ext2fs_readwrite.c revision 1.7
1 /* $NetBSD: ext2fs_readwrite.c,v 1.7 1998/08/02 18:57:23 kleink 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 "opt_uvm.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/resourcevar.h> 45 #include <sys/kernel.h> 46 #include <sys/file.h> 47 #include <sys/stat.h> 48 #include <sys/buf.h> 49 #include <sys/proc.h> 50 #include <sys/conf.h> 51 #include <sys/mount.h> 52 #include <sys/vnode.h> 53 #include <sys/malloc.h> 54 #include <sys/signalvar.h> 55 56 #include <vm/vm.h> 57 #if defined(UVM) 58 #include <uvm/uvm_extern.h> 59 #endif 60 61 #include <ufs/ufs/quota.h> 62 #include <ufs/ufs/inode.h> 63 #include <ufs/ext2fs/ext2fs.h> 64 #include <ufs/ext2fs/ext2fs_extern.h> 65 66 67 #define doclusterread 0 /* XXX underway */ 68 #define doclusterwrite 0 69 70 /* 71 * Vnode op for reading. 72 */ 73 /* ARGSUSED */ 74 int 75 ext2fs_read(v) 76 void *v; 77 { 78 struct vop_read_args /* { 79 struct vnode *a_vp; 80 struct uio *a_uio; 81 int a_ioflag; 82 struct ucred *a_cred; 83 } */ *ap = v; 84 register struct vnode *vp; 85 register struct inode *ip; 86 register struct uio *uio; 87 register struct m_ext2fs *fs; 88 struct buf *bp; 89 struct timespec ts; 90 ufs_daddr_t lbn, nextlbn; 91 off_t bytesinfile; 92 long size, xfersize, blkoffset; 93 int error; 94 95 vp = ap->a_vp; 96 ip = VTOI(vp); 97 uio = ap->a_uio; 98 99 #ifdef DIAGNOSTIC 100 if (uio->uio_rw != UIO_READ) 101 panic("%s: mode", "ext2fs_read"); 102 103 if (vp->v_type == VLNK) { 104 if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen || 105 (vp->v_mount->mnt_maxsymlinklen == 0 && 106 ip->i_e2fs_nblock == 0)) 107 panic("%s: short symlink", "ext2fs_read"); 108 } else if (vp->v_type != VREG && vp->v_type != VDIR) 109 panic("%s: type %d", "ext2fs_read", vp->v_type); 110 #endif 111 fs = ip->i_e2fs; 112 if ((u_int64_t)uio->uio_offset > 113 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 114 return (EFBIG); 115 if (uio->uio_resid == 0) 116 return (0); 117 118 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 119 if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 0) 120 break; 121 lbn = lblkno(fs, uio->uio_offset); 122 nextlbn = lbn + 1; 123 size = fs->e2fs_bsize; 124 blkoffset = blkoff(fs, uio->uio_offset); 125 xfersize = fs->e2fs_bsize - blkoffset; 126 if (uio->uio_resid < xfersize) 127 xfersize = uio->uio_resid; 128 if (bytesinfile < xfersize) 129 xfersize = bytesinfile; 130 131 if (lblktosize(fs, nextlbn) >= ip->i_e2fs_size) 132 error = bread(vp, lbn, size, NOCRED, &bp); 133 else if (doclusterread) 134 error = cluster_read(vp, 135 ip->i_e2fs_size, lbn, size, NOCRED, &bp); 136 else if (lbn - 1 == vp->v_lastr) { 137 int nextsize = fs->e2fs_bsize; 138 error = breadn(vp, lbn, 139 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 140 } else 141 error = bread(vp, lbn, size, NOCRED, &bp); 142 if (error) 143 break; 144 vp->v_lastr = lbn; 145 146 /* 147 * We should only get non-zero b_resid when an I/O error 148 * has occurred, which should cause us to break above. 149 * However, if the short read did not cause an error, 150 * then we want to ensure that we do not uiomove bad 151 * or uninitialized data. 152 */ 153 size -= bp->b_resid; 154 if (size < xfersize) { 155 if (size == 0) 156 break; 157 xfersize = size; 158 } 159 error = uiomove((char *)bp->b_data + blkoffset, (int)xfersize, 160 uio); 161 if (error) 162 break; 163 brelse(bp); 164 } 165 if (bp != NULL) 166 brelse(bp); 167 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 168 ip->i_flag |= IN_ACCESS; 169 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) { 170 TIMEVAL_TO_TIMESPEC(&time, &ts); 171 error = VOP_UPDATE(vp, &ts, &ts, 1); 172 } 173 } 174 return (error); 175 } 176 177 /* 178 * Vnode op for writing. 