ext2fs_readwrite.c revision 1.16.6.3
1 /* $NetBSD: ext2fs_readwrite.c,v 1.16.6.3 2002/09/26 22:04:52 jdolecek Exp $ */ 2 3 /*- 4 * Copyright (c) 1997 Manuel Bouyer. 5 * Copyright (c) 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94 37 * Modified for ext2fs by Manuel Bouyer. 38 */ 39 40 #include <sys/cdefs.h> 41 __KERNEL_RCSID(0, "$NetBSD: ext2fs_readwrite.c,v 1.16.6.3 2002/09/26 22:04:52 jdolecek Exp $"); 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/resourcevar.h> 46 #include <sys/kernel.h> 47 #include <sys/file.h> 48 #include <sys/stat.h> 49 #include <sys/buf.h> 50 #include <sys/proc.h> 51 #include <sys/conf.h> 52 #include <sys/mount.h> 53 #include <sys/vnode.h> 54 #include <sys/malloc.h> 55 #include <sys/signalvar.h> 56 57 #include <ufs/ufs/inode.h> 58 #include <ufs/ext2fs/ext2fs.h> 59 #include <ufs/ext2fs/ext2fs_extern.h> 60 61 62 #define doclusterread 0 /* XXX underway */ 63 #define doclusterwrite 0 64 65 /* 66 * Vnode op for reading. 67 */ 68 /* ARGSUSED */ 69 int 70 ext2fs_read(v) 71 void *v; 72 { 73 struct vop_read_args /* { 74 struct vnode *a_vp; 75 struct uio *a_uio; 76 int a_ioflag; 77 struct ucred *a_cred; 78 } */ *ap = v; 79 struct vnode *vp; 80 struct inode *ip; 81 struct uio *uio; 82 struct m_ext2fs *fs; 83 struct buf *bp; 84 void *win; 85 vsize_t bytelen; 86 ufs_daddr_t lbn, nextlbn; 87 off_t bytesinfile; 88 long size, xfersize, blkoffset; 89 int error; 90 91 vp = ap->a_vp; 92 ip = VTOI(vp); 93 uio = ap->a_uio; 94 95 #ifdef DIAGNOSTIC 96 if (uio->uio_rw != UIO_READ) 97 panic("%s: mode", "ext2fs_read"); 98 99 if (vp->v_type == VLNK) { 100 if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen || 101 (vp->v_mount->mnt_maxsymlinklen == 0 && 102 ip->i_e2fs_nblock == 0)) 103 panic("%s: short symlink", "ext2fs_read"); 104 } else if (vp->v_type != VREG && vp->v_type != VDIR) 105 panic("%s: type %d", "ext2fs_read", vp->v_type); 106 #endif 107 fs = ip->i_e2fs; 108 if ((u_int64_t)uio->uio_offset > 109 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 110 return (EFBIG); 111 if (uio->uio_resid == 0) 112 return (0); 113 if (uio->uio_offset >= ip->i_e2fs_size) 114 return (0); 115 116 if (vp->v_type == VREG) { 117 error = 0; 118 while (uio->uio_resid > 0) { 119 bytelen = MIN(ip->i_e2fs_size - uio->uio_offset, 120 uio->uio_resid); 121 122 if (bytelen == 0) { 123 break; 124 } 125 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 126 &bytelen, UBC_READ); 127 error = uiomove(win, bytelen, uio); 128 ubc_release(win, 0); 129 if (error) { 130 break; 131 } 132 } 133 goto out; 134 } 135 136 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 137 if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 0) 138 break; 139 lbn = lblkno(fs, uio->uio_offset); 140 nextlbn = lbn + 1; 141 size = fs->e2fs_bsize; 142 blkoffset = blkoff(fs, uio->uio_offset); 143 xfersize = fs->e2fs_bsize - blkoffset; 144 if (uio->uio_resid < xfersize) 145 xfersize = uio->uio_resid; 146 if (bytesinfile < xfersize) 147 xfersize = bytesinfile; 148 149 if (lblktosize(fs, nextlbn) >= ip->i_e2fs_size) 150 error = bread(vp, lbn, size, NOCRED, &bp); 151 else { 152 int nextsize = fs->e2fs_bsize; 153 error = breadn(vp, lbn, 154 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 155 } 156 if (error) 157 break; 158 159 /* 160 * We should only get non-zero b_resid when an I/O error 161 * has occurred, which should cause us to break above. 162 * However, if the short read did not cause an error, 163 * then we want to ensure that we do not uiomove bad 164 * or uninitialized data. 165 */ 166 size -= bp->b_resid; 167 if (size < xfersize) { 168 if (size == 0) 169 break; 170 xfersize = size; 171 } 172 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 173 if (error) 174 break; 175 brelse(bp); 176 } 177 if (bp != NULL) 178 brelse(bp); 179 180 out: 181 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 182 ip->i_flag |= IN_ACCESS; 183 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) 184 error = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT); 185 } 186 return (error); 187 } 188 189 /* 190 * Vnode op for writing. 