From 4a309747aca08707cdced0d36f66d040f9977bb3 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Thu, 20 Jul 2017 15:10:35 -0700 Subject: [PATCH] Btrfs: fix early ENOSPC due to delalloc commit 17024ad0a0fdfcfe53043afb969b813d3e020c21 upstream. 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, as well as early ENOSPCs Christoph saw when doing a big cp -r onto Btrfs. Fixes: 957780eb2788 ("Btrfs: introduce ticketed enospc infrastructure") Tested-by: Christoph Anton Mitterer Reviewed-by: Josef Bacik Signed-off-by: Omar Sandoval Signed-off-by: David Sterba Signed-off-by: Nikolay Borisov Signed-off-by: Greg Kroah-Hartman --- 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 33d979e9ea2a3..83eecd33ad96c 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4776,10 +4776,6 @@ skip_async: 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); -- 2.47.2