[PATCH 3/3] xfs: repair AGI unlinked inode bucket lists

Darrick J. Wong
2024-03-27T02:06:40Z

Teach the AGI repair code to rebuild the unlinked buckets and lists.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/scrub/agheader_repair.c | 774 ++++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/agino_bitmap.h | 49 +++
fs/xfs/scrub/trace.h | 255 +++++++++++++
3 files changed, 1074 insertions(+), 4 deletions(-)
create mode 100644 fs/xfs/scrub/agino_bitmap.h

diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c
index d210bd7d5eb13..0dbc484b182f9 100644
--- a/fs/xfs/scrub/agheader_repair.c
+++ b/fs/xfs/scrub/agheader_repair.c
@@ -21,13 +21,18 @@
#include "xfs_rmap_btree.h"
#include "xfs_refcount_btree.h"
#include "xfs_ag.h"
+#include "xfs_inode.h"
+#include "xfs_iunlink_item.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
#include "scrub/repair.h"
#include "scrub/bitmap.h"
#include "scrub/agb_bitmap.h"
+#include "scrub/agino_bitmap.h"
#include "scrub/reap.h"
+#include "scrub/xfile.h"
+#include "scrub/xfarray.h"

/* Superblock */

@@ -796,6 +801,8 @@ enum {
XREP_AGI_MAX
};

+#define XREP_AGI_LOOKUP_BATCH 32
+
struct xrep_agi {
struct xfs_scrub *sc;

@@ -807,8 +814,34 @@ struct xrep_agi {

/* old AGI contents in case we have to revert */
struct xfs_agi old_agi;
+
+ /* bitmap of which inodes are unlinked */
+ struct xagino_bitmap iunlink_bmp;
+
+ /* heads of the unlinked inode bucket lists */
+ xfs_agino_t iunlink_heads[XFS_AGI_UNLINKED_BUCKETS];
+
+ /* scratchpad for batched lookups of the radix tree */
+ struct xfs_inode *lookup_batch[XREP_AGI_LOOKUP_BATCH];
+
+ /* Map of ino -> next_ino for unlinked inode processing. */
+ struct xfarray *iunlink_next;
+
+ /* Map of ino -> prev_ino for unlinked inode processing. */
+ struct xfarray *iunlink_prev;
};

+static void
+xrep_agi_buf_cleanup(
+ void *buf)
+{
+ struct xrep_agi *ragi = buf;
+
+ xfarray_destroy(ragi->iunlink_prev);
+ xfarray_destroy(ragi->iunlink_next);
+ xagino_bitmap_destroy(&ragi->iunlink_bmp);
+}
+
/*
* Given the inode btree roots described by *fab, find the roots, check them
* for sanity, and pass the root data back out via *fab.
@@ -871,10 +904,6 @@ xrep_agi_init_header(
if (xfs_has_crc(mp))
uuid_copy(&agi->agi_uuid, &mp->m_sb.sb_meta_uuid);

- /* We don't know how to fix the unlinked list yet. */
- memcpy(&agi->agi_unlinked, &old_agi->agi_unlinked,
- sizeof(agi->agi_unlinked));
-
/* Mark the incore AGF data stale until we're done fixing things. */
ASSERT(xfs_perag_initialised_agi(pag));
clear_bit(XFS_AGSTATE_AGI_INIT, &pag->pag_opstate);
@@ -946,6 +975,714 @@ xrep_agi_calc_from_btrees(
return error;
}

