[PATCH 3/5] xfs: repair free space btrees

Darrick J. Wong
2023-11-24T23:50:34Z

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

Rebuild the free space btrees from the gaps in the rmap btree.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/Makefile | 1
fs/xfs/libxfs/xfs_ag.h | 9
fs/xfs/libxfs/xfs_ag_resv.c | 2
fs/xfs/libxfs/xfs_alloc.c | 18 +
fs/xfs/libxfs/xfs_alloc.h | 2
fs/xfs/libxfs/xfs_alloc_btree.c | 13 +
fs/xfs/libxfs/xfs_types.h | 7
fs/xfs/scrub/alloc.c | 16 +
fs/xfs/scrub/alloc_repair.c | 914 +++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/common.h | 19 +
fs/xfs/scrub/newbt.c | 48 ++
fs/xfs/scrub/newbt.h | 6
fs/xfs/scrub/repair.c | 69 +++
fs/xfs/scrub/repair.h | 24 +
fs/xfs/scrub/scrub.c | 14 -
fs/xfs/scrub/scrub.h | 8
fs/xfs/scrub/trace.h | 24 +
fs/xfs/scrub/xfarray.h | 22 +
fs/xfs/xfs_extent_busy.c | 13 +
fs/xfs/xfs_extent_busy.h | 2
20 files changed, 1212 insertions(+), 19 deletions(-)
create mode 100644 fs/xfs/scrub/alloc_repair.c

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 1537d66e5ab01..026591681937d 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -181,6 +181,7 @@ xfs-$(CONFIG_XFS_QUOTA) += scrub/quota.o
ifeq ($(CONFIG_XFS_ONLINE_REPAIR),y)
xfs-y += $(addprefix scrub/, \
agheader_repair.o \
+ alloc_repair.o \
newbt.o \
reap.o \
repair.o \
diff --git a/fs/xfs/libxfs/xfs_ag.h b/fs/xfs/libxfs/xfs_ag.h
index 2e0aef87d633e..686f4eadd5743 100644
--- a/fs/xfs/libxfs/xfs_ag.h
+++ b/fs/xfs/libxfs/xfs_ag.h
@@ -80,6 +80,15 @@ struct xfs_perag {
*/
uint16_t pag_checked;
uint16_t pag_sick;
+
+#ifdef CONFIG_XFS_ONLINE_REPAIR
+ /*
+ * Alternate btree heights so that online repair won't trip the write
+ * verifiers while rebuilding the AG btrees.
+ */
+ uint8_t pagf_alt_levels[XFS_BTNUM_AGF];
+#endif
+
spinlock_t pag_state_lock;

spinlock_t pagb_lock; /* lock for pagb_tree */
diff --git a/fs/xfs/libxfs/xfs_ag_resv.c b/fs/xfs/libxfs/xfs_ag_resv.c
index 7fd1fea95552f..da1057bd0e606 100644
--- a/fs/xfs/libxfs/xfs_ag_resv.c
+++ b/fs/xfs/libxfs/xfs_ag_resv.c
@@ -411,6 +411,8 @@ xfs_ag_resv_free_extent(
fallthrough;
case XFS_AG_RESV_NONE:
xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (int64_t)len);
+ fallthrough;
+ case XFS_AG_RESV_IGNORE:
return;
}

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 4940f9377f21a..f33914455bf83 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -243,14 +243,11 @@ xfs_alloc_btrec_to_irec(
irec->ar_blockcount = be32_to_cpu(rec->alloc.ar_blockcount);
}

-/* Simple checks for free space records. */
-xfs_failaddr_t
-xfs_alloc_check_irec(
- struct xfs_btree_cur *cur,
+inline xfs_failaddr_t
+xfs_alloc_check_perag_irec(
+ struct xfs_perag *pag,
const struct xfs_alloc_rec_incore *irec)
{
- struct xfs_perag *pag = cur->bc_ag.pag;
-
if (irec->ar_blockcount == 0)
return __this_address;

@@ -261,6 +258,15 @@ xfs_alloc_check_irec(
return NULL;
}

+/* Simple checks for free space records. */
+xfs_failaddr_t
+xfs_alloc_check_irec(
+ struct xfs_btree_cur *cur,
+ const struct xfs_alloc_rec_incore *irec)
+{
+ return xfs_alloc_check_perag_irec(cur->bc_ag.pag, irec);
+}
+
static inline int
xfs_alloc_complain_bad_rec(
struct xfs_btree_cur *cur,
diff --git a/fs/xfs/libxfs/xfs_alloc.h b/fs/xfs/libxfs/xfs_alloc.h
index 851cafbd64494..68ffe058a420f 100644
--- a/fs/xfs/libxfs/xfs_alloc.h
+++ b/fs/xfs/libxfs/xfs_alloc.h
@@ -185,6 +185,8 @@ xfs_alloc_get_rec(
union xfs_btree_rec;
void xfs_alloc_btrec_to_irec(const union xfs_btree_rec *rec,
struct xfs_alloc_rec_incore *irec);
+xfs_failaddr_t xfs_alloc_check_perag_irec(struct xfs_perag *pag,
+ const struct xfs_alloc_rec_incore *irec);
xfs_failaddr_t xfs_alloc_check_irec(struct xfs_btree_cur *cur,
const struct xfs_alloc_rec_incore *irec);

diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c
index c65228efed4ae..90c7cb8c54ab0 100644
--- a/fs/xfs/libxfs/xfs_alloc_btree.c
+++ b/fs/xfs/libxfs/xfs_alloc_btree.c
@@ -323,7 +323,18 @@ xfs_allocbt_verify(
if (bp->b_ops->magic[0] == cpu_to_be32(XFS_ABTC_MAGIC))
btnum = XFS_BTNUM_CNTi;
if (pag && xfs_perag_initialised_agf(pag)) {
- if (level >= pag->pagf_levels[btnum])
+ unsigned int maxlevel = pag->pagf_levels[btnum];
+
+#ifdef CONFIG_XFS_ONLINE_REPAIR
+ /*
+ * Online repair could be rewriting the free space btrees, so
+ * we'll validate against the larger of either tree while this
+ * is going on.
+ */
+ maxlevel = max_t(unsigned int, maxlevel,
+ pag->pagf_alt_levels[btnum]);
+#endif
+ if (level >= maxlevel)
return __this_address;
} else if (level >= mp->m_alloc_maxlevels)
return __this_address;
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index 533200c4ccc25..035bf703d719a 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/fs/xfs/libxfs/xfs_types.h
@@ -208,6 +208,13 @@ enum xfs_ag_resv_type {
XFS_AG_RESV_AGFL,
XFS_AG_RESV_METADATA,
XFS_AG_RESV_RMAPBT,
+
+ /*
+ * Don't increase fdblocks when freeing extent. This is a pony for
+ * the bnobt repair functions to re-free the free space without
+ * altering fdblocks. If you think you need this you're wrong.
+ */
+ XFS_AG_RESV_IGNORE,
};

