ext2fs_readwrite.c revision 1.9
1 /* $NetBSD: ext2fs_readwrite.c,v 1.9 1999/03/05 21:09:49 mycroft 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 ufs_daddr_t lbn, nextlbn; 92 off_t bytesinfile; 93 long size, xfersize, blkoffset; 94 int error; 95 96 vp = ap->a_vp; 97 ip = VTOI(vp); 98 uio = ap->a_uio; 99 100 #ifdef DIAGNOSTIC 101 if (uio->uio_rw != UIO_READ) 102 panic("%s: mode", "ext2fs_read"); 103 104 if (vp->v_type == VLNK) { 105 if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen || 106 (vp->v_mount->mnt_maxsymlinklen == 0 && 107 ip->i_e2fs_nblock == 0)) 108 panic("%s: short symlink", "ext2fs_read"); 109 } else if (vp->v_type != VREG && vp->v_type != VDIR) 110 panic("%s: type %d", "ext2fs_read", vp->v_type); 111 #endif 112 fs = ip->i_e2fs; 113 if ((u_int64_t)uio->uio_offset > 114 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 115 return (EFBIG); 116 if (uio->uio_resid == 0) 117 return (0); 118 119 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 120 if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 0) 121 break; 122 lbn = lblkno(fs, uio->uio_offset); 123 nextlbn = lbn + 1; 124 size = fs->e2fs_bsize; 125 blkoffset = blkoff(fs, uio->uio_offset); 126 xfersize = fs->e2fs_bsize - blkoffset; 127 if (uio->uio_resid < xfersize) 128 xfersize = uio->uio_resid; 129 if (bytesinfile < xfersize) 130 xfersize = bytesinfile; 131 132 if (lblktosize(fs, nextlbn) >= ip->i_e2fs_size) 133 error = bread(vp, lbn, size, NOCRED, &bp); 134 else if (doclusterread) 135 error = cluster_read(vp, 136 ip->i_e2fs_size, lbn, size, NOCRED, &bp); 137 else if (lbn - 1 == vp->v_lastr) { 138 int nextsize = fs->e2fs_bsize; 139 error = breadn(vp, lbn, 140 size, &nextlbn, &nextsize, 1, NOCRED, &bp); 141 } else 142 error = bread(vp, lbn, size, NOCRED, &bp); 143 if (error) 144 break; 145 vp->v_lastr = lbn; 146 147 /* 148 * We should only get non-zero b_resid when an I/O error 149 * has occurred, which should cause us to break above. 150 * However, if the short read did not cause an error, 151 * then we want to ensure that we do not uiomove bad 152 * or uninitialized data. 153 */ 154 size -= bp->b_resid; 155 if (size < xfersize) { 156 if (size == 0) 157 break; 158 xfersize = size; 159 } 160 error = uiomove((char *)bp->b_data + blkoffset, (int)xfersize, 161 uio); 162 if (error) 163 break; 164 brelse(bp); 165 } 166 if (bp != NULL) 167 brelse(bp); 168 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 169 ip->i_flag |= IN_ACCESS; 170 if ((ap->a_ioflag & IO_SYNC) == IO_SYNC) 171 error = VOP_UPDATE(vp, NULL, NULL, 1); 172 } 173 return (error); 174 } 175 176 /* 177 * Vnode op for writing. 178 */ 179 int 180 ext2fs_write(v) 181 void *v; 182 { 183 struct vop_write_args /* { 184 struct vnode *a_vp; 185 struct uio *a_uio; 186 int a_ioflag; 187 struct ucred *a_cred; 188 } */ *ap = v; 189 register struct vnode *vp; 190 register struct uio *uio; 191 register struct inode *ip; 192 register struct m_ext2fs *fs; 193 struct buf *bp; 194 struct proc *p; 195 ufs_daddr_t lbn; 196 off_t osize; 197 int blkoffset, error, flags, ioflag, resid, size, xfersize; 198 199 ioflag = ap->a_ioflag; 200 uio = ap->a_uio; 201 