Main code for the ext2fs filesystem. Please refer to the COPYRIGHT.INFO

file for GPL restrictions.  This code was ported to the BSD platform
by Godmar Back <gback@facility.cs.utah.edu> and specifically to FreeBSD
by John Dyson.  This code is still green and should be used with caution.
Additional changes to UFS necessary to make this code work will be commited
seperately.
Submitted by:	Godmar Back <gback@facility.cs.utah.edu>
Obtained from:	Lites/Mach4

1 files changed, 316 insertions, 0 deletions

diff --git a/sys/gnu/ext2fs/ext2_readwrite.c b/sys/gnu/ext2fs/ext2_readwrite.c
new file mode 100644
index 0000000..be01831
--- /dev/null
+++ b/sys/gnu/ext2fs/ext2_readwrite.c
@@ -0,0 +1,316 @@
+/*
+ *  modified for Lites 1.1
+ *
+ *  Aug 1995, Godmar Back (gback@cs.utah.edu)
+ *  University of Utah, Department of Computer Science
+ */
+/*
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)ufs_readwrite.c	8.7 (Berkeley) 1/21/94
+ */
+
+#if !defined(__FreeBSD__)
+#include "diagnostic.h"
+#endif
+
+#define	BLKSIZE(a, b, c)	blksize(a, b, c)
+#define	FS			struct ext2_sb_info
+#define	I_FS			i_e2fs
+#define	READ			ext2_read
+#define	READ_S			"ext2_read"
+#define	WRITE			ext2_write
+#define	WRITE_S			"ext2_write"
+
+/*
+ * Vnode op for reading.
+ */
+/* ARGSUSED */
+int
+READ(ap)
+	struct vop_read_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	register struct vnode *vp;
+	register struct inode *ip;
+	register struct uio *uio;
+	register FS *fs;
+	struct buf *bp;
+	daddr_t lbn, nextlbn;
+	off_t bytesinfile;
+	long size, xfersize, blkoffset;
+	int error;
+	u_short mode;
+
+	vp = ap->a_vp;
+	ip = VTOI(vp);
+	mode = ip->i_mode;
+	uio = ap->a_uio;
+
+#if DIAGNOSTIC
+	if (uio->uio_rw != UIO_READ)
+		panic("%s: mode", READ_S);
+
+	if (vp->v_type == VLNK) {
+		if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
+			panic("%s: short symlink", READ_S);
+	} else if (vp->v_type != VREG && vp->v_type != VDIR)
+		panic("%s: type %d", READ_S, vp->v_type);
+#endif
+	fs = ip->I_FS;
+#if 0
+	if ((u_quad_t)uio->uio_offset > fs->fs_maxfilesize)
+		return (EFBIG);
+#endif
+
+	for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
+		if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
+			break;
+		lbn = lblkno(fs, uio->uio_offset);
+		nextlbn = lbn + 1;
+		size = BLKSIZE(fs, ip, lbn);
+		blkoffset = blkoff(fs, uio->uio_offset);
+		xfersize = fs->s_frag_size - blkoffset;
+		if (uio->uio_resid < xfersize)
+			xfersize = uio->uio_resid;
+		if (bytesinfile < xfersize)
+			xfersize = bytesinfile;
+
+		if (lblktosize(fs, nextlbn) > ip->i_size)
+			error = bread(vp, lbn, size, NOCRED, &bp);
+		else if (doclusterread)
+			error = cluster_read(vp,
+			    ip->i_size, lbn, size, NOCRED, &bp);
+		else if (lbn - 1 == vp->v_lastr) {
+			int nextsize = BLKSIZE(fs, ip, nextlbn);
+			error = breadn(vp, lbn,
+			    size, &nextlbn, &nextsize, 1, NOCRED, &bp);
+		} else
+			error = bread(vp, lbn, size, NOCRED, &bp);
+		if (error)
+			break;
+		vp->v_lastr = lbn;
+
+		/*
+		 * We should only get non-zero b_resid when an I/O error
+		 * has occurred, which should cause us to break above.
+		 * However, if the short read did not cause an error,
+		 * then we want to ensure that we do not uiomove bad
+		 * or uninitialized data.
+		 */
+		size -= bp->b_resid;
+		if (size < xfersize) {
+			if (size == 0)
+				break;
+			xfersize = size;
+		}
+		if (error =
+		    uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio))
+			break;
+
+#if !defined(__FreeBSD__)
+		if (S_ISREG(mode) && (xfersize + blkoffset == fs->s_frag_size ||
+		    uio->uio_offset == ip->i_size))
+			bp->b_flags |= B_AGE;
+#endif
+		brelse(bp);
+	}
+	if (bp != NULL)
+		brelse(bp);
+	ip->i_flag |= IN_ACCESS;
