patch-2.4.5 linux/fs/freevxfs/vxfs_bmap.c

• Lines: 277
• Date: Thu May 24 15:00:59 2001
• Orig file: v2.4.4/linux/fs/freevxfs/vxfs_bmap.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.4/linux/fs/freevxfs/vxfs_bmap.c linux/fs/freevxfs/vxfs_bmap.c
@@ -0,0 +1,276 @@
+/*
+ * Copyright (c) 2000-2001 Christoph Hellwig.
+ * 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,
+ *    without modification.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL").
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#ident "$Id: vxfs_bmap.c,v 1.20 2001/04/25 18:11:23 hch Exp hch $"
+
+/*
+ * Veritas filesystem driver - filesystem to disk block mapping.
+ */
+#include <linux/fs.h>
+#include <linux/kernel.h>
+
+#include "vxfs.h"
+#include "vxfs_inode.h"
+
+
+#ifdef DIAGNOSTIC
+static void
+vxfs_typdump(struct vxfs_typed *typ)
+{
+	printk(KERN_DEBUG "type=%Lu ", typ->vt_hdr >> VXFS_TYPED_TYPESHIFT);
+	printk("offset=%Lx ", typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
+	printk("block=%x ", typ->vt_block);
+	printk("size=%x\n", typ->vt_size);
+}
+#endif
+
+/**
+ * vxfs_bmap_ext4 - do bmap for ext4 extents
+ * @ip:		pointer to the inode we do bmap for
+ * @iblock:	logical block.
+ *
+ * Description:
+ *   vxfs_bmap_ext4 performs the bmap operation for inodes with
+ *   ext4-style extents (which are much like the traditional UNIX
+ *   inode organisation).
+ *
+ * Returns:
+ *   The physical block number on success, else Zero.
+ */
+static daddr_t
+vxfs_bmap_ext4(struct inode *ip, long iblock)
+{
+	struct vxfs_inode_info		*vip = VXFS_INO(ip);
+	struct super_block		*sbp = ip->i_sb;
+	kdev_t				dev = ip->i_dev;
+	u_long				bsize = sbp->s_blocksize;
+	u_long				size = 0;
+	int				i;
+
+	for (i = 0; i < VXFS_NDADDR; i++) {
+		struct direct		*dp = vip->vii_ext4.ve4_direct + i;
+
+#ifdef DIAGNOSTIC
+		printk(KERN_DEBUG "iblock: %ld, %d (size: %lu)\n", iblock, i, size);
+		printk(KERN_DEBUG "dp->extent: %d, dp->size: %d\n", dp->extent, dp->size);
+#endif
+
+		if (iblock >= size && iblock < (size + dp->size))
+			return ((iblock - size) + dp->extent);
+		size += dp->size;
+	}
+
+	iblock -= size;
+
+	if (!(iblock / (vip->vii_ext4.ve4_indsize * vip->vii_ext4.ve4_indsize * bsize >> 2))) {
+		struct buffer_head	*bp;
+		daddr_t			pblock;
+
+		/*
+		 * XXX: is the second indir only used for
+		 *	double indirect extents?
+		 */
+		bp = bread(dev, vip->vii_ext4.ve4_indir[0],
+				bsize * ((vip->vii_ext4.ve4_indsize) / bsize) + 1);
+		pblock = *(bp->b_data + ((iblock / vip->vii_ext4.ve4_indsize) %
+					(vip->vii_ext4.ve4_indsize * bsize)));
+
+		brelse(bp);
+		return (pblock + (iblock % vip->vii_ext4.ve4_indsize));
+	} else
+		printk(KERN_WARNING "no matching indir?");
+
+	return 0;
+}
+
+/**
+ * vxfs_bmap_indir - recursion for vxfs_bmap_typed
+ * @ip:		pointer to the inode we do bmap for
+ * @indir:	indirect block we start reading at
+ * @size:	size of the typed area to search
+ * @block:	partially result from further searches
+ *
+ * Description:
+ *   vxfs_bmap_indir reads a &struct vxfs_typed at @indir
+ *   and performs the type-defined action.
+ *
+ * Return Value:
+ *   The physical block number on success, else Zero.
+ *
+ * Note:
+ *   Kernelstack is rare.  Unrecurse?
