--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2021-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include <libxfs.h>
+#include "btree.h"
+#include "err_protos.h"
+#include "libxlog.h"
+#include "incore.h"
+#include "globals.h"
+#include "dinode.h"
+#include "slab.h"
+#include "rmap.h"
+#include "bulkload.h"
+
+/*
+ * Realtime Reference Count (RTREFCBT) Repair
+ * ==========================================
+ *
+ * Gather all the reference count records for the realtime device, reset the
+ * incore fork, then recreate the btree.
+ */
+struct xrep_rtrefc {
+ /* rtrefcbt slab cursor */
+ struct xfs_slab_cursor *slab_cursor;
+
+ /* New fork. */
+ struct bulkload new_fork_info;
+ struct xfs_btree_bload rtrefc_bload;
+
+ struct repair_ctx *sc;
+ struct xfs_rtgroup *rtg;
+
+ /* Estimated free space after building all rt btrees */
+ xfs_filblks_t est_fdblocks;
+};
+
+/* Retrieve rtrefc data for bulk load. */
+STATIC int
+xrep_rtrefc_get_records(
+ struct xfs_btree_cur *cur,
+ unsigned int idx,
+ struct xfs_btree_block *block,
+ unsigned int nr_wanted,
+ void *priv)
+{
+ struct xfs_refcount_irec *rec;
+ struct xrep_rtrefc *rc = priv;
+ union xfs_btree_rec *block_rec;
+ unsigned int loaded;
+
+ for (loaded = 0; loaded < nr_wanted; loaded++, idx++) {
+ rec = pop_slab_cursor(rc->slab_cursor);
+ memcpy(&cur->bc_rec.rc, rec, sizeof(struct xfs_refcount_irec));
+
+ block_rec = libxfs_btree_rec_addr(cur, idx, block);
+ cur->bc_ops->init_rec_from_cur(cur, block_rec);
+ }
+
+ return loaded;
+}
+
+/* Feed one of the new btree blocks to the bulk loader. */
+STATIC int
+xrep_rtrefc_claim_block(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_ptr *ptr,
+ void *priv)
+{
+ struct xrep_rtrefc *rr = priv;
+
+ return bulkload_claim_block(cur, &rr->new_fork_info, ptr);
+}
+
+/* Figure out how much space we need to create the incore btree root block. */
+STATIC size_t
+xrep_rtrefc_iroot_size(
+ struct xfs_btree_cur *cur,
+ unsigned int level,
+ unsigned int nr_this_level,
+ void *priv)
+{
+ return xfs_rtrefcount_broot_space_calc(cur->bc_mp, level,
+ nr_this_level);
+}
+
+/* Reserve new btree blocks and bulk load all the rtrmap records. */
+STATIC int
+xrep_rtrefc_btree_load(
+ struct xrep_rtrefc *rr,
+ struct xfs_btree_cur *rtrmap_cur)
+{
+ struct repair_ctx *sc = rr->sc;
+ int error;
+
+ rr->rtrefc_bload.get_records = xrep_rtrefc_get_records;
+ rr->rtrefc_bload.claim_block = xrep_rtrefc_claim_block;
+ rr->rtrefc_bload.iroot_size = xrep_rtrefc_iroot_size;
+ bulkload_estimate_inode_slack(sc->mp, &rr->rtrefc_bload,
+ rr->est_fdblocks);
+
+ /* Compute how many blocks we'll need. */
+ error = -libxfs_btree_bload_compute_geometry(rtrmap_cur,
+ &rr->rtrefc_bload,
+ refcount_record_count(sc->mp, true, rr->rtg->rtg_rgno));
+ if (error)
+ return error;
+
+ /*
+ * Guess how many blocks we're going to need to rebuild an entire
+ * rtrefcountbt from the number of extents we found, and pump up our
+ * transaction to have sufficient block reservation.
+ */
+ error = -libxfs_trans_reserve_more(sc->tp, rr->rtrefc_bload.nr_blocks,
+ 0);
+ if (error)
+ return error;
+
+ /*
+ * Reserve the space we'll need for the new btree. Drop the cursor
+ * while we do this because that can roll the transaction and cursors
+ * can't handle that.
