Btrfs: Don't substract too much from the allocation target (avoid wrapping) (5b7c3fcc) · Commits · 戴 / test

When metadata allocation clustering has to fall back to unclustered allocs because large free areas could not be found, it was sometimes substracting too much from the total bytes to allocate. This would make it wrap below zero. Signed-off-by:

Chris Mason <chris.mason@oracle.com>

fs/btrfs/extent-tree.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -2255,9 +2255,9 @@ new_group:
		mutex_unlock(&block_group->alloc_mutex);
		new_group_no_lock:
		last_wanted = 0;
		if (!allowed_chunk_alloc && loop > 0) {
		total_needed -= empty_cluster;
		empty_cluster = 0;
		if (!allowed_chunk_alloc) {
		total_needed -= empty_size;
		empty_size = 0;
		}
		/*
		* Here's how this works.
		@@ -2277,8 +2277,8 @@ new_group_no_lock:
		loop++;
		} else if (loop == 1 && cur == head) {

		total_needed -= empty_cluster;
		empty_cluster = 0;
		total_needed -= empty_size;
		empty_size = 0;

		if (allowed_chunk_alloc && !chunk_alloc_done) {
		up_read(&space_info->groups_sem);

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