1 /* $NetBSD: ext2fs_readwrite.c,v 1.55 2009/10/19 18:41:17 bouyer 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 * 47 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 48 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 49 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 50 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 51 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 52 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 53 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 54 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 55 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 56 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 57 * 58 * @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94 59 * Modified for ext2fs by Manuel Bouyer. 60 */ 61 62 #include <sys/cdefs.h> 63 __KERNEL_RCSID(0, "$NetBSD: ext2fs_readwrite.c,v 1.55 2009/10/19 18:41:17 bouyer Exp $"); 64 65 #include <sys/param.h> 66 #include <sys/systm.h> 67 #include <sys/resourcevar.h> 68 #include <sys/kernel.h> 69 #include <sys/file.h> 70 #include <sys/stat.h> 71 #include <sys/buf.h> 72 #include <sys/proc.h> 73 #include <sys/mount.h> 74 #include <sys/vnode.h> 75 #include <sys/malloc.h> 76 #include <sys/signalvar.h> 77 #include <sys/kauth.h> 78 79 #include <ufs/ufs/inode.h> 80 #include <ufs/ufs/ufsmount.h> 81 #include <ufs/ufs/ufs_extern.h> 82 #include <ufs/ext2fs/ext2fs.h> 83 #include <ufs/ext2fs/ext2fs_extern.h> 84 85 86 #define doclusterread 0 /* XXX underway */ 87 #define doclusterwrite 0 88 89 /* 90 * Vnode op for reading. 91 */ 92 /* ARGSUSED */ 93 int 94 ext2fs_read(void *v) 95 { 96 struct vop_read_args /* { 97 struct vnode *a_vp; 98 struct uio *a_uio; 99 int a_ioflag; 100 kauth_cred_t a_cred; 101 } */ *ap = v; 102 struct vnode *vp; 103 struct inode *ip; 104 struct uio *uio; 105 struct m_ext2fs *fs; 106 struct buf *bp; 107 struct ufsmount *ump; 108 vsize_t bytelen; 109 daddr_t lbn, nextlbn; 110 off_t bytesinfile; 111 long size, xfersize, blkoffset; 112 int error; 113 114 vp = ap->a_vp; 115 ip = VTOI(vp); 116 ump = ip->i_ump; 117 uio = ap->a_uio; 118 error = 0; 119 120 #ifdef DIAGNOSTIC 121 if (uio->uio_rw != UIO_READ) 122 panic("%s: mode", "ext2fs_read"); 123 124 if (vp->v_type == VLNK) { 125 if (ext2fs_size(ip) < ump->um_maxsymlinklen || 126 (ump->um_maxsymlinklen == 0 && ip->i_e2fs_nblock == 0)) 127 panic("%s: short symlink", "ext2fs_read"); 128 } else if (vp->v_type != VREG && vp->v_type != VDIR) 129 panic("%s: type %d", "ext2fs_read", vp->v_type); 130 #endif 131 fs = ip->i_e2fs; 132 if ((uint64_t)uio->uio_offset > ump->um_maxfilesize) 133 return (EFBIG); 134 if (uio->uio_resid == 0) 135 return (0); 136 if (uio->uio_offset >= ext2fs_size(ip)) 137 goto out; 138 139 if (vp->v_type == VREG) { 140 const int advice = IO_ADV_DECODE(ap->a_ioflag); 141 142 while (uio->uio_resid > 0) { 143 bytelen = MIN(ext2fs_size(ip) - uio->uio_offset, 144 uio->uio_resid); 145 if (bytelen == 0) 146 break; 147 148 error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, 149 UBC_READ | UBC_PARTIALOK | UBC_UNMAP_FLAG(vp)); 150 if (error) 151 break; 152 } 153 goto out; 154 } 155 156 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 157 bytesinfile = ext2fs_size(ip) - uio->uio_offset; 158 if (bytesinfile <= 0) 159 break; 