e2fs_nblock == 0)) 132 panic("%s: short symlink", "ext2fs_read"); 133 } else if (vp->v_type != VREG && vp->v_type != VDIR) 134 panic("%s: type %d", "ext2fs_read", vp->v_type); 135 #endif 136 fs = ip->i_e2fs; 137 if ((u_int64_t)uio->uio_offset > ump->um_maxfilesize) 138 return (EFBIG); 139 if (uio->uio_resid == 0) 140 return (0); 141 if (uio->uio_offset >= ext2fs_size(ip)) 142 goto out; 143 144 if (vp->v_type == VREG) { 145 const int advice = IO_ADV_DECODE(ap->a_ioflag); 146 147 while (uio->uio_resid > 0) { 148 bytelen = MIN(ext2fs_size(ip) - uio->uio_offset, 149 uio->uio_resid); 150 if (bytelen == 0) 151 break; 152 153 error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, 154 UBC_READ | UBC_PARTIALOK | UBC_UNMAP_FLAG(vp)); 155 if (error) 156 break; 157 } 158 goto out; 159 } 160 161 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 162 bytesinfile = ext2fs_size(ip) - uio->uio_offset; 163 if (bytesinfile <= 0) 164 break; 165 lbn = lblkno(fs, uio->uio_offset); 166 nextlbn = lbn + 1; 167 size = fs->e2fs_bsize; 168 blkoffset = blkoff(fs, uio->uio_offset); 169 xfersize = fs->e2fs_bsize - blkoffset; 170 if (uio->uio_resid < xfersize) 171 xfersize = uio->uio_resid; 172 if (bytesinfile < xfersize) 173 xfersize = bytesinfile; 174 175 if (lblktosize(fs, nextlbn) >= ext2fs_size(ip)) 176 error = bread(vp, lbn, size, NOCRED, 0, &bp); 177 else { 178 int nextsize = fs->e2fs_bsize; 179 error = breadn(vp, lbn, 180 size, &nextlbn, &nextsize, 1, NOCRED, 0, &bp); 181 } 182 if (error) 183 break; 184 185 /* 186 * We should only get non-zero b_resid when an I/O error 187 * has occurred, which should cause us to break above. 188 * However, if the short read did not cause an error, 189 * then we want to ensure that we do not uiomove bad 190 * or uninitialized data. 191 */ 192 size -= bp->b_resid; 193 if (size < xfersize) { 194 if (size == 0) 195 break; 196 xfersize = size; 197 } 198 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 199 if (error) 200 break; 201 brelse(bp, 0); 202 } 203 if (bp != NULL) 204 brelse(bp, 0); 205 206 out: 207 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 208 ip->i_flag |= IN_ACCESS; 209 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) 210 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 211 } 212 return (error); 213 } 214 215 /* 216 * Vnode op for writing. 217 */ 218 int 219 ext2fs_write(void *v) 220 { 221 struct vop_write_args /* { 222 struct vnode *a_vp; 223 struct uio *a_uio; 224 int a_ioflag; 225 kauth_cred_t a_cred; 226 } */ *ap = v; 227 struct vnode *vp; 228 struct uio *uio; 229 struct inode *ip; 230 struct m_ext2fs *fs; 231 struct buf *bp; 232 struct proc *p; 233 struct ufsmount *ump; 234 daddr_t lbn; 235 off_t osize; 236 int blkoffset, error, flags, ioflag, resid, xfersize; 237 vsize_t bytelen; 238 off_t oldoff = 0; /* XXX */ 239 bool async; 240 int extended = 0; 241 int advice; 242 243 ioflag = ap->a_ioflag; 244 advice = IO_ADV_DECODE(ioflag); 245 uio = ap->a_uio; 246 vp = ap->a_vp; 247 ip = VTOI(vp); 248 ump = ip->i_ump; 249 error = 0; 250 251 #ifdef DIAGNOSTIC 252 if (uio->uio_rw != UIO_WRITE) 253 panic("%s: mode", "ext2fs_write"); 254 #endif 255 256 switch (vp->v_type) { 257 case VREG: 258 if (ioflag & IO_APPEND) 259 uio->uio_offset = ext2fs_size(ip); 260 if ((ip->i_e2fs_flags & EXT2_APPEND) && 261 uio->uio_offset != ext2fs_size(ip)) 262 return (EPERM); 263 /* FALLTHROUGH */ 264 case VLNK: 265 break; 266 case VDIR: 267 if ((ioflag & IO_SYNC) == 0) 268 panic("%s: nonsync dir write", "ext2fs_write"); 269 break; 270 default: 271 panic("%s: type", "ext2fs_write"); 272 } 273 274 fs = ip->i_e2fs; 275 if (uio->uio_offset < 0 || 276 (u_int64_t)uio->uio_offset + uio->uio_resid > ump->um_maxfilesize) 277 return (EFBIG); 278 /* 279 * Maybe this should be above the vnode op call, but so long as 280 * file servers have no limits, I don't think it matters. 