ext2fs_readwrite.c revision 1.1
1 /* $NetBSD: ext2fs_readwrite.c,v 1.1 1997/06/11 09:34:01 bouyer 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 <vm/vm.h> 55 56 #include <ufs/ufs/quota.h> 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 register struct vnode *vp; 80 register struct inode *ip; 81 register struct uio *uio; 82 register struct m_ext2fs *fs; 83 struct buf *bp; 84 daddr_t lbn, nextlbn; 85 off_t bytesinfile; 86 long size, xfersize, blkoffset; 87 int error; 88 u_short mode; 89 90 vp = ap->a_vp; 91 ip = VTOI(vp); 92 mode = ip->i_e2fs_mode; 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); 113 114 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 115 if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 0) 116 break; 117 lbn = lblkno(fs, uio->uio_offset); 118 nextlbn = lbn + 1; 119 size = fs->e2fs_bsize; 120 blkoffset = blkoff(fs, uio->uio_offset); 121 xfersize = fs->e2fs_bsize - blkoffset; 122 if (uio->uio_resid < xfersize) 123 xfersize = uio->uio_resid; 124 if (bytesinfile < xfersize) 125 xfersize = bytesinfile; 126 127 if (lblktosize(fs, nextlbn) >= ip->i_e2fs_size) 128 error = bread(vp, lbn, size, NOCRED, &bp); 129 else if (doclusterread) 130 error = cluster_read(vp, 131 ip->i_e2fs_size, lbn, size, NOCRED, &bp); 132 else if (lbn - 1 == vp->v_lastr) { 133 int nextsize = fs->e2fs_bsize; 134 error = breadn(vp, lbn, 135 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 136 } else 137 error = bread(vp, lbn, size, NOCRED, &bp); 138 if (error) 139 break; 140 vp->v_lastr = lbn; 141 142 /* 143 * We should only get non-zero b_resid when an I/O error 144 * has occurred, which should cause us to break above. 145 * However, if the short read did not cause an error, 146 * then we want to ensure that we do not uiomove bad 147 * or uninitialized data. 148 */ 149 size -= bp->b_resid; 150 if (size < xfersize) { 151 if (size == 0) 152 break; 153 xfersize = size; 154 } 155 error = uiomove((char *)bp->b_data + blkoffset, (int)xfersize, 156 uio); 157 if (error) 158 break; 159 brelse(bp); 160 } 161 if (bp != NULL) 162 brelse(bp); 163 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) 164 ip->i_flag |= IN_ACCESS; 165 return (error); 166 } 167 168 /* 169 * Vnode op for writing. 170 */ 171 int 172 ext2fs_write(v) 173 void *v; 174 { 175 struct vop_write_args /* { 176 struct vnode *a_vp; 177 struct uio *a_uio; 178 int a_ioflag; 179 struct ucred *a_cred; 180 } */ *ap = v; 181 register struct vnode *vp; 182 register struct uio *uio; 183 register struct inode *ip; 184 register struct m_ext2fs *fs; 185 struct buf *bp; 186 struct proc *p; 187 daddr_t lbn; 188 off_t osize; 189 int blkoffset, error, flags, ioflag, resid, size, xfersize; 190 struct timespec ts; 191 192 ioflag = ap->a_ioflag; 193 uio = ap->a_uio; 194 vp = ap->a_vp; 195 ip = VTOI(vp); 196 197 #ifdef DIAGNOSTIC 198 if (uio->uio_rw != UIO_WRITE) 199 panic("%s: mode", "ext2fs_write"); 200 #endif 201 202 switch (vp->v_type) { 203 case VREG: 204 if (ioflag & IO_APPEND) 205 uio->uio_offset = ip->i_e2fs_size; 206 if ((ip->i_e2fs_flags & EXT2_APPEND) && 207 uio->uio_offset != ip->i_e2fs_size) 208 return (EPERM); 209 /* FALLTHROUGH */ 210 case VLNK: 211 break; 212 case VDIR: 213 if ((ioflag & IO_SYNC) == 0) 214 panic("%s: nonsync dir write", "ext2fs_write"); 215 break; 216 default: 217 panic("%s: type", "ext2fs_write"); 218 } 219 220 fs = ip->i_e2fs; 221 if (uio->uio_offset < 0 || 222 (u_int64_t)uio->uio_offset + uio->uio_resid > 223 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 224 return (EFBIG); 225 /* 226 * Maybe this should be above the vnode op call, but so long as 227 * file servers have no limits, I don't think it matters. 228 */ 229 p = uio->uio_procp; 230 if (vp->v_type == VREG && p && 231 uio->uio_offset + uio->uio_resid > 232 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 233 psignal(p, SIGXFSZ); 234 return (EFBIG); 235 } 236 237 resid = uio->uio_resid; 238 osize = ip->i_e2fs_size; 239 flags = ioflag & IO_SYNC ? B_SYNC : 0; 240 241 for (error = 0; uio->uio_resid > 0;) { 242 lbn = lblkno(fs, uio->uio_offset); 243 blkoffset = blkoff(fs, uio->uio_offset); 244 xfersize = fs->e2fs_bsize - blkoffset; 245 if (uio->uio_resid < xfersize) 246 xfersize = uio->uio_resid; 247 if (fs->e2fs_bsize > xfersize) 248 flags |= B_CLRBUF; 249 else 250 flags &= ~B_CLRBUF; 251 252 error = ext2fs_balloc(ip, 253 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 254 if (error) 255 break; 256 if (uio->uio_offset + xfersize > ip->i_e2fs_size) { 257 ip->i_e2fs_size = uio->uio_offset + xfersize; 258 vnode_pager_setsize(vp, (u_long)ip->i_e2fs_size); 259 } 260 (void)vnode_pager_uncache(vp); 261 262 size = fs->e2fs_bsize - bp->b_resid; 263 if (size < xfersize) 264 xfersize = size; 265 266 error = 267 uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); 268 if (ioflag & IO_SYNC) 269 (void)bwrite(bp); 270 else if (xfersize + blkoffset == fs->e2fs_bsize) 271 if (doclusterwrite) 272 cluster_write(bp, ip->i_e2fs_size); 273 else 274 bawrite(bp); 275 else 276 bdwrite(bp); 277 if (error || xfersize == 0) 278 break; 279 ip->i_flag |= IN_CHANGE | IN_UPDATE; 280 } 281 /* 282 * If we successfully wrote any data, and we are not the superuser 283 * we clear the setuid and setgid bits as a precaution against 284 * tampering. 285 */ 286 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 287 ip->i_e2fs_mode &= ~(ISUID | ISGID); 288 if (error) { 289 if (ioflag & IO_UNIT) { 290 (void)VOP_TRUNCATE(vp, osize, 291 ioflag & IO_SYNC, ap->a_cred, uio->uio_procp); 292 uio->uio_offset -= resid - uio->uio_resid; 293 uio->uio_resid = resid; 294 } 295 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) { 296 TIMEVAL_TO_TIMESPEC(&time, &ts); 297 error = VOP_UPDATE(vp, &ts, &ts, 1); 298 } 299 return (error); 300 } 301
Indexes created Tue Sep 30 20:09:53 GMT 2025