bcachefs-tools/c_src/include/linux/seqlock.h
Thomas Bertschinger f5baaf48e3 move Rust sources to top level, C sources into c_src
This moves the Rust sources out of rust_src/ and into the top level.
Running the bcachefs executable out of the development tree is now:

$ ./target/release/bcachefs command
or
$ cargo run --profile release -- command

instead of "./bcachefs command".

Building and installing is still:

$ make && make install

Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-16 01:47:05 -05:00

48 lines
759 B
C

#ifndef __LINUX_SEQLOCK_H
#define __LINUX_SEQLOCK_H
#include <linux/compiler.h>
typedef struct seqcount {
unsigned sequence;
} seqcount_t;
static inline void seqcount_init(seqcount_t *s)
{
s->sequence = 0;
}
static inline unsigned read_seqcount_begin(const seqcount_t *s)
{
unsigned ret;
repeat:
ret = READ_ONCE(s->sequence);
if (unlikely(ret & 1)) {
cpu_relax();
goto repeat;
}
smp_rmb();
return ret;
}
static inline int read_seqcount_retry(const seqcount_t *s, unsigned start)
{
smp_rmb();
return unlikely(s->sequence != start);
}
static inline void write_seqcount_begin(seqcount_t *s)
{
s->sequence++;
smp_wmb();
}
static inline void write_seqcount_end(seqcount_t *s)
{
smp_wmb();
s->sequence++;
}
#endif /* __LINUX_SEQLOCK_H */