ext2fs_readwrite.c revision 1.8
1 /* $NetBSD: ext2fs_readwrite.c,v 1.8 1998/09/29 10:24:58 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 #if defined(_KERNEL) && !defined(_LKM) 41 #include "opt_uvm.h" 42 #endif 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/resourcevar.h> 47 #include <sys/kernel.h> 48 #include <sys/file.h> 49 #include <sys/stat.h> 50 #include <sys/buf.h> 51 #include <sys/proc.h> 52 #include <sys/conf.h> 53 #include <sys/mount.h> 54 #include <sys/vnode.h> 55 #include <sys/malloc.h> 56 #include <sys/signalvar.h> 57 58 #include <vm/vm.h> 59 #if defined(UVM) 60 #include <uvm/uvm_extern.h> 61 #endif 62 63 #include <ufs/ufs/quota.h> 64 #include <ufs/ufs/inode.h> 65 #include <ufs/ext2fs/ext2fs.h> 66 #include <ufs/ext2fs/ext2fs_extern.h> 67 68 69 #define doclusterread 0 /* XXX underway */ 70 #define doclusterwrite 0 71 72 /* 73 * Vnode op for reading. 74 */ 75 /* ARGSUSED */ 76 int 77 ext2fs_read(v) 78 void *v; 79 { 80 struct vop_read_args /* { 81 struct vnode *a_vp; 82 struct uio *a_uio; 83 int a_ioflag; 84 struct ucred *a_cred; 85 } */ *ap = v; 86 register struct vnode *vp; 87 register struct inode *ip; 88 register struct uio *uio; 89 register struct m_ext2fs *fs; 90 struct buf *bp; 91 struct timespec ts; 92 ufs_daddr_t lbn, nextlbn; 93 off_t bytesinfile; 94 long size, xfersize, blkoffset; 95 int error; 96 97 vp = ap->a_vp; 98 ip = VTOI(vp); 99 uio = ap->a_uio; 100 101 #ifdef DIAGNOSTIC 102 if (uio->uio_rw != UIO_READ) 103 panic("%s: mode", "ext2fs_read"); 104 105 if (vp->v_type == VLNK) { 106 if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen || 107 (vp->v_mount->mnt_maxsymlinklen == 0 && 108 ip->i_e2fs_nblock == 0)) 109 panic("%s: short symlink", "ext2fs_read"); 110 } else if (vp->v_type != VREG && vp->v_type != VDIR) 111 panic("%s: type %d", "ext2fs_read", vp->v_type); 112 #endif 113 fs = ip->i_e2fs; 114 if ((u_int64_t)uio->uio_offset > 115 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 116 return (EFBIG); 117 if (uio->uio_resid == 0) 118 return (0); 119 120 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 121 if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 0) 122 break; 123 lbn = lblkno(fs, uio->uio_offset); 124 nextlbn = lbn + 1; 125 size = fs->e2fs_bsize; 126 blkoffset = blkoff(fs, uio->uio_offset); 127 xfersize = fs->e2fs_bsize - blkoffset; 128 if (uio->uio_resid < xfersize) 129 xfersize = uio->uio_resid; 130 if (bytesinfile < xfersize) 131 xfersize = bytesinfile; 132 133 if (lblktosize(fs, nextlbn) >= ip->i_e2fs_size) 134 error = bread(vp, lbn, size, NOCRED, &bp); 135 else if (doclusterread) 136 error = cluster_read(vp, 137 ip->i_e2fs_size, lbn, size, NOCRED, &bp); 138 else if (lbn - 1 == vp->v_lastr) { 139 int nextsize = fs->e2fs_bsize; 140 error = breadn(vp, lbn, 141 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 142 } else 143 error = bread(vp, lbn, size, NOCRED, &bp); 144 if (error) 145 break; 146 vp->v_lastr = lbn; 147 148 /* 149 * We should only get non-zero b_resid when an I/O error 150 * has occurred, which should cause us to break above. 151 * However, if the short read did not cause an error, 152 * then we want to ensure that we do not uiomove bad 153 * or uninitialized data. 154 */ 155 size -= bp->b_resid; 156 if (size < xfersize) { 157 if (size == 0) 158 break; 159 xfersize = size; 160 } 161 error = uiomove((char *)bp->b_data + blkoffset, (int)xfersize, 162 uio); 163 if (error) 164 break; 165 brelse(bp); 166 } 167 if (bp != NULL) 168 brelse(bp); 169 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 170 ip->i_flag |= IN_ACCESS; 171 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) { 172 TIMEVAL_TO_TIMESPEC(&time, &ts); 173 error = VOP_UPDATE(vp, &ts, &ts, 1); 174 } 175 } 176 return (error); 177 } 178 179 /* 180 * Vnode op for writing. 