/* Results of scanning a btree keyspace to check occupancy. */
diff --git a/fs/xfs/scrub/alloc.c b/fs/xfs/scrub/alloc.c
index 279af72b1671d..964089e24ca6d 100644
--- a/fs/xfs/scrub/alloc.c
+++ b/fs/xfs/scrub/alloc.c
@@ -9,13 +9,16 @@
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
#include "xfs_btree.h"
#include "xfs_alloc.h"
#include "xfs_rmap.h"
+#include "xfs_ag.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/btree.h"
-#include "xfs_ag.h"
+#include "scrub/repair.h"

/*
* Set us up to scrub free space btrees.
@@ -24,10 +27,19 @@ int
xchk_setup_ag_allocbt(
struct xfs_scrub *sc)
{
+ int error;
+
if (xchk_need_intent_drain(sc))
xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);

- return xchk_setup_ag_btree(sc, false);
+ error = xchk_setup_ag_btree(sc, false);
+ if (error)
+ return error;
+
+ if (xchk_could_repair(sc))
+ return xrep_setup_ag_allocbt(sc);
+
+ return 0;
}

/* Free space btree scrubber. */
diff --git a/fs/xfs/scrub/alloc_repair.c b/fs/xfs/scrub/alloc_repair.c
new file mode 100644
index 0000000000000..917307e08bc16
--- /dev/null
+++ b/fs/xfs/scrub/alloc_repair.c
@@ -0,0 +1,914 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2018-2023 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_btree_staging.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_alloc.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_inode.h"
+#include "xfs_refcount.h"
+#include "xfs_extent_busy.h"
+#include "xfs_health.h"
+#include "xfs_bmap.h"
+#include "xfs_ialloc.h"
+#include "xfs_ag.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+#include "scrub/repair.h"
+#include "scrub/bitmap.h"
+#include "scrub/xfile.h"
+#include "scrub/xfarray.h"
+#include "scrub/newbt.h"
+#include "scrub/reap.h"
+
+/*
+ * Free Space Btree Repair
+ * =======================
+ *
+ * The reverse mappings are supposed to record all space usage for the entire
+ * AG. Therefore, we can recalculate the free extents in an AG by looking for
+ * gaps in the physical extents recorded in the rmapbt. On a reflink
+ * filesystem this is a little more tricky in that we have to be aware that
+ * the rmap records are allowed to overlap.
+ *
+ * We derive which blocks belonged to the old bnobt/cntbt by recording all the
+ * OWN_AG extents and subtracting out the blocks owned by all other OWN_AG
+ * metadata: the rmapbt blocks visited while iterating the reverse mappings
+ * and the AGFL blocks.
+ *
+ * Once we have both of those pieces, we can reconstruct the bnobt and cntbt
+ * by blowing out the free block state and freeing all the extents that we
+ * found. This adds the requirement that we can't have any busy extents in
+ * the AG because the busy code cannot handle duplicate records.
+ *
+ * Note that we can only rebuild both free space btrees at the same time
+ * because the regular extent freeing infrastructure loads both btrees at the
+ * same time.
+ *
+ * We use the prefix 'xrep_abt' here because we regenerate both free space
+ * allocation btrees at the same time.
+ */
+
+struct xrep_abt {
+ /* Blocks owned by the rmapbt or the agfl. */
+ struct xagb_bitmap not_allocbt_blocks;
+
+ /* All OWN_AG blocks. */
+ struct xagb_bitmap old_allocbt_blocks;
+
+ /*
+ * New bnobt information. All btree block reservations are added to
+ * the reservation list in new_bnobt.
+ */
+ struct xrep_newbt new_bnobt;
+
+ /* new cntbt information */
+ struct xrep_newbt new_cntbt;
+
+ /* Free space extents. */
+ struct xfarray *free_records;
+
+ struct xfs_scrub *sc;
+
+ /* Number of non-null records in @free_records. */
+ uint64_t nr_real_records;
+
+ /* get_records()'s position in the free space record array. */
+ xfarray_idx_t array_cur;
+
+ /*
+ * Next block we anticipate seeing in the rmap records. If the next
+ * rmap record is greater than next_agbno, we have found unused space.
+ */
+ xfs_agblock_t next_agbno;
+
+ /* Number of free blocks in this AG. */
+ xfs_agblock_t nr_blocks;
+
+ /* Longest free extent we found in the AG. */
+ xfs_agblock_t longest;
+};
+
+/* Set up to repair AG free space btrees. */
+int
+xrep_setup_ag_allocbt(
+ struct xfs_scrub *sc)
+{
+ unsigned int busy_gen;
+
+ /*
+ * Make sure the busy extent list is clear because we can't put extents
+ * on there twice.
+ */
+ busy_gen = READ_ONCE(sc->sa.pag->pagb_gen);
+ if (xfs_extent_busy_list_empty(sc->sa.pag))
+ return 0;
+
+ return xfs_extent_busy_flush(sc->tp, sc->sa.pag, busy_gen, 0);
+}
+
+/* Check for any obvious conflicts in the free extent. */
+STATIC int
+xrep_abt_check_free_ext(
+ struct xfs_scrub *sc,
+ const struct xfs_alloc_rec_incore *rec)
+{
+ enum xbtree_recpacking outcome;
+ int error;
+
+ if (xfs_alloc_check_perag_irec(sc->sa.pag, rec) != NULL)
+ return -EFSCORRUPTED;
+
+ /* Must not be an inode chunk. */
+ error = xfs_ialloc_has_inodes_at_extent(sc->sa.ino_cur,
+ rec->ar_startblock, rec->ar_blockcount, &outcome);
+ if (error)
+ return error;
+ if (outcome != XBTREE_RECPACKING_EMPTY)
+ return -EFSCORRUPTED;
+
+ /* Must not be shared or CoW staging. */
+ if (sc->sa.refc_cur) {
+ error = xfs_refcount_has_records(sc->sa.refc_cur,
+ XFS_REFC_DOMAIN_SHARED, rec->ar_startblock,
+ rec->ar_blockcount, &outcome);
+ if (error)
+ return error;
+ if (outcome != XBTREE_RECPACKING_EMPTY)
+ return -EFSCORRUPTED;
+
+ error = xfs_refcount_has_records(sc->sa.refc_cur,
+ XFS_REFC_DOMAIN_COW, rec->ar_startblock,
+ rec->ar_blockcount, &outcome);
+ if (error)
+ return error;
+ if (outcome != XBTREE_RECPACKING_EMPTY)
+ return -EFSCORRUPTED;
+ }
+
+ return 0;
+}
+
+/*
+ * Stash a free space record for all the space since the last bno we found
+ * all the way up to @end.
+ */
+static int
+xrep_abt_stash(
+ struct xrep_abt *ra,
+ xfs_agblock_t end)
+{
+ struct xfs_alloc_rec_incore arec = {
+ .ar_startblock = ra->next_agbno,
+ .ar_blockcount = end - ra->next_agbno,
+ };
+ struct xfs_scrub *sc = ra->sc;
+ int error = 0;
+
+ if (xchk_should_terminate(sc, &error))
+ return error;
+
+ error = xrep_abt_check_free_ext(ra->sc, &arec);
+ if (error)
+ return error;
+
+ trace_xrep_abt_found(sc->mp, sc->sa.pag->pag_agno, &arec);
+
+ error = xfarray_append(ra->free_records, &arec);
+ if (error)
+ return error;
+
+ ra->nr_blocks += arec.ar_blockcount;
+ return 0;
+}
+
+/* Record extents that aren't in use from gaps in the rmap records. */
+STATIC int
+xrep_abt_walk_rmap(
+ struct xfs_btree_cur *cur,
+ const struct xfs_rmap_irec *rec,
+ void *priv)
+{
+ struct xrep_abt *ra = priv;
+ int error;
+
+ /* Record all the OWN_AG blocks... */
+ if (rec->rm_owner == XFS_RMAP_OWN_AG) {
+ error = xagb_bitmap_set(&ra->old_allocbt_blocks,
+ rec->rm_startblock, rec->rm_blockcount);
+ if (error)
+ return error;
+ }
+
+ /* ...and all the rmapbt blocks... */
+ error = xagb_bitmap_set_btcur_path(&ra->not_allocbt_blocks, cur);
+ if (error)
+ return error;
+
+ /* ...and all the free space. */
+ if (rec->rm_startblock > ra->next_agbno) {
+ error = xrep_abt_stash(ra, rec->rm_startblock);
+ if (error)
+ return error;
+ }
+
+ /*
+ * rmap records can overlap on reflink filesystems, so project
+ * next_agbno as far out into the AG space as we currently know about.
+ */
+ ra->next_agbno = max_t(xfs_agblock_t, ra->next_agbno,
+ rec->rm_startblock + rec->rm_blockcount);
+ return 0;
+}
+
+/* Collect an AGFL block for the not-to-release list. */
+static int
+xrep_abt_walk_agfl(
+ struct xfs_mount *mp,
+ xfs_agblock_t agbno,
+ void *priv)
+{
+ struct xrep_abt *ra = priv;
+
+ return xagb_bitmap_set(&ra->not_allocbt_blocks, agbno, 1);
+}
+
+/*
+ * Compare two free space extents by block number. We want to sort in order of
+ * increasing block number.
+ */
+static int
+xrep_bnobt_extent_cmp(
+ const void *a,
+ const void *b)
+{
+ const struct xfs_alloc_rec_incore *ap = a;
+ const struct xfs_alloc_rec_incore *bp = b;
+
+ if (ap->ar_startblock > bp->ar_startblock)
+ return 1;
+ else if (ap->ar_startblock < bp->ar_startblock)
+ return -1;
+ return 0;
+}
+
+/*
+ * Re-sort the free extents by block number so that we can put the records into
+ * the bnobt in the correct order. Make sure the records do not overlap in
+ * physical space.
+ */
+STATIC int
+xrep_bnobt_sort_records(
+ struct xrep_abt *ra)
+{
+ struct xfs_alloc_rec_incore arec;
+ xfarray_idx_t cur = XFARRAY_CURSOR_INIT;
+ xfs_agblock_t next_agbno = 0;
+ int error;
+
+ error = xfarray_sort(ra->free_records, xrep_bnobt_extent_cmp, 0);
+ if (error)
+ return error;
+
+ while ((error = xfarray_iter(ra->free_records, &cur, &arec)) == 1) {
+ if (arec.ar_startblock < next_agbno)
+ return -EFSCORRUPTED;
+
+ next_agbno = arec.ar_startblock + arec.ar_blockcount;
+ }
+
+ return error;
+}
+
+/*
+ * Compare two free space extents by length and then block number. We want
+ * to sort first in order of increasing length and then in order of increasing
+ * block number.
+ */
+static int
+xrep_cntbt_extent_cmp(
