From: Omar Sandoval <[email protected]> If a lot of metadata is reserved for outstanding delayed allocations, we rely on shrink_delalloc() to reclaim metadata space in order to fulfill reservation tickets. However, shrink_delalloc() has a shortcut where if it determines that space can be overcommitted, it will stop early. This made sense before the ticketed enospc system, but now it means that shrink_delalloc() will often not reclaim enough space to fulfill any tickets, leading to an early ENOSPC. (Reservation tickets don't care about being able to overcommit, they need every byte accounted for.)
Fix it by getting rid of the shortcut so that shrink_delalloc() reclaims all of the metadata it is supposed to. This fixes early ENOSPCs we were seeing when doing a btrfs receive to populate a new filesystem. Signed-off-by: Omar Sandoval <[email protected]> --- I don't have a good reproducer for this except for the btrfs send stream I was given by someone internally, unfortunately. fs/btrfs/extent-tree.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 33d979e9ea2a..83eecd33ad96 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4776,10 +4776,6 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig, else flush = BTRFS_RESERVE_NO_FLUSH; spin_lock(&space_info->lock); - if (can_overcommit(root, space_info, orig, flush)) { - spin_unlock(&space_info->lock); - break; - } if (list_empty(&space_info->tickets) && list_empty(&space_info->priority_tickets)) { spin_unlock(&space_info->lock); -- 2.13.2 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
