[PATCH 3/5] metadump: separate single block objects from multiblock objects

[Dave Chinner <david@xxxxxxxxxxxxx>]

From: Dave Chinner <dchinner@xxxxxxxxxx>

When trying to dump objects, we have to treat multi-block objects
differently to single block objects. Separate out the code paths for
single block vs multi-block objects so we can add a separate path
for multi-block objects.

Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
 db/metadump.c | 119 ++++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 82 insertions(+), 37 deletions(-)

diff --git a/db/metadump.c b/db/metadump.c
index a8bc297..9fc08ed 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -1361,9 +1361,79 @@ obfuscate_attr_blocks(
        }
 }
 
-/* inode copy routines */
+static int
+process_single_fsb_objects(
+       xfs_dfiloff_t   o,
+       xfs_dfsbno_t    s,
+       xfs_dfilblks_t  c,
+       typnm_t         btype,
+       xfs_dfiloff_t   last)
+{
+       int             ret = 0;
+
+       push_cur();
+       set_cur(&typtab[btype], XFS_FSB_TO_DADDR(mp, s), c * blkbb,
+                       DB_RING_IGN, NULL);
+
+       if (!iocur_top->data) {
+               xfs_agnumber_t  agno = XFS_FSB_TO_AGNO(mp, s);
+               xfs_agblock_t   agbno = XFS_FSB_TO_AGBNO(mp, s);
+
+               print_warning("cannot read %s block %u/%u (%llu)",
+                               typtab[btype].name, agno, agbno, s);
+               if (stop_on_read_error)
+                       ret = -EIO;
+               goto out_pop;
+
+       }
+
+       if (dont_obfuscate) {
+               ret = write_buf(iocur_top);
+               goto out_pop;
+       }
+
+       switch (btype) {
+       case TYP_DIR2:
+               if (o >= mp->m_dirleafblk)
+                       break;
+
+               obfuscate_dir_data_blocks(iocur_top->data, o, c,
+                                        last == mp->m_dirblkfsbs);
+               break;
+       case TYP_SYMLINK:
+               obfuscate_symlink_blocks(iocur_top->data, c);
+               break;
+       case TYP_ATTR:
+               obfuscate_attr_blocks(iocur_top->data, o, c);
+               break;
+       default:
+               break;
+       }
+       ret = write_buf(iocur_top);
+
+out_pop:
+       pop_cur();
+       return ret;
+}
 
 static int
+process_multi_fsb_objects(
+       xfs_dfiloff_t   o,
+       xfs_dfsbno_t    s,
+       xfs_dfilblks_t  c,
+       typnm_t         btype,
+       xfs_dfiloff_t   last)
+{
+       if (btype != TYP_DIR2) {
+               print_warning("bad type for multi-fsb object %d", btype);
+               return -EINVAL;
+       }
+
+       return process_single_fsb_objects(o, s, c, btype, last);
+}
+
+/* inode copy routines */
+static int
 process_bmbt_reclist(
        xfs_bmbt_rec_t          *rp,
        int                     numrecs,
@@ -1377,6 +1447,7 @@ process_bmbt_reclist(
        xfs_dfiloff_t           last;
        xfs_agnumber_t          agno;
        xfs_agblock_t           agbno;
+       int                     error;
 
        if (btype == TYP_DATA)
                return 1;
@@ -1438,44 +1509,18 @@ process_bmbt_reclist(
                        break;
                }
 
-               push_cur();
-               set_cur(&typtab[btype], XFS_FSB_TO_DADDR(mp, s), c * blkbb,
-                               DB_RING_IGN, NULL);
-               if (iocur_top->data == NULL) {
-                       print_warning("cannot read %s block %u/%u (%llu)",
-                                       typtab[btype].name, agno, agbno, s);
-                       if (stop_on_read_error) {
-                               pop_cur();
-                               return 0;
-                       }
-               } else {
-                       if (!dont_obfuscate)
-                           switch (btype) {
-                               case TYP_DIR2:
-                                       if (o < mp->m_dirleafblk)
-                                               obfuscate_dir_data_blocks(
-                                                       iocur_top->data, o, c,
-                                                       last == 
mp->m_dirblkfsbs);
-                                       break;
-
-                               case TYP_SYMLINK:
-                                       obfuscate_symlink_blocks(
-                                               iocur_top->data, c);
-                                       break;
-
-                               case TYP_ATTR:
-                                       obfuscate_attr_blocks(iocur_top->data,
-                                               o, c);
-                                       break;
-
-                               default: ;
-                           }
-                       if (write_buf(iocur_top)) {
-                               pop_cur();
+               /* single filesystem block objects are trivial to handle */
+               if (btype != TYP_DIR2 || mp->m_dirblkfsbs == 1) {
+                       error = process_single_fsb_objects(o, s, c, btype, 
last);
+                       if (error)
                                return 0;
-                       }
+                       continue;
                }
-               pop_cur();
+
+               /* multi-extent directory blocks */
+               error = process_multi_fsb_objects(o, s, c, btype, last);
+               if (error)
+                       return 0;
        }
 
        return 1;
-- 
1.8.4.rc3