+ const void *a,
+ const void *b)
+{
+ const struct xfs_alloc_rec_incore *ap = a;
+ const struct xfs_alloc_rec_incore *bp = b;
+
+ if (ap->ar_blockcount > bp->ar_blockcount)
+ return 1;
+ else if (ap->ar_blockcount < bp->ar_blockcount)
+ return -1;
+ return xrep_bnobt_extent_cmp(a, b);
+}
+
+/*
+ * Sort the free extents by length so so that we can put the records into the
+ * cntbt in the correct order. Don't let userspace kill us if we're resorting
+ * after allocating btree blocks.
+ */
+STATIC int
+xrep_cntbt_sort_records(
+ struct xrep_abt *ra,
+ bool is_resort)
+{
+ return xfarray_sort(ra->free_records, xrep_cntbt_extent_cmp,
+ is_resort ? 0 : XFARRAY_SORT_KILLABLE);
+}
+
+/*
+ * Iterate all reverse mappings to find (1) the gaps between rmap records (all
+ * unowned space), (2) the OWN_AG extents (which encompass the free space
+ * btrees, the rmapbt, and the agfl), (3) the rmapbt blocks, and (4) the AGFL
+ * blocks. The free space is (1) + (2) - (3) - (4).
+ */
+STATIC int
+xrep_abt_find_freespace(
+ struct xrep_abt *ra)
+{
+ struct xfs_scrub *sc = ra->sc;
+ struct xfs_mount *mp = sc->mp;
+ struct xfs_agf *agf = sc->sa.agf_bp->b_addr;
+ struct xfs_buf *agfl_bp;
+ xfs_agblock_t agend;
+ int error;
+
+ xagb_bitmap_init(&ra->not_allocbt_blocks);
+
+ xrep_ag_btcur_init(sc, &sc->sa);
+
+ /*
+ * Iterate all the reverse mappings to find gaps in the physical
+ * mappings, all the OWN_AG blocks, and all the rmapbt extents.
+ */
+ error = xfs_rmap_query_all(sc->sa.rmap_cur, xrep_abt_walk_rmap, ra);
+ if (error)
+ goto err;
+
+ /* Insert a record for space between the last rmap and EOAG. */
+ agend = be32_to_cpu(agf->agf_length);
+ if (ra->next_agbno < agend) {
+ error = xrep_abt_stash(ra, agend);
+ if (error)
+ goto err;
+ }
+
+ /* Collect all the AGFL blocks. */
+ error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp);
+ if (error)
+ goto err;
+
+ error = xfs_agfl_walk(mp, agf, agfl_bp, xrep_abt_walk_agfl, ra);
+ if (error)
+ goto err_agfl;
+
+ /* Compute the old bnobt/cntbt blocks. */
+ error = xagb_bitmap_disunion(&ra->old_allocbt_blocks,
+ &ra->not_allocbt_blocks);
+ if (error)
+ goto err_agfl;
+
+ ra->nr_real_records = xfarray_length(ra->free_records);
+err_agfl:
+ xfs_trans_brelse(sc->tp, agfl_bp);
+err:
+ xchk_ag_btcur_free(&sc->sa);
+ xagb_bitmap_destroy(&ra->not_allocbt_blocks);
+ return error;
+}
+
+/*
+ * We're going to use the observed free space records to reserve blocks for the
+ * new free space btrees, so we play an iterative game where we try to converge
+ * on the number of blocks we need:
+ *
+ * 1. Estimate how many blocks we'll need to store the records.
+ * 2. If the first free record has more blocks than we need, we're done.
+ * We will have to re-sort the records prior to building the cntbt.
+ * 3. If that record has exactly the number of blocks we need, null out the
+ * record. We're done.
+ * 4. Otherwise, we still need more blocks. Null out the record, subtract its
+ * length from the number of blocks we need, and go back to step 1.
+ *
+ * Fortunately, we don't have to do any transaction work to play this game, so
+ * we don't have to tear down the staging cursors.
+ */
+STATIC int
+xrep_abt_reserve_space(
+ struct xrep_abt *ra,
+ struct xfs_btree_cur *bno_cur,
+ struct xfs_btree_cur *cnt_cur,
+ bool *needs_resort)
+{
+ struct xfs_scrub *sc = ra->sc;
+ xfarray_idx_t record_nr;
+ unsigned int allocated = 0;
+ int error = 0;
+
+ record_nr = xfarray_length(ra->free_records) - 1;
+ do {
+ struct xfs_alloc_rec_incore arec;
+ uint64_t required;
+ unsigned int desired;
+ unsigned int len;
+
+ /* Compute how many blocks we'll need. */
+ error = xfs_btree_bload_compute_geometry(cnt_cur,
+ &ra->new_cntbt.bload, ra->nr_real_records);
+ if (error)
+ break;
+
+ error = xfs_btree_bload_compute_geometry(bno_cur,
+ &ra->new_bnobt.bload, ra->nr_real_records);
+ if (error)
+ break;
+
+ /* How many btree blocks do we need to store all records? */
+ required = ra->new_bnobt.bload.nr_blocks +
+ ra->new_cntbt.bload.nr_blocks;
+ ASSERT(required < INT_MAX);
+
+ /* If we've reserved enough blocks, we're done. */
+ if (allocated >= required)
+ break;
+
+ desired = required - allocated;
+
+ /* We need space but there's none left; bye! */
+ if (ra->nr_real_records == 0) {
+ error = -ENOSPC;
+ break;
+ }
+
+ /* Grab the first record from the list. */
+ error = xfarray_load(ra->free_records, record_nr, &arec);
+ if (error)
+ break;
+
+ ASSERT(arec.ar_blockcount <= UINT_MAX);
+ len = min_t(unsigned int, arec.ar_blockcount, desired);
+
+ trace_xrep_newbt_alloc_ag_blocks(sc->mp, sc->sa.pag->pag_agno,
+ arec.ar_startblock, len, XFS_RMAP_OWN_AG);
+
+ error = xrep_newbt_add_extent(&ra->new_bnobt, sc->sa.pag,
+ arec.ar_startblock, len);
+ if (error)
+ break;
+ allocated += len;
+ ra->nr_blocks -= len;
+
+ if (arec.ar_blockcount > desired) {
+ /*
+ * Record has more space than we need. The number of
+ * free records doesn't change, so shrink the free
+ * record, inform the caller that the records are no
+ * longer sorted by length, and exit.
+ */
+ arec.ar_startblock += desired;
+ arec.ar_blockcount -= desired;
+ error = xfarray_store(ra->free_records, record_nr,
+ &arec);
+ if (error)
+ break;
+
+ *needs_resort = true;
+ return 0;
+ }
+
+ /*
+ * We're going to use up the entire record, so unset it and
+ * move on to the next one. This changes the number of free
+ * records (but doesn't break the sorting order), so we must
+ * go around the loop once more to re-run _bload_init.
+ */
+ error = xfarray_unset(ra->free_records, record_nr);
+ if (error)
+ break;
+ ra->nr_real_records--;
+ record_nr--;
+ } while (1);
+
+ return error;
+}
+
+STATIC int
+xrep_abt_dispose_one(
+ struct xrep_abt *ra,
+ struct xrep_newbt_resv *resv)
+{
+ struct xfs_scrub *sc = ra->sc;
+ struct xfs_perag *pag = sc->sa.pag;
+ xfs_agblock_t free_agbno = resv->agbno + resv->used;
+ xfs_extlen_t free_aglen = resv->len - resv->used;
+ int error;
+
+ ASSERT(pag == resv->pag);
+
+ /* Add a deferred rmap for each extent we used. */
+ if (resv->used > 0)
+ xfs_rmap_alloc_extent(sc->tp, pag->pag_agno, resv->agbno,
+ resv->used, XFS_RMAP_OWN_AG);
+
+ /*
+ * For each reserved btree block we didn't use, add it to the free
+ * space btree. We didn't touch fdblocks when we reserved them, so
+ * we don't touch it now.
+ */
+ if (free_aglen == 0)
+ return 0;
+
+ trace_xrep_newbt_free_blocks(sc->mp, resv->pag->pag_agno, free_agbno,
+ free_aglen, ra->new_bnobt.oinfo.oi_owner);
+
+ error = __xfs_free_extent(sc->tp, resv->pag, free_agbno, free_aglen,
+ &ra->new_bnobt.oinfo, XFS_AG_RESV_IGNORE, true);
+ if (error)
+ return error;
+
+ return xrep_defer_finish(sc);
+}
+
+/*
+ * Deal with all the space we reserved. Blocks that were allocated for the
+ * free space btrees need to have a (deferred) rmap added for the OWN_AG
+ * allocation, and blocks that didn't get used can be freed via the usual
+ * (deferred) means.
+ */
+STATIC void
+xrep_abt_dispose_reservations(
+ struct xrep_abt *ra,
+ int error)
+{
+ struct xrep_newbt_resv *resv, *n;
+
+ if (error)
+ goto junkit;
+
+ for_each_xrep_newbt_reservation(&ra->new_bnobt, resv, n) {
+ error = xrep_abt_dispose_one(ra, resv);
+ if (error)
+ goto junkit;
+ }
+
+junkit:
+ for_each_xrep_newbt_reservation(&ra->new_bnobt, resv, n) {
+ xfs_perag_put(resv->pag);
+ list_del(&resv->list);
+ kfree(resv);
+ }
+
+ xrep_newbt_cancel(&ra->new_bnobt);
+ xrep_newbt_cancel(&ra->new_cntbt);
+}
+
+/* Retrieve free space data for bulk load. */
+STATIC int
+xrep_abt_get_records(
+ struct xfs_btree_cur *cur,
+ unsigned int idx,
+ struct xfs_btree_block *block,
+ unsigned int nr_wanted,
+ void *priv)
+{
+ struct xfs_alloc_rec_incore *arec = &cur->bc_rec.a;
+ struct xrep_abt *ra = priv;
+ union xfs_btree_rec *block_rec;
+ unsigned int loaded;
+ int error;
+
+ for (loaded = 0; loaded < nr_wanted; loaded++, idx++) {
+ error = xfarray_load_next(ra->free_records, &ra->array_cur,
+ arec);
+ if (error)
+ return error;
+
+ ra->longest = max(ra->longest, arec->ar_blockcount);
+
+ block_rec = xfs_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_abt_claim_block(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_ptr *ptr,
+ void *priv)
+{
+ struct xrep_abt *ra = priv;
+
+ return xrep_newbt_claim_block(cur, &ra->new_bnobt, ptr);
+}
+
+/*
+ * Reset the AGF counters to reflect the free space btrees that we just
+ * rebuilt, then reinitialize the per-AG data.
+ */
+STATIC int
+xrep_abt_reset_counters(
+ struct xrep_abt *ra)
+{
+ struct xfs_scrub *sc = ra->sc;
+ struct xfs_perag *pag = sc->sa.pag;
+ struct xfs_agf *agf = sc->sa.agf_bp->b_addr;
+ unsigned int freesp_btreeblks = 0;
+
+ /*
+ * Compute the contribution to agf_btreeblks for the new free space
+ * btrees. This is the computed btree size minus anything we didn't
+ * use.
+ */
+ freesp_btreeblks += ra->new_bnobt.bload.nr_blocks - 1;
