There is a small bug from 2011, where btrfs_next_bg (formally
btrfs_next_metadata) function will always skip the first chunk.
That's OK for that time, as there is always 3 empty temporary chunks.
But now, we may ended up with only one metadata or system chunk, with
empty chunk auto-remove from kernel or new mkfs.btrfs.
So fix it by checking the initial value so btrfs_next_bg() will return
the first chunk if its *logical parameter is 0.
Signed-off-by: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx>
---
volumes.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/volumes.c b/volumes.c
index a94be0e..059c4f4 100644
--- a/volumes.c
+++ b/volumes.c
@@ -1170,14 +1170,23 @@ int btrfs_next_bg(struct btrfs_mapping_tree *map_tree, u64 *logical,
{
struct cache_extent *ce;
struct map_lookup *map;
+ u64 cur = *logical;
- ce = search_cache_extent(&map_tree->cache_tree, *logical);
+ ce = search_cache_extent(&map_tree->cache_tree, cur);
while (ce) {
- ce = next_cache_extent(ce);
- if (!ce)
- return -ENOENT;
+ /*
+ * only jump to next bg if our cur is not 0
+ * As the initial logical for btrfs_next_bg() is 0, and
+ * if we jump to next bg, we skipped a valid bg.
+ */
+ if (cur) {
+ ce = next_cache_extent(ce);
+ if (!ce)
+ return -ENOENT;
+ }
+ cur = ce->start;
map = container_of(ce, struct map_lookup, ce);
if (map->type & type) {
*logical = ce->start;
--
2.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
