xfs_db: metadump should handle symlinks properly

Remote symlink target blocks are multi-fsb objects on XFS v5 filesystems
because we only write one rmt header per data fork extent.  For fs
blocksize >= 2048 we never have more than one block and therefore nobody
noticed, but for blocksize == 1024 this is definitely not true and leads
to metadump spraying error messages about symlink block crc errors.
Therefore, reformulate the symlink metadump into a multi-fsb dump
function.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
[sandeen: shrink the map declaration]
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/db/metadump.c b/db/metadump.c
index 23ecf3b740fc4186efd4744a33da5a5eed9301bd..ef9fab8a134eb7af2114f2704736ca8265e0e7ad 100644 (file)
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -1638,11 +1638,34 @@ process_dir_data_block(
        }
 }
 
-static void
+static int
 process_symlink_block(
-       char                    *block)
+       xfs_fileoff_t   o,
+       xfs_fsblock_t   s,
+       xfs_filblks_t   c,
+       typnm_t         btype,
+       xfs_fileoff_t   last)
 {
-       char *link = block;
+       struct bbmap    map;
+       char            *link;
+       int             ret = 0;
+
+       push_cur();
+       map.nmaps = 1;
+       map.b[0].bm_bn = XFS_FSB_TO_DADDR(mp, s);
+       map.b[0].bm_len = XFS_FSB_TO_BB(mp, c);
+       set_cur(&typtab[btype], 0, 0, DB_RING_IGN, &map);
+       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 = -1;
+               goto out_pop;
+       }
+       link = iocur_top->data;
 
        if (xfs_sb_version_hascrc(&(mp)->m_sb))
                link += sizeof(struct xfs_dsymlink_hdr);
@@ -1660,6 +1683,12 @@ process_symlink_block(
                if (zlen < mp->m_sb.sb_blocksize)
                        memset(link + linklen, 0, zlen);
        }
+
+       iocur_top->need_crc = 1;
+       ret = write_buf(iocur_top);
+out_pop:
+       pop_cur();
+       return ret;
 }
 
 #define MAX_REMOTE_VALS                4095
@@ -1879,10 +1908,6 @@ process_single_fsb_objects(
                        }
                        iocur_top->need_crc = 1;
                        break;
-               case TYP_SYMLINK:
-                       process_symlink_block(dp);
-                       iocur_top->need_crc = 1;
-                       break;
                case TYP_ATTR:
                        process_attr_block(dp, o);
                        iocur_top->need_crc = 1;
@@ -1986,6 +2011,8 @@ is_multi_fsb_object(
 {
        if (btype == TYP_DIR2 && mp->m_dir_geo->fsbcount > 1)
                return true;
+       if (btype == TYP_SYMLINK)
+               return true;
        return false;
 }
 
@@ -2000,6 +2027,8 @@ process_multi_fsb_objects(
        switch (btype) {
        case TYP_DIR2:
                return process_multi_fsb_dir(o, s, c, btype, last);
+       case TYP_SYMLINK:
+               return process_symlink_block(o, s, c, btype, last);
        default:
                print_warning("bad type for multi-fsb object %d", btype);
                return -EINVAL;