1 /* $OpenBSD: ext2fs_readwrite.c,v 1.23 2011/07/04 04:30:41 tedu Exp $ */ 2 /* $NetBSD: ext2fs_readwrite.c,v 1.16 2001/02/27 04:37:47 chs Exp $ */ 3 4 /*- 5 * Copyright (c) 1997 Manuel Bouyer. 6 * Copyright (c) 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94 34 * Modified for ext2fs by Manuel Bouyer. 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/resourcevar.h> 40 #include <sys/kernel.h> 41 #include <sys/file.h> 42 #include <sys/stat.h> 43 #include <sys/buf.h> 44 #include <sys/proc.h> 45 #include <sys/conf.h> 46 #include <sys/mount.h> 47 #include <sys/vnode.h> 48 #include <sys/malloc.h> 49 #include <sys/signalvar.h> 50 51 #include <ufs/ufs/quota.h> 52 #include <ufs/ufs/inode.h> 53 #include <ufs/ext2fs/ext2fs.h> 54 #include <ufs/ext2fs/ext2fs_extern.h> 55 56 57 #define doclusterread 0 /* XXX underway */ 58 #define doclusterwrite 0 59 60 /* 61 * Vnode op for reading. 62 */ 63 /* ARGSUSED */ 64 int 65 ext2fs_read(void *v) 66 { 67 struct vop_read_args *ap = v; 68 struct vnode *vp; 69 struct inode *ip; 70 struct uio *uio; 71 struct m_ext2fs *fs; 72 struct buf *bp; 73 daddr64_t lbn, nextlbn; 74 off_t bytesinfile; 75 long size, xfersize, blkoffset; 76 int error; 77 78 vp = ap->a_vp; 79 ip = VTOI(vp); 80 uio = ap->a_uio; 81 82 #ifdef DIAGNOSTIC 83 if (uio->uio_rw != UIO_READ) 84 panic("%s: mode", "ext2fs_read"); 85 86 if (vp->v_type == VLNK) { 87 if ((int)ext2fs_size(ip) < vp->v_mount->mnt_maxsymlinklen || 88 (vp->v_mount->mnt_maxsymlinklen == 0 && 89 ip->i_e2fs_nblock == 0)) 90 panic("%s: short symlink", "ext2fs_read"); 91 } else if (vp->v_type != VREG && vp->v_type != VDIR) 92 panic("%s: type %d", "ext2fs_read", vp->v_type); 93 #endif 94 fs = ip->i_e2fs; 95 if ((u_int64_t)uio->uio_offset > 96 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 97 return (EFBIG); 98 if (uio->uio_resid == 0) 99 return (0); 100 101 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 102 if ((bytesinfile = ext2fs_size(ip) - uio->uio_offset) <= 0) 103 break; 104 lbn = lblkno(fs, uio->uio_offset); 105 nextlbn = lbn + 1; 106 size = fs->e2fs_bsize; 107 blkoffset = blkoff(fs, uio->uio_offset); 108 xfersize = fs->e2fs_bsize - blkoffset; 109 if (uio->uio_resid < xfersize) 110 xfersize = uio->uio_resid; 111 if (bytesinfile < xfersize) 112 xfersize = bytesinfile; 113 114 if (lblktosize(fs, nextlbn) >= ext2fs_size(ip)) 115 error = bread(vp, lbn, size, &bp); 116 else if (lbn - 1 == ip->i_ci.ci_lastr) { 117 int nextsize = fs->e2fs_bsize; 118 error = breadn(vp, lbn, size, &nextlbn, &nextsize, 119 1, &bp); 120 } else 121 error = bread(vp, lbn, size, &bp); 122 if (error) 123 break; 124 ip->i_ci.ci_lastr = lbn; 125 126 /* 127 * We should only get non-zero b_resid when an I/O error 128 * has occurred, which should cause us to break above. 129 * However, if the short read did not cause an error, 130 * then we want to ensure that we do not uiomove bad 131 * or uninitialized data. 132 */ 133 size -= bp->b_resid; 134 if (size < xfersize) { 135 if (size == 0) 136 break; 137 xfersize = size; 138 } 139 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio); 140 if (error) 141 break; 142 brelse(bp); 143 } 144 if (bp != NULL) 145 brelse(bp); 146 147 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) { 148 ip->i_flag |= IN_ACCESS; 149 } 150 return (error); 151 } 152 153 /* 154 * Vnode op for writing. 