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author | Matthew Wilcox <willy@linux.intel.com> | 2016-05-20 17:02:20 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-20 17:58:30 -0700 |
commit | 858299544efcf2577511bb018b9e73637ac71a2f (patch) | |
tree | 83572e5d6287b5dce72aad2caf48f4dfc1ffefa5 /lib/radix-tree.c | |
parent | afe0e395b6d1817fa5393f1ad6fcbf71406b016d (diff) | |
download | op-kernel-dev-858299544efcf2577511bb018b9e73637ac71a2f.zip op-kernel-dev-858299544efcf2577511bb018b9e73637ac71a2f.tar.gz |
radix-tree: rewrite __radix_tree_lookup
Use the new multi-order support functions to rewrite __radix_tree_lookup()
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>
Diffstat (limited to 'lib/radix-tree.c')
-rw-r--r-- | lib/radix-tree.c | 48 |
1 files changed, 16 insertions, 32 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c index a1ba417..f14ada9 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -634,44 +634,28 @@ void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index, struct radix_tree_node **nodep, void ***slotp) { struct radix_tree_node *node, *parent; - unsigned int height, shift; + unsigned long maxindex; + unsigned int shift; void **slot; - node = rcu_dereference_raw(root->rnode); - if (node == NULL) - return NULL; - - if (!radix_tree_is_indirect_ptr(node)) { - if (index > 0) - return NULL; - - if (nodep) - *nodep = NULL; - if (slotp) - *slotp = (void **)&root->rnode; - return node; - } - node = indirect_to_ptr(node); - - height = node->path & RADIX_TREE_HEIGHT_MASK; - if (index > radix_tree_maxindex(height)) + restart: + parent = NULL; + slot = (void **)&root->rnode; + shift = radix_tree_load_root(root, &node, &maxindex); + if (index > maxindex) return NULL; - shift = (height-1) * RADIX_TREE_MAP_SHIFT; - - do { - parent = node; - slot = node->slots + ((index >> shift) & RADIX_TREE_MAP_MASK); - node = rcu_dereference_raw(*slot); - if (node == NULL) - return NULL; - if (!radix_tree_is_indirect_ptr(node)) - break; - node = indirect_to_ptr(node); + while (radix_tree_is_indirect_ptr(node)) { + unsigned offset; + if (node == RADIX_TREE_RETRY) + goto restart; + parent = indirect_to_ptr(node); shift -= RADIX_TREE_MAP_SHIFT; - height--; - } while (height > 0); + offset = (index >> shift) & RADIX_TREE_MAP_MASK; + offset = radix_tree_descend(parent, &node, offset); + slot = parent->slots + offset; + } if (nodep) *nodep = parent; |