ext2fs_readwrite.c revision 1.19
1 /* $NetBSD: ext2fs_readwrite.c,v 1.19 2001/10/26 05:56:08 lukem 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/param.h> 41 #include <sys/systm.h> 42 #include <sys/resourcevar.h> 43 #include <sys/kernel.h> 44 #include <sys/file.h> 45 #include <sys/stat.h> 46 #include <sys/buf.h> 47 #include <sys/proc.h> 48 #include <sys/conf.h> 49 #include <sys/mount.h> 50 #include <sys/vnode.h> 51 #include <sys/malloc.h> 52 #include <sys/signalvar.h> 53 54 #include <ufs/ufs/inode.h> 55 #include <ufs/ext2fs/ext2fs.h> 56 #include <ufs/ext2fs/ext2fs_extern.h> 57 58 59 #define doclusterread 0 /* XXX underway */ 60 #define doclusterwrite 0 61 62 /* 63 * Vnode op for reading. 64 */ 65 /* ARGSUSED */ 66 int 67 ext2fs_read(v) 68 void *v; 69 { 70 struct vop_read_args /* { 71 struct vnode *a_vp; 72 struct uio *a_uio; 73 int a_ioflag; 74 struct ucred *a_cred; 75 } */ *ap = v; 76 struct vnode *vp; 77 struct inode *ip; 78 struct uio *uio; 79 struct m_ext2fs *fs; 80 struct buf *bp; 81 void *win; 82 vsize_t bytelen; 83 ufs_daddr_t lbn, nextlbn; 84 off_t bytesinfile; 85 long size, xfersize, blkoffset; 86 int error; 87 88 vp = ap->a_vp; 89 ip = VTOI(vp); 90 uio = ap->a_uio; 91 92 #ifdef DIAGNOSTIC 93 if (uio->uio_rw != UIO_READ) 94 panic("%s: mode", "ext2fs_read"); 95 96 if (vp->v_type == VLNK) { 97 if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen || 98 (vp->v_mount->mnt_maxsymlinklen == 0 && 99 ip->i_e2fs_nblock == 0)) 100 panic("%s: short symlink", "ext2fs_read"); 101 } else if (vp->v_type != VREG && vp->v_type != VDIR) 102 panic("%s: type %d", "ext2fs_read", vp->v_type); 103 #endif 104 fs = ip->i_e2fs; 105 if ((u_int64_t)uio->uio_offset > 106 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 107 return (EFBIG); 108 if (uio->uio_resid == 0) 109 return (0); 110 if (uio->uio_offset >= ip->i_e2fs_size) 111 return (0); 112 113 if (vp->v_type == VREG) { 114 error = 0; 115 while (uio->uio_resid > 0) { 116 bytelen = MIN(ip->i_e2fs_size - uio->uio_offset, 117 uio->uio_resid); 118 119 if (bytelen == 0) { 120 break; 121 } 122 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 123 &bytelen, UBC_READ); 124 error = uiomove(win, bytelen, uio); 125 ubc_release(win, 0); 126 if (error) { 127 break; 128 } 129 } 130 goto out; 131 } 132 133 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 134 if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 0) 135 break; 136 lbn = lblkno(fs, uio->uio_offset); 137 nextlbn = lbn + 1; 138 size = fs->e2fs_bsize; 139 blkoffset = blkoff(fs, uio->uio_offset); 140 xfersize = fs->e2fs_bsize - blkoffset; 141 if (uio->uio_resid < xfersize) 142 xfersize = uio->uio_resid; 143 if (bytesinfile < xfersize) 144 xfersize = bytesinfile; 145 146 if (lblktosize(fs, nextlbn) >= ip->i_e2fs_size) 147 error = bread(vp, lbn, size, NOCRED, &bp); 148 else { 149 int nextsize = fs->e2fs_bsize; 150 error = breadn(vp, lbn, 151 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 152 } 153 if (error) 154 break; 155 156 /* 157 * We should only get non-zero b_resid when an I/O error 158 * has occurred, which should cause us to break above. 159 * However, if the short read did not cause an error, 160 * then we want to ensure that we do not uiomove bad 161 * or uninitialized data. 162 */ 163 size -= bp->b_resid; 164 if (size < xfersize) { 165 if (size == 0) 166 break; 167 xfersize = size; 168 } 169 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 170 if (error) 171 break; 172 brelse(bp); 173 } 174 if (bp != NULL) 175 brelse(bp); 176 177 out: 178 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 179 ip->i_flag |= IN_ACCESS; 180 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) 181 error = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT); 182 } 183 return (error); 184 } 185 186 /* 187 * Vnode op for writing. 