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115 lines
2.4 KiB
115 lines
2.4 KiB
/* 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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