281 */ 282 p = curproc; 283 if (vp->v_type == VREG && p && 284 uio->uio_offset + uio->uio_resid > 285 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 286 mutex_enter(proc_lock); 287 psignal(p, SIGXFSZ); 288 mutex_exit(proc_lock); 289 return (EFBIG); 290 } 291 if (uio->uio_resid == 0) 292 return (0); 293 294 async = vp->v_mount->mnt_flag & MNT_ASYNC; 295 resid = uio->uio_resid; 296 osize = ext2fs_size(ip); 297 298 if (vp->v_type == VREG) { 299 while (uio->uio_resid > 0) { 300 oldoff = uio->uio_offset; 301 blkoffset = blkoff(fs, uio->uio_offset); 302 bytelen = MIN(fs->e2fs_bsize - blkoffset, 303 uio->uio_resid); 304 305 if (vp->v_size < oldoff + bytelen) { 306 uvm_vnp_setwritesize(vp, oldoff + bytelen); 307 } 308 error = ufs_balloc_range(vp, uio->uio_offset, 309 bytelen, ap->a_cred, 0); 310 if (error) 311 break; 312 error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, 313 UBC_WRITE | UBC_UNMAP_FLAG(vp)); 314 if (error) 315 break; 316 317 /* 318 * update UVM's notion of the size now that we've 319 * copied the data into the vnode's pages. 320 */ 321 322 if (vp->v_size < uio->uio_offset) { 323 uvm_vnp_setsize(vp, uio->uio_offset); 324 extended = 1; 325 } 326 327 /* 328 * flush what we just wrote if necessary. 329 * XXXUBC simplistic async flushing. 330 */ 331 332 if (!async && oldoff >> 16 != uio->uio_offset >> 16) { 333 mutex_enter(&vp->v_interlock); 334 error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16, 335 (uio->uio_offset >> 16) << 16, PGO_CLEANIT); 336 } 337 } 338 if (error == 0 && ioflag & IO_SYNC) { 339 mutex_enter(&vp->v_interlock); 340 error = VOP_PUTPAGES(vp, trunc_page(oldoff), 341 round_page(blkroundup(fs, uio->uio_offset)), 342 PGO_CLEANIT | PGO_SYNCIO); 343 } 344 345 goto out; 346 } 347 348 flags = ioflag & IO_SYNC ? B_SYNC : 0; 349 for (error = 0; uio->uio_resid > 0;) { 350 lbn = lblkno(fs, uio->uio_offset); 351 blkoffset = blkoff(fs, uio->uio_offset); 352 xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); 353 if (xfersize < fs->e2fs_bsize) 354 flags |= B_CLRBUF; 355 else 356 flags &= ~B_CLRBUF; 357 error = ext2fs_balloc(ip, 358 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 359 if (error) 360 break; 361 if (ext2fs_size(ip) < uio->uio_offset + xfersize) { 362 error = ext2fs_setsize(ip, uio->uio_offset + xfersize); 363 if (error) 364 break; 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 && 397 kauth_authorize_generic(ap->a_cred, KAUTH_GENERIC_ISSUSER, NULL)) 398 ip->i_e2fs_mode &= ~(ISUID | ISGID); 399 if (resid > uio->uio_resid) 400 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); 401 if (error) { 402 (void) ext2fs_truncate(vp, osize, ioflag & IO_SYNC, ap->a_cred); 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 = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 407 KASSERT(vp->v_size == ext2fs_size(ip)); 408 return (error); 409 } 410
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