179 */ 180 int 181 ext2fs_write(v) 182 void *v; 183 { 184 struct vop_write_args /* { 185 struct vnode *a_vp; 186 struct uio *a_uio; 187 int a_ioflag; 188 struct ucred *a_cred; 189 } */ *ap = v; 190 register struct vnode *vp; 191 register struct uio *uio; 192 register struct inode *ip; 193 register struct m_ext2fs *fs; 194 struct buf *bp; 195 struct proc *p; 196 ufs_daddr_t lbn; 197 off_t osize; 198 int blkoffset, error, flags, ioflag, resid, size, xfersize; 199 struct timespec ts; 200 201 ioflag = ap->a_ioflag; 202 uio = ap->a_uio; 203 vp = ap->a_vp; 204 ip = VTOI(vp); 205 206 #ifdef DIAGNOSTIC 207 if (uio->uio_rw != UIO_WRITE) 208 panic("%s: mode", "ext2fs_write"); 209 #endif 210 211 switch (vp->v_type) { 212 case VREG: 213 if (ioflag & IO_APPEND) 214 uio->uio_offset = ip->i_e2fs_size; 215 if ((ip->i_e2fs_flags & EXT2_APPEND) && 216 uio->uio_offset != ip->i_e2fs_size) 217 return (EPERM); 218 /* FALLTHROUGH */ 219 case VLNK: 220 break; 221 case VDIR: 222 if ((ioflag & IO_SYNC) == 0) 223 panic("%s: nonsync dir write", "ext2fs_write"); 224 break; 225 default: 226 panic("%s: type", "ext2fs_write"); 227 } 228 229 fs = ip->i_e2fs; 230 if (uio->uio_offset < 0 || 231 (u_int64_t)uio->uio_offset + uio->uio_resid > 232 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 233 return (EFBIG); 234 /* 235 * Maybe this should be above the vnode op call, but so long as 236 * file servers have no limits, I don't think it matters. 237 */ 238 p = uio->uio_procp; 239 if (vp->v_type == VREG && p && 240 uio->uio_offset + uio->uio_resid > 241 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 242 psignal(p, SIGXFSZ); 243 return (EFBIG); 244 } 245 246 resid = uio->uio_resid; 247 osize = ip->i_e2fs_size; 248 flags = ioflag & IO_SYNC ? B_SYNC : 0; 249 250 for (error = 0; uio->uio_resid > 0;) { 251 lbn = lblkno(fs, uio->uio_offset); 252 blkoffset = blkoff(fs, uio->uio_offset); 253 xfersize = fs->e2fs_bsize - blkoffset; 254 if (uio->uio_resid < xfersize) 255 xfersize = uio->uio_resid; 256 if (fs->e2fs_bsize > xfersize) 257 flags |= B_CLRBUF; 258 else 259 flags &= ~B_CLRBUF; 260 261 error = ext2fs_balloc(ip, 262 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 263 if (error) 264 break; 265 if (uio->uio_offset + xfersize > ip->i_e2fs_size) { 266 ip->i_e2fs_size = uio->uio_offset + xfersize; 267 #if defined(UVM) 268 uvm_vnp_setsize(vp, ip->i_e2fs_size); 269 #else 270 vnode_pager_setsize(vp, ip->i_e2fs_size); 271 #endif 272 } 273 #if defined(UVM) 274 (void)uvm_vnp_uncache(vp); 275 #else 276 (void)vnode_pager_uncache(vp); 277 #endif 278 279 size = fs->e2fs_bsize - bp->b_resid; 280 if (size < xfersize) 281 xfersize = size; 282 283 error = 284 uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); 285 if (ioflag & IO_SYNC) 286 (void)bwrite(bp); 287 else if (xfersize + blkoffset == fs->e2fs_bsize) 288 if (doclusterwrite) 289 cluster_write(bp, ip->i_e2fs_size); 290 else 291 bawrite(bp); 292 else 293 bdwrite(bp); 294 if (error || xfersize == 0) 295 break; 296 ip->i_flag |= IN_CHANGE | IN_UPDATE; 297 } 298 /* 299 * If we successfully wrote any data, and we are not the superuser 300 * we clear the setuid and setgid bits as a precaution against 301 * tampering. 302 */ 303 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 304 ip->i_e2fs_mode &= ~(ISUID | ISGID); 305 if (error) { 306 if (ioflag & IO_UNIT) { 307 (void)VOP_TRUNCATE(vp, osize, 308 ioflag & IO_SYNC, ap->a_cred, uio->uio_procp); 309 uio->uio_offset -= resid - uio->uio_resid; 310 uio->uio_resid = resid; 311 } 312 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) { 313 TIMEVAL_TO_TIMESPEC(&time, &ts); 314 error = VOP_UPDATE(vp, &ts, &ts, 1); 315 } 316 return (error); 317 } 318
Indexes created Tue Sep 30 20:09:53 GMT 2025