+ freesp_btreeblks += ra->new_cntbt.bload.nr_blocks - 1;
+
+ freesp_btreeblks -= xrep_newbt_unused_blocks(&ra->new_bnobt);
+ freesp_btreeblks -= xrep_newbt_unused_blocks(&ra->new_cntbt);
+
+ /*
+ * The AGF header contains extra information related to the free space
+ * btrees, so we must update those fields here.
+ */
+ agf->agf_btreeblks = cpu_to_be32(freesp_btreeblks +
+ (be32_to_cpu(agf->agf_rmap_blocks) - 1));
+ agf->agf_freeblks = cpu_to_be32(ra->nr_blocks);
+ agf->agf_longest = cpu_to_be32(ra->longest);
+ xfs_alloc_log_agf(sc->tp, sc->sa.agf_bp, XFS_AGF_BTREEBLKS |
+ XFS_AGF_LONGEST |
+ XFS_AGF_FREEBLKS);
+
+ /*
+ * After we commit the new btree to disk, it is possible that the
+ * process to reap the old btree blocks will race with the AIL trying
+ * to checkpoint the old btree blocks into the filesystem. If the new
+ * tree is shorter than the old one, the allocbt write verifier will
+ * fail and the AIL will shut down the filesystem.
+ *
+ * To avoid this, save the old incore btree height values as the alt
+ * height values before re-initializing the perag info from the updated
+ * AGF to capture all the new values.
+ */
+ pag->pagf_alt_levels[XFS_BTNUM_BNOi] = pag->pagf_levels[XFS_BTNUM_BNOi];
+ pag->pagf_alt_levels[XFS_BTNUM_CNTi] = pag->pagf_levels[XFS_BTNUM_CNTi];
+
+ /* Reinitialize with the values we just logged. */
+ return xrep_reinit_pagf(sc);
+}
+
+/*
+ * Use the collected free space information to stage new free space btrees.
+ * 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_abt_build_new_trees(
+ struct xrep_abt *ra)
+{
+ struct xfs_scrub *sc = ra->sc;
+ struct xfs_btree_cur *bno_cur;
+ struct xfs_btree_cur *cnt_cur;
+ struct xfs_perag *pag = sc->sa.pag;
+ bool needs_resort = false;
+ int error;
+
+ /*
+ * Sort the free extents by length so that we can set up the free space
+ * btrees in as few extents as possible. This reduces the amount of
+ * deferred rmap / free work we have to do at the end.
+ */
+ error = xrep_cntbt_sort_records(ra, false);
+ if (error)
+ return error;
+
+ /*
+ * Prepare to construct the new btree by reserving disk space for the
+ * new btree and setting up all the accounting information we'll need
+ * to root the new btree while it's under construction and before we
+ * attach it to the AG header.
+ */
+ xrep_newbt_init_bare(&ra->new_bnobt, sc);
+ xrep_newbt_init_bare(&ra->new_cntbt, sc);
+
+ ra->new_bnobt.bload.get_records = xrep_abt_get_records;
+ ra->new_cntbt.bload.get_records = xrep_abt_get_records;
+
+ ra->new_bnobt.bload.claim_block = xrep_abt_claim_block;
+ ra->new_cntbt.bload.claim_block = xrep_abt_claim_block;
+
+ /* Allocate cursors for the staged btrees. */
+ bno_cur = xfs_allocbt_stage_cursor(sc->mp, &ra->new_bnobt.afake,
+ pag, XFS_BTNUM_BNO);
+ cnt_cur = xfs_allocbt_stage_cursor(sc->mp, &ra->new_cntbt.afake,
+ pag, XFS_BTNUM_CNT);
+
+ /* Last chance to abort before we start committing fixes. */
+ if (xchk_should_terminate(sc, &error))
+ goto err_cur;
+
+ /* Reserve the space we'll need for the new btrees. */
+ error = xrep_abt_reserve_space(ra, bno_cur, cnt_cur, &needs_resort);
+ if (error)
+ goto err_cur;
+
+ /*
+ * If we need to re-sort the free extents by length, do so so that we
+ * can put the records into the cntbt in the correct order.
+ */
+ if (needs_resort) {
+ error = xrep_cntbt_sort_records(ra, needs_resort);
+ if (error)
+ goto err_cur;
+ }
+
+ /*
+ * Due to btree slack factors, it's possible for a new btree to be one
+ * level taller than the old btree. Update the alternate incore btree
+ * height so that we don't trip the verifiers when writing the new
+ * btree blocks to disk.
+ */
+ pag->pagf_alt_levels[XFS_BTNUM_BNOi] =
+ ra->new_bnobt.bload.btree_height;
+ pag->pagf_alt_levels[XFS_BTNUM_CNTi] =
+ ra->new_cntbt.bload.btree_height;
+
+ /* Load the free space by length tree. */
+ ra->array_cur = XFARRAY_CURSOR_INIT;
+ ra->longest = 0;
+ error = xfs_btree_bload(cnt_cur, &ra->new_cntbt.bload, ra);
+ if (error)
+ goto err_levels;
+
+ error = xrep_bnobt_sort_records(ra);
+ if (error)
+ return error;
+
+ /* Load the free space by block number tree. */
+ ra->array_cur = XFARRAY_CURSOR_INIT;
+ error = xfs_btree_bload(bno_cur, &ra->new_bnobt.bload, ra);
+ if (error)
+ goto err_levels;
+
+ /*
+ * Install the new btrees in the AG header. After this point the old
+ * btrees are no longer accessible and the new trees are live.
+ */
+ xfs_allocbt_commit_staged_btree(bno_cur, sc->tp, sc->sa.agf_bp);
+ xfs_btree_del_cursor(bno_cur, 0);
+ xfs_allocbt_commit_staged_btree(cnt_cur, sc->tp, sc->sa.agf_bp);
+ xfs_btree_del_cursor(cnt_cur, 0);
+
+ /* Reset the AGF counters now that we've changed the btree shape. */
+ error = xrep_abt_reset_counters(ra);
+ if (error)
+ goto err_newbt;
+
+ /* Dispose of any unused blocks and the accounting information. */
+ xrep_abt_dispose_reservations(ra, error);
+
+ return xrep_roll_ag_trans(sc);
+
+err_levels:
+ pag->pagf_alt_levels[XFS_BTNUM_BNOi] = 0;
+ pag->pagf_alt_levels[XFS_BTNUM_CNTi] = 0;
+err_cur:
+ xfs_btree_del_cursor(cnt_cur, error);
+ xfs_btree_del_cursor(bno_cur, error);
+err_newbt:
+ xrep_abt_dispose_reservations(ra, error);
+ return error;
+}
+
+/*
+ * Now that we've logged the roots of the new btrees, invalidate all of the
+ * old blocks and free them.
+ */
+STATIC int
+xrep_abt_remove_old_trees(
+ struct xrep_abt *ra)
+{
+ struct xfs_perag *pag = ra->sc->sa.pag;
+ int error;
+
+ /* Free the old btree blocks if they're not in use. */
+ error = xrep_reap_agblocks(ra->sc, &ra->old_allocbt_blocks,
+ &XFS_RMAP_OINFO_AG, XFS_AG_RESV_IGNORE);
+ if (error)
+ return error;
+
+ /*
+ * Now that we've zapped all the old allocbt blocks we can turn off
+ * the alternate height mechanism.
+ */
+ pag->pagf_alt_levels[XFS_BTNUM_BNOi] = 0;
+ pag->pagf_alt_levels[XFS_BTNUM_CNTi] = 0;
+ return 0;
+}
+
+/* Repair the freespace btrees for some AG. */
+int
+xrep_allocbt(
+ struct xfs_scrub *sc)
+{
+ struct xrep_abt *ra;
+ struct xfs_mount *mp = sc->mp;
+ char *descr;
+ int error;
+
+ /* We require the rmapbt to rebuild anything. */
+ if (!xfs_has_rmapbt(mp))
+ return -EOPNOTSUPP;
+
+ ra = kzalloc(sizeof(struct xrep_abt), XCHK_GFP_FLAGS);
+ if (!ra)
+ return -ENOMEM;
+ ra->sc = sc;
+
+ /* We rebuild both data structures. */
+ sc->sick_mask = XFS_SICK_AG_BNOBT | XFS_SICK_AG_CNTBT;
+
+ /*
+ * Make sure the busy extent list is clear because we can't put extents
+ * on there twice. In theory we cleared this before we started, but
+ * let's not risk the filesystem.
+ */
+ if (!xfs_extent_busy_list_empty(sc->sa.pag)) {
+ error = -EDEADLOCK;
+ goto out_ra;
+ }
+
+ /* Set up enough storage to handle maximally fragmented free space. */
+ descr = xchk_xfile_ag_descr(sc, "free space records");
+ error = xfarray_create(descr, mp->m_sb.sb_agblocks / 2,
+ sizeof(struct xfs_alloc_rec_incore),
+ &ra->free_records);
+ kfree(descr);
+ if (error)
+ goto out_ra;
+
+ /* Collect the free space data and find the old btree blocks. */
+ xagb_bitmap_init(&ra->old_allocbt_blocks);
+ error = xrep_abt_find_freespace(ra);
+ if (error)
+ goto out_bitmap;
+
+ /* Rebuild the free space information. */
+ error = xrep_abt_build_new_trees(ra);
+ if (error)
+ goto out_bitmap;
+
+ /* Kill the old trees. */
+ error = xrep_abt_remove_old_trees(ra);
+ if (error)
+ goto out_bitmap;
+
+out_bitmap:
+ xagb_bitmap_destroy(&ra->old_allocbt_blocks);
+ xfarray_destroy(ra->free_records);
+out_ra:
+ kfree(ra);
+ return error;
+}
+
+/* Make sure both btrees are ok after we've rebuilt them. */
+int
+xrep_revalidate_allocbt(
+ struct xfs_scrub *sc)
+{
+ __u32 old_type = sc->sm->sm_type;
+ int error;
+
+ /*
+ * We must update sm_type temporarily so that the tree-to-tree cross
+ * reference checks will work in the correct direction, and also so
+ * that tracing will report correctly if there are more errors.
+ */
+ sc->sm->sm_type = XFS_SCRUB_TYPE_BNOBT;
+ error = xchk_bnobt(sc);
+ if (error)
+ goto out;
+
+ sc->sm->sm_type = XFS_SCRUB_TYPE_CNTBT;
+ error = xchk_cntbt(sc);
+out:
+ sc->sm->sm_type = old_type;
+ return error;
+}
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index a39dbe6be1e59..4b666f254d700 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -194,8 +194,21 @@ static inline bool xchk_needs_repair(const struct xfs_scrub_metadata *sm)
XFS_SCRUB_OFLAG_XCORRUPT |
XFS_SCRUB_OFLAG_PREEN);
}
+
+/*
+ * "Should we prepare for a repair?"
+ *
+ * Return true if the caller permits us to repair metadata and we're not
+ * setting up for a post-repair evaluation.
+ */
+static inline bool xchk_could_repair(const struct xfs_scrub *sc)
+{
+ return (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) &&
+ !(sc->flags & XREP_ALREADY_FIXED);
+}
#else
# define xchk_needs_repair(sc) (false)
+# define xchk_could_repair(sc) (false)
#endif /* CONFIG_XFS_ONLINE_REPAIR */

