ext2fs_readwrite.c revision 1.6
1 /* $NetBSD: ext2fs_readwrite.c,v 1.6 1998/03/01 02:23:46 fvdl 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 ufs_daddr_t lbn, nextlbn; 90 off_t bytesinfile; 91 long size, xfersize, blkoffset; 92 int error; 93 94 vp = ap->a_vp; 95 ip = VTOI(vp); 96 uio = ap->a_uio; 97 98 #ifdef DIAGNOSTIC 99 if (uio->uio_rw != UIO_READ) 100 panic("%s: mode", "ext2fs_read"); 101 102 if (vp->v_type == VLNK) { 103 if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen || 104 (vp->v_mount->mnt_maxsymlinklen == 0 && 105 ip->i_e2fs_nblock == 0)) 106 panic("%s: short symlink", "ext2fs_read"); 107 } else if (vp->v_type != VREG && vp->v_type != VDIR) 108 panic("%s: type %d", "ext2fs_read", vp->v_type); 109 #endif 110 fs = ip->i_e2fs; 111 if ((u_int64_t)uio->uio_offset > 112 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 113 return (EFBIG); 114 if (uio->uio_resid == 0) 115 return (0); 116 117 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 118 if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 0) 119 break; 120 lbn = lblkno(fs, uio->uio_offset); 121 nextlbn = lbn + 1; 122 size = fs->e2fs_bsize; 123 blkoffset = blkoff(fs, uio->uio_offset); 124 xfersize = fs->e2fs_bsize - blkoffset; 125 if (uio->uio_resid < xfersize) 126 xfersize = uio->uio_resid; 127 if (bytesinfile < xfersize) 128 xfersize = bytesinfile; 129 130 if (lblktosize(fs, nextlbn) >= ip->i_e2fs_size) 131 error = bread(vp, lbn, size, NOCRED, &bp); 132 else if (doclusterread) 133 error = cluster_read(vp, 134 ip->i_e2fs_size, lbn, size, NOCRED, &bp); 135 else if (lbn - 1 == vp->v_lastr) { 136 int nextsize = fs->e2fs_bsize; 137 error = breadn(vp, lbn, 138 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 139 } else 140 error = bread(vp, lbn, size, NOCRED, &bp); 141 if (error) 142 break; 143 vp->v_lastr = lbn; 144 145 /* 146 * We should only get non-zero b_resid when an I/O error 147 * has occurred, which should cause us to break above. 148 * However, if the short read did not cause an error, 149 * then we want to ensure that we do not uiomove bad 150 * or uninitialized data. 151 */ 152 size -= bp->b_resid; 153 if (size < xfersize) { 154 if (size == 0) 155 break; 156 xfersize = size; 157 } 158 error = uiomove((char *)bp->b_data + blkoffset, (int)xfersize, 159 uio); 160 if (error) 161 break; 162 brelse(bp); 163 } 164 if (bp != NULL) 165 brelse(bp); 166 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) 167 ip->i_flag |= IN_ACCESS; 168 return (error); 169 } 170 171 /* 172 * Vnode op for writing. 173 */ 174 int 175 ext2fs_write(v) 176 void *v; 177 { 178 struct vop_write_args /* { 179 struct vnode *a_vp; 180 struct uio *a_uio; 181 int a_ioflag; 182 struct ucred *a_cred; 183 } */ *ap = v; 184 register struct vnode *vp; 185 register struct uio *uio; 186 register struct inode *ip; 187 register struct m_ext2fs *fs; 188 struct buf *bp; 189 struct proc *p; 190 ufs_daddr_t lbn; 191 off_t osize; 192 int blkoffset, error, flags, ioflag, resid, size, xfersize; 193 struct timespec ts; 194 195 ioflag = ap->a_ioflag; 196 uio = ap->a_uio; 197 vp = ap->a_vp; 198 ip = VTOI(vp); 199 200 #ifdef