Btrfs: skip looking for delalloc if we don't have ->fill_delalloc
We always look for delalloc bytes in our io_tree so we can fill in delalloc.
This is fine in most cases, but if we're writing out the btree_inode this is
just a superfluous tree search on the io_tree, and if we have a lot of metadata
dirty this could be an expensive check. So instead check to see if our io_tree
has a ->fill_delalloc op, and if not don't even bother doing the lookup.
Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index d418164..7d5e556 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2136,6 +2136,7 @@
int compressed;
int write_flags;
unsigned long nr_written = 0;
+ bool fill_delalloc = true;
if (wbc->sync_mode == WB_SYNC_ALL)
write_flags = WRITE_SYNC;
@@ -2166,10 +2167,13 @@
set_page_extent_mapped(page);
+ if (!tree->ops || !tree->ops->fill_delalloc)
+ fill_delalloc = false;
+
delalloc_start = start;
delalloc_end = 0;
page_started = 0;
- if (!epd->extent_locked) {
+ if (!epd->extent_locked && fill_delalloc) {
u64 delalloc_to_write = 0;
/*
* make sure the wbc mapping index is at least updated