int xchk_metadata_inode_forks(struct xfs_scrub *sc);
@@ -207,6 +220,12 @@ int xchk_metadata_inode_forks(struct xfs_scrub *sc);
#define xchk_xfile_descr(sc, fmt, ...) \
kasprintf(XCHK_GFP_FLAGS, "XFS (%s): " fmt, \
(sc)->mp->m_super->s_id, ##__VA_ARGS__)
+#define xchk_xfile_ag_descr(sc, fmt, ...) \
+ kasprintf(XCHK_GFP_FLAGS, "XFS (%s): AG 0x%x " fmt, \
+ (sc)->mp->m_super->s_id, \
+ (sc)->sa.pag ? (sc)->sa.pag->pag_agno : (sc)->sm->sm_agno, \
+ ##__VA_ARGS__)
+

/*
* Setting up a hook to wait for intents to drain is costly -- we have to take
diff --git a/fs/xfs/scrub/newbt.c b/fs/xfs/scrub/newbt.c
index 73e21a9e5e929..deb45d7982f7e 100644
--- a/fs/xfs/scrub/newbt.c
+++ b/fs/xfs/scrub/newbt.c
@@ -153,11 +153,13 @@ xrep_newbt_add_blocks(
resv->used = 0;
resv->pag = xfs_perag_hold(pag);