DIAGNOSTIC 201 if (uio->uio_rw != UIO_WRITE) 202 panic("%s: mode", "ext2fs_write"); 203 #endif 204 205 switch (vp->v_type) { 206 case VREG: 207 if (ioflag & IO_APPEND) 208 uio->uio_offset = ip->i_e2fs_size; 209 if ((ip->i_e2fs_flags & EXT2_APPEND) && 210 uio->uio_offset != ip->i_e2fs_size) 211 return (EPERM); 212 /* FALLTHROUGH */ 213 case VLNK: 214 break; 215 case VDIR: 216 if ((ioflag & IO_SYNC) == 0) 217 panic("%s: nonsync dir write", "ext2fs_write"); 218 break; 219 default: 220 panic("%s: type", "ext2fs_write"); 221 } 222 223 fs = ip->i_e2fs; 224 if (uio->uio_offset < 0 || 225 (u_int64_t)uio->uio_offset + uio->uio_resid > 226 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 227 return (EFBIG); 228 /* 229 * Maybe this should be above the vnode op call, but so long as 230 * file servers have no limits, I don't think it matters. 231 */ 232 p = uio->uio_procp; 233 if (vp->v_type == VREG && p && 234 uio->uio_offset + uio->uio_resid > 235 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 236 psignal(p, SIGXFSZ); 237 return (EFBIG); 238 } 239 240 resid = uio->uio_resid; 241 osize = ip->i_e2fs_size; 242 flags = ioflag & IO_SYNC ? B_SYNC : 0; 243 244 for (error = 0; uio->uio_resid > 0;) { 245 lbn = lblkno(fs, uio->uio_offset); 246 blkoffset = blkoff(fs, uio->uio_offset); 247 xfersize = fs->e2fs_bsize - blkoffset; 248 if (uio->uio_resid < xfersize) 249 xfersize = uio->uio_resid; 250 if (fs->e2fs_bsize > xfersize) 251 flags |= B_CLRBUF; 252 else 253 flags &= ~B_CLRBUF; 254 255 error = ext2fs_balloc(ip, 256 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 257 if (error) 258 break; 259 if (uio->uio_offset + xfersize > ip->i_e2fs_size) { 260 ip->i_e2fs_size = uio->uio_offset + xfersize; 261 #if defined(UVM) 262 uvm_vnp_setsize(vp, ip->i_e2fs_size); 263 #else 264 vnode_pager_setsize(vp, ip->i_e2fs_size); 265 #endif 266 } 267 #if defined(UVM) 268 (void)uvm_vnp_uncache(vp); 269 #else 270 (void)vnode_pager_uncache(vp); 271 #endif 272 273 size = fs->e2fs_bsize - bp->b_resid; 274 if (size < xfersize) 275 xfersize = size; 276 277 error = 278 uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); 279 if (ioflag & IO_SYNC) 280 (void)bwrite(bp); 281 else if (xfersize + blkoffset == fs->e2fs_bsize) 282 if (doclusterwrite) 283 cluster_write(bp, ip->i_e2fs_size); 284 else 285 bawrite(bp); 286 else 287 bdwrite(bp); 288 if (error || xfersize == 0) 289 break; 290 ip->i_flag |= IN_CHANGE | IN_UPDATE; 291 } 292 /* 293 * If we successfully wrote any data, and we are not the superuser 294 * we clear the setuid and setgid bits as a precaution against 295 * tampering. 296 */ 297 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 298 ip->i_e2fs_mode &= ~(ISUID | ISGID); 299 if (error) { 300 if (ioflag & IO_UNIT) { 301 (void)VOP_TRUNCATE(vp, osize, 302 ioflag & IO_SYNC, ap->a_cred, uio->uio_procp); 303 uio->uio_offset -= resid - uio->uio_resid; 304 uio->uio_resid = resid; 305 } 306 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) { 307 TIMEVAL_TO_TIMESPEC(&time, &ts); 308 error = VOP_UPDATE(vp, &ts, &ts, 1); 309 } 310 return (error); 311 } 312
Indexes created Tue Sep 30 20:09:53 GMT 2025