[PATCH] xfs_metadump: obfuscate attrs on CRC fs

[Eric Sandeen]

Lots of issues in xfs_metadump obfuscation of extended
attributes with CRC filesystems; this fixes it up.

The main issues are that the headers differ, and the
space in the remote blocks differ.

Tested with a script I'm using to do other metadump
work; I still owe an xfstest for this and other bits.

Signed-off-by: Eric Sandeen <sandeen at redhat.com>
---

Brief/hacky testcase; populate w/ many attr types with:

	MNTPT=/mount/test

        # FMT_LOCAL
        touch $MNTPT/S_IFREG.ATTR.FMT_LOCAL
        setfattr -n user.localattrname -v localattrvalue $MNTPT/S_IFREG.ATTR.FMT_LOCAL

        # FMT_EXTENTS
        touch $MNTPT/S_IFREG.ATTR.FMT_EXTENTS
        for I in `seq 1 50`; do
                setfattr -n user.extentattrname$I -v extentattrvalue $MNTPT/S_IFREG.ATTR.FMT_EXTENTS
        done

        # FMT_EXTENTS with a single remote 3k value, fill with "C"
        touch $MNTPT/S_IFREG.ATTR.FMT_EXTENTS_REMOTE3K
        xfs_io -f -c "pwrite -S 0x43 0 3k" attrvalfile &>/dev/null
        attr -q -s user.remotebtreeattrname $MNTPT/S_IFREG.ATTR.FMT_EXTENTS_REMOTE3K < attrvalfile

        # FMT_EXTENTS with a single remote 4k value, fill with "D"
        touch $MNTPT/S_IFREG.ATTR.FMT_EXTENTS_REMOTE4K
        xfs_io -f -c "pwrite -S 0x44 0 4k" attrvalfile &>/dev/null
        attr -q -s user.remotebtreeattrname $MNTPT/S_IFREG.ATTR.FMT_EXTENTS_REMOTE4K < attrvalfile

        # FMT_BTREE
        touch $MNTPT/S_IFREG.ATTR.FMT_BTREE
        for I in `seq 1 1000`; do
                setfattr -n user.btreeattrname$I -v btreelongerattrvalue $MNTPT/S_IFREG.ATTR.FMT_BTREE
        done

on a crc filesystem, an obfuscated metadump will show all these attrs in the clear
with getfattr -dR $MNTPT

diff --git a/db/metadump.c b/db/metadump.c
index 94f92bc..793f39e 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -1268,39 +1268,54 @@ add_remote_vals(
 	}
 }
 
+/* Handle remote and leaf attributes */
 static void
 obfuscate_attr_block(
-	char			*block,
-	xfs_fileoff_t		offset)
+	char				*block,
+	xfs_fileoff_t			offset)
 {
-	xfs_attr_leafblock_t	*leaf;
-	int			i;
-	int			nentries;
-	xfs_attr_leaf_entry_t 	*entry;
-	xfs_attr_leaf_name_local_t *local;
-	xfs_attr_leaf_name_remote_t *remote;
+	struct xfs_attr_leafblock	*leaf;
+	struct xfs_attr3_icleaf_hdr	hdr;
+	int				i;
+	int				nentries;
+	xfs_attr_leaf_entry_t 		*entry;
+	xfs_attr_leaf_name_local_t 	*local;
+	xfs_attr_leaf_name_remote_t 	*remote;
+	__uint32_t			bs = mp->m_sb.sb_blocksize;
+
 
 	leaf = (xfs_attr_leafblock_t *)block;
 
-	if (be16_to_cpu(leaf->hdr.info.magic) != XFS_ATTR_LEAF_MAGIC) {
+	/* Get header; accounts for crc & non-crc */
+	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &hdr, leaf);
+
+	/* Remote attributes */
+	if ((hdr.magic != XFS_ATTR_LEAF_MAGIC) &&
+	    (hdr.magic != XFS_ATTR3_LEAF_MAGIC)) {
 		for (i = 0; i < attr_data.remote_val_count; i++) {
-			/* XXX: need to handle CRC headers */
 			if (attr_data.remote_vals[i] == offset)
-				memset(block, 0, mp->m_sb.sb_blocksize);
+				/* magic to handle attr and attr3 */
+				memset(block +
+					(bs - XFS_ATTR3_RMT_BUF_SPACE(mp, bs)),
+				      0, XFS_ATTR3_RMT_BUF_SPACE(mp, bs));
 		}
 		return;
 	}
 
-	nentries = be16_to_cpu(leaf->hdr.count);
+	nentries = hdr.count;
+
 	if (nentries * sizeof(xfs_attr_leaf_entry_t) +
-			sizeof(xfs_attr_leaf_hdr_t) > mp->m_sb.sb_blocksize) {
+			xfs_attr3_leaf_hdr_size(leaf) >
+				XFS_ATTR3_RMT_BUF_SPACE(mp, bs)) {
 		if (show_warnings)
 			print_warning("invalid attr count in inode %llu",
 					(long long)cur_ino);
 		return;
 	}
 
-	for (i = 0, entry = &leaf->entries[0]; i < nentries; i++, entry++) {
+	entry = xfs_attr3_leaf_entryp(leaf);
+
+	for (i = 0; i < nentries; i++, entry++) {
 		if (be16_to_cpu(entry->nameidx) > mp->m_sb.sb_blocksize) {
 			if (show_warnings)
 				print_warning(