+/*
+ * Record a forwards unlinked chain pointer from agino -> next_agino in our
+ * staging information.
+ */
+static inline int
+xrep_iunlink_store_next(
+ struct xrep_agi *ragi,
+ xfs_agino_t agino,
+ xfs_agino_t next_agino)
+{
+ ASSERT(next_agino != 0);
+
+ return xfarray_store(ragi->iunlink_next, agino, &next_agino);
+}
+
+/*
+ * Record a backwards unlinked chain pointer from prev_ino <- agino in our
+ * staging information.
+ */
+static inline int
+xrep_iunlink_store_prev(
+ struct xrep_agi *ragi,
+ xfs_agino_t agino,
+ xfs_agino_t prev_agino)
+{
+ ASSERT(prev_agino != 0);
+
+ return xfarray_store(ragi->iunlink_prev, agino, &prev_agino);
+}
+
+/*
+ * Given an @agino, look up the next inode in the iunlink bucket. Returns
+ * NULLAGINO if we're at the end of the chain, 0 if @agino is not in memory
+ * like it should be, or a per-AG inode number.
+ */
+static inline xfs_agino_t
+xrep_iunlink_next(
+ struct xfs_scrub *sc,
+ xfs_agino_t agino)
+{
+ struct xfs_inode *ip;
+
+ ip = xfs_iunlink_lookup(sc->sa.pag, agino);
+ if (!ip)
+ return 0;
+
+ return ip->i_next_unlinked;
+}
+
+/*
+ * Load the inode @agino into memory, set its i_prev_unlinked, and drop the
+ * inode so it can be inactivated. Returns NULLAGINO if we're at the end of
+ * the chain or if we should stop walking the chain due to corruption; or a
+ * per-AG inode number.
+ */
+STATIC xfs_agino_t
+xrep_iunlink_reload_next(
+ struct xrep_agi *ragi,
+ xfs_agino_t prev_agino,
+ xfs_agino_t agino)
+{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_inode *ip;
+ xfs_ino_t ino;
+ xfs_agino_t ret = NULLAGINO;
+ int error;
+
+ ino = XFS_AGINO_TO_INO(sc->mp, sc->sa.pag->pag_agno, agino);
+ error = xchk_iget(ragi->sc, ino, &ip);
+ if (error)
+ return ret;
+
+ trace_xrep_iunlink_reload_next(ip, prev_agino);
+
+ /* If this is a linked inode, stop processing the chain. */
+ if (VFS_I(ip)->i_nlink != 0) {
+ xrep_iunlink_store_next(ragi, agino, NULLAGINO);
+ goto rele;
+ }
+
+ ip->i_prev_unlinked = prev_agino;
+ ret = ip->i_next_unlinked;
+
+ /*
+ * Drop the inode reference that we just took. We hold the AGI, so
+ * this inode cannot move off the unlinked list and hence cannot be
+ * reclaimed.
+ */
+rele:
+ xchk_irele(sc, ip);
+ return ret;
+}
+
+/*
+ * Walk an AGI unlinked bucket's list to load incore any unlinked inodes that
+ * still existed at mount time. This can happen if iunlink processing fails
+ * during log recovery.
+ */
+STATIC int
+xrep_iunlink_walk_ondisk_bucket(
+ struct xrep_agi *ragi,
+ unsigned int bucket)
+{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_agi *agi = sc->sa.agi_bp->b_addr;
+ xfs_agino_t prev_agino = NULLAGINO;
+ xfs_agino_t next_agino;
+ int error = 0;
+
+ next_agino = be32_to_cpu(agi->agi_unlinked[bucket]);
+ while (next_agino != NULLAGINO) {
+ xfs_agino_t agino = next_agino;
+
+ if (xchk_should_terminate(ragi->sc, &error))
+ return error;
+
+ trace_xrep_iunlink_walk_ondisk_bucket(sc->sa.pag, bucket,
+ prev_agino, agino);
+
+ if (bucket != agino % XFS_AGI_UNLINKED_BUCKETS)
+ break;
+
+ next_agino = xrep_iunlink_next(sc, agino);
+ if (!next_agino)
+ next_agino = xrep_iunlink_reload_next(ragi, prev_agino,
+ agino);
+
+ prev_agino = agino;
+ }
+
+ return 0;
+}
+
+/* Decide if this is an unlinked inode in this AG. */
+STATIC bool
+xrep_iunlink_igrab(
+ struct xfs_perag *pag,
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = pag->pag_mount;
+
+ if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
+ return false;
+
+ if (!xfs_inode_on_unlinked_list(ip))
+ return false;
+
+ return true;
+}
+
+/*
+ * Mark the given inode in the lookup batch in our unlinked inode bitmap, and
+ * remember if this inode is the start of the unlinked chain.
+ */
+STATIC int
+xrep_iunlink_visit(
+ struct xrep_agi *ragi,
+ unsigned int batch_idx)
+{
+ struct xfs_mount *mp = ragi->sc->mp;
+ struct xfs_inode *ip = ragi->lookup_batch[batch_idx];
+ xfs_agino_t agino;
+ unsigned int bucket;
+ int error;
+
+ ASSERT(XFS_INO_TO_AGNO(mp, ip->i_ino) == ragi->sc->sa.pag->pag_agno);
+ ASSERT(xfs_inode_on_unlinked_list(ip));
+
+ agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
+ bucket = agino % XFS_AGI_UNLINKED_BUCKETS;
+
+ trace_xrep_iunlink_visit(ragi->sc->sa.pag, bucket,
+ ragi->iunlink_heads[bucket], ip);
+
+ error = xagino_bitmap_set(&ragi->iunlink_bmp, agino, 1);
+ if (error)
+ return error;
+
+ if (ip->i_prev_unlinked == NULLAGINO) {
+ if (ragi->iunlink_heads[bucket] == NULLAGINO)
+ ragi->iunlink_heads[bucket] = agino;
+ }
+
+ return 0;
+}
+
+/*
