Cached pointers now have backpointers. This means that we'll be able to kill cached pointers in the bucket_invalidate path, when invalidating/reusing buckets containing cached data, instead of leaving them around to be cleaned up by gc_gens garbago collection - which requires a full metadata scan.
Signed-off-by: Kent Overstreet <[email protected]> --- fs/bcachefs/backpointers.c | 14 +++++++------- fs/bcachefs/bcachefs_format.h | 3 ++- fs/bcachefs/buckets.c | 8 +++----- fs/bcachefs/sb-downgrade.c | 3 +++ 4 files changed, 15 insertions(+), 13 deletions(-) diff --git a/fs/bcachefs/backpointers.c b/fs/bcachefs/backpointers.c index bb799b86aa69..c9dfc3657696 100644 --- a/fs/bcachefs/backpointers.c +++ b/fs/bcachefs/backpointers.c @@ -611,9 +611,6 @@ static int check_extent_to_backpointers(struct btree_trans *trans, struct extent_ptr_decoded p; bkey_for_each_ptr_decode(k.k, ptrs, p, entry) { - if (p.ptr.cached) - continue; - if (p.ptr.dev == BCH_SB_MEMBER_INVALID) continue; @@ -621,9 +618,11 @@ static int check_extent_to_backpointers(struct btree_trans *trans, struct bch_dev *ca = bch2_dev_rcu_noerror(c, p.ptr.dev); bool check = ca && test_bit(PTR_BUCKET_NR(ca, &p.ptr), ca->bucket_backpointer_mismatches); bool empty = ca && test_bit(PTR_BUCKET_NR(ca, &p.ptr), ca->bucket_backpointer_empty); + + bool stale = p.ptr.cached && (!ca || dev_ptr_stale_rcu(ca, &p.ptr)); rcu_read_unlock(); - if (check || empty) { + if ((check || empty) && !stale) { struct bkey_i_backpointer bp; bch2_extent_ptr_to_bp(c, btree, level, k, p, entry, &bp); @@ -857,9 +856,8 @@ static int check_bucket_backpointer_mismatch(struct btree_trans *trans, struct b goto err; } - /* Cached pointers don't have backpointers: */ - if (sectors[ALLOC_dirty] != a->dirty_sectors || + sectors[ALLOC_cached] != a->cached_sectors || sectors[ALLOC_stripe] != a->stripe_sectors) { if (c->sb.version_upgrade_complete >= bcachefs_metadata_version_backpointer_bucket_gen) { ret = bch2_backpointers_maybe_flush(trans, alloc_k, last_flushed); @@ -868,6 +866,7 @@ static int check_bucket_backpointer_mismatch(struct btree_trans *trans, struct b } if (sectors[ALLOC_dirty] > a->dirty_sectors || + sectors[ALLOC_cached] > a->cached_sectors || sectors[ALLOC_stripe] > a->stripe_sectors) { ret = check_bucket_backpointers_to_extents(trans, ca, alloc_k.k->p) ?: -BCH_ERR_transaction_restart_nested; @@ -875,7 +874,8 @@ static int check_bucket_backpointer_mismatch(struct btree_trans *trans, struct b } if (!sectors[ALLOC_dirty] && - !sectors[ALLOC_stripe]) + !sectors[ALLOC_stripe] && + !sectors[ALLOC_cached]) __set_bit(alloc_k.k->p.offset, ca->bucket_backpointer_empty); else __set_bit(alloc_k.k->p.offset, ca->bucket_backpointer_mismatches); diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h index f70f0108401f..ef5009b18dd5 100644 --- a/fs/bcachefs/bcachefs_format.h +++ b/fs/bcachefs/bcachefs_format.h @@ -686,7 +686,8 @@ struct bch_sb_field_ext { x(inode_depth, BCH_VERSION(1, 17)) \ x(persistent_inode_cursors, BCH_VERSION(1, 18)) \ x(autofix_errors, BCH_VERSION(1, 19)) \ - x(directory_size, BCH_VERSION(1, 20)) + x(directory_size, BCH_VERSION(1, 20)) \ + x(cached_backpointers, BCH_VERSION(1, 21)) enum bcachefs_metadata_version { bcachefs_metadata_version_min = 9, diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c index 88af61bc799d..bb7742cf0014 100644 --- a/fs/bcachefs/buckets.c +++ b/fs/bcachefs/buckets.c @@ -590,11 +590,9 @@ static int bch2_trigger_pointer(struct btree_trans *trans, if (ret) goto err; - if (!p.ptr.cached) { - ret = bch2_bucket_backpointer_mod(trans, k, &bp, insert); - if (ret) - goto err; - } + ret = bch2_bucket_backpointer_mod(trans, k, &bp, insert); + if (ret) + goto err; } if (flags & BTREE_TRIGGER_gc) { diff --git a/fs/bcachefs/sb-downgrade.c b/fs/bcachefs/sb-downgrade.c index 14f6b6a5fb38..34fd897680b3 100644 --- a/fs/bcachefs/sb-downgrade.c +++ b/fs/bcachefs/sb-downgrade.c @@ -94,6 +94,9 @@ x(directory_size, \ BIT_ULL(BCH_RECOVERY_PASS_check_inodes), \ BCH_FSCK_ERR_directory_size_mismatch) \ + x(cached_backpointers, \ + BIT_ULL(BCH_RECOVERY_PASS_check_extents_to_backpointers),\ + BCH_FSCK_ERR_ptr_to_missing_backpointer) #define DOWNGRADE_TABLE() \ x(bucket_stripe_sectors, \ -- 2.45.2