160 lbn = lblkno(fs, uio->uio_offset); 161 nextlbn = lbn + 1; 162 size = fs->e2fs_bsize; 163 blkoffset = blkoff(fs, uio->uio_offset); 164 xfersize = fs->e2fs_bsize - blkoffset; 165 if (uio->uio_resid < xfersize) 166 xfersize = uio->uio_resid; 167 if (bytesinfile < xfersize) 168 xfersize = bytesinfile; 169 170 if (lblktosize(fs, nextlbn) >= ext2fs_size(ip)) 171 error = bread(vp, lbn, size, NOCRED, 0, &bp); 172 else { 173 int nextsize = fs->e2fs_bsize; 174 error = breadn(vp, lbn, 175 size, &nextlbn, &nextsize, 1, NOCRED, 0, &bp); 176 } 177 if (error) 178 break; 179 180 /* 181 * We should only get non-zero b_resid when an I/O error 182 * has occurred, which should cause us to break above. 183 * However, if the short read did not cause an error, 184 * then we want to ensure that we do not uiomove bad 185 * or uninitialized data. 186 */ 187 size -= bp->b_resid; 188 if (size < xfersize) { 189 if (size == 0) 190 break; 191 xfersize = size; 192 } 193 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 194 if (error) 195 break; 196 brelse(bp, 0); 197 } 198 if (bp != NULL) 199 brelse(bp, 0); 200 201 out: 202 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 203 ip->i_flag |= IN_ACCESS; 204 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) 205 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 206 } 207 return (error); 208 } 209 210 /* 211 * Vnode op for writing. 212 */ 213 int 214 ext2fs_write(void *v) 215 { 216 struct vop_write_args /* { 217 struct vnode *a_vp; 218 struct uio *a_uio; 219 int a_ioflag; 220 kauth_cred_t a_cred; 221 } */ *ap = v; 222 struct vnode *vp; 223 struct uio *uio; 224 struct inode *ip; 225 struct m_ext2fs *fs; 226 struct buf *bp; 227 struct proc *p; 228 struct ufsmount *ump; 229 daddr_t lbn; 230 off_t osize; 231 int blkoffset, error, flags, ioflag, resid, xfersize; 232 vsize_t bytelen; 233 off_t oldoff = 0; /* XXX */ 234 bool async; 235 int extended = 0; 236 int advice; 237 238 ioflag = ap->a_ioflag; 239 advice = IO_ADV_DECODE(ioflag); 240 uio = ap->a_uio; 241 vp = ap->a_vp; 242 ip = VTOI(vp); 243 ump = ip->i_ump; 244 error = 0; 245 246 #ifdef DIAGNOSTIC 247 if (uio->uio_rw != UIO_WRITE) 248 panic("%s: mode", "ext2fs_write"); 249 #endif 250 251 switch (vp->v_type) { 252 case VREG: 253 if (ioflag & IO_APPEND) 254 uio->uio_offset = ext2fs_size(ip); 255 if ((ip->i_e2fs_flags & EXT2_APPEND) && 256 uio->uio_offset != ext2fs_size(ip)) 257 return (EPERM); 258 /* FALLTHROUGH */ 259 case VLNK: 260 break; 261 case VDIR: 262 if ((ioflag & IO_SYNC) == 0) 263 panic("%s: nonsync dir write", "ext2fs_write"); 264 break; 265 default: 266 panic("%s: type", "ext2fs_write"); 267 } 268 269 fs = ip->i_e2fs; 270 if (uio->uio_offset < 0 || 271 (uint64_t)uio->uio_offset + uio->uio_resid > ump->um_maxfilesize) 272 return (EFBIG); 273 /* 274 * Maybe this should be above the vnode op call, but so long as 275 * file servers have no limits, I don't think it matters. 