metadump: Zero unused portions of attribute blocks

Attribute blocks may contain stale disk data either
between names (and/or values), and between the entries
array and the actual names/values.  Zero out both of
these regions.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/db/metadump.c b/db/metadump.c
index c40c896e05f60938925265dd3cc60260c4ddffc8..32a2f70369dd248fe4fe579e1f91561fad9d943f 100644 (file)
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -1332,7 +1332,7 @@ add_remote_vals(
 
 /* Handle remote and leaf attributes */
 static void
-obfuscate_attr_block(
+process_attr_block(
        char                            *block,
        xfs_fileoff_t                   offset)
 {
@@ -1344,6 +1344,7 @@ obfuscate_attr_block(
        xfs_attr_leaf_name_local_t      *local;
        xfs_attr_leaf_name_remote_t     *remote;
        __uint32_t                      bs = mp->m_sb.sb_blocksize;
+       char                            *first_name;
 
 
        leaf = (xfs_attr_leafblock_t *)block;
@@ -1352,7 +1353,7 @@ obfuscate_attr_block(
        if ((be16_to_cpu(leaf->hdr.info.magic) != XFS_ATTR_LEAF_MAGIC) &&
            (be16_to_cpu(leaf->hdr.info.magic) != XFS_ATTR3_LEAF_MAGIC)) {
                for (i = 0; i < attr_data.remote_val_count; i++) {
-                       if (attr_data.remote_vals[i] == offset)
+                       if (obfuscate && attr_data.remote_vals[i] == offset)
                                /* Macros to handle both attr and attr3 */
                                memset(block +
                                        (bs - XFS_ATTR3_RMT_BUF_SPACE(mp, bs)),
@@ -1375,7 +1376,15 @@ obfuscate_attr_block(
        }
 
        entry = xfs_attr3_leaf_entryp(leaf);
+       /* We will move this as we parse */
+       first_name = NULL;
        for (i = 0; i < nentries; i++, entry++) {
+               int nlen, vlen, zlen;
+
+               /* Grows up; if this name is topmost, move first_name */
+               if (!first_name || xfs_attr3_leaf_name(leaf, i) < first_name)
+                       first_name = xfs_attr3_leaf_name(leaf, i);
+
                if (be16_to_cpu(entry->nameidx) > XFS_LBSIZE(mp)) {
                        if (show_warnings)
                                print_warning(
@@ -1392,10 +1401,20 @@ obfuscate_attr_block(
                                                (long long)cur_ino);
                                break;
                        }
-                       generate_obfuscated_name(0, local->namelen,
-                               &local->nameval[0]);
-                       memset(&local->nameval[local->namelen], 'v',
-                               be16_to_cpu(local->valuelen));
+                       if (obfuscate) {
+                               generate_obfuscated_name(0, local->namelen,
+                                       &local->nameval[0]);
+                               memset(&local->nameval[local->namelen], 'v',
+                                       be16_to_cpu(local->valuelen));
+                       }
+                       /* zero from end of nameval[] to next name start */
+                       nlen = local->namelen;
+                       vlen = be16_to_cpu(local->valuelen);
+                       zlen = xfs_attr_leaf_entsize_local(nlen, vlen) -
+                               (sizeof(xfs_attr_leaf_name_local_t) - 1 +
+                                nlen + vlen);
+                       if (zero_stale_data)
+                               memset(&local->nameval[nlen + vlen], 0, zlen);
                } else {
                        remote = xfs_attr3_leaf_name_remote(leaf, i);
                        if (remote->namelen == 0 || remote->valueblk == 0) {
@@ -1405,14 +1424,33 @@ obfuscate_attr_block(
                                                (long long)cur_ino);
                                break;
                        }
-                       generate_obfuscated_name(0, remote->namelen,
-                                                &remote->name[0]);
-                       add_remote_vals(be32_to_cpu(remote->valueblk),
-                                       be32_to_cpu(remote->valuelen));
+                       if (obfuscate) {
+                               generate_obfuscated_name(0, remote->namelen,
+                                                        &remote->name[0]);
+                               add_remote_vals(be32_to_cpu(remote->valueblk),
+                                               be32_to_cpu(remote->valuelen));
+                       }
+                       /* zero from end of name[] to next name start */
+                       nlen = remote->namelen;
+                       zlen = xfs_attr_leaf_entsize_remote(nlen) -
+                               (sizeof(xfs_attr_leaf_name_remote_t) - 1 +
+                                nlen);
+                       if (zero_stale_data)
+                               memset(&remote->name[nlen], 0, zlen);
                }
        }
+
+       /* Zero from end of entries array to the first name/val */
+       if (zero_stale_data) {
+               struct xfs_attr_leaf_entry *entries;
+
+               entries = xfs_attr3_leaf_entryp(leaf);
+               memset(&entries[nentries], 0,
+                      first_name - (char *)&entries[nentries]);
+       }
 }
 
+/* Processes symlinks, attrs, directories ... */
 static int
 process_single_fsb_objects(
        xfs_dfiloff_t   o,
@@ -1460,10 +1498,8 @@ process_single_fsb_objects(
                        iocur_top->need_crc = 1;
                        break;
                case TYP_ATTR:
-                       if (obfuscate) {
-                               obfuscate_attr_block(dp, o);
-                               iocur_top->need_crc = 1;
-                       }
+                       process_attr_block(dp, o);
+                       iocur_top->need_crc = 1;
                        break;
                default:
                        break;