diff options
author | Matthew Wilcox | 2016-12-14 15:09:31 -0800 |
---|---|---|
committer | Linus Torvalds | 2016-12-14 16:04:10 -0800 |
commit | e8de4340767dd002978c285e3adddaeda8ac652c (patch) | |
tree | 3e14e4a3b7b0874e4e824b7873558a1017d2e368 /lib/radix-tree.c | |
parent | bbe9d71f2c545398987a6fea5090a6ca76f4a8dc (diff) |
radix-tree: ensure counts are initialised
radix_tree_join() was freeing nodes with a non-zero ->exceptional count,
and radix_tree_split() wasn't zeroing ->exceptional when it allocated
the new node. Fix this by making all callers of radix_tree_node_alloc()
pass in the new counts (and some other always-initialised fields), which
will prevent the problem recurring if in future we decide to do
something similar.
Link: http://lkml.kernel.org/r/1481667692-14500-3-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/radix-tree.c')
-rw-r--r-- | lib/radix-tree.c | 41 |
1 files changed, 20 insertions, 21 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c index d09c17dd60ae..0019aca0f328 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -288,7 +288,10 @@ static void radix_tree_dump(struct radix_tree_root *root) * that the caller has pinned this thread of control to the current CPU. */ static struct radix_tree_node * -radix_tree_node_alloc(struct radix_tree_root *root) +radix_tree_node_alloc(struct radix_tree_root *root, + struct radix_tree_node *parent, + unsigned int shift, unsigned int offset, + unsigned int count, unsigned int exceptional) { struct radix_tree_node *ret = NULL; gfp_t gfp_mask = root_gfp_mask(root); @@ -333,6 +336,13 @@ radix_tree_node_alloc(struct radix_tree_root *root) ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask); out: BUG_ON(radix_tree_is_internal_node(ret)); + if (ret) { + ret->parent = parent; + ret->shift = shift; + ret->offset = offset; + ret->count = count; + ret->exceptional = exceptional; + } return ret; } @@ -538,8 +548,8 @@ static int radix_tree_extend(struct radix_tree_root *root, goto out; do { - struct radix_tree_node *node = radix_tree_node_alloc(root); - + struct radix_tree_node *node = radix_tree_node_alloc(root, + NULL, shift, 0, 1, 0); if (!node) return -ENOMEM; @@ -550,16 +560,11 @@ static int radix_tree_extend(struct radix_tree_root *root, } BUG_ON(shift > BITS_PER_LONG); - node->shift = shift; - node->offset = 0; - node->count = 1; - node->parent = NULL; if (radix_tree_is_internal_node(slot)) { entry_to_node(slot)->parent = node; - } else { + } else if (radix_tree_exceptional_entry(slot)) { /* Moving an exceptional root->rnode to a node */ - if (radix_tree_exceptional_entry(slot)) - node->exceptional = 1; + node->exceptional = 1; } node->slots[0] = slot; slot = node_to_entry(node); @@ -712,14 +717,10 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, shift -= RADIX_TREE_MAP_SHIFT; if (child == NULL) { /* Have to add a child node. */ - child = radix_tree_node_alloc(root); + child = radix_tree_node_alloc(root, node, shift, + offset, 0, 0); if (!child) return -ENOMEM; - child->shift = shift; - child->offset = offset; - child->count = 0; - child->exceptional = 0; - child->parent = node; rcu_assign_pointer(*slot, node_to_entry(child)); if (node) node->count++; @@ -1209,13 +1210,11 @@ int radix_tree_split(struct radix_tree_root *root, unsigned long index, for (;;) { if (node->shift > order) { - child = radix_tree_node_alloc(root); + child = radix_tree_node_alloc(root, node, + node->shift - RADIX_TREE_MAP_SHIFT, + offset, 0, 0); if (!child) goto nomem; - child->shift = node->shift - RADIX_TREE_MAP_SHIFT; - child->offset = offset; - child->count = 0; - child->parent = node; if (node != parent) { node->count++; node->slots[offset] = node_to_entry(child); |