+ */
+ error = bulkload_alloc_file_blocks(&rr->new_fork_info,
+ rr->rtrefc_bload.nr_blocks);
+ if (error)
+ return error;
+
+ /* Add all observed rtrmap records. */
+ error = init_refcount_cursor(true, rr->rtg->rtg_rgno, &rr->slab_cursor);
+ if (error)
+ return error;
+ error = -libxfs_btree_bload(rtrmap_cur, &rr->rtrefc_bload, rr);
+ free_slab_cursor(&rr->slab_cursor);
+ return error;
+}
+
+/* Update the inode counters. */
+STATIC int
+xrep_rtrefc_reset_counters(
+ struct xrep_rtrefc *rr)
+{
+ struct repair_ctx *sc = rr->sc;
+
+ /*
+ * Update the inode block counts to reflect the btree we just
+ * generated.
+ */
+ sc->ip->i_nblocks = rr->new_fork_info.ifake.if_blocks;
+ libxfs_trans_log_inode(sc->tp, sc->ip, XFS_ILOG_CORE);
+
+ /* Quotas don't exist so we're done. */
+ return 0;
+}
+
+/*
+ * Use the collected rmap information to stage a new rt refcount btree. If
+ * this is successful we'll return with the new btree root information logged
+ * to the repair transaction but not yet committed.
+ */
+static int
+xrep_rtrefc_build_new_tree(
+ struct xrep_rtrefc *rr)
+{
+ struct xfs_owner_info oinfo;
+ struct xfs_btree_cur *cur;
+ struct repair_ctx *sc = rr->sc;
+ struct xbtree_ifakeroot *ifake = &rr->new_fork_info.ifake;
+ int error;
+
+ /*
+ * Prepare to construct the new fork by initializing the new btree
+ * structure and creating a fake ifork in the ifakeroot structure.
+ */
+ libxfs_rmap_ino_bmbt_owner(&oinfo, sc->ip->i_ino, XFS_DATA_FORK);
+ bulkload_init_inode(&rr->new_fork_info, sc, XFS_DATA_FORK, &oinfo);
+ cur = libxfs_rtrefcountbt_init_cursor(sc->mp, NULL, rr->rtg, sc->ip);
+ libxfs_btree_stage_ifakeroot(cur, ifake);
+
+ /*
+ * Figure out the size and format of the new fork, then fill it with
+ * all the rtrmap records we've found. Join the inode to the
+ * transaction so that we can roll the transaction while holding the
+ * inode locked.
+ */
+ libxfs_trans_ijoin(sc->tp, sc->ip, 0);
+ ifake->if_fork->if_format = XFS_DINODE_FMT_REFCOUNT;
+ error = xrep_rtrefc_btree_load(rr, cur);
+ if (error)
+ goto err_cur;
+
+ /*
+ * Install the new fork in the inode. After this point the old mapping
+ * data are no longer accessible and the new tree is live. We delete
+ * the cursor immediately after committing the staged root because the
+ * staged fork might be in extents format.
+ */
+ libxfs_rtrefcountbt_commit_staged_btree(cur, sc->tp);
+ libxfs_btree_del_cursor(cur, 0);
+
+ /* Reset the inode counters now that we've changed the fork. */
+ error = xrep_rtrefc_reset_counters(rr);
+ if (error)
+ goto err_newbt;
+
+ /* Dispose of any unused blocks and the accounting infomation. */
+ error = bulkload_commit(&rr->new_fork_info);
+ if (error)
+ return error;
+
+ return -libxfs_trans_roll_inode(&sc->tp, sc->ip);
+err_cur:
+ if (cur)
+ libxfs_btree_del_cursor(cur, error);
+err_newbt:
+ bulkload_cancel(&rr->new_fork_info);
+ return error;
+}
+
+/* Store the realtime reference counts in the rtrefcbt. */
+int
+populate_rtgroup_refcountbt(
+ struct xfs_rtgroup *rtg,
+ xfs_filblks_t est_fdblocks)
+{
+ struct xfs_mount *mp = rtg->rtg_mount;
+ struct xfs_inode *ip = rtg->rtg_inodes[XFS_RTG_REFCOUNT];
+ struct repair_ctx sc = {
+ .mp = mp,
+ .ip = ip,
+ };
+ struct xrep_rtrefc rr = {
+ .sc = &sc,
+ .rtg = rtg,
+ .est_fdblocks = est_fdblocks,
+ };
+ int error;
+
+ if (!xfs_has_rtreflink(mp))
+ return 0;
+
+ error = -libxfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0,
+ &sc.tp);
+ if (error)
+ return error;
+
+ error = xrep_rtrefc_build_new_tree(&rr);
+ if (error)
+ goto out_cancel;
+
+ return -libxfs_trans_commit(sc.tp);
+
+out_cancel:
+ libxfs_trans_cancel(sc.tp);
+ return error;
+}