+ * Find all incore unlinked inodes so that we can rebuild the unlinked buckets.
+ * We hold the AGI so there should not be any modifications to the unlinked
+ * list.
+ */
+STATIC int
+xrep_iunlink_mark_incore(
+ struct xrep_agi *ragi)
+{
+ struct xfs_perag *pag = ragi->sc->sa.pag;
+ struct xfs_mount *mp = pag->pag_mount;
+ uint32_t first_index = 0;
+ bool done = false;
+ unsigned int nr_found = 0;
+
+ do {
+ unsigned int i;
+ int error = 0;
+
+ if (xchk_should_terminate(ragi->sc, &error))
+ return error;
+
+ rcu_read_lock();
+
+ nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
+ (void **)&ragi->lookup_batch, first_index,
+ XREP_AGI_LOOKUP_BATCH);
+ if (!nr_found) {
+ rcu_read_unlock();
+ return 0;
+ }
+
+ for (i = 0; i < nr_found; i++) {
+ struct xfs_inode *ip = ragi->lookup_batch[i];
+
+ if (done || !xrep_iunlink_igrab(pag, ip))
+ ragi->lookup_batch[i] = NULL;
+
+ /*
+ * Update the index for the next lookup. Catch
+ * overflows into the next AG range which can occur if
+ * we have inodes in the last block of the AG and we
+ * are currently pointing to the last inode.
+ *
+ * Because we may see inodes that are from the wrong AG
+ * due to RCU freeing and reallocation, only update the
+ * index if it lies in this AG. It was a race that lead
+ * us to see this inode, so another lookup from the
+ * same index will not find it again.
+ */
+ if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
+ continue;
+ first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
+ if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
+ done = true;
+ }
+
+ /* unlock now we've grabbed the inodes. */
+ rcu_read_unlock();
+
+ for (i = 0; i < nr_found; i++) {
+ if (!ragi->lookup_batch[i])
+ continue;
+ error = xrep_iunlink_visit(ragi, i);
+ if (error)
+ return error;
+ }
+ } while (!done);
+
+ return 0;
+}
+
+/* Mark all the unlinked ondisk inodes in this inobt record in iunlink_bmp. */
+STATIC int
+xrep_iunlink_mark_ondisk_rec(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_rec *rec,
+ void *priv)
+{
+ struct xfs_inobt_rec_incore irec;
+ struct xrep_agi *ragi = priv;
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_agino_t agino;
+ unsigned int i;
+ int error = 0;
+
+ xfs_inobt_btrec_to_irec(mp, rec, &irec);
+
+ for (i = 0, agino = irec.ir_startino;
+ i < XFS_INODES_PER_CHUNK;
+ i++, agino++) {
+ struct xfs_inode *ip;
+ unsigned int len = 1;
+
+ /* Skip free inodes */
+ if (XFS_INOBT_MASK(i) & irec.ir_free)
+ continue;
+ /* Skip inodes we've seen before */
+ if (xagino_bitmap_test(&ragi->iunlink_bmp, agino, &len))
+ continue;
+
+ /*
+ * Skip incore inodes; these were already picked up by
+ * the _mark_incore step.
+ */
+ rcu_read_lock();
+ ip = radix_tree_lookup(&sc->sa.pag->pag_ici_root, agino);
+ rcu_read_unlock();
+ if (ip)
+ continue;
+
+ /*
+ * Try to look up this inode. If we can't get it, just move
+ * on because we haven't actually scrubbed the inobt or the
+ * inodes yet.
+ */
+ error = xchk_iget(ragi->sc,
+ XFS_AGINO_TO_INO(mp, sc->sa.pag->pag_agno,
+ agino),
+ &ip);
+ if (error)
+ continue;
+
+ trace_xrep_iunlink_reload_ondisk(ip);
+
+ if (VFS_I(ip)->i_nlink == 0)
+ error = xagino_bitmap_set(&ragi->iunlink_bmp, agino, 1);
+ xchk_irele(sc, ip);
+ if (error)
+ break;
+ }
+
+ return error;
+}
+
+/*
+ * Find ondisk inodes that are unlinked and not in cache, and mark them in
+ * iunlink_bmp. We haven't checked the inobt yet, so we don't error out if
+ * the btree is corrupt.
+ */
+STATIC void
+xrep_iunlink_mark_ondisk(
+ struct xrep_agi *ragi)
+{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_buf *agi_bp = ragi->agi_bp;
+ struct xfs_btree_cur *cur;
+ int error;
+
+ cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp, agi_bp);
+ error = xfs_btree_query_all(cur, xrep_iunlink_mark_ondisk_rec, ragi);
+ xfs_btree_del_cursor(cur, error);
+}
+
+/*
+ * Walk an iunlink bucket's inode list. For each inode that should be on this
+ * chain, clear its entry in in iunlink_bmp because it's ok and we don't need
+ * to touch it further.
+ */
+STATIC int
+xrep_iunlink_resolve_bucket(
+ struct xrep_agi *ragi,
+ unsigned int bucket)
+{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_inode *ip;
+ xfs_agino_t prev_agino = NULLAGINO;
+ xfs_agino_t next_agino = ragi->iunlink_heads[bucket];
+ int error = 0;
+
+ while (next_agino != NULLAGINO) {
+ if (xchk_should_terminate(ragi->sc, &error))
+ return error;
+
+ /* Find the next inode in the chain. */
+ ip = xfs_iunlink_lookup(sc->sa.pag, next_agino);
+ if (!ip) {
+ /* Inode not incore? Terminate the chain. */
