Hello,
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%.
Regards
YZ
----
diff -r 433cf4043126 extent-tree.c
--- a/extent-tree.c Sun Nov 11 08:22:00 2007 -0500
+++ b/extent-tree.c Mon Nov 12 18:44:36 2007 +0800
@@ -161,7 +161,8 @@ struct btrfs_block_group_cache *btrfs_lo
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;
@@ -221,7 +222,8 @@ wrapped:
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;
@@ -955,8 +957,8 @@ static int find_free_extent(struct btrfs
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);
