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e9a28dc52a
Structure tree_entry provides a very simple rb_tree which only uses bytenr as search index. That tree_entry is used in 3 structures: backref_node, mapping_node and tree_block. Since we're going to make backref_node independnt from relocation, it's a good time to extract the tree_entry into rb_simple_node, and export it into misc.h. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
116 lines
2.4 KiB
C
116 lines
2.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef BTRFS_MISC_H
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#define BTRFS_MISC_H
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include <asm/div64.h>
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#include <linux/rbtree.h>
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#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
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static inline void cond_wake_up(struct wait_queue_head *wq)
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{
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/*
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* This implies a full smp_mb barrier, see comments for
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* waitqueue_active why.
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*/
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if (wq_has_sleeper(wq))
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wake_up(wq);
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}
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static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
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{
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/*
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* Special case for conditional wakeup where the barrier required for
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* waitqueue_active is implied by some of the preceding code. Eg. one
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* of such atomic operations (atomic_dec_and_return, ...), or a
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* unlock/lock sequence, etc.
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*/
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if (waitqueue_active(wq))
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wake_up(wq);
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}
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static inline u64 div_factor(u64 num, int factor)
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{
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if (factor == 10)
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return num;
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num *= factor;
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return div_u64(num, 10);
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}
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static inline u64 div_factor_fine(u64 num, int factor)
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{
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if (factor == 100)
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return num;
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num *= factor;
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return div_u64(num, 100);
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}
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/* Copy of is_power_of_two that is 64bit safe */
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static inline bool is_power_of_two_u64(u64 n)
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{
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return n != 0 && (n & (n - 1)) == 0;
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}
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static inline bool has_single_bit_set(u64 n)
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{
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return is_power_of_two_u64(n);
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}
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/*
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* Simple bytenr based rb_tree relate structures
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*
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* Any structure wants to use bytenr as single search index should have their
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* structure start with these members.
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*/
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struct rb_simple_node {
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struct rb_node rb_node;
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u64 bytenr;
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};
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static inline struct rb_node *rb_simple_search(struct rb_root *root, u64 bytenr)
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{
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struct rb_node *node = root->rb_node;
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struct rb_simple_node *entry;
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while (node) {
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entry = rb_entry(node, struct rb_simple_node, rb_node);
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if (bytenr < entry->bytenr)
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node = node->rb_left;
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else if (bytenr > entry->bytenr)
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node = node->rb_right;
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else
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return node;
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}
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return NULL;
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}
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static inline struct rb_node *rb_simple_insert(struct rb_root *root, u64 bytenr,
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struct rb_node *node)
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{
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struct rb_node **p = &root->rb_node;
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struct rb_node *parent = NULL;
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struct rb_simple_node *entry;
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while (*p) {
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parent = *p;
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entry = rb_entry(parent, struct rb_simple_node, rb_node);
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if (bytenr < entry->bytenr)
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p = &(*p)->rb_left;
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else if (bytenr > entry->bytenr)
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p = &(*p)->rb_right;
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else
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return parent;
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}
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rb_link_node(node, parent, p);
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rb_insert_color(node, root);
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return NULL;
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}
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#endif
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