diff options
author | Thomas Bertschinger <tahbertschinger@gmail.com> | 2024-01-15 23:41:02 -0700 |
---|---|---|
committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-01-16 01:47:05 -0500 |
commit | f5baaf48e3e82b1caf9f5cd1207d4d6feba3a2e5 (patch) | |
tree | 59f7b0e4667df7a9d3d5a45725f2aaab3e79b4c5 /c_src/include/linux/random.h | |
parent | fb35dbfdc5a9446fbb856dae5542b23963e28b89 (diff) |
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>
Diffstat (limited to 'c_src/include/linux/random.h')
-rw-r--r-- | c_src/include/linux/random.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/c_src/include/linux/random.h b/c_src/include/linux/random.h new file mode 100644 index 00000000..3203d13c --- /dev/null +++ b/c_src/include/linux/random.h @@ -0,0 +1,70 @@ +/* + * include/linux/random.h + * + * Include file for the random number generator. + */ +#ifndef _LINUX_RANDOM_H +#define _LINUX_RANDOM_H + +#include <unistd.h> +#include <sys/syscall.h> +#include <linux/bug.h> +#include <linux/log2.h> + +#ifdef SYS_getrandom +static inline int getrandom(void *buf, size_t buflen, unsigned int flags) +{ + return syscall(SYS_getrandom, buf, buflen, flags); +} +#else +extern int urandom_fd; + +static inline int getrandom(void *buf, size_t buflen, unsigned int flags) +{ + return read(urandom_fd, buf, buflen); +} +#endif + +static inline void get_random_bytes(void *buf, int nbytes) +{ + BUG_ON(getrandom(buf, nbytes, 0) != nbytes); +} + +#define get_random_type(type) \ +static inline type get_random_##type(void) \ +{ \ + type v; \ + \ + get_random_bytes(&v, sizeof(v)); \ + return v; \ +} + +get_random_type(int); +get_random_type(long); +get_random_type(u8); +get_random_type(u16); +get_random_type(u32); +get_random_type(u64); + +static inline u32 get_random_u32_below(u32 ceil) +{ + if (ceil <= 1) + return 0; + for (;;) { + if (ceil <= 1U << 8) { + u32 mult = ceil * get_random_u8(); + if (likely(is_power_of_2(ceil) || (u8)mult >= (1U << 8) % ceil)) + return mult >> 8; + } else if (ceil <= 1U << 16) { + u32 mult = ceil * get_random_u16(); + if (likely(is_power_of_2(ceil) || (u16)mult >= (1U << 16) % ceil)) + return mult >> 16; + } else { + u64 mult = (u64)ceil * get_random_u32(); + if (likely(is_power_of_2(ceil) || (u32)mult >= -ceil % ceil)) + return mult >> 32; + } + } +} + +#endif /* _LINUX_RANDOM_H */ |