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radix-tree: fix multiorder BUG_ON in radix_tree_insert

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These BUG_ON tests are to ensure that all the tags are clear when
inserting a new entry.  If we insert a multiorder entry, we'll end up
looking at the tags for a different node, and so the BUG_ON can end up
triggering spuriously.

Also, we now have three tags, not two, so check all three are clear, and
check all the root tags with a single call to BUG_ON since the bits are
stored contiguously.

Include a test-case to ensure this problem does not reoccur.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox
2016-05-20 17:02:23 -07:00
committed by Linus Torvalds
parent 858299544e
commit 7b60e9ad59
2 changed files with 22 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
tools/testing/radix-tree/multiorder.c
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@@ -81,6 +81,17 @@ static void multiorder_shrink(unsigned long index, int order)
item_check_absent(&tree, i);
}
static void multiorder_insert_bug(void)
{
RADIX_TREE(tree, GFP_KERNEL);
item_insert(&tree, 0);
radix_tree_tag_set(&tree, 0, 0);
item_insert_order(&tree, 3 << 6, 6);
item_kill_tree(&tree);
}
void multiorder_checks(void)
{
int i;
@@ -94,4 +105,5 @@ void multiorder_checks(void)
for (i = 0; i < 15; i++)
multiorder_shrink((1UL << (i + RADIX_TREE_MAP_SHIFT)), i);
multiorder_insert_bug();
}