- ASSERT(xnr->oinfo.oi_offset == 0);
+ if (args->tp) {
+ ASSERT(xnr->oinfo.oi_offset == 0);

- error = xfs_alloc_schedule_autoreap(args, true, &resv->autoreap);
- if (error)
- goto out_pag;
+ error = xfs_alloc_schedule_autoreap(args, true, &resv->autoreap);
+ if (error)
+ goto out_pag;
+ }

list_add_tail(&resv->list, &xnr->resv_list);
return 0;
@@ -167,6 +169,30 @@ xrep_newbt_add_blocks(
return error;
}

+/*
+ * Add an extent to the new btree reservation pool. Callers are required to
+ * reap this reservation manually if the repair is cancelled. @pag must be a
+ * passive reference.
+ */
+int
+xrep_newbt_add_extent(
+ struct xrep_newbt *xnr,
+ struct xfs_perag *pag,
+ xfs_agblock_t agbno,
+ xfs_extlen_t len)
+{
+ struct xfs_mount *mp = xnr->sc->mp;
+ struct xfs_alloc_arg args = {
+ .tp = NULL, /* no autoreap */
+ .oinfo = xnr->oinfo,
+ .fsbno = XFS_AGB_TO_FSB(mp, pag->pag_agno, agbno),
+ .len = len,
+ .resv = xnr->resv,
+ };
+
+ return xrep_newbt_add_blocks(xnr, pag, &args);
+}
+
/* Don't let our allocation hint take us beyond this AG */
static inline void
xrep_newbt_validate_ag_alloc_hint(
@@ -368,6 +394,7 @@ xrep_newbt_free_extent(
free_aglen, xnr->oinfo.oi_owner);

