Btrfs: Add full_scan parameter to find_search_start
This patch adds a new parameter 'full_scan' to 'find_search_start',
thereby 'find_search_start' can know whether 'find_free_extent' is in
full scan phrase. I feel that 'find_search_start' should skip calling
'btrfs_find_block_group' when 'find_free_extent' is in full scan
phrase. In my test on a 2GB volume, Oops occurs when space usage is
about 76%. After apply the patch, Oops occurs when space usage is
near 100%.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 4ef6dc3..e534067 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -158,10 +158,10 @@
return NULL;
}
-
static u64 find_search_start(struct btrfs_root *root,
struct btrfs_block_group_cache **cache_ret,
- u64 search_start, int num, int data)
+ u64 search_start, int num,
+ int data, int full_scan)
{
int ret;
struct btrfs_block_group_cache *cache = *cache_ret;
@@ -218,10 +218,10 @@
if (cache_miss && !cache->cached) {
cache_block_group(root, cache);
last = cache_miss;
-
cache = btrfs_lookup_block_group(root->fs_info, last);
}
- cache = btrfs_find_block_group(root, cache, last, data, 0);
+ if (!full_scan)
+ cache = btrfs_find_block_group(root, cache, last, data, 0);
*cache_ret = cache;
cache_miss = 0;
goto again;
@@ -979,12 +979,10 @@
total_needed += empty_size;
path = btrfs_alloc_path();
-
check_failed:
- search_start = find_search_start(root, &block_group,
- search_start, total_needed, data);
+ search_start = find_search_start(root, &block_group, search_start,
+ total_needed, data, full_scan);
cached_start = search_start;
-
btrfs_init_path(path);
ins->objectid = search_start;
ins->offset = 0;