+ */
+static daddr_t
+vxfs_bmap_indir(struct inode *ip, long indir, int size, long block)
+{
+	struct buffer_head		*bp = NULL;
+	daddr_t				pblock = 0;
+	int				i;
+
+	for (i = 0; i < size * VXFS_TYPED_PER_BLOCK(ip->i_sb); i++) {
+		struct vxfs_typed	*typ;
+		u_int64_t		off;
+
+		bp = bread(ip->i_dev,
+				indir + (i / VXFS_TYPED_PER_BLOCK(ip->i_sb)),
+				ip->i_sb->s_blocksize);
+		if (!buffer_mapped(bp))
+			return 0;
+
+		typ = ((struct vxfs_typed *)bp->b_data) +
+			(i % VXFS_TYPED_PER_BLOCK(ip->i_sb));
+		off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
+
+		if (block < off) {
+			brelse(bp);
+			continue;
+		}
+
+		switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
+		case VXFS_TYPED_INDIRECT:
+			pblock = vxfs_bmap_indir(ip, typ->vt_block,
+					typ->vt_size, block - off);
+			if (pblock == -2)
+				break;
+			goto out;
+		case VXFS_TYPED_DATA:
+			if ((block - off) >= typ->vt_size)
+				break;
+			pblock = (typ->vt_block + block - off);
+			goto out;
+		case VXFS_TYPED_INDIRECT_DEV4:
+		case VXFS_TYPED_DATA_DEV4: {
+			struct vxfs_typed_dev4	*typ4 = (struct vxfs_typed_dev4 *)typ;
+			printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
+			printk(KERN_INFO "block: %Ld\tsize: %Ld\tdev: %d\n",
+			       (long long)typ4->vd4_block, (long long)typ4->vd4_size, typ4->vd4_dev);
+			goto fail;
+		}
+		default:
+			BUG();
+		}
+		brelse(bp);
+	}
+
+fail:
+	pblock = 0;
+out:
+	brelse(bp);
+	return (pblock);
+}
+
+/**
+ * vxfs_bmap_typed - bmap for typed extents
+ * @ip:		pointer to the inode we do bmap for
+ * @iblock:	logical block
+ *
+ * Description:
+ *   Performs the bmap operation for typed extents.
+ *
+ * Return Value:
+ *   The physical block number on success, else Zero.
+ */
+static daddr_t
+vxfs_bmap_typed(struct inode *ip, long iblock)
+{
+	struct vxfs_inode_info		*vip = VXFS_INO(ip);
+	daddr_t				pblock = 0;
+	int				i;
+
+	for (i = 0; i < VXFS_NTYPED; i++) {
+		struct vxfs_typed	*typ = vip->vii_org.typed + i;
+		u_int64_t		off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
+
+#ifdef DIAGNOSTIC
+		vxfs_typdump(typ);
+#endif
+		if (iblock < off)
+			continue;
+		switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
+		case VXFS_TYPED_INDIRECT:
+			pblock = vxfs_bmap_indir(ip, typ->vt_block,
+					typ->vt_size, iblock - off);
+			if (pblock == -2)
+				break;
+			return (pblock);
+		case VXFS_TYPED_DATA:
+			if ((iblock - off) < typ->vt_size)
+				return (typ->vt_block + iblock - off);
+			break;
+		case VXFS_TYPED_INDIRECT_DEV4:
+		case VXFS_TYPED_DATA_DEV4: {
+			struct vxfs_typed_dev4	*typ4 = (struct vxfs_typed_dev4 *)typ;
+			printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
+			printk(KERN_INFO "block: %Ld\tsize: %Ld\tdev: %d\n",
+			       (long long)typ4->vd4_block, (long long)typ4->vd4_size, typ4->vd4_dev);
+			return 0;
+		}
+		default:
+			BUG();
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * vxfs_bmap1 - vxfs-internal bmap operation
+ * @ip:			pointer to the inode we do bmap for
+ * @iblock:		logical block
+ *
+ * Description:
+ *   vxfs_bmap1 perfoms a logical to physical block mapping
+ *   for vxfs-internal purposes.
+ *
+ * Return Value:
+ *   The physical block number on success, else Zero.
+ */
+daddr_t
+vxfs_bmap1(struct inode *ip, long iblock)
+{
+	struct vxfs_inode_info		*vip = VXFS_INO(ip);
+
+	if (VXFS_ISEXT4(vip))
+		return vxfs_bmap_ext4(ip, iblock);
+	if (VXFS_ISTYPED(vip))
+		return vxfs_bmap_typed(ip, iblock);
+	if (VXFS_ISNONE(vip))
+		goto unsupp;
+	if (VXFS_ISIMMED(vip))
+		goto unsupp;
+
+	printk(KERN_WARNING "vxfs: inode %ld has no valid orgtype (%x)\n",
+			ip->i_ino, vip->vii_orgtype);
+	BUG();
+
+unsupp:
+	printk(KERN_WARNING "vxfs: inode %ld has an unsupported orgtype (%x)\n",
+			ip->i_ino, vip->vii_orgtype);
+	return 0;
+}