mirrors/scoutfs
1
0
Fork 0
mirror of https://github.com/versity/scoutfs.git synced 2026-07-27 10:33:08 +00:00
Code Issues Packages Projects Releases Wiki Activity

scoutfs: add unused item page rbtree verification

Browse Source 
Add a quick function that walks the rbtree and makes sure it doesn't see
any obvious key errors.  This is far too expensive to use regularly but
it's handy to have around and add calls to when debugging.

Signed-off-by: Zach Brown <zab@versity.com>
This commit is contained in:
Zach Brown
2020-10-26 15:19:03 -07:00
committed by Zach Brown
parent 005cf99f42
commit e347ca3606
1 changed files with 88 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kmod/src/item.c
+88
View File
@@ -236,6 +236,94 @@ static void rbtree_replace_node(struct rb_node *victim, struct rb_node *new,
RB_CLEAR_NODE(victim);
}
/*
* This is far too expensive to use regularly, but it's very helpful for
* discovering corruption after modifications to cached pages.
*/
static __attribute__((unused)) void verify_page_rbtree(struct rb_root *root)
{
struct cached_item *item;
struct cached_page *par;
struct cached_page *pg;
struct cached_page *n;
char *reason = NULL;
struct rb_node *p;
int cmp;
rbtree_postorder_for_each_entry_safe(pg, n, root, node) {
item = NULL;
par = NULL;
if (scoutfs_key_compare(&pg->start, &pg->end) > 0) {
reason = "start > end";
break;
}
item = first_item(&pg->item_root);
if (item && scoutfs_key_compare(&item->key, &pg->start) < 0) {
reason = "first item < start";
break;
}
item = last_item(&pg->item_root);
if (item && scoutfs_key_compare(&item->key, &pg->end) > 0) {
reason = "last item > end";
break;
}
p = rb_parent(&pg->node);
if (!p)
continue;
par = rb_entry(p, struct cached_page, node);
cmp = scoutfs_key_compare_ranges(&pg->start, &pg->end,
&par->start, &par->end);
if (cmp == 0) {
reason = "parent and child overlap";
break;
}
if (par->node.rb_right == &pg->node && cmp < 0) {
reason = "right child < parent";
break;
}
if (par->node.rb_left == &pg->node && cmp > 0) {
reason = "left child > parent";
break;
}
}
if (!reason)
return;
printk("bad item page rbtree: %s\n", reason);
printk("pg %p start "SK_FMT" end "SK_FMT"\n",
pg, SK_ARG(&pg->start), SK_ARG(&pg->end));
if (par)
printk("par %p start "SK_FMT" end "SK_FMT"\n",
par, SK_ARG(&par->start), SK_ARG(&par->end));
if (item)
printk("item %p key "SK_FMT"\n", item, SK_ARG(&item->key));
rbtree_postorder_for_each_entry_safe(pg, n, root, node) {
printk(" pg %p left %p right %p start "SK_FMT" end "SK_FMT"\n",
pg,
pg->node.rb_left ? rb_entry(pg->node.rb_left,
struct cached_page, node) :
NULL,
pg->node.rb_right ? rb_entry(pg->node.rb_right,
struct cached_page, node) :
NULL,
SK_ARG(&pg->start),
SK_ARG(&pg->end));
}
BUG();
}
/*
* This lets us lock newly allocated pages without having to add nesting
* annotation. The non-acquired path is never executed.