misc.h

  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(&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))
 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))
 98		wake_up(wq);
 99}
100
101static inline u64 mult_perc(u64 num, u32 percent)
102{
103	return div_u64(num * percent, 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(&simple_node->rb_node, root, 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, start + nbits, 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, start + nbits, start);
216	return (found_set == start + nbits);
217}
218
219#endif