188 */ 189 int 190 ext2fs_write(v) 191 void *v; 192 { 193 struct vop_write_args /* { 194 struct vnode *a_vp; 195 struct uio *a_uio; 196 int a_ioflag; 197 struct ucred *a_cred; 198 } */ *ap = v; 199 struct vnode *vp; 200 struct uio *uio; 201 struct inode *ip; 202 struct m_ext2fs *fs; 203 struct buf *bp; 204 struct proc *p; 205 ufs_daddr_t lbn; 206 off_t osize; 207 int blkoffset, error, flags, ioflag, resid, xfersize; 208 vsize_t bytelen; 209 void *win; 210 off_t oldoff; 211 212 ioflag = ap->a_ioflag; 213 uio = ap->a_uio; 214 vp = ap->a_vp; 215 ip = VTOI(vp); 216 error = 0; 217 218 #ifdef DIAGNOSTIC 219 if (uio->uio_rw != UIO_WRITE) 220 panic("%s: mode", "ext2fs_write"); 221 #endif 222 223 switch (vp->v_type) { 224 case VREG: 225 if (ioflag & IO_APPEND) 226 uio->uio_offset = ip->i_e2fs_size; 227 if ((ip->i_e2fs_flags & EXT2_APPEND) && 228 uio->uio_offset != ip->i_e2fs_size) 229 return (EPERM); 230 /* FALLTHROUGH */ 231 case VLNK: 232 break; 233 case VDIR: 234 if ((ioflag & IO_SYNC) == 0) 235 panic("%s: nonsync dir write", "ext2fs_write"); 236 break; 237 default: 238 panic("%s: type", "ext2fs_write"); 239 } 240 241 fs = ip->i_e2fs; 242 if (uio->uio_offset < 0 || 243 (u_int64_t)uio->uio_offset + uio->uio_resid > 244 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 245 return (EFBIG); 246 /* 247 * Maybe this should be above the vnode op call, but so long as 248 * file servers have no limits, I don't think it matters. 249 */ 250 p = uio->uio_procp; 251 if (vp->v_type == VREG && p && 252 uio->uio_offset + uio->uio_resid > 253 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 254 psignal(p, SIGXFSZ); 255 return (EFBIG); 256 } 257 258 resid = uio->uio_resid; 259 osize = ip->i_e2fs_size; 260 261 if (vp->v_type == VREG) { 262 while (uio->uio_resid > 0) { 263 oldoff = uio->uio_offset; 264 blkoffset = blkoff(fs, uio->uio_offset); 265 bytelen = MIN(fs->e2fs_bsize - blkoffset, 266 uio->uio_resid); 267 268 error = ext2fs_balloc_range(vp, uio->uio_offset, 269 bytelen, ap->a_cred, 0); 270 if (error) { 271 break; 272 } 273 win = ubc_alloc(&vp->v_uobj, uio->uio_offset, 274 &bytelen, UBC_WRITE); 275 error = uiomove(win, bytelen, uio); 276 ubc_release(win, 0); 277 if (error) { 278 break; 279 } 280 281 /* 282 * flush what we just wrote if necessary. 283 * XXXUBC simplistic async flushing. 284 */ 285 286 if (oldoff >> 16 != uio->uio_offset >> 16) { 287 simple_lock(&vp->v_uobj.vmobjlock); 288 error = vp->v_uobj.pgops->pgo_put( 289 &vp->v_uobj, (oldoff >> 16) << 16, 290 (uio->uio_offset >> 16) << 16, PGO_CLEANIT); 291 } 292 } 293 if (error == 0 && ioflag & IO_SYNC) { 294 simple_lock(&vp->v_uobj.vmobjlock); 295 error = vp->v_uobj.pgops->pgo_put(&vp->v_uobj, oldoff, 296 oldoff + bytelen, PGO_CLEANIT|PGO_SYNCIO); 297 } 298 299 goto out; 300 } 301 302 flags = ioflag & IO_SYNC ? B_SYNC : 0; 303 for (error = 0; uio->uio_resid > 0;) { 304 lbn = lblkno(fs, uio->uio_offset); 305 blkoffset = blkoff(fs, uio->uio_offset); 306 xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid); 307 if (xfersize < fs->e2fs_bsize) 308 flags |= B_CLRBUF; 309 else 310 flags &= ~B_CLRBUF; 311 error = ext2fs_balloc(ip, 312 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 313 if (error) 314 break; 315 if (ip->i_e2fs_size < uio->uio_offset + xfersize) { 316 ip->i_e2fs_size = uio->uio_offset + xfersize; 317 } 318 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 319 if (ioflag & IO_SYNC) 320 (void)bwrite(bp); 321 else if (xfersize + blkoffset == fs->e2fs_bsize) 322 bawrite(bp); 323 else 324 bdwrite(bp); 325 if (error || xfersize == 0) 326 break; 327 } 328 /* 329 * If we successfully wrote any data, and we are not the superuser 330 * we clear the setuid and setgid bits as a precaution against 331 * tampering. 332 */ 333 out: 334 ip->i_flag |= IN_CHANGE | IN_UPDATE; 335 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 336 ip->i_e2fs_mode &= ~(ISUID | ISGID); 337 if (error) { 338 (void) VOP_TRUNCATE(vp, osize, ioflag & IO_SYNC, ap->a_cred, 339 uio->uio_procp); 340 uio->uio_offset -= resid - uio->uio_resid; 341 uio->uio_resid = resid; 342 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) 343 error = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT); 344 KASSERT(vp->v_size == ip->i_e2fs_size); 345 return (error); 346 } 347
Indexes created Tue Sep 30 20:09:53 GMT 2025