+ trace_xrep_iunlink_resolve_uncached(sc->sa.pag,
+ bucket, prev_agino, next_agino);
+
+ next_agino = NULLAGINO;
+ break;
+ }
+
+ if (next_agino % XFS_AGI_UNLINKED_BUCKETS != bucket) {
+ /*
+ * Inode is in the wrong bucket. Advance the list,
+ * but pretend we didn't see this inode.
+ */
+ trace_xrep_iunlink_resolve_wronglist(sc->sa.pag,
+ bucket, prev_agino, next_agino);
+
+ next_agino = ip->i_next_unlinked;
+ continue;
+ }
+
+ if (!xfs_inode_on_unlinked_list(ip)) {
+ /*
+ * Incore inode doesn't think this inode is on an
+ * unlinked list. This is probably because we reloaded
+ * it from disk. Advance the list, but pretend we
+ * didn't see this inode; we'll fix that later.
+ */
+ trace_xrep_iunlink_resolve_nolist(sc->sa.pag,
+ bucket, prev_agino, next_agino);
+ next_agino = ip->i_next_unlinked;
+ continue;
+ }
+
+ trace_xrep_iunlink_resolve_ok(sc->sa.pag, bucket, prev_agino,
+ next_agino);
+
+ /*
+ * Otherwise, this inode's unlinked pointers are ok. Clear it
+ * from the unlinked bitmap since we're done with it, and make
+ * sure the chain is still correct.
+ */
+ error = xagino_bitmap_clear(&ragi->iunlink_bmp, next_agino, 1);
+ if (error)
+ return error;
+
+ /* Remember the previous inode's next pointer. */
+ if (prev_agino != NULLAGINO) {
+ error = xrep_iunlink_store_next(ragi, prev_agino,
+ next_agino);
+ if (error)
+ return error;
+ }
+
+ /* Remember this inode's previous pointer. */
+ error = xrep_iunlink_store_prev(ragi, next_agino, prev_agino);
+ if (error)
+ return error;
+
+ /* Advance the list and remember this inode. */
+ prev_agino = next_agino;
+ next_agino = ip->i_next_unlinked;
+ }
+
+ /* Update the previous inode's next pointer. */
+ if (prev_agino != NULLAGINO) {
+ error = xrep_iunlink_store_next(ragi, prev_agino, next_agino);
+ if (error)
+ return error;
+ }
+
+ return 0;
+}
+
+/* Reinsert this unlinked inode into the head of the staged bucket list. */
+STATIC int
+xrep_iunlink_add_to_bucket(
+ struct xrep_agi *ragi,
+ xfs_agino_t agino)
+{
+ xfs_agino_t current_head;
+ unsigned int bucket;
+ int error;
+
+ bucket = agino % XFS_AGI_UNLINKED_BUCKETS;
+
+ /* Point this inode at the current head of the bucket list. */
+ current_head = ragi->iunlink_heads[bucket];
+
+ trace_xrep_iunlink_add_to_bucket(ragi->sc->sa.pag, bucket, agino,
+ current_head);
+
+ error = xrep_iunlink_store_next(ragi, agino, current_head);
+ if (error)
+ return error;
+
+ /* Remember the head inode's previous pointer. */
+ if (current_head != NULLAGINO) {
+ error = xrep_iunlink_store_prev(ragi, current_head, agino);
+ if (error)
+ return error;
+ }
+
+ ragi->iunlink_heads[bucket] = agino;
+ return 0;
+}
+
+/* Reinsert unlinked inodes into the staged iunlink buckets. */
+STATIC int
+xrep_iunlink_add_lost_inodes(
+ uint32_t start,
+ uint32_t len,
+ void *priv)
+{
+ struct xrep_agi *ragi = priv;
+ int error;
+
+ for (; len > 0; start++, len--) {
+ error = xrep_iunlink_add_to_bucket(ragi, start);
+ if (error)
+ return error;
+ }
+
+ return 0;
+}
+
+/*
+ * Figure out the iunlink bucket values and find inodes that need to be
+ * reinserted into the list.
+ */
+STATIC int
+xrep_iunlink_rebuild_buckets(
+ struct xrep_agi *ragi)
+{
+ unsigned int i;
+ int error;
+
+ /*
+ * Walk the ondisk AGI unlinked list to find inodes that are on the
+ * list but aren't in memory. This can happen if a past log recovery
+ * tried to clear the iunlinked list but failed. Our scan rebuilds the
+ * unlinked list using incore inodes, so we must load and link them
+ * properly.
+ */
+ for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
+ error = xrep_iunlink_walk_ondisk_bucket(ragi, i);
+ if (error)
+ return error;
+ }
+
+ /*
+ * Record all the incore unlinked inodes in iunlink_bmp that we didn't
+ * find by walking the ondisk iunlink buckets. This shouldn't happen,
+ * but we can't risk forgetting an inode somewhere.
+ */
+ error = xrep_iunlink_mark_incore(ragi);
+ if (error)
+ return error;
+
+ /*
+ * If there are ondisk inodes that are unlinked and are not been loaded
+ * into cache, record them in iunlink_bmp.
+ */
+ xrep_iunlink_mark_ondisk(ragi);
+
+ /*
+ * Walk each iunlink bucket to (re)construct as much of the incore list
+ * as would be correct. For each inode that survives this step, mark
+ * it clear in iunlink_bmp; we're done with those inodes.
+ */
+ for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
+ error = xrep_iunlink_resolve_bucket(ragi, i);
+ if (error)
+ return error;
+ }
+
+ /*
+ * Any unlinked inodes that we didn't find through the bucket list