ASSERT(xnr->resv != XFS_AG_RESV_AGFL);
+ ASSERT(xnr->resv != XFS_AG_RESV_IGNORE);

/*
* Use EFIs to free the reservations. This reduces the chance
@@ -513,3 +540,16 @@ xrep_newbt_claim_block(
/* Relog all the EFIs. */
return xrep_defer_finish(xnr->sc);
}
+
+/* How many reserved blocks are unused? */
+unsigned int
+xrep_newbt_unused_blocks(
+ struct xrep_newbt *xnr)
+{
+ struct xrep_newbt_resv *resv;
+ unsigned int unused = 0;
+
+ list_for_each_entry(resv, &xnr->resv_list, list)
+ unused += resv->len - resv->used;
+ return unused;
+}
diff --git a/fs/xfs/scrub/newbt.h b/fs/xfs/scrub/newbt.h
index d2baffa17b1ae..c158d92562787 100644
--- a/fs/xfs/scrub/newbt.h
+++ b/fs/xfs/scrub/newbt.h
@@ -50,6 +50,9 @@ struct xrep_newbt {
enum xfs_ag_resv_type resv;
};

+#define for_each_xrep_newbt_reservation(xnr, resv, n) \
+ list_for_each_entry_safe((resv), (n), &(xnr)->resv_list, list)
+
void xrep_newbt_init_bare(struct xrep_newbt *xnr, struct xfs_scrub *sc);
void xrep_newbt_init_ag(struct xrep_newbt *xnr, struct xfs_scrub *sc,
const struct xfs_owner_info *oinfo, xfs_fsblock_t alloc_hint,
@@ -57,9 +60,12 @@ void xrep_newbt_init_ag(struct xrep_newbt *xnr, struct xfs_scrub *sc,
int xrep_newbt_init_inode(struct xrep_newbt *xnr, struct xfs_scrub *sc,
int whichfork, const struct xfs_owner_info *oinfo);
int xrep_newbt_alloc_blocks(struct xrep_newbt *xnr, uint64_t nr_blocks);
+int xrep_newbt_add_extent(struct xrep_newbt *xnr, struct xfs_perag *pag,
+ xfs_agblock_t agbno, xfs_extlen_t len);
void xrep_newbt_cancel(struct xrep_newbt *xnr);
int xrep_newbt_commit(struct xrep_newbt *xnr);
int xrep_newbt_claim_block(struct xfs_btree_cur *cur, struct xrep_newbt *xnr,
union xfs_btree_ptr *ptr);
+unsigned int xrep_newbt_unused_blocks(struct xrep_newbt *xnr);

#endif /* __XFS_SCRUB_NEWBT_H__ */
diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index 1b8b5439f2d7f..828c0585701a4 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -734,3 +734,72 @@ xrep_ino_dqattach(

return error;
}
+
+/* Initialize all the btree cursors for an AG repair. */
+void
+xrep_ag_btcur_init(
+ struct xfs_scrub *sc,
+ struct xchk_ag *sa)
+{
+ struct xfs_mount *mp = sc->mp;
+
+ /* Set up a bnobt cursor for cross-referencing. */
+ if (sc->sm->sm_type != XFS_SCRUB_TYPE_BNOBT &&
+ sc->sm->sm_type != XFS_SCRUB_TYPE_CNTBT) {
+ sa->bno_cur = xfs_allocbt_init_cursor(mp, sc->tp, sa->agf_bp,
+ sc->sa.pag, XFS_BTNUM_BNO);
+ sa->cnt_cur = xfs_allocbt_init_cursor(mp, sc->tp, sa->agf_bp,
+ sc->sa.pag, XFS_BTNUM_CNT);
+ }
+
+ /* Set up a inobt cursor for cross-referencing. */
+ if (sc->sm->sm_type != XFS_SCRUB_TYPE_INOBT &&
+ sc->sm->sm_type != XFS_SCRUB_TYPE_FINOBT) {
+ sa->ino_cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp,
+ sa->agi_bp, XFS_BTNUM_INO);
+ if (xfs_has_finobt(mp))
+ sa->fino_cur = xfs_inobt_init_cursor(sc->sa.pag,
+ sc->tp, sa->agi_bp, XFS_BTNUM_FINO);
+ }
+
+ /* Set up a rmapbt cursor for cross-referencing. */
+ if (sc->sm->sm_type != XFS_SCRUB_TYPE_RMAPBT &&
+ xfs_has_rmapbt(mp))
+ sa->rmap_cur = xfs_rmapbt_init_cursor(mp, sc->tp, sa->agf_bp,
+ sc->sa.pag);
+
+ /* Set up a refcountbt cursor for cross-referencing. */
+ if (sc->sm->sm_type != XFS_SCRUB_TYPE_REFCNTBT &&
+ xfs_has_reflink(mp))
+ sa->refc_cur = xfs_refcountbt_init_cursor(mp, sc->tp,
+ sa->agf_bp, sc->sa.pag);
+}
+
+/*
+ * Reinitialize the in-core AG state after a repair by rereading the AGF
+ * buffer. We had better get the same AGF buffer as the one that's attached
+ * to the scrub context.
+ */
+int
+xrep_reinit_pagf(
+ struct xfs_scrub *sc)
+{
+ struct xfs_perag *pag = sc->sa.pag;
+ struct xfs_buf *bp;
+ int error;
+
+ ASSERT(pag);
+ ASSERT(xfs_perag_initialised_agf(pag));
+
+ clear_bit(XFS_AGSTATE_AGF_INIT, &pag->pag_opstate);
+ error = xfs_alloc_read_agf(pag, sc->tp, 0, &bp);
+ if (error)
+ return error;
+
+ if (bp != sc->sa.agf_bp) {
+ ASSERT(bp == sc->sa.agf_bp);
+ return -EFSCORRUPTED;
+ }
+
+ return 0;
+}
diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index 60d2a9ae5f2ec..bc3353ecae8a1 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -60,6 +60,15 @@ int xrep_find_ag_btree_roots(struct xfs_scrub *sc, struct xfs_buf *agf_bp,
void xrep_force_quotacheck(struct xfs_scrub *sc, xfs_dqtype_t type);
int xrep_ino_dqattach(struct xfs_scrub *sc);

+/* Repair setup functions */
+int xrep_setup_ag_allocbt(struct xfs_scrub *sc);
+
+void xrep_ag_btcur_init(struct xfs_scrub *sc, struct xchk_ag *sa);
+
+/* Metadata revalidators */
+
+int xrep_revalidate_allocbt(struct xfs_scrub *sc);
+
/* Metadata repairers */

int xrep_probe(struct xfs_scrub *sc);
@@ -67,6 +76,9 @@ int xrep_superblock(struct xfs_scrub *sc);
int xrep_agf(struct xfs_scrub *sc);
int xrep_agfl(struct xfs_scrub *sc);
int xrep_agi(struct xfs_scrub *sc);
+int xrep_allocbt(struct xfs_scrub *sc);
+
+int xrep_reinit_pagf(struct xfs_scrub *sc);

