ext2fs_readwrite.c revision 1.4
1 /* $NetBSD: ext2fs_readwrite.c,v 1.4 1998/02/05 08:00:30 mrg 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 #if defined(UVM) 56 #include <uvm/uvm_extern.h> 57 #endif 58 59 #include <ufs/ufs/quota.h> 60 #include <ufs/ufs/inode.h> 61 #include <ufs/ext2fs/ext2fs.h> 62 #include <ufs/ext2fs/ext2fs_extern.h> 63 64 65 #define doclusterread 0 /* XXX underway */ 66 #define doclusterwrite 0 67 68 /* 69 * Vnode op for reading. 70 */ 71 /* ARGSUSED */ 72 int 73 ext2fs_read(v) 74 void *v; 75 { 76 struct vop_read_args /* { 77 struct vnode *a_vp; 78 struct uio *a_uio; 79 int a_ioflag; 80 struct ucred *a_cred; 81 } */ *ap = v; 82 register struct vnode *vp; 83 register struct inode *ip; 84 register struct uio *uio; 85 register struct m_ext2fs *fs; 86 struct buf *bp; 87 daddr_t lbn, nextlbn; 88 off_t bytesinfile; 89 long size, xfersize, blkoffset; 90 int error; 91 92 vp = ap->a_vp; 93 ip = VTOI(vp); 94 uio = ap->a_uio; 95 96 #ifdef DIAGNOSTIC 97 if (uio->uio_rw != UIO_READ) 98 panic("%s: mode", "ext2fs_read"); 99 100 if (vp->v_type == VLNK) { 101 if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen || 102 (vp->v_mount->mnt_maxsymlinklen == 0 && 103 ip->i_e2fs_nblock == 0)) 104 panic("%s: short symlink", "ext2fs_read"); 105 } else if (vp->v_type != VREG && vp->v_type != VDIR) 106 panic("%s: type %d", "ext2fs_read", vp->v_type); 107 #endif 108 fs = ip->i_e2fs; 109 if ((u_int64_t)uio->uio_offset > 110 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 111 return (EFBIG); 112 if (uio->uio_resid == 0) 113 return (0); 114 115 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 116 if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 0) 117 break; 118 lbn = lblkno(fs, uio->uio_offset); 119 nextlbn = lbn + 1; 120 size = fs->e2fs_bsize; 121 blkoffset = blkoff(fs, uio->uio_offset); 122 xfersize = fs->e2fs_bsize - blkoffset; 123 if (uio->uio_resid < xfersize) 124 xfersize = uio->uio_resid; 125 if (bytesinfile < xfersize) 126 xfersize = bytesinfile; 127 128 if (lblktosize(fs, nextlbn) >= ip->i_e2fs_size) 129 error = bread(vp, lbn, size, NOCRED, &bp); 130 else if (doclusterread) 131 error = cluster_read(vp, 132 ip->i_e2fs_size, lbn, size, NOCRED, &bp); 133 else if (lbn - 1 == vp->v_lastr) { 134 int nextsize = fs->e2fs_bsize; 135 error = breadn(vp, lbn, 136 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 137 } else 138 error = bread(vp, lbn, size, NOCRED, &bp); 139 if (error) 140 break; 141 vp->v_lastr = lbn; 142 143 /* 144 * We should only get non-zero b_resid when an I/O error 145 * has occurred, which should cause us to break above. 146 * However, if the short read did not cause an error, 147 * then we want to ensure that we do not uiomove bad 148 * or uninitialized data. 149 */ 150 size -= bp->b_resid; 151 if (size < xfersize) { 152 if (size == 0) 153 break; 154 xfersize = size; 155 } 156 error = uiomove((char *)bp->b_data + blkoffset, (int)xfersize, 157 uio); 158 if (error) 159 break; 160 brelse(bp); 161 } 162 if (bp != NULL) 163 brelse(bp); 164 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) 165 ip->i_flag |= IN_ACCESS; 166 return (error); 167 } 168 169 /* 170 * Vnode op for writing. 