276 */ 277 p = curproc; 278 if (vp->v_type == VREG && p && 279 uio->uio_offset + uio->uio_resid > 280 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 281 mutex_enter(proc_lock); 282 psignal(p, SIGXFSZ); 283 mutex_exit(proc_lock); 284 return (EFBIG); 285 } 286 if (uio->uio_resid == 0) 287 return (0); 288 289 async = vp->v_mount->mnt_flag & MNT_ASYNC; 290 resid = uio->uio_resid; 291 osize = ext2fs_size(ip); 292 293 if (vp->v_type == VREG) { 294 while (uio->uio_resid > 0) { 295 oldoff = uio->uio_offset; 296 blkoffset = blkoff(fs, uio->uio_offset); 297 bytelen = MIN(fs->e2fs_bsize - blkoffset, 298 uio->uio_resid); 299 300 if (vp->v_size < oldoff + bytelen) { 301 uvm_vnp_setwritesize(vp, oldoff + bytelen); 302 } 303 error = ufs_balloc_range(vp, uio->uio_offset, 304 bytelen, ap->a_cred, 0); 305 if (error) 306 break; 307 error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, 308 UBC_WRITE | UBC_UNMAP_FLAG(vp)); 309 if (error) 310 break; 311 312 /* 313 * update UVM's notion of the size now that we've 314 * copied the data into the vnode's pages. 315 */ 316 317 if (vp->v_size < uio->uio_offset) { 318 uvm_vnp_setsize(vp, uio->uio_offset); 319 extended = 1; 320 } 321 322 /* 323 * flush what we just wrote if necessary. 324 * XXXUBC simplistic async flushing. 325 */ 326 327 if (!async && oldoff >> 16 != uio->uio_offset >> 16) { 328 mutex_enter(&vp->v_interlock); 329 error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16, 330 (uio->uio_offset >> 16) << 16, PGO_CLEANIT); 331 } 332 } 333 if (error == 0 && ioflag & IO_SYNC) { 334 mutex_enter(&vp->v_interlock); 335 error = VOP_PUTPAGES(vp, trunc_page(oldoff), 336 round_page(blkroundup(fs, uio->uio_offset)), 337 PGO_CLEANIT | PGO_SYNCIO); 338 } 339 340 goto out; 341 } 342 343 flags = ioflag & IO_SYNC ? B_SYNC : 0; 344 for (error = 0; uio->uio_resid > 0;) { 345 lbn = lblkno(fs, uio->uio_offset); 346 blkoffset = blkoff(fs, uio->uio_offset); 347 xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); 348 if (xfersize < fs->e2fs_bsize) 349 flags |= B_CLRBUF; 350 else 351 flags &= ~B_CLRBUF; 352 error = ext2fs_balloc(ip, 353 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 354 if (error) 355 break; 356 if (ext2fs_size(ip) < uio->uio_offset + xfersize) { 357 error = ext2fs_setsize(ip, uio->uio_offset + xfersize); 358 if (error) 359 break; 360 } 361 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 362 363 /* 364 * update UVM's notion of the size now that we've 365 * copied the data into the vnode's pages. 366 */ 367 368 if (vp->v_size < uio->uio_offset) { 369 uvm_vnp_setsize(vp, uio->uio_offset); 370 extended = 1; 371 } 372 373 if (ioflag & IO_SYNC) 374 (void)bwrite(bp); 375 else if (xfersize + blkoffset == fs->e2fs_bsize) 376 bawrite(bp); 377 else 378 bdwrite(bp); 379 if (error || xfersize == 0) 380 break; 381 } 382 383 /* 384 * If we successfully wrote any data, and we are not the superuser 385 * we clear the setuid and setgid bits as a precaution against 386 * tampering. 387 */ 388 389 out: 390 ip->i_flag |= IN_CHANGE | IN_UPDATE; 391 if (resid > uio->uio_resid && ap->a_cred && 392 kauth_authorize_generic(ap->a_cred, KAUTH_GENERIC_ISSUSER, NULL)) 393 ip->i_e2fs_mode &= ~(ISUID | ISGID); 394 if (resid > uio->uio_resid) 395 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); 396 if (error) { 397 (void) ext2fs_truncate(vp, osize, ioflag & IO_SYNC, ap->a_cred); 398 uio->uio_offset -= resid - uio->uio_resid; 399 uio->uio_resid = resid; 400 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) 401 error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT); 402 KASSERT(vp->v_size == ext2fs_size(ip)); 403 return (error); 404 } 405