Btrfs: Don't substract too much from the allocation target (avoid wrapping)

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>
This commit is contained in:
Chris Mason 2008-11-10 07:26:33 -05:00
parent 5f2cc086cc
commit 5b7c3fcc46

View file

@ -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);