+	return (error);
+}
+
+/*
+ * Vnode op for writing.
+ */
+int
+WRITE(ap)
+	struct vop_write_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	register struct vnode *vp;
+	register struct uio *uio;
+	register struct inode *ip;
+	register FS *fs;
+	struct buf *bp;
+	struct proc *p;
+	daddr_t lbn;
+	off_t osize;
+	int blkoffset, error, flags, ioflag, resid, size, xfersize;
+
+	ioflag = ap->a_ioflag;
+	uio = ap->a_uio;
+	vp = ap->a_vp;
+	ip = VTOI(vp);
+
+#if DIAGNOSTIC
+	if (uio->uio_rw != UIO_WRITE)
+		panic("%s: mode", WRITE_S);
+#endif
+
+	switch (vp->v_type) {
+	case VREG:
+		if (ioflag & IO_APPEND)
+			uio->uio_offset = ip->i_size;
+		if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
+			return (EPERM);
+		/* FALLTHROUGH */
+	case VLNK:
+		break;
+	case VDIR:
+		if ((ioflag & IO_SYNC) == 0)
+			panic("%s: nonsync dir write", WRITE_S);
+		break;
+	default:
+		panic("%s: type", WRITE_S);
+	}
+
+	fs = ip->I_FS;
+#if 0
+	if (uio->uio_offset < 0 ||
+	    (u_quad_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
+		return (EFBIG);
+#endif
+	/*
+	 * Maybe this should be above the vnode op call, but so long as
+	 * file servers have no limits, I don't think it matters.
+	 */
+	p = uio->uio_procp;
+	if (vp->v_type == VREG && p &&
+	    uio->uio_offset + uio->uio_resid >
+	    p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
+		psignal(p, SIGXFSZ);
+		return (EFBIG);
+	}
+
+	resid = uio->uio_resid;
+	osize = ip->i_size;
+	flags = ioflag & IO_SYNC ? B_SYNC : 0;
+
+	for (error = 0; uio->uio_resid > 0;) {
+		lbn = lblkno(fs, uio->uio_offset);
+		blkoffset = blkoff(fs, uio->uio_offset);
+		xfersize = fs->s_frag_size - blkoffset;
+		if (uio->uio_resid < xfersize)
+			xfersize = uio->uio_resid;
+
+#if defined(__FreeBSD__)
+		if (uio->uio_offset + xfersize > ip->i_size)
+			vnode_pager_setsize(vp, (u_long)uio->uio_offset + xfersize);
+#endif
+
+		if (fs->s_frag_size > xfersize)
+			flags |= B_CLRBUF;
+		else
+			flags &= ~B_CLRBUF;
+
+		error = ext2_balloc(ip,
+		    lbn, blkoffset + xfersize, ap->a_cred, &bp, flags);
+
+		if (error)
+			break;
+		if (uio->uio_offset + xfersize > ip->i_size) {
+			ip->i_size = uio->uio_offset + xfersize;
+#if !defined(__FreeBSD__)
+			vnode_pager_setsize(vp, (u_long)ip->i_size);
+#endif
+		}
+#if !defined(__FreeBSD__)
+		(void)vnode_pager_uncache(vp);
+#endif
+
+		size = BLKSIZE(fs, ip, lbn) - bp->b_resid;
+		if (size < xfersize)
+			xfersize = size;
+
+		error =
+		    uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
+
+		if (ioflag & IO_SYNC)
+			(void)bwrite(bp);
+		else if (xfersize + blkoffset == fs->s_frag_size) {
+			if (doclusterwrite) {
+#if defined(__FreeBSD__)
+				bp->b_flags |= B_CLUSTEROK;
+#endif
+				cluster_write(bp, ip->i_size);
+			} else {
+#if !defined(__FreeBSD__)
+				bp->b_flags |= B_AGE;
+#endif
+				bawrite(bp);
+			}
+		} else {
+#if defined(__FreeBSD__)
+			bp->b_flags |= B_CLUSTEROK;
+#endif
+			bdwrite(bp);
+		}
+
+		if (error || xfersize == 0)
+			break;
+		ip->i_flag |= IN_CHANGE | IN_UPDATE;
+	}
+	/*
+	 * If we successfully wrote any data, and we are not the superuser
+	 * we clear the setuid and setgid bits as a precaution against
+	 * tampering.
+	 */
+	if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
+		ip->i_mode &= ~(ISUID | ISGID);
+	if (error) {
+		if (ioflag & IO_UNIT) {
+			(void)VOP_TRUNCATE(vp, osize,
+			    ioflag & IO_SYNC, ap->a_cred, uio->uio_procp);
+			uio->uio_offset -= resid - uio->uio_resid;
+			uio->uio_resid = resid;
+		}
+	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
+		struct timeval tv;
+#if !defined(__FreeBSD__)
+		get_time(&tv);
+#else
+		tv = time;
+#endif
+		error = VOP_UPDATE(vp, &tv, &tv, 1);
+	}
+	return (error);
+}