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https://github.com/koverstreet/bcachefs-tools.git
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56 lines
1.5 KiB
C
56 lines
1.5 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _BCACHEFS_NOCOW_LOCKING_H
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#define _BCACHEFS_NOCOW_LOCKING_H
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#include "bcachefs_format.h"
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#include "two_state_shared_lock.h"
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#include <linux/siphash.h>
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#define BUCKET_NOCOW_LOCKS (1U << 10)
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struct bucket_nocow_lock_table {
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siphash_key_t key;
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two_state_lock_t l[BUCKET_NOCOW_LOCKS];
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};
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#define BUCKET_NOCOW_LOCK_UPDATE (1 << 0)
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static inline two_state_lock_t *bucket_nocow_lock(struct bucket_nocow_lock_table *t,
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struct bpos bucket)
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{
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u64 dev_bucket = bucket.inode << 56 | bucket.offset;
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unsigned h = siphash_1u64(dev_bucket, &t->key);
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return t->l + (h & (BUCKET_NOCOW_LOCKS - 1));
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}
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static inline bool bch2_bucket_nocow_is_locked(struct bucket_nocow_lock_table *t,
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struct bpos bucket)
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{
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two_state_lock_t *l = bucket_nocow_lock(t, bucket);
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return atomic_long_read(&l->v) != 0;
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}
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static inline void bch2_bucket_nocow_unlock(struct bucket_nocow_lock_table *t,
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struct bpos bucket, int flags)
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{
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two_state_lock_t *l = bucket_nocow_lock(t, bucket);
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bch2_two_state_unlock(l, flags & BUCKET_NOCOW_LOCK_UPDATE);
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}
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void __bch2_bucket_nocow_lock(struct bucket_nocow_lock_table *, struct bpos, int);
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static inline void bch2_bucket_nocow_lock(struct bucket_nocow_lock_table *t,
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struct bpos bucket, int flags)
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{
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two_state_lock_t *l = bucket_nocow_lock(t, bucket);
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if (!bch2_two_state_trylock(l, flags & BUCKET_NOCOW_LOCK_UPDATE))
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__bch2_bucket_nocow_lock(t, bucket, flags);
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}
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#endif /* _BCACHEFS_NOCOW_LOCKING_H */
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