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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_NOCOW_LOCKING_H
#define _BCACHEFS_NOCOW_LOCKING_H
#include "bcachefs_format.h"
#include "two_state_shared_lock.h"
#include <linux/hash.h>
#define BUCKET_NOCOW_LOCKS_BITS 10
#define BUCKET_NOCOW_LOCKS (1U << BUCKET_NOCOW_LOCKS_BITS)
struct bucket_nocow_lock_table {
two_state_lock_t l[BUCKET_NOCOW_LOCKS];
};
#define BUCKET_NOCOW_LOCK_UPDATE (1 << 0)
static inline two_state_lock_t *bucket_nocow_lock(struct bucket_nocow_lock_table *t,
struct bpos bucket)
{
u64 dev_bucket = bucket.inode << 56 | bucket.offset;
unsigned h = hash_64(dev_bucket, BUCKET_NOCOW_LOCKS_BITS);
return t->l + (h & (BUCKET_NOCOW_LOCKS - 1));
}
static inline bool bch2_bucket_nocow_is_locked(struct bucket_nocow_lock_table *t,
struct bpos bucket)
{
two_state_lock_t *l = bucket_nocow_lock(t, bucket);
return atomic_long_read(&l->v) != 0;
}
static inline void bch2_bucket_nocow_unlock(struct bucket_nocow_lock_table *t,
struct bpos bucket, int flags)
{
two_state_lock_t *l = bucket_nocow_lock(t, bucket);
bch2_two_state_unlock(l, flags & BUCKET_NOCOW_LOCK_UPDATE);
}
void __bch2_bucket_nocow_lock(struct bucket_nocow_lock_table *, two_state_lock_t *, int);
static inline void bch2_bucket_nocow_lock(struct bucket_nocow_lock_table *t,
struct bpos bucket, int flags)
{
two_state_lock_t *l = bucket_nocow_lock(t, bucket);
if (!bch2_two_state_trylock(l, flags & BUCKET_NOCOW_LOCK_UPDATE))
__bch2_bucket_nocow_lock(t, l, flags);
}
#endif /* _BCACHEFS_NOCOW_LOCKING_H */
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