+ * walk (or was ignored by the walk) must be inserted into the bucket
+ * list. Stage this in memory for now.
+ */
+ return xagino_bitmap_walk(&ragi->iunlink_bmp,
+ xrep_iunlink_add_lost_inodes, ragi);
+}
+
+/* Update i_next_iunlinked for the inode @agino. */
+STATIC int
+xrep_iunlink_relink_next(
+ struct xrep_agi *ragi,
+ xfarray_idx_t idx,
+ xfs_agino_t next_agino)
+{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_perag *pag = sc->sa.pag;
+ struct xfs_inode *ip;
+ xfarray_idx_t agino = idx - 1;
+ bool want_rele = false;
+ int error = 0;
+
+ ip = xfs_iunlink_lookup(pag, agino);
+ if (!ip) {
+ xfs_ino_t ino;
+ xfs_agino_t prev_agino;
+
+ /*
+ * No inode exists in cache. Load it off the disk so that we
+ * can reinsert it into the incore unlinked list.
+ */
+ ino = XFS_AGINO_TO_INO(sc->mp, pag->pag_agno, agino);
+ error = xchk_iget(sc, ino, &ip);
+ if (error)
+ return -EFSCORRUPTED;
+
+ want_rele = true;
+
+ /* Set the backward pointer since this just came off disk. */
+ error = xfarray_load(ragi->iunlink_prev, agino, &prev_agino);
+ if (error)
+ goto out_rele;
+
+ trace_xrep_iunlink_relink_prev(ip, prev_agino);
+ ip->i_prev_unlinked = prev_agino;
+ }
+
+ /* Update the forward pointer. */
+ if (ip->i_next_unlinked != next_agino) {
+ error = xfs_iunlink_log_inode(sc->tp, ip, pag, next_agino);
+ if (error)
+ goto out_rele;
+
+ trace_xrep_iunlink_relink_next(ip, next_agino);
+ ip->i_next_unlinked = next_agino;
+ }
+
+out_rele:
+ /*
+ * The iunlink lookup doesn't igrab because we hold the AGI buffer lock
+ * and the inode cannot be reclaimed. However, if we used iget to load
+ * a missing inode, we must irele it here.
+ */
+ if (want_rele)
+ xchk_irele(sc, ip);
+ return error;
+}
+
+/* Update i_prev_iunlinked for the inode @agino. */
+STATIC int
+xrep_iunlink_relink_prev(
+ struct xrep_agi *ragi,
+ xfarray_idx_t idx,
+ xfs_agino_t prev_agino)
+{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_perag *pag = sc->sa.pag;
+ struct xfs_inode *ip;
+ xfarray_idx_t agino = idx - 1;
+ bool want_rele = false;
+ int error = 0;
+
+ ASSERT(prev_agino != 0);
+
+ ip = xfs_iunlink_lookup(pag, agino);
+ if (!ip) {
+ xfs_ino_t ino;
+ xfs_agino_t next_agino;
+
+ /*
+ * No inode exists in cache. Load it off the disk so that we
+ * can reinsert it into the incore unlinked list.
+ */
+ ino = XFS_AGINO_TO_INO(sc->mp, pag->pag_agno, agino);
+ error = xchk_iget(sc, ino, &ip);
+ if (error)
+ return -EFSCORRUPTED;
+
+ want_rele = true;
+
+ /* Set the forward pointer since this just came off disk. */
+ error = xfarray_load(ragi->iunlink_prev, agino, &next_agino);
+ if (error)
+ goto out_rele;
+
+ error = xfs_iunlink_log_inode(sc->tp, ip, pag, next_agino);
+ if (error)
+ goto out_rele;
+
+ trace_xrep_iunlink_relink_next(ip, next_agino);
+ ip->i_next_unlinked = next_agino;
+ }
+
+ /* Update the backward pointer. */
+ if (ip->i_prev_unlinked != prev_agino) {
+ trace_xrep_iunlink_relink_prev(ip, prev_agino);
+ ip->i_prev_unlinked = prev_agino;
+ }
+
+out_rele:
+ /*
+ * The iunlink lookup doesn't igrab because we hold the AGI buffer lock
+ * and the inode cannot be reclaimed. However, if we used iget to load
+ * a missing inode, we must irele it here.
+ */
+ if (want_rele)
+ xchk_irele(sc, ip);
+ return error;
+}
+
+/* Log all the iunlink updates we need to finish regenerating the AGI. */
+STATIC int
+xrep_iunlink_commit(
+ struct xrep_agi *ragi)
+{
+ struct xfs_agi *agi = ragi->agi_bp->b_addr;
+ xfarray_idx_t idx = XFARRAY_CURSOR_INIT;
+ xfs_agino_t agino;
+ unsigned int i;
+ int error;
+
+ /* Fix all the forward links */
+ while ((error = xfarray_iter(ragi->iunlink_next, &idx, &agino)) == 1) {
+ error = xrep_iunlink_relink_next(ragi, idx, agino);
+ if (error)
+ return error;
+ }
+
+ /* Fix all the back links */
+ idx = XFARRAY_CURSOR_INIT;
+ while ((error = xfarray_iter(ragi->iunlink_prev, &idx, &agino)) == 1) {
+ error = xrep_iunlink_relink_prev(ragi, idx, agino);
+ if (error)
+ return error;
+ }
+
+ /* Copy the staged iunlink buckets to the new AGI. */
+ for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
+ trace_xrep_iunlink_commit_bucket(ragi->sc->sa.pag, i,
+ be32_to_cpu(ragi->old_agi.agi_unlinked[i]),
+ ragi->iunlink_heads[i]);
+
+ agi->agi_unlinked[i] = cpu_to_be32(ragi->iunlink_heads[i]);
+ }
+
+ return 0;
+}
+
/* Trigger reinitialization of the in-core data. */
STATIC int
xrep_agi_commit_new(
@@ -979,6 +1716,8 @@ xrep_agi(
{
struct xrep_agi *ragi;
struct xfs_mount *mp = sc->mp;
+ char *descr;
+ unsigned int i;
int error;

