Re: [PATCH V2] bcache: replace snprintf in show functions with sysfs_emit

From: Coly Li
Date: Mon Oct 18 2021 - 10:47:08 EST


On 10/13/21 7:58 PM, Qing Wang wrote:
coccicheck complains about the use of snprintf() in sysfs show functions.

Fix the following coccicheck warning:
drivers/md/bcache/sysfs.h:54:12-20: WARNING: use scnprintf or sprintf.

Implement sysfs_print() by sysfs_emit() and remove snprint() since no one
uses it any more.

Suggested-by: Coly Li <colyli@xxxxxxx>
Signed-off-by: Qing Wang <wangqing@xxxxxxxx>

It looks fine to me. Let me add it into my for-test directory.

Thanks for the fix up.

Coly Li

---
drivers/md/bcache/sysfs.h | 18 ++++++++++++++++--
drivers/md/bcache/util.h | 17 -----------------
2 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/drivers/md/bcache/sysfs.h b/drivers/md/bcache/sysfs.h
index 215df32..c1752ba
--- a/drivers/md/bcache/sysfs.h
+++ b/drivers/md/bcache/sysfs.h
@@ -51,13 +51,27 @@ STORE(fn) \
#define sysfs_printf(file, fmt, ...) \
do { \
if (attr == &sysfs_ ## file) \
- return snprintf(buf, PAGE_SIZE, fmt "\n", __VA_ARGS__); \
+ return sysfs_emit(buf, fmt "\n", __VA_ARGS__); \
} while (0)
#define sysfs_print(file, var) \
do { \
if (attr == &sysfs_ ## file) \
- return snprint(buf, PAGE_SIZE, var); \
+ return sysfs_emit(buf, \
+ __builtin_types_compatible_p(typeof(var), int) \
+ ? "%i\n" : \
+ __builtin_types_compatible_p(typeof(var), unsigned int) \
+ ? "%u\n" : \
+ __builtin_types_compatible_p(typeof(var), long) \
+ ? "%li\n" : \
+ __builtin_types_compatible_p(typeof(var), unsigned long)\
+ ? "%lu\n" : \
+ __builtin_types_compatible_p(typeof(var), int64_t) \
+ ? "%lli\n" : \
+ __builtin_types_compatible_p(typeof(var), uint64_t) \
+ ? "%llu\n" : \
+ __builtin_types_compatible_p(typeof(var), const char *) \
+ ? "%s\n" : "%i\n", var); \
} while (0)
#define sysfs_hprint(file, val) \
diff --git a/drivers/md/bcache/util.h b/drivers/md/bcache/util.h
index b64460a..fecdea1
--- a/drivers/md/bcache/util.h
+++ b/drivers/md/bcache/util.h
@@ -340,23 +340,6 @@ static inline int bch_strtoul_h(const char *cp, long *res)
_r; \
})
-#define snprint(buf, size, var) \
- snprintf(buf, size, \
- __builtin_types_compatible_p(typeof(var), int) \
- ? "%i\n" : \
- __builtin_types_compatible_p(typeof(var), unsigned int) \
- ? "%u\n" : \
- __builtin_types_compatible_p(typeof(var), long) \
- ? "%li\n" : \
- __builtin_types_compatible_p(typeof(var), unsigned long)\
- ? "%lu\n" : \
- __builtin_types_compatible_p(typeof(var), int64_t) \
- ? "%lli\n" : \
- __builtin_types_compatible_p(typeof(var), uint64_t) \
- ? "%llu\n" : \
- __builtin_types_compatible_p(typeof(var), const char *) \
- ? "%s\n" : "%i\n", var)
-
ssize_t bch_hprint(char *buf, int64_t v);
bool bch_is_zero(const char *p, size_t n);