1 files changed, 32 insertions, 17 deletions

diff --git a/fs/bcachefs/extents.c b/fs/bcachefs/extents.c
index e317df3644a1..324303bf4353 100644
--- a/fs/bcachefs/extents.c
+++ b/fs/bcachefs/extents.c
@@ -781,14 +781,17 @@ static union bch_extent_entry *extent_entry_prev(struct bkey_ptrs ptrs,
 /*
  * Returns pointer to the next entry after the one being dropped:
  */
-union bch_extent_entry *bch2_bkey_drop_ptr_noerror(struct bkey_s k,
-						   struct bch_extent_ptr *ptr)
+void bch2_bkey_drop_ptr_noerror(struct bkey_s k, struct bch_extent_ptr *ptr)
 {
 	struct bkey_ptrs ptrs = bch2_bkey_ptrs(k);
 	union bch_extent_entry *entry = to_entry(ptr), *next;
-	union bch_extent_entry *ret = entry;
 	bool drop_crc = true;
 
+	if (k.k->type == KEY_TYPE_stripe) {
+		ptr->dev = BCH_SB_MEMBER_INVALID;
+		return;
+	}
+
 	EBUG_ON(ptr < &ptrs.start->ptr ||
 		ptr >= &ptrs.end->ptr);
 	EBUG_ON(ptr->type != 1 << BCH_EXTENT_ENTRY_ptr);
@@ -811,21 +814,16 @@ union bch_extent_entry *bch2_bkey_drop_ptr_noerror(struct bkey_s k,
 			break;
 
 		if ((extent_entry_is_crc(entry) && drop_crc) ||
-		    extent_entry_is_stripe_ptr(entry)) {
-			ret = (void *) ret - extent_entry_bytes(entry);
+		    extent_entry_is_stripe_ptr(entry))
 			extent_entry_drop(k, entry);
-		}
 	}
-
-	return ret;
 }
 
-union bch_extent_entry *bch2_bkey_drop_ptr(struct bkey_s k,
-					   struct bch_extent_ptr *ptr)
+void bch2_bkey_drop_ptr(struct bkey_s k, struct bch_extent_ptr *ptr)
 {
 	bool have_dirty = bch2_bkey_dirty_devs(k.s_c).nr;
-	union bch_extent_entry *ret =
-		bch2_bkey_drop_ptr_noerror(k, ptr);
+
+	bch2_bkey_drop_ptr_noerror(k, ptr);
 
 	/*
 	 * If we deleted all the dirty pointers and there's still cached
@@ -837,14 +835,10 @@ union bch_extent_entry *bch2_bkey_drop_ptr(struct bkey_s k,
 	    !bch2_bkey_dirty_devs(k.s_c).nr) {
 		k.k->type = KEY_TYPE_error;
 		set_bkey_val_u64s(k.k, 0);
-		ret = NULL;
 	} else if (!bch2_bkey_nr_ptrs(k.s_c)) {
 		k.k->type = KEY_TYPE_deleted;
 		set_bkey_val_u64s(k.k, 0);
-		ret = NULL;
 	}
-
-	return ret;
 }
 
 void bch2_bkey_drop_device(struct bkey_s k, unsigned dev)
@@ -929,8 +923,29 @@ bool bch2_extents_match(struct bkey_s_c k1, struct bkey_s_c k2)
 			bkey_for_each_ptr_decode(k2.k, ptrs2, p2, entry2)
 				if (p1.ptr.dev		== p2.ptr.dev &&
 				    p1.ptr.gen		== p2.ptr.gen &&
+
+				    /*
+				     * This checks that the two pointers point
+				     * to the same region on disk - adjusting
+				     * for the difference in where the extents
+				     * start, since one may have been trimmed:
+				     */
 				    (s64) p1.ptr.offset + p1.crc.offset - bkey_start_offset(k1.k) ==
-				    (s64) p2.ptr.offset + p2.crc.offset - bkey_start_offset(k2.k))
+				    (s64) p2.ptr.offset + p2.crc.offset - bkey_start_offset(k2.k) &&
+
+				    /*
+				     * This additionally checks that the
+				     * extents overlap on disk, since the
+				     * previous check may trigger spuriously
+				     * when one extent is immediately partially
+				     * overwritten with another extent (so that
+				     * on disk they are adjacent) and
+				     * compression is in use:
+				     */
+				    ((p1.ptr.offset >= p2.ptr.offset &&
+				      p1.ptr.offset  < p2.ptr.offset + p2.crc.compressed_size) ||
+				     (p2.ptr.offset >= p1.ptr.offset &&
+				      p2.ptr.offset  < p1.ptr.offset + p1.crc.compressed_size)))
 					return true;
 
 		return false;