a43313668f
Reiser4 uses radix trees to solve a trouble reiser4_readdir has serving nfs requests. Unfortunately, radix tree api lacks an operation suitable for modifying existing entry. This patch adds radix_tree_lookup_slot which returns pointer to found item within the tree. That location can be then updated. Both Nick and Christoph Lameter have patches which need this as well. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
72 lines
2.4 KiB
C
72 lines
2.4 KiB
C
/*
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* Copyright (C) 2001 Momchil Velikov
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* Portions Copyright (C) 2001 Christoph Hellwig
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2, or (at
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* your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#ifndef _LINUX_RADIX_TREE_H
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#define _LINUX_RADIX_TREE_H
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#include <linux/preempt.h>
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#include <linux/types.h>
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struct radix_tree_root {
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unsigned int height;
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gfp_t gfp_mask;
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struct radix_tree_node *rnode;
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};
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#define RADIX_TREE_INIT(mask) { \
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.height = 0, \
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.gfp_mask = (mask), \
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.rnode = NULL, \
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}
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#define RADIX_TREE(name, mask) \
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struct radix_tree_root name = RADIX_TREE_INIT(mask)
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#define INIT_RADIX_TREE(root, mask) \
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do { \
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(root)->height = 0; \
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(root)->gfp_mask = (mask); \
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(root)->rnode = NULL; \
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} while (0)
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int radix_tree_insert(struct radix_tree_root *, unsigned long, void *);
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void *radix_tree_lookup(struct radix_tree_root *, unsigned long);
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void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long);
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void *radix_tree_delete(struct radix_tree_root *, unsigned long);
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unsigned int
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radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
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unsigned long first_index, unsigned int max_items);
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int radix_tree_preload(gfp_t gfp_mask);
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void radix_tree_init(void);
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void *radix_tree_tag_set(struct radix_tree_root *root,
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unsigned long index, int tag);
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void *radix_tree_tag_clear(struct radix_tree_root *root,
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unsigned long index, int tag);
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int radix_tree_tag_get(struct radix_tree_root *root,
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unsigned long index, int tag);
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unsigned int
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radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
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unsigned long first_index, unsigned int max_items, int tag);
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int radix_tree_tagged(struct radix_tree_root *root, int tag);
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static inline void radix_tree_preload_end(void)
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{
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preempt_enable();
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}
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#endif /* _LINUX_RADIX_TREE_H */
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