/* We require the rmapbt to rebuild anything. */
@@ -1005,6 +1744,26 @@ xrep_agi(
.buf_ops = NULL,
};

+ for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)
+ ragi->iunlink_heads[i] = NULLAGINO;
+
+ xagino_bitmap_init(&ragi->iunlink_bmp);
+ sc->buf_cleanup = xrep_agi_buf_cleanup;
+
+ descr = xchk_xfile_ag_descr(sc, "iunlinked next pointers");
+ error = xfarray_create(descr, 0, sizeof(xfs_agino_t),
+ &ragi->iunlink_next);
+ kfree(descr);
+ if (error)
+ return error;
+
+ descr = xchk_xfile_ag_descr(sc, "iunlinked prev pointers");
+ error = xfarray_create(descr, 0, sizeof(xfs_agino_t),
+ &ragi->iunlink_prev);
+ kfree(descr);
+ if (error)
+ return error;
+
/*
* Make sure we have the AGI buffer, as scrub might have decided it
* was corrupt after xfs_ialloc_read_agi failed with -EFSCORRUPTED.
@@ -1022,6 +1781,10 @@ xrep_agi(
if (error)
return error;

+ error = xrep_iunlink_rebuild_buckets(ragi);
+ if (error)
+ return error;
+
/* Last chance to abort before we start committing fixes. */
if (xchk_should_terminate(sc, &error))
return error;
@@ -1030,6 +1793,9 @@ xrep_agi(
xrep_agi_init_header(ragi);
xrep_agi_set_roots(ragi);
error = xrep_agi_calc_from_btrees(ragi);
+ if (error)
+ goto out_revert;
+ error = xrep_iunlink_commit(ragi);
if (error)
goto out_revert;

