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| author | Coly Li <colyli@suse.de> | 2019-02-09 05:53:02 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-02-09 15:18:32 +0100 |
| commit | e4db37fb69d56d9523bb540bd8e07bf221aa9f6d (patch) | |
| tree | bb3ec98aebd4ad6e39bd6b85b2d77f876279da99 | |
| parent | bcache: fix input overflow to sequential_cutoff (diff) | |
| download | linux-e4db37fb69d56d9523bb540bd8e07bf221aa9f6d.tar.xz linux-e4db37fb69d56d9523bb540bd8e07bf221aa9f6d.zip | |
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>
| -rw-r--r-- | drivers/md/bcache/sysfs.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/md/bcache/sysfs.h b/drivers/md/bcache/sysfs.h index 0ad2715a884e..215df32f567b 100644 --- a/drivers/md/bcache/sysfs.h +++ b/drivers/md/bcache/sysfs.h @@ -79,6 +79,16 @@ do { \ 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) { \ |