vp = ap->a_vp; 202 ip = VTOI(vp); 203 204 #ifdef DIAGNOSTIC 205 if (uio->uio_rw != UIO_WRITE) 206 panic("%s: mode", "ext2fs_write"); 207 #endif 208 209 switch (vp->v_type) { 210 case VREG: 211 if (ioflag & IO_APPEND) 212 uio->uio_offset = ip->i_e2fs_size; 213 if ((ip->i_e2fs_flags & EXT2_APPEND) && 214 uio->uio_offset != ip->i_e2fs_size) 215 return (EPERM); 216 /* FALLTHROUGH */ 217 case VLNK: 218 break; 219 case VDIR: 220 if ((ioflag & IO_SYNC) == 0) 221 panic("%s: nonsync dir write", "ext2fs_write"); 222 break; 223 default: 224 panic("%s: type", "ext2fs_write"); 225 } 226 227 fs = ip->i_e2fs; 228 if (uio->uio_offset < 0 || 229 (u_int64_t)uio->uio_offset + uio->uio_resid > 230 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 231 return (EFBIG); 232 /* 233 * Maybe this should be above the vnode op call, but so long as 234 * file servers have no limits, I don't think it matters. 235 */ 236 p = uio->uio_procp; 237 if (vp->v_type == VREG && p && 238 uio->uio_offset + uio->uio_resid > 239 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 240 psignal(p, SIGXFSZ); 241 return (EFBIG); 242 } 243 244 resid = uio->uio_resid; 245 osize = ip->i_e2fs_size; 246 flags = ioflag & IO_SYNC ? B_SYNC : 0; 247 248 for (error = 0; uio->uio_resid > 0;) { 249 lbn = lblkno(fs, uio->uio_offset); 250 blkoffset = blkoff(fs, uio->uio_offset); 251 xfersize = fs->e2fs_bsize - blkoffset; 252 if (uio->uio_resid < xfersize) 253 xfersize = uio->uio_resid; 254 if (fs->e2fs_bsize > xfersize) 255 flags |= B_CLRBUF; 256 else 257 flags &= ~B_CLRBUF; 258 259 error = ext2fs_balloc(ip, 260 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 261 if (error) 262 break; 263 if (uio->uio_offset + xfersize > ip->i_e2fs_size) { 264 ip->i_e2fs_size = uio->uio_offset + xfersize; 265 #if defined(UVM) 266 uvm_vnp_setsize(vp, ip->i_e2fs_size); 267 #else 268 vnode_pager_setsize(vp, ip->i_e2fs_size); 269 #endif 270 } 271 #if defined(UVM) 272 (void)uvm_vnp_uncache(vp); 273 #else 274 (void)vnode_pager_uncache(vp); 275 #endif 276 277 size = fs->e2fs_bsize - bp->b_resid; 278 if (size < xfersize) 279 xfersize = size; 280 281 error = 282 uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); 283 if (ioflag & IO_SYNC) 284 (void)bwrite(bp); 285 else if (xfersize + blkoffset == fs->e2fs_bsize) 286 if (doclusterwrite) 287 cluster_write(bp, ip->i_e2fs_size); 288 else 289 bawrite(bp); 290 else 291 bdwrite(bp); 292 if (error || xfersize == 0) 293 break; 294 ip->i_flag |= IN_CHANGE | IN_UPDATE; 295 } 296 /* 297 * If we successfully wrote any data, and we are not the superuser 298 * we clear the setuid and setgid bits as a precaution against 299 * tampering. 300 */ 301 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 302 ip->i_e2fs_mode &= ~(ISUID | ISGID); 303 if (error) { 304 if (ioflag & IO_UNIT) { 305 (void)VOP_TRUNCATE(vp, osize, 306 ioflag & IO_SYNC, ap->a_cred, uio->uio_procp); 307 uio->uio_offset -= resid - uio->uio_resid; 308 uio->uio_resid = resid; 309 } 310 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) 311 error = VOP_UPDATE(vp, NULL, NULL, 1); 312 return (error); 313 } 314
Indexes created Tue Sep 30 20:09:53 GMT 2025