[PATCH 26/37] xfs: walk the rt reverse mapping tree when rebuilding rmap

Darrick J. Wong
2024-12-13T01:07:22Z

From: Darrick J. Wong <djwong@kernel.org>

When we're rebuilding the data device rmap, if we encounter an "rmap"
format fork, we have to walk the (realtime) rmap btree inode to build
the appropriate mappings.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
fs/xfs/scrub/rmap_repair.c | 53 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 52 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/scrub/rmap_repair.c b/fs/xfs/scrub/rmap_repair.c
index 2a0b9e3d0fbaee..91c17feb49768b 100644
--- a/fs/xfs/scrub/rmap_repair.c
+++ b/fs/xfs/scrub/rmap_repair.c
@@ -31,6 +31,8 @@
#include "xfs_refcount.h"
#include "xfs_refcount_btree.h"
#include "xfs_ag.h"
+#include "xfs_rtrmap_btree.h"
+#include "xfs_rtgroup.h"
#include "scrub/xfs_scrub.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
@@ -504,7 +506,56 @@ xrep_rmap_scan_meta_btree(
struct xrep_rmap_ifork *rf,
struct xfs_inode *ip)
{
- return -EFSCORRUPTED; /* XXX placeholder */
+ struct xfs_scrub *sc = rf->rr->sc;
+ struct xfs_rtgroup *rtg = NULL;
+ struct xfs_btree_cur *cur = NULL;
+ enum xfs_rtg_inodes type;
+ int error;
+
+ if (rf->whichfork != XFS_DATA_FORK)
+ return -EFSCORRUPTED;
+
+ switch (ip->i_metatype) {
+ case XFS_METAFILE_RTRMAP:
+ type = XFS_RTGI_RMAP;
+ break;
+ default:
+ ASSERT(0);
+ return -EFSCORRUPTED;
+ }
+
+ while ((rtg = xfs_rtgroup_next(sc->mp, rtg))) {
+ if (ip == rtg->rtg_inodes[type])
+ goto found;
+ }
+
+ /*
+ * We should never find an rt metadata btree inode that isn't
+ * associated with an rtgroup yet has ondisk blocks allocated to it.
+ */
+ if (ip->i_nblocks) {
+ ASSERT(0);
+ return -EFSCORRUPTED;
+ }
+
+ return 0;
+
+found:
+ switch (ip->i_metatype) {
+ case XFS_METAFILE_RTRMAP:
+ cur = xfs_rtrmapbt_init_cursor(sc->tp, rtg);
+ break;
+ default:
+ ASSERT(0);
+ error = -EFSCORRUPTED;
+ goto out_rtg;
+ }
+
+ error = xrep_rmap_scan_iroot_btree(rf, cur);
+ xfs_btree_del_cursor(cur, error);
+out_rtg:
+ xfs_rtgroup_rele(rtg);
+ return error;
}

/* Find all the extents from a given AG in an inode fork. */