While messing with the overcommit logic I noticed that sometimes we'd ENOSPC out when really we should have run out of space much earlier. It turns out it's because we'll only reserve up to the free amount left in the space info for the global reserve, but that doesn't make sense with overcommit because we could be well above our actual size. This results in the global reserve not carving out it's entire reservation, and thus not putting enough pressure on the rest of the infrastructure to do the right thing and ENOSPC out at a convenient time. Fix this by always taking our full reservation amount for the global reserve.
Signed-off-by: Josef Bacik <[email protected]> --- fs/btrfs/block-rsv.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/block-rsv.c b/fs/btrfs/block-rsv.c index 657675eef443..18a0af20ee5a 100644 --- a/fs/btrfs/block-rsv.c +++ b/fs/btrfs/block-rsv.c @@ -295,15 +295,10 @@ void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info) block_rsv->size = min_t(u64, num_bytes, SZ_512M); if (block_rsv->reserved < block_rsv->size) { - num_bytes = btrfs_space_info_used(sinfo, true); - if (sinfo->total_bytes > num_bytes) { - num_bytes = sinfo->total_bytes - num_bytes; - num_bytes = min(num_bytes, - block_rsv->size - block_rsv->reserved); - block_rsv->reserved += num_bytes; - btrfs_space_info_update_bytes_may_use(fs_info, sinfo, - num_bytes); - } + num_bytes = block_rsv->size - block_rsv->reserved; + block_rsv->reserved += num_bytes; + btrfs_space_info_update_bytes_may_use(fs_info, sinfo, + num_bytes); } else if (block_rsv->reserved > block_rsv->size) { num_bytes = block_rsv->reserved - block_rsv->size; btrfs_space_info_update_bytes_may_use(fs_info, sinfo, -- 2.21.0