diff --git a/fs/xfs/scrub/agino_bitmap.h b/fs/xfs/scrub/agino_bitmap.h
new file mode 100644
index 0000000000000..56d7db5f16999
--- /dev/null
+++ b/fs/xfs/scrub/agino_bitmap.h
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2018-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SCRUB_AGINO_BITMAP_H__
+#define __XFS_SCRUB_AGINO_BITMAP_H__
+
+/* Bitmaps, but for type-checked for xfs_agino_t */
+
+struct xagino_bitmap {
+ struct xbitmap32 aginobitmap;
+};
+
+static inline void xagino_bitmap_init(struct xagino_bitmap *bitmap)
+{
+ xbitmap32_init(&bitmap->aginobitmap);
+}
+
+static inline void xagino_bitmap_destroy(struct xagino_bitmap *bitmap)
+{
+ xbitmap32_destroy(&bitmap->aginobitmap);
+}
+
+static inline int xagino_bitmap_clear(struct xagino_bitmap *bitmap,
+ xfs_agino_t agino, unsigned int len)
+{
+ return xbitmap32_clear(&bitmap->aginobitmap, agino, len);
+}
+
+static inline int xagino_bitmap_set(struct xagino_bitmap *bitmap,
+ xfs_agino_t agino, unsigned int len)
+{
+ return xbitmap32_set(&bitmap->aginobitmap, agino, len);
+}
+
+static inline bool xagino_bitmap_test(struct xagino_bitmap *bitmap,
+ xfs_agino_t agino, unsigned int *len)
+{
+ return xbitmap32_test(&bitmap->aginobitmap, agino, len);
+}
+
+static inline int xagino_bitmap_walk(struct xagino_bitmap *bitmap,
+ xbitmap32_walk_fn fn, void *priv)
+{
+ return xbitmap32_walk(&bitmap->aginobitmap, fn, priv);
+}
+
+#endif /* __XFS_SCRUB_AGINO_BITMAP_H__ */
diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index 4e9c9922a4140..0bc63b67a39d4 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -2751,6 +2751,261 @@ DEFINE_EVENT(xrep_symlink_class, name, \
DEFINE_XREP_SYMLINK_EVENT(xrep_symlink_rebuild);
DEFINE_XREP_SYMLINK_EVENT(xrep_symlink_reset_fork);