191 */ 192 int 193 ext2fs_write(v) 194 void *v; 195 { 196 struct vop_write_args /* { 197 struct vnode *a_vp; 198 struct uio *a_uio; 199 int a_ioflag; 200 struct ucred *a_cred; 201 } */ *ap = v; 202 struct vnode *vp; 203 struct uio *uio; 204 struct inode *ip; 205 struct m_ext2fs *fs; 206 struct buf *bp; 207 struct proc *p; 208 ufs_daddr_t lbn; 209 off_t osize; 210 int blkoffset, error, flags, ioflag, resid, xfersize; 211 vsize_t bytelen; 212 void *win; 213 off_t oldoff; 214 boolean_t async; 215 int extended=0; 216 217 ioflag = ap->a_ioflag; 218 uio = ap->a_uio; 219 vp = ap->a_vp; 220 ip = VTOI(vp); 221 error = 0; 222 223 #ifdef DIAGNOSTIC 224 if (uio->uio_rw != UIO_WRITE) 225 panic("%s: mode", "ext2fs_write"); 226 #endif 227 228 switch (vp->v_type) { 229 case VREG: 230 if (ioflag & IO_APPEND) 231 uio->uio_offset = ip->i_e2fs_size; 232 if ((ip->i_e2fs_flags & EXT2_APPEND) && 233 uio->uio_offset != ip->i_e2fs_size) 234 return (EPERM); 235 /* FALLTHROUGH */ 236 case VLNK: 237 break; 238 case VDIR: 239 if ((ioflag & IO_SYNC) == 0) 240 panic("%s: nonsync dir write", "ext2fs_write"); 241 break; 242 default: 243 panic("%s: type", "ext2fs_write"); 244 } 245 246 fs = ip->i_e2fs; 247 if (uio->uio_offset < 0 || 248 (u_int64_t)uio->uio_offset + uio->uio_resid > 249 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 250 return (EFBIG); 251 /* 252 * Maybe this should be above the vnode op call, but so long as 253 * file servers have no limits, I don't think it matters. 254 */ 255 p = uio->uio_procp; 256 if (vp->v_type == VREG && p && 257 uio->uio_offset + uio->uio_resid > 258 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 259 psignal(p, SIGXFSZ); 260 return (EFBIG); 261 } 262 if (uio->uio_resid == 0) 263 return (0); 264 265 async = vp->v_mount->mnt_flag & MNT_ASYNC; 266 resid = uio->uio_resid; 267 osize = ip->i_e2fs_size; 268 269 if (vp->v_type == VREG) { 270 while (uio->uio_resid > 0) { 271 oldoff = uio->uio_offset; 272 blkoffset = blkoff(fs, uio->uio_offset); 273 bytelen = MIN(fs->e2fs_bsize - blkoffset, 274 uio->uio_resid); 275 276 error = ext2fs_balloc_range(vp, uio->uio_offset, 277 bytelen, ap->a_cred, 0); 278 if (error) { 279 break; 280 } 281 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 282 &bytelen, UBC_WRITE); 283 error = uiomove(win, bytelen, uio); 284 ubc_release(win, 0); 285 if (error) { 286 break; 287 } 288 289 /* 290 * update UVM's notion of the size now that we've 291 * copied the data into the vnode's pages. 292 */ 293 294 if (vp->v_size < uio->uio_offset) { 295 uvm_vnp_setsize(vp, uio->uio_offset); 296 extended = 1; 297 } 298 299 /* 300 * flush what we just wrote if necessary. 301 * XXXUBC simplistic async flushing. 302 */ 303 304 if (!async && oldoff >> 16 != uio->uio_offset >> 16) { 305 simple_lock(&vp->v_interlock); 306 error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16, 307 (uio->uio_offset >> 16) << 16, PGO_CLEANIT); 308 } 309 } 310 if (error == 0 && ioflag & IO_SYNC) { 311 simple_lock(&vp->v_interlock); 312 error = VOP_PUTPAGES(vp, trunc_page(oldoff), 313 round_page(blkroundup(fs, uio->uio_offset)), 314 PGO_CLEANIT | PGO_SYNCIO); 315 } 316 317 goto out; 318 } 319 320 flags = ioflag & IO_SYNC ? B_SYNC : 0; 321 for (error = 0; uio->uio_resid > 0;) { 322 lbn = lblkno(fs, uio->uio_offset); 323 blkoffset = blkoff(fs, uio->uio_offset); 324 xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); 325 if (xfersize < fs->e2fs_bsize) 326 flags |= B_CLRBUF; 327 else 328 flags &= ~B_CLRBUF; 329 error = ext2fs_balloc(ip, 330 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 331 if (error) 332 break; 333 if (ip->i_e2fs_size < uio->uio_offset + xfersize) { 334 ip->i_e2fs_size = uio->uio_offset + xfersize; 335 } 336 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 337 338 /* 339 * update UVM's notion of the size now that we've 340 * copied the data into the vnode's pages. 341 */ 342 343 if (vp->v_size < uio->uio_offset) { 344 uvm_vnp_setsize(vp, uio->uio_offset); 345 extended = 1; 346 } 347 348 if (ioflag & IO_SYNC) 349 (void)bwrite(bp); 350 else if (xfersize + blkoffset == fs->e2fs_bsize) 351 bawrite(bp); 352 else 353 bdwrite(bp); 354 if (error || xfersize == 0) 355 break; 356 } 357 358 /* 359 * If we successfully wrote any data, and we are not the superuser 360 * we clear the setuid and setgid bits as a precaution against 361 * tampering. 362 */ 363 364 out: 365 ip->i_flag |= IN_CHANGE | IN_UPDATE; 366 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 367 ip->i_e2fs_mode &= ~(ISUID | ISGID); 368 if (resid > uio->uio_resid) 369 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); 370 if (error) { 371 (void) VOP_TRUNCATE(vp, osize, ioflag & IO_SYNC, ap->a_cred, 372 uio->uio_procp); 373 uio->uio_offset -= resid - uio->uio_resid; 374 uio->uio_resid = resid; 375 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) 376 error = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT); 377 KASSERT(vp->v_size == ip->i_e2fs_size); 378 return (error); 379 } 380
Indexes created Tue Sep 30 20:09:53 GMT 2025