155 */ 156 int 157 ext2fs_write(void *v) 158 { 159 struct vop_write_args *ap = v; 160 struct vnode *vp; 161 struct uio *uio; 162 struct inode *ip; 163 struct m_ext2fs *fs; 164 struct buf *bp; 165 struct proc *p; 166 int32_t lbn; 167 off_t osize; 168 int blkoffset, error, flags, ioflag, resid, size, xfersize; 169 170 ioflag = ap->a_ioflag; 171 uio = ap->a_uio; 172 vp = ap->a_vp; 173 ip = VTOI(vp); 174 175 #ifdef DIAGNOSTIC 176 if (uio->uio_rw != UIO_WRITE) 177 panic("%s: mode", "ext2fs_write"); 178 #endif 179 180 /* 181 * If writing 0 bytes, succeed and do not change 182 * update time or file offset (standards compliance) 183 */ 184 if (uio->uio_resid == 0) 185 return (0); 186 187 switch (vp->v_type) { 188 case VREG: 189 if (ioflag & IO_APPEND) 190 uio->uio_offset = ext2fs_size(ip); 191 if ((ip->i_e2fs_flags & EXT2_APPEND) && 192 uio->uio_offset != ext2fs_size(ip)) 193 return (EPERM); 194 /* FALLTHROUGH */ 195 case VLNK: 196 break; 197 case VDIR: 198 if ((ioflag & IO_SYNC) == 0) 199 panic("%s: nonsync dir write", "ext2fs_write"); 200 break; 201 default: 202 panic("%s: type", "ext2fs_write"); 203 } 204 205 fs = ip->i_e2fs; 206 if (uio->uio_offset < 0 || 207 (u_int64_t)uio->uio_offset + uio->uio_resid > 208 ((u_int64_t)0x80000000 * fs->e2fs_bsize - 1)) 209 return (EFBIG); 210 /* 211 * Maybe this should be above the vnode op call, but so long as 212 * file servers have no limits, I don't think it matters. 213 */ 214 p = uio->uio_procp; 215 if (vp->v_type == VREG && p && 216 uio->uio_offset + uio->uio_resid > 217 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 218 psignal(p, SIGXFSZ); 219 return (EFBIG); 220 } 221 222 resid = uio->uio_resid; 223 osize = ext2fs_size(ip); 224 flags = ioflag & IO_SYNC ? B_SYNC : 0; 225 226 for (error = 0; uio->uio_resid > 0;) { 227 lbn = lblkno(fs, uio->uio_offset); 228 blkoffset = blkoff(fs, uio->uio_offset); 229 xfersize = fs->e2fs_bsize - blkoffset; 230 if (uio->uio_resid < xfersize) 231 xfersize = uio->uio_resid; 232 if (fs->e2fs_bsize > xfersize) 233 flags |= B_CLRBUF; 234 else 235 flags &= ~B_CLRBUF; 236 237 error = ext2fs_buf_alloc(ip, 238 lbn, blkoffset + xfersize, ap->a_cred, &bp, flags); 239 if (error) 240 break; 241 if (uio->uio_offset + xfersize > ext2fs_size(ip)) { 242 error = ext2fs_setsize(ip, uio->uio_offset + xfersize); 243 if (error) 244 break; 245 uvm_vnp_setsize(vp, ip->i_e2fs_size); 246 } 247 uvm_vnp_uncache(vp); 248 249 size = fs->e2fs_bsize - bp->b_resid; 250 if (size < xfersize) 251 xfersize = size; 252 253 error = 254 uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); 255 if (ioflag & IO_SYNC) 256 (void)bwrite(bp); 257 else if (xfersize + blkoffset == fs->e2fs_bsize) { 258 if (doclusterwrite) 259 cluster_write(bp, &ip->i_ci, ext2fs_size(ip)); 260 else 261 bawrite(bp); 262 } else 263 bdwrite(bp); 264 if (error || xfersize == 0) 265 break; 266 ip->i_flag |= IN_CHANGE | IN_UPDATE; 267 } 268 /* 269 * If we successfully wrote any data, and we are not the superuser 270 * we clear the setuid and setgid bits as a precaution against 271 * tampering. 272 */ 273 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 274 ip->i_e2fs_mode &= ~(ISUID | ISGID); 275 if (error) { 276 if (ioflag & IO_UNIT) { 277 (void)ext2fs_truncate(ip, osize, 278 ioflag & IO_SYNC, ap->a_cred); 279 uio->uio_offset -= resid - uio->uio_resid; 280 uio->uio_resid = resid; 281 } 282 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) { 283 error = ext2fs_update(ip, NULL, NULL, 1); 284 } 285 return (error); 286 } 287