181 */ 182 int 183 ext2fs_write(v) 184 void *v; 185 { 186 struct vop_write_args /* { 187 struct vnode *a_vp; 188 struct uio *a_uio; 189 int a_ioflag; 190 struct ucred *a_cred; 191 } */ *ap = v; 192 register struct vnode *vp; 193 register struct uio *uio; 194 register struct inode *ip; 195 register struct m_ext2fs *fs; 196 struct buf *bp; 197 struct proc *p; 198 ufs_daddr_t lbn; 199 off_t osize; 200 int blkoffset, error, flags, ioflag, resid, size, xfersize; 201 struct timespec ts; 202 203 ioflag = ap->a_ioflag; 204 uio = ap->a_uio; 205 vp = ap->a_vp; 206 ip = VTOI(vp); 207 208 #ifdef DIAGNOSTIC 209 if (uio->uio_rw != UIO_WRITE) 210 panic("%s: mode", "ext2fs_write"); 211 #endif 212 213 switch (vp->v_type) { 214 case VREG: 215 if (ioflag & IO_APPEND) 216 uio->uio_offset = ip->i_e2fs_size; 217 if ((ip->i_e2fs_flags & EXT2_APPEND) && 218 uio->uio_offset != ip->i_e2fs_size) 219 return (EPERM); 220 /* FALLTHROUGH */ 221 case VLNK: 222 break; 223 case VDIR: 224 if ((ioflag & IO_SYNC) == 0) 225 panic("%s: nonsync dir write", "ext2fs_write"); 226 break; 227 default: 228 panic("%s: type", "ext2fs_write"); 229 } 230 231 fs = ip->i_e2fs; 232 if (uio->uio_offset < 0 || 233 (u_int64_t)uio->uio_offset + uio->uio_resid > 234 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 235 return (EFBIG); 236 /* 237 * Maybe this should be above the vnode op call, but so long as 238 * file servers have no limits, I don't think it matters. 239 */ 240 p = uio->uio_procp; 241 if (vp->v_type == VREG && p && 242 uio->uio_offset + uio->uio_resid > 243 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 244 psignal(p, SIGXFSZ); 245 return (EFBIG); 246 } 247 248 resid = uio->uio_resid; 249 osize = ip->i_e2fs_size; 250 flags = ioflag & IO_SYNC ? B_SYNC : 0; 251 252 for (error = 0; uio->uio_resid > 0;) { 253 lbn = lblkno(fs, uio->uio_offset); 254 blkoffset = blkoff(fs, uio->uio_offset); 255 xfersize = fs->e2fs_bsize - blkoffset; 256 if (uio->uio_resid < xfersize) 257 xfersize = uio->uio_resid; 258 if (fs->e2fs_bsize > xfersize) 259 flags |= B_CLRBUF; 260 else 261 flags &= ~B_CLRBUF; 262 263 error = ext2fs_balloc(ip, 264 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 265 if (error) 266 break; 267 if (uio->uio_offset + xfersize > ip->i_e2fs_size) { 268 ip->i_e2fs_size = uio->uio_offset + xfersize; 269 #if defined(UVM) 270 uvm_vnp_setsize(vp, ip->i_e2fs_size); 271 #else 272 vnode_pager_setsize(vp, ip->i_e2fs_size); 273 #endif 274 } 275 #if defined(UVM) 276 (void)uvm_vnp_uncache(vp); 277 #else 278 (void)vnode_pager_uncache(vp); 279 #endif 280 281 size = fs->e2fs_bsize - bp->b_resid; 282 if (size < xfersize) 283 xfersize = size; 284 285 error = 286 uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); 287 if (ioflag & IO_SYNC) 288 (void)bwrite(bp); 289 else if (xfersize + blkoffset == fs->e2fs_bsize) 290 if (doclusterwrite) 291 cluster_write(bp, ip->i_e2fs_size); 292 else 293 bawrite(bp); 294 else 295 bdwrite(bp); 296 if (error || xfersize == 0) 297 break; 298 ip->i_flag |= IN_CHANGE | IN_UPDATE; 299 } 300 /* 301 * If we successfully wrote any data, and we are not the superuser 302 * we clear the setuid and setgid bits as a precaution against 303 * tampering. 304 */ 305 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 306 ip->i_e2fs_mode &= ~(ISUID | ISGID); 307 if (error) { 308 if (ioflag & IO_UNIT) { 309 (void)VOP_TRUNCATE(vp, osize, 310 ioflag & IO_SYNC, ap->a_cred, uio->uio_procp); 311 uio->uio_offset -= resid - uio->uio_resid; 312 uio->uio_resid = resid; 313 } 314 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) { 315 TIMEVAL_TO_TIMESPEC(&time, &ts); 316 error = VOP_UPDATE(vp, &ts, &ts, 1); 317 } 318 return (error); 319 } 320
Indexes created Tue Sep 30 20:09:53 GMT 2025