#else

@@ -87,11 +99,23 @@ xrep_calc_ag_resblks(
return 0;
}

+/* repair setup functions for no-repair */
+static inline int
+xrep_setup_nothing(
+ struct xfs_scrub *sc)
+{
+ return 0;
+}
+#define xrep_setup_ag_allocbt xrep_setup_nothing
+
+#define xrep_revalidate_allocbt (NULL)
+
#define xrep_probe xrep_notsupported
#define xrep_superblock xrep_notsupported
#define xrep_agf xrep_notsupported
#define xrep_agfl xrep_notsupported
#define xrep_agi xrep_notsupported
+#define xrep_allocbt xrep_notsupported

#endif /* CONFIG_XFS_ONLINE_REPAIR */

diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index 474f4c4a9cd3b..ebfaeb3793154 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -241,13 +241,15 @@ static const struct xchk_meta_ops meta_scrub_ops[] = {
.type = ST_PERAG,
.setup = xchk_setup_ag_allocbt,
.scrub = xchk_bnobt,
- .repair = xrep_notsupported,
+ .repair = xrep_allocbt,
+ .repair_eval = xrep_revalidate_allocbt,
},
[XFS_SCRUB_TYPE_CNTBT] = { /* cntbt */
.type = ST_PERAG,
.setup = xchk_setup_ag_allocbt,
.scrub = xchk_cntbt,
- .repair = xrep_notsupported,
+ .repair = xrep_allocbt,
+ .repair_eval = xrep_revalidate_allocbt,
},
[XFS_SCRUB_TYPE_INOBT] = { /* inobt */
.type = ST_PERAG,
@@ -533,7 +535,10 @@ xfs_scrub_metadata(

/* Scrub for errors. */
check_start = xchk_stats_now();
- error = sc->ops->scrub(sc);
+ if ((sc->flags & XREP_ALREADY_FIXED) && sc->ops->repair_eval != NULL)
+ error = sc->ops->repair_eval(sc);
+ else
+ error = sc->ops->scrub(sc);
run.scrub_ns += xchk_stats_elapsed_ns(check_start);
if (error == -EDEADLOCK && !(sc->flags & XCHK_TRY_HARDER))
goto try_harder;
@@ -544,8 +549,7 @@ xfs_scrub_metadata(

xchk_update_health(sc);

- if ((sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) &&
- !(sc->flags & XREP_ALREADY_FIXED)) {
+ if (xchk_could_repair(sc)) {
bool needs_fix = xchk_needs_repair(sc->sm);

/* Userspace asked us to rebuild the structure regardless. */
diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h
index 1ef9c6b4842a1..cb6294e629836 100644
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -35,6 +35,14 @@ struct xchk_meta_ops {
/* Repair or optimize the metadata. */
int (*repair)(struct xfs_scrub *);

+ /*
+ * Re-scrub the metadata we repaired, in case there's extra work that
+ * we need to do to check our repair work. If this is NULL, we'll use
+ * the ->scrub function pointer, assuming that the regular scrub is
+ * sufficient.
+ */
+ int (*repair_eval)(struct xfs_scrub *sc);
+
/* Decide if we even have this piece of metadata. */
bool (*has)(struct xfs_mount *);

diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index aa76830753196..ea518712efa81 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -1172,11 +1172,33 @@ DEFINE_EVENT(xrep_rmap_class, name, \
xfs_agblock_t agbno, xfs_extlen_t len, \
uint64_t owner, uint64_t offset, unsigned int flags), \
TP_ARGS(mp, agno, agbno, len, owner, offset, flags))
-DEFINE_REPAIR_RMAP_EVENT(xrep_alloc_extent_fn);
DEFINE_REPAIR_RMAP_EVENT(xrep_ialloc_extent_fn);
DEFINE_REPAIR_RMAP_EVENT(xrep_rmap_extent_fn);
DEFINE_REPAIR_RMAP_EVENT(xrep_bmap_extent_fn);

+TRACE_EVENT(xrep_abt_found,
+ TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
+ const struct xfs_alloc_rec_incore *rec),
+ TP_ARGS(mp, agno, rec),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(xfs_agblock_t, startblock)
+ __field(xfs_extlen_t, blockcount)
+ ),
+ TP_fast_assign(
+ __entry->dev = mp->m_super->s_dev;
+ __entry->agno = agno;
+ __entry->startblock = rec->ar_startblock;
+ __entry->blockcount = rec->ar_blockcount;
+ ),
+ TP_printk("dev %d:%d agno 0x%x agbno 0x%x fsbcount 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->startblock,
+ __entry->blockcount)
+)
+
TRACE_EVENT(xrep_refcount_extent_fn,
TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
struct xfs_refcount_irec *irec),
diff --git a/fs/xfs/scrub/xfarray.h b/fs/xfs/scrub/xfarray.h
index 4ecac01363d9f..62b9c506fdd1b 100644
--- a/fs/xfs/scrub/xfarray.h
+++ b/fs/xfs/scrub/xfarray.h
@@ -54,6 +54,28 @@ static inline int xfarray_append(struct xfarray *array, const void *ptr)
uint64_t xfarray_length(struct xfarray *array);
int xfarray_load_next(struct xfarray *array, xfarray_idx_t *idx, void *rec);

+/*
+ * Iterate the non-null elements in a sparse xfarray. Callers should
+ * initialize *idx to XFARRAY_CURSOR_INIT before the first call; on return, it
+ * will be set to one more than the index of the record that was retrieved.
+ * Returns 1 if a record was retrieved, 0 if there weren't any more records, or
+ * a negative errno.
+ */
+static inline int
+xfarray_iter(
+ struct xfarray *array,
+ xfarray_idx_t *idx,
+ void *rec)
+{
+ int ret = xfarray_load_next(array, idx, rec);
+
+ if (ret == -ENODATA)
+ return 0;
+ if (ret == 0)
+ return 1;
+ return ret;
+}
+
/* Declarations for xfile array sort functionality. */

typedef cmp_func_t xfarray_cmp_fn;
diff --git a/fs/xfs/xfs_extent_busy.c b/fs/xfs/xfs_extent_busy.c
index 9ecfdcdc752f7..2ccde32c9a9e9 100644
--- a/fs/xfs/xfs_extent_busy.c
+++ b/fs/xfs/xfs_extent_busy.c
@@ -678,3 +678,16 @@ xfs_extent_busy_ag_cmp(
diff = b1->bno - b2->bno;
return diff;
}
+
+/* Are there any busy extents in this AG? */
+bool
+xfs_extent_busy_list_empty(
+ struct xfs_perag *pag)
+{
+ bool res;
+
+ spin_lock(&pag->pagb_lock);
+ res = RB_EMPTY_ROOT(&pag->pagb_tree);
+ spin_unlock(&pag->pagb_lock);
+ return res;
+}
diff --git a/fs/xfs/xfs_extent_busy.h b/fs/xfs/xfs_extent_busy.h
index 0639aab336f3f..470032de31391 100644
--- a/fs/xfs/xfs_extent_busy.h
+++ b/fs/xfs/xfs_extent_busy.h
@@ -85,4 +85,6 @@ static inline void xfs_extent_busy_sort(struct list_head *list)
list_sort(NULL, list, xfs_extent_busy_ag_cmp);
}

+bool xfs_extent_busy_list_empty(struct xfs_perag *pag);
+
#endif /* __XFS_EXTENT_BUSY_H__ */