171 */ 172 int 173 ext2fs_write(v) 174 void *v; 175 { 176 struct vop_write_args /* { 177 struct vnode *a_vp; 178 struct uio *a_uio; 179 int a_ioflag; 180 struct ucred *a_cred; 181 } */ *ap = v; 182 register struct vnode *vp; 183 register struct uio *uio; 184 register struct inode *ip; 185 register struct m_ext2fs *fs; 186 struct buf *bp; 187 struct proc *p; 188 daddr_t lbn; 189 off_t osize; 190 int blkoffset, error, flags, ioflag, resid, size, xfersize; 191 struct timespec ts; 192 193 ioflag = ap->a_ioflag; 194 uio = ap->a_uio; 195 vp = ap->a_vp; 196 ip = VTOI(vp); 197 198 #ifdef DIAGNOSTIC 199 if (uio->uio_rw != UIO_WRITE) 200 panic("%s: mode", "ext2fs_write"); 201 #endif 202 203 switch (vp->v_type) { 204 case VREG: 205 if (ioflag & IO_APPEND) 206 uio->uio_offset = ip->i_e2fs_size; 207 if ((ip->i_e2fs_flags & EXT2_APPEND) && 208 uio->uio_offset != ip->i_e2fs_size) 209 return (EPERM); 210 /* FALLTHROUGH */ 211 case VLNK: 212 break; 213 case VDIR: 214 if ((ioflag & IO_SYNC) == 0) 215 panic("%s: nonsync dir write", "ext2fs_write"); 216 break; 217 default: 218 panic("%s: type", "ext2fs_write"); 219 } 220 221 fs = ip->i_e2fs; 222 if (uio->uio_offset < 0 || 223 (u_int64_t)uio->uio_offset + uio->uio_resid > 224 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 225 return (EFBIG); 226 /* 227 * Maybe this should be above the vnode op call, but so long as 228 * file servers have no limits, I don't think it matters. 229 */ 230 p = uio->uio_procp; 231 if (vp->v_type == VREG && p && 232 uio->uio_offset + uio->uio_resid > 233 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 234 psignal(p, SIGXFSZ); 235 return (EFBIG); 236 } 237 238 resid = uio->uio_resid; 239 osize = ip->i_e2fs_size; 240 flags = ioflag & IO_SYNC ? B_SYNC : 0; 241 242 for (error = 0; uio->uio_resid > 0;) { 243 lbn = lblkno(fs, uio->uio_offset); 244 blkoffset = blkoff(fs, uio->uio_offset); 245 xfersize = fs->e2fs_bsize - blkoffset; 246 if (uio->uio_resid < xfersize) 247 xfersize = uio->uio_resid; 248 if (fs->e2fs_bsize > xfersize) 249 flags |= B_CLRBUF; 250 else 251 flags &= ~B_CLRBUF; 252 253 error = ext2fs_balloc(ip, 254 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 255 if (error) 256 break; 257 if (uio->uio_offset + xfersize > ip->i_e2fs_size) { 258 ip->i_e2fs_size = uio->uio_offset + xfersize; 259 #if defined(UVM) 260 uvm_vnp_setsize(vp, ip->i_e2fs_size); 261 #else 262 vnode_pager_setsize(vp, ip->i_e2fs_size); 263 #endif 264 } 265 #if defined(UVM) 266 (void)uvm_vnp_uncache(vp); 267 #else 268 (void)vnode_pager_uncache(vp); 269 #endif 270 271 size = fs->e2fs_bsize - bp->b_resid; 272 if (size < xfersize) 273 xfersize = size; 274 275 error = 276 uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); 277 if (ioflag & IO_SYNC) 278 (void)bwrite(bp); 279 else if (xfersize + blkoffset == fs->e2fs_bsize) 280 if (doclusterwrite) 281 cluster_write(bp, ip->i_e2fs_size); 282 else 283 bawrite(bp); 284 else 285 bdwrite(bp); 286 if (error || xfersize == 0) 287 break; 288 ip->i_flag |= IN_CHANGE | IN_UPDATE; 289 } 290 /* 291 * If we successfully wrote any data, and we are not the superuser 292 * we clear the setuid and setgid bits as a precaution against 293 * tampering. 294 */ 295 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 296 ip->i_e2fs_mode &= ~(ISUID | ISGID); 297 if (error) { 298 if (ioflag & IO_UNIT) { 299 (void)VOP_TRUNCATE(vp, osize, 300 ioflag & IO_SYNC, ap->a_cred, uio->uio_procp); 301 uio->uio_offset -= resid - uio->uio_resid; 302 uio->uio_resid = resid; 303 } 304 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) { 305 TIMEVAL_TO_TIMESPEC(&time, &ts); 306 error = VOP_UPDATE(vp, &ts, &ts, 1); 307 } 308 return (error); 309 } 310
Indexes created Tue Sep 30 20:09:53 GMT 2025