bcachefs: More improvements for alloc info checks

 - Move checks for whether the device & bucket are valid from the
   .key_invalid method to bch2_check_alloc_key(). This is because
   .key_invalid() is called on keys that may no longer exist (post
   journal replay), which is a problem when removing/resizing devices.

 - We weren't checking the need_discard btree to ensure that every set
   bucket has a corresponding alloc key. This refactors the code for
   checking the freespace btree, so that it now checks both.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c
index 5b78e8f983a1..31720093de45 100644
--- a/fs/bcachefs/buckets.c
+++ b/fs/bcachefs/buckets.c
@@ -511,14 +511,9 @@ int bch2_mark_alloc(struct btree_trans *trans,
 	u64 journal_seq = trans->journal_res.seq;
 	struct bch_fs *c = trans->c;
 	struct bch_alloc_v4 old_a, new_a;
-	struct bch_dev *ca = bch_dev_bkey_exists(c, new.k->p.inode);
+	struct bch_dev *ca;
 	int ret = 0;
 
-	if (bch2_trans_inconsistent_on(new.k->p.offset < ca->mi.first_bucket ||
-				       new.k->p.offset >= ca->mi.nbuckets, trans,
-				       "alloc key outside range of device's buckets"))
-		return -EIO;
-
 	/*
 	 * alloc btree is read in by bch2_alloc_read, not gc:
 	 */
@@ -526,6 +521,12 @@ int bch2_mark_alloc(struct btree_trans *trans,
 	    !(flags & BTREE_TRIGGER_BUCKET_INVALIDATE))
 		return 0;
 
+	if (bch2_trans_inconsistent_on(!bch2_dev_bucket_exists(c, new.k->p), trans,
+				       "alloc key for invalid device or bucket"))
+		return -EIO;
+
+	ca = bch_dev_bkey_exists(c, new.k->p.inode);
+
 	bch2_alloc_to_v4(old, &old_a);
 	bch2_alloc_to_v4(new, &new_a);