From c9163bb03b81e465019cf56d2edf47b70798e3ee Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Tue, 21 Feb 2023 19:22:44 -0500 Subject: bcachefs: Cached pointers should not be erasure coded There's no reason to erasure code cached pointers: we'll always have another copy, and it'll be cheaper to read the other copy than do a reconstruct read. And erasure coded cached pointers would add complications that we'd rather not have to deal with, so let's make sure to disallow them. Signed-off-by: Kent Overstreet --- fs/bcachefs/extents.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) (limited to 'fs/bcachefs/extents.c') diff --git a/fs/bcachefs/extents.c b/fs/bcachefs/extents.c index 4b865949768f..2e41545dc1e9 100644 --- a/fs/bcachefs/extents.c +++ b/fs/bcachefs/extents.c @@ -950,6 +950,29 @@ bool bch2_extent_has_ptr(struct bkey_s_c k1, struct extent_ptr_decoded p1, return false; } +void bch2_extent_ptr_set_cached(struct bkey_s k, struct bch_extent_ptr *ptr) +{ + struct bkey_ptrs ptrs = bch2_bkey_ptrs(k); + union bch_extent_entry *entry; + union bch_extent_entry *ec = NULL; + + bkey_extent_entry_for_each(ptrs, entry) { + if (&entry->ptr == ptr) { + ptr->cached = true; + if (ec) + extent_entry_drop(k, ec); + return; + } + + if (extent_entry_is_stripe_ptr(entry)) + ec = entry; + else if (extent_entry_is_ptr(entry)) + ec = NULL; + } + + BUG(); +} + /* * bch_extent_normalize - clean up an extent, dropping stale pointers etc. * @@ -1093,7 +1116,7 @@ int bch2_bkey_ptrs_invalid(const struct bch_fs *c, struct bkey_s_c k, unsigned size_ondisk = k.k->size; unsigned nonce = UINT_MAX; unsigned nr_ptrs = 0; - bool unwritten = false; + bool unwritten = false, have_ec = false; int ret; if (bkey_is_btree_ptr(k.k)) @@ -1129,7 +1152,13 @@ int bch2_bkey_ptrs_invalid(const struct bch_fs *c, struct bkey_s_c k, return -BCH_ERR_invalid_bkey; } + if (entry->ptr.cached && have_ec) { + prt_printf(err, "cached, erasure coded ptr"); + return -BCH_ERR_invalid_bkey; + } + unwritten = entry->ptr.unwritten; + have_ec = false; nr_ptrs++; break; case BCH_EXTENT_ENTRY_crc32: @@ -1165,6 +1194,7 @@ int bch2_bkey_ptrs_invalid(const struct bch_fs *c, struct bkey_s_c k, } break; case BCH_EXTENT_ENTRY_stripe_ptr: + have_ec = true; break; } } -- cgit v1.2.3