1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef BTRFS_MISC_H
4#define BTRFS_MISC_H
5
6#include <linux/types.h>
7#include <linux/bitmap.h>
8#include <linux/sched.h>
9#include <linux/wait.h>
10#include <linux/mm.h>
11#include <linux/pagemap.h>
12#include <linux/math64.h>
13#include <linux/rbtree.h>
14#include <linux/bio.h>
15
16/*
17 * Convenience macros to define a pointer with the __free(kfree) and
18 * __free(kvfree) cleanup attributes and initialized to NULL.
19 */
20#define AUTO_KFREE(name) *name __free(kfree) = NULL
21#define AUTO_KVFREE(name) *name __free(kvfree) = NULL
22
23/*
24 * Enumerate bits using enum autoincrement. Define the @name as the n-th bit.
25 */
26#define ENUM_BIT(name) \
27 __ ## name ## _BIT, \
28 name = (1U << __ ## name ## _BIT), \
29 __ ## name ## _SEQ = __ ## name ## _BIT
30
31static inline phys_addr_t bio_iter_phys(struct bio *bio, struct bvec_iter *iter)
32{
33 struct bio_vec bv = bio_iter_iovec(bio, *iter);
34
35 return bvec_phys(bvec: &bv);
36}
37
38/*
39 * Iterate bio using btrfs block size.
40 *
41 * This will handle large folio and highmem.
42 *
43 * @paddr: Physical memory address of each iteration
44 * @bio: The bio to iterate
45 * @iter: The bvec_iter (pointer) to use.
46 * @blocksize: The blocksize to iterate.
47 *
48 * This requires all folios in the bio to cover at least one block.
49 */
50#define btrfs_bio_for_each_block(paddr, bio, iter, blocksize) \
51 for (; (iter)->bi_size && \
52 (paddr = bio_iter_phys((bio), (iter)), 1); \
53 bio_advance_iter_single((bio), (iter), (blocksize)))
54
55/* Initialize a bvec_iter to the size of the specified bio. */
56static inline struct bvec_iter init_bvec_iter_for_bio(struct bio *bio)
57{
58 struct bio_vec *bvec;
59 u32 bio_size = 0;
60 int i;
61
62 bio_for_each_bvec_all(bvec, bio, i)
63 bio_size += bvec->bv_len;
64
65 return (struct bvec_iter) {
66 .bi_sector = 0,
67 .bi_size = bio_size,
68 .bi_idx = 0,
69 .bi_bvec_done = 0,
70 };
71}
72
73#define btrfs_bio_for_each_block_all(paddr, bio, blocksize) \
74 for (struct bvec_iter iter = init_bvec_iter_for_bio(bio); \
75 (iter).bi_size && \
76 (paddr = bio_iter_phys((bio), &(iter)), 1); \
77 bio_advance_iter_single((bio), &(iter), (blocksize)))
78
79static inline void cond_wake_up(struct wait_queue_head *wq)
80{
81 /*
82 * This implies a full smp_mb barrier, see comments for
83 * waitqueue_active why.
84 */
85 if (wq_has_sleeper(wq_head: wq))
86 wake_up(wq);
87}
88
89static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
90{
91 /*
92 * Special case for conditional wakeup where the barrier required for
93 * waitqueue_active is implied by some of the preceding code. Eg. one
94 * of such atomic operations (atomic_dec_and_return, ...), or a
95 * unlock/lock sequence, etc.
96 */
97 if (waitqueue_active(wq_head: wq))
98 wake_up(wq);
99}
100
101static inline u64 mult_perc(u64 num, u32 percent)
102{
103 return div_u64(dividend: num * percent, divisor: 100);
104}
105/* Copy of is_power_of_two that is 64bit safe */
106static inline bool is_power_of_two_u64(u64 n)
107{
108 return n != 0 && (n & (n - 1)) == 0;
109}
110
111static inline bool has_single_bit_set(u64 n)
112{
113 return is_power_of_two_u64(n);
114}
115
116/*
117 * Simple bytenr based rb_tree relate structures
118 *
119 * Any structure wants to use bytenr as single search index should have their
120 * structure start with these members.
121 */
122struct rb_simple_node {
123 struct rb_node rb_node;
124 u64 bytenr;
125};
126
127static inline struct rb_node *rb_simple_search(const struct rb_root *root, u64 bytenr)
128{
129 struct rb_node *node = root->rb_node;
130 struct rb_simple_node *entry;
131
132 while (node) {
133 entry = rb_entry(node, struct rb_simple_node, rb_node);
134
135 if (bytenr < entry->bytenr)
136 node = node->rb_left;
137 else if (bytenr > entry->bytenr)
138 node = node->rb_right;
139 else
140 return node;
141 }
142 return NULL;
143}
144
145/*
146 * Search @root from an entry that starts or comes after @bytenr.
147 *
148 * @root: the root to search.
149 * @bytenr: bytenr to search from.
150 *
151 * Return the rb_node that start at or after @bytenr. If there is no entry at
152 * or after @bytner return NULL.
153 */
154static inline struct rb_node *rb_simple_search_first(const struct rb_root *root,
155 u64 bytenr)
156{
157 struct rb_node *node = root->rb_node, *ret = NULL;
158 struct rb_simple_node *entry, *ret_entry = NULL;
159
160 while (node) {
161 entry = rb_entry(node, struct rb_simple_node, rb_node);
162
163 if (bytenr < entry->bytenr) {
164 if (!ret || entry->bytenr < ret_entry->bytenr) {
165 ret = node;
166 ret_entry = entry;
167 }
168
169 node = node->rb_left;
170 } else if (bytenr > entry->bytenr) {
171 node = node->rb_right;
172 } else {
173 return node;
174 }
175 }
176
177 return ret;
178}
179
180static int rb_simple_node_bytenr_cmp(struct rb_node *new, const struct rb_node *existing)
181{
182 struct rb_simple_node *new_entry = rb_entry(new, struct rb_simple_node, rb_node);
183 struct rb_simple_node *existing_entry = rb_entry(existing, struct rb_simple_node, rb_node);
184
185 if (new_entry->bytenr < existing_entry->bytenr)
186 return -1;
187 else if (new_entry->bytenr > existing_entry->bytenr)
188 return 1;
189
190 return 0;
191}
192
193static inline struct rb_node *rb_simple_insert(struct rb_root *root,
194 struct rb_simple_node *simple_node)
195{
196 return rb_find_add(node: &simple_node->rb_node, tree: root, cmp: rb_simple_node_bytenr_cmp);
197}
198
199static inline bool bitmap_test_range_all_set(const unsigned long *addr,
200 unsigned long start,
201 unsigned long nbits)
202{
203 unsigned long found_zero;
204
205 found_zero = find_next_zero_bit(addr, size: start + nbits, offset: start);
206 return (found_zero == start + nbits);
207}
208
209static inline bool bitmap_test_range_all_zero(const unsigned long *addr,
210 unsigned long start,
211 unsigned long nbits)
212{
213 unsigned long found_set;
214
215 found_set = find_next_bit(addr, size: start + nbits, offset: start);
216 return (found_set == start + nbits);
217}
218
219#endif
220

source code of linux/fs/btrfs/misc.h