metadump: Zero sparse/unused regions of dir2

dir2 data has explicitly unused regions as well as
padding between entries; zero this out to avoid copying
stale data.

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 775deb5274fd1995e0b8f12c5b4e8235c8bace46..462623652b6ffe4a4c6834d30877c131546ddab0 100644 (file)
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -1153,7 +1153,7 @@ process_sf_attr(
 }
 
 static void
-obfuscate_dir_data_block(
+process_dir_data_block(
        char            *block,
        xfs_dfiloff_t   offset,
        int             is_block_format)
@@ -1229,6 +1229,20 @@ obfuscate_dir_data_block(
                                return;
                        dir_offset += length;
                        ptr += length;
+                       /*
+                        * Zero the unused space up to the tag - the tag is
+                        * actually at a variable offset, so zeroing &dup->tag
+                        * is zeroing the free space in between
+                        */
+                       if (zero_stale_data) {
+                               int zlen = length -
+                                               sizeof(xfs_dir2_data_unused_t);
+
+                               if (zlen > 0) {
+                                       memset(&dup->tag, 0, zlen);
+                                       iocur_top->need_crc = 1;
+                               }
+                       }
                        if (dir_offset >= end_of_data || ptr >= endptr)
                                return;
                }
@@ -1247,10 +1261,23 @@ obfuscate_dir_data_block(
                if (be16_to_cpu(*xfs_dir3_data_entry_tag_p(mp, dep)) !=
                                dir_offset)
                        return;
-               generate_obfuscated_name(be64_to_cpu(dep->inumber),
+
+               if (obfuscate)
+                       generate_obfuscated_name(be64_to_cpu(dep->inumber),
                                         dep->namelen, &dep->name[0]);
                dir_offset += length;
                ptr += length;
+               /* Zero the unused space after name, up to the tag */
+               if (zero_stale_data) {
+                       /* 1 byte for ftype; don't bother with conditional */
+                       int zlen =
+                               (char *)xfs_dir3_data_entry_tag_p(mp, dep) -
+                               (char *)&dep->name[dep->namelen] - 1;
+                       if (zlen > 0) {
+                               memset(&dep->name[dep->namelen] + 1, 0, zlen);
+                               iocur_top->need_crc = 1;
+                       }
+               }
        }
 }
 
@@ -1403,7 +1430,7 @@ process_single_fsb_objects(
 
                }
 
-               if (!obfuscate)
+               if (!obfuscate && !zero_stale_data)
                        goto write;
 
                dp = iocur_top->data;
@@ -1412,17 +1439,21 @@ process_single_fsb_objects(
                        if (o >= mp->m_dirleafblk)
                                break;
 
-                       obfuscate_dir_data_block(dp, o,
+                       process_dir_data_block(dp, o,
                                                 last == mp->m_dirblkfsbs);
                        iocur_top->need_crc = 1;
                        break;
                case TYP_SYMLINK:
-                       obfuscate_symlink_block(dp);
-                       iocur_top->need_crc = 1;
+                       if (obfuscate) {
+                               obfuscate_symlink_block(dp);
+                               iocur_top->need_crc = 1;
+                       }
                        break;
                case TYP_ATTR:
-                       obfuscate_attr_block(dp, o);
-                       iocur_top->need_crc = 1;
+                       if (obfuscate) {
+                               obfuscate_attr_block(dp, o);
+                               iocur_top->need_crc = 1;
+                       }
                        break;
                default:
                        break;
@@ -1495,13 +1526,14 @@ process_multi_fsb_objects(
 
                        }
 
-                       if (!obfuscate || o >= mp->m_dirleafblk) {
+                       if ((!obfuscate && !zero_stale_data) ||
+                            o >= mp->m_dirleafblk) {
                                ret = write_buf(iocur_top);
                                goto out_pop;
                        }
 
-                       obfuscate_dir_data_block(iocur_top->data, o,
-                                                 last == mp->m_dirblkfsbs);
+                       process_dir_data_block(iocur_top->data, o,
+                                              last == mp->m_dirblkfsbs);
                        iocur_top->need_crc = 1;
                        ret = write_buf(iocur_top);
 out_pop: