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https://github.com/torvalds/linux
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4c7a6f74ce
We are really suffering from now ulist's implementation, some developers gave their try, and i just gave some of my ideas for things: 1. use list+rb_tree instead of arrary+rb_tree 2. add cur_list to iterator rather than ulist structure. 3. add seqnum into every node when they are added, this is used to do selfcheck when iterating node. I noticed Zach Brown's comments before, long term is to kick off ulist implementation, however, for now, we need at least avoid arrary from ulist. Cc: Liu Bo <bo.li.liu@oracle.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Zach Brown <zab@redhat.com> Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
67 lines
1.5 KiB
C
67 lines
1.5 KiB
C
/*
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* Copyright (C) 2011 STRATO AG
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* written by Arne Jansen <sensille@gmx.net>
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* Distributed under the GNU GPL license version 2.
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*
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*/
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#ifndef __ULIST__
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#define __ULIST__
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#include <linux/list.h>
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#include <linux/rbtree.h>
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/*
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* ulist is a generic data structure to hold a collection of unique u64
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* values. The only operations it supports is adding to the list and
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* enumerating it.
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* It is possible to store an auxiliary value along with the key.
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*
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*/
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struct ulist_iterator {
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#ifdef CONFIG_BTRFS_DEBUG
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int i;
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#endif
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struct list_head *cur_list; /* hint to start search */
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};
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/*
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* element of the list
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*/
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struct ulist_node {
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u64 val; /* value to store */
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u64 aux; /* auxiliary value saved along with the val */
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#ifdef CONFIG_BTRFS_DEBUG
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int seqnum; /* sequence number this node is added */
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#endif
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struct list_head list; /* used to link node */
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struct rb_node rb_node; /* used to speed up search */
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};
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struct ulist {
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/*
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* number of elements stored in list
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*/
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unsigned long nnodes;
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struct list_head nodes;
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struct rb_root root;
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};
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void ulist_init(struct ulist *ulist);
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void ulist_fini(struct ulist *ulist);
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void ulist_reinit(struct ulist *ulist);
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struct ulist *ulist_alloc(gfp_t gfp_mask);
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void ulist_free(struct ulist *ulist);
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int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);
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int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
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u64 *old_aux, gfp_t gfp_mask);
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struct ulist_node *ulist_next(struct ulist *ulist,
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struct ulist_iterator *uiter);
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#define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL)
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#endif
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