linux/drivers/md/bcache/sysfs.h
Coly Li e4db37fb69 bcache: add sysfs_strtoul_bool() for setting bit-field variables
When setting bool values via sysfs interface, e.g. writeback_metadata,
if writing 1 into writeback_metadata file, dc->writeback_metadata is
set to 1, but if writing 2 into the file, dc->writeback_metadata is
0. This is misleading, a better result should be 1 for all non-zero
input value.

It is because dc->writeback_metadata is a bit-field variable, and
current code simply use d_strtoul() to convert a string into integer
and takes the lowest bit value. To fix such error, we need a routine
to convert the input string into unsigned integer, and set target
variable to 1 if the converted integer is non-zero.

This patch introduces a new macro called sysfs_strtoul_bool(), it can
be used to convert input string into bool value, we can use it to set
bool value for bit-field vairables.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-09 07:18:32 -07:00

129 lines
3.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHE_SYSFS_H_
#define _BCACHE_SYSFS_H_
#define KTYPE(type) \
struct kobj_type type ## _ktype = { \
.release = type ## _release, \
.sysfs_ops = &((const struct sysfs_ops) { \
.show = type ## _show, \
.store = type ## _store \
}), \
.default_attrs = type ## _files \
}
#define SHOW(fn) \
static ssize_t fn ## _show(struct kobject *kobj, struct attribute *attr,\
char *buf) \
#define STORE(fn) \
static ssize_t fn ## _store(struct kobject *kobj, struct attribute *attr,\
const char *buf, size_t size) \
#define SHOW_LOCKED(fn) \
SHOW(fn) \
{ \
ssize_t ret; \
mutex_lock(&bch_register_lock); \
ret = __ ## fn ## _show(kobj, attr, buf); \
mutex_unlock(&bch_register_lock); \
return ret; \
}
#define STORE_LOCKED(fn) \
STORE(fn) \
{ \
ssize_t ret; \
mutex_lock(&bch_register_lock); \
ret = __ ## fn ## _store(kobj, attr, buf, size); \
mutex_unlock(&bch_register_lock); \
return ret; \
}
#define __sysfs_attribute(_name, _mode) \
static struct attribute sysfs_##_name = \
{ .name = #_name, .mode = _mode }
#define write_attribute(n) __sysfs_attribute(n, 0200)
#define read_attribute(n) __sysfs_attribute(n, 0444)
#define rw_attribute(n) __sysfs_attribute(n, 0644)
#define sysfs_printf(file, fmt, ...) \
do { \
if (attr == &sysfs_ ## file) \
return snprintf(buf, PAGE_SIZE, fmt "\n", __VA_ARGS__); \
} while (0)
#define sysfs_print(file, var) \
do { \
if (attr == &sysfs_ ## file) \
return snprint(buf, PAGE_SIZE, var); \
} while (0)
#define sysfs_hprint(file, val) \
do { \
if (attr == &sysfs_ ## file) { \
ssize_t ret = bch_hprint(buf, val); \
strcat(buf, "\n"); \
return ret + 1; \
} \
} while (0)
#define var_printf(_var, fmt) sysfs_printf(_var, fmt, var(_var))
#define var_print(_var) sysfs_print(_var, var(_var))
#define var_hprint(_var) sysfs_hprint(_var, var(_var))
#define sysfs_strtoul(file, var) \
do { \
if (attr == &sysfs_ ## file) \
return strtoul_safe(buf, var) ?: (ssize_t) size; \
} while (0)
#define sysfs_strtoul_bool(file, var) \
do { \
if (attr == &sysfs_ ## file) { \
unsigned long v = strtoul_or_return(buf); \
\
var = v ? 1 : 0; \
return size; \
} \
} while (0)
#define sysfs_strtoul_clamp(file, var, min, max) \
do { \
if (attr == &sysfs_ ## file) { \
unsigned long v = 0; \
ssize_t ret; \
ret = strtoul_safe_clamp(buf, v, min, max); \
if (!ret) { \
var = v; \
return size; \
} \
return ret; \
} \
} while (0)
#define strtoul_or_return(cp) \
({ \
unsigned long _v; \
int _r = kstrtoul(cp, 10, &_v); \
if (_r) \
return _r; \
_v; \
})
#define strtoi_h_or_return(cp, v) \
do { \
int _r = strtoi_h(cp, &v); \
if (_r) \
return _r; \
} while (0)
#define sysfs_hatoi(file, var) \
do { \
if (attr == &sysfs_ ## file) \
return strtoi_h(buf, &var) ?: (ssize_t) size; \
} while (0)
#endif /* _BCACHE_SYSFS_H_ */