From e9e22899de661af94cb9995885fd04e4c738838b Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 24 Jan 2011 21:43:19 +0000 Subject: Btrfs: do not release more reserved bytes to the global_block_rsv than we need When we do btrfs_block_rsv_release, if global_block_rsv is not full we will release all the extra bytes to global_block_rsv, even if it's only a little short of the amount of space that we need to reserve. This causes us to starve ourselves of reservable space during the transaction which will force us to shrink delalloc bytes and commit the transaction more often than we should. So instead just add the amount of bytes we need to add to the global reserve so reserved == size, and then add the rest back into the space_info for general use. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 98ee139..7af618d 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3589,8 +3589,20 @@ void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv, if (num_bytes > 0) { if (dest) { - block_rsv_add_bytes(dest, num_bytes, 0); - } else { + spin_lock(&dest->lock); + if (!dest->full) { + u64 bytes_to_add; + + bytes_to_add = dest->size - dest->reserved; + bytes_to_add = min(num_bytes, bytes_to_add); + dest->reserved += bytes_to_add; + if (dest->reserved >= dest->size) + dest->full = 1; + num_bytes -= bytes_to_add; + } + spin_unlock(&dest->lock); + } + if (num_bytes) { spin_lock(&space_info->lock); space_info->bytes_reserved -= num_bytes; spin_unlock(&space_info->lock); -- cgit v1.1