+TRACE_EVENT(xrep_iunlink_visit,
+ TP_PROTO(struct xfs_perag *pag, unsigned int bucket,
+ xfs_agino_t bucket_agino, struct xfs_inode *ip),
+ TP_ARGS(pag, bucket, bucket_agino, ip),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(xfs_agino_t, agino)
+ __field(unsigned int, bucket)
+ __field(xfs_agino_t, bucket_agino)
+ __field(xfs_agino_t, prev_agino)
+ __field(xfs_agino_t, next_agino)
+ ),
+ TP_fast_assign(
+ __entry->dev = pag->pag_mount->m_super->s_dev;
+ __entry->agno = pag->pag_agno;
+ __entry->agino = XFS_INO_TO_AGINO(pag->pag_mount, ip->i_ino);
+ __entry->bucket = bucket;
+ __entry->bucket_agino = bucket_agino;
+ __entry->prev_agino = ip->i_prev_unlinked;
+ __entry->next_agino = ip->i_next_unlinked;
+ ),
+ TP_printk("dev %d:%d agno 0x%x bucket %u agino 0x%x bucket_agino 0x%x prev_agino 0x%x next_agino 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->bucket,
+ __entry->agino,
+ __entry->bucket_agino,
+ __entry->prev_agino,
+ __entry->next_agino)
+);
+
+TRACE_EVENT(xrep_iunlink_reload_next,
+ TP_PROTO(struct xfs_inode *ip, xfs_agino_t prev_agino),
+ TP_ARGS(ip, prev_agino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(xfs_agino_t, agino)
+ __field(xfs_agino_t, old_prev_agino)
+ __field(xfs_agino_t, prev_agino)
+ __field(xfs_agino_t, next_agino)
+ __field(unsigned int, nlink)
+ ),
+ TP_fast_assign(
+ __entry->dev = ip->i_mount->m_super->s_dev;
+ __entry->agno = XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino);
+ __entry->agino = XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino);
+ __entry->old_prev_agino = ip->i_prev_unlinked;
+ __entry->prev_agino = prev_agino;
+ __entry->next_agino = ip->i_next_unlinked;
+ __entry->nlink = VFS_I(ip)->i_nlink;
+ ),
+ TP_printk("dev %d:%d agno 0x%x bucket %u agino 0x%x nlink %u old_prev_agino %u prev_agino 0x%x next_agino 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->agino % XFS_AGI_UNLINKED_BUCKETS,
+ __entry->agino,
+ __entry->nlink,
+ __entry->old_prev_agino,
+ __entry->prev_agino,
+ __entry->next_agino)
+);
+
+TRACE_EVENT(xrep_iunlink_reload_ondisk,
+ TP_PROTO(struct xfs_inode *ip),
+ TP_ARGS(ip),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(xfs_agino_t, agino)
+ __field(unsigned int, nlink)
+ __field(xfs_agino_t, next_agino)
+ ),
+ TP_fast_assign(
+ __entry->dev = ip->i_mount->m_super->s_dev;
+ __entry->agno = XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino);
+ __entry->agino = XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino);
+ __entry->nlink = VFS_I(ip)->i_nlink;
+ __entry->next_agino = ip->i_next_unlinked;
+ ),
+ TP_printk("dev %d:%d agno 0x%x bucket %u agino 0x%x nlink %u next_agino 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->agino % XFS_AGI_UNLINKED_BUCKETS,
+ __entry->agino,
+ __entry->nlink,
+ __entry->next_agino)
+);
+
+TRACE_EVENT(xrep_iunlink_walk_ondisk_bucket,
+ TP_PROTO(struct xfs_perag *pag, unsigned int bucket,
+ xfs_agino_t prev_agino, xfs_agino_t next_agino),
+ TP_ARGS(pag, bucket, prev_agino, next_agino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(unsigned int, bucket)
+ __field(xfs_agino_t, prev_agino)
+ __field(xfs_agino_t, next_agino)
+ ),
+ TP_fast_assign(
+ __entry->dev = pag->pag_mount->m_super->s_dev;
+ __entry->agno = pag->pag_agno;
+ __entry->bucket = bucket;
+ __entry->prev_agino = prev_agino;
+ __entry->next_agino = next_agino;
+ ),
+ TP_printk("dev %d:%d agno 0x%x bucket %u prev_agino 0x%x next_agino 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->bucket,
+ __entry->prev_agino,
+ __entry->next_agino)
+);
+
+DECLARE_EVENT_CLASS(xrep_iunlink_resolve_class,
+ TP_PROTO(struct xfs_perag *pag, unsigned int bucket,
+ xfs_agino_t prev_agino, xfs_agino_t next_agino),
+ TP_ARGS(pag, bucket, prev_agino, next_agino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(unsigned int, bucket)
+ __field(xfs_agino_t, prev_agino)
+ __field(xfs_agino_t, next_agino)
+ ),
+ TP_fast_assign(
+ __entry->dev = pag->pag_mount->m_super->s_dev;
+ __entry->agno = pag->pag_agno;
+ __entry->bucket = bucket;
+ __entry->prev_agino = prev_agino;
+ __entry->next_agino = next_agino;
+ ),
+ TP_printk("dev %d:%d agno 0x%x bucket %u prev_agino 0x%x next_agino 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->bucket,
+ __entry->prev_agino,
+ __entry->next_agino)
+);
+#define DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(name) \
+DEFINE_EVENT(xrep_iunlink_resolve_class, name, \
+ TP_PROTO(struct xfs_perag *pag, unsigned int bucket, \
+ xfs_agino_t prev_agino, xfs_agino_t next_agino), \
+ TP_ARGS(pag, bucket, prev_agino, next_agino))
+DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(xrep_iunlink_resolve_uncached);
+DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(xrep_iunlink_resolve_wronglist);
+DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(xrep_iunlink_resolve_nolist);
+DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(xrep_iunlink_resolve_ok);
+
+TRACE_EVENT(xrep_iunlink_relink_next,
+ TP_PROTO(struct xfs_inode *ip, xfs_agino_t next_agino),
+ TP_ARGS(ip, next_agino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(xfs_agino_t, agino)
+ __field(xfs_agino_t, next_agino)
+ __field(xfs_agino_t, new_next_agino)
+ ),
+ TP_fast_assign(
+ __entry->dev = ip->i_mount->m_super->s_dev;
+ __entry->agno = XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino);
+ __entry->agino = XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino);
+ __entry->next_agino = ip->i_next_unlinked;
+ __entry->new_next_agino = next_agino;
+ ),
+ TP_printk("dev %d:%d agno 0x%x bucket %u agino 0x%x next_agino 0x%x -> 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->agino % XFS_AGI_UNLINKED_BUCKETS,
+ __entry->agino,
+ __entry->next_agino,
+ __entry->new_next_agino)
+);
+
+TRACE_EVENT(xrep_iunlink_relink_prev,
+ TP_PROTO(struct xfs_inode *ip, xfs_agino_t prev_agino),
+ TP_ARGS(ip, prev_agino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(xfs_agino_t, agino)
+ __field(xfs_agino_t, prev_agino)
+ __field(xfs_agino_t, new_prev_agino)
+ ),
+ TP_fast_assign(
+ __entry->dev = ip->i_mount->m_super->s_dev;
+ __entry->agno = XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino);
+ __entry->agino = XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino);
+ __entry->prev_agino = ip->i_prev_unlinked;
+ __entry->new_prev_agino = prev_agino;
+ ),
+ TP_printk("dev %d:%d agno 0x%x bucket %u agino 0x%x prev_agino 0x%x -> 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->agino % XFS_AGI_UNLINKED_BUCKETS,
+ __entry->agino,
+ __entry->prev_agino,
+ __entry->new_prev_agino)
+);
+
+TRACE_EVENT(xrep_iunlink_add_to_bucket,
+ TP_PROTO(struct xfs_perag *pag, unsigned int bucket,
+ xfs_agino_t agino, xfs_agino_t curr_head),
+ TP_ARGS(pag, bucket, agino, curr_head),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(unsigned int, bucket)
+ __field(xfs_agino_t, agino)
+ __field(xfs_agino_t, next_agino)
+ ),
+ TP_fast_assign(
+ __entry->dev = pag->pag_mount->m_super->s_dev;
+ __entry->agno = pag->pag_agno;
+ __entry->bucket = bucket;
+ __entry->agino = agino;
+ __entry->next_agino = curr_head;
+ ),
+ TP_printk("dev %d:%d agno 0x%x bucket %u agino 0x%x next_agino 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->bucket,
+ __entry->agino,
+ __entry->next_agino)
+);
+
+TRACE_EVENT(xrep_iunlink_commit_bucket,
+ TP_PROTO(struct xfs_perag *pag, unsigned int bucket,
+ xfs_agino_t old_agino, xfs_agino_t agino),
+ TP_ARGS(pag, bucket, old_agino, agino),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(xfs_agnumber_t, agno)
+ __field(unsigned int, bucket)
+ __field(xfs_agino_t, old_agino)
+ __field(xfs_agino_t, agino)
+ ),
+ TP_fast_assign(
+ __entry->dev = pag->pag_mount->m_super->s_dev;
+ __entry->agno = pag->pag_agno;
+ __entry->bucket = bucket;
+ __entry->old_agino = old_agino;
+ __entry->agino = agino;
+ ),
+ TP_printk("dev %d:%d agno 0x%x bucket %u agino 0x%x -> 0x%x",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->agno,
+ __entry->bucket,
+ __entry->old_agino,
+ __entry->agino)
+);
+
#endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */

#endif /* _TRACE_XFS_SCRUB_TRACE_H */