Annotation of sys/ufs/ext2fs/ext2fs_readwrite.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: ext2fs_readwrite.c,v 1.22 2007/06/17 20:15:25 jasper 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, NOCRED, &bp);
! 116: else if (lbn - 1 == ip->i_ci.ci_lastr) {
! 117: int nextsize = fs->e2fs_bsize;
! 118: error = breadn(vp, lbn,
! 119: size, &nextlbn, &nextsize, 1, NOCRED, &bp);
! 120: } else
! 121: error = bread(vp, lbn, size, NOCRED, &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: }
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