block/mq-deadline: Improve the sysfs show and store macros

Define separate macros for integers and jiffies to improve readability.
Use sysfs_emit() and kstrtoint() instead of sprintf() and simple_strtol().
The former functions are the recommended functions.

Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210618004456.7280-11-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 69126beff77dbc66c9d5890da8d2067652cc102f..f92224ff0256c3b19562dbd98c358e3d40c4f890 100644 (file)
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -605,58 +605,50 @@ static bool dd_has_work(struct blk_mq_hw_ctx *hctx)
 /*
  * sysfs parts below
  */
-static ssize_t
-deadline_var_show(int var, char *page)
-{
-       return sprintf(page, "%d\n", var);
-}
-
-static void
-deadline_var_store(int *var, const char *page)
-{
-       char *p = (char *) page;
-
-       *var = simple_strtol(p, &p, 10);
-}
-
-#define SHOW_FUNCTION(__FUNC, __VAR, __CONV)                           \
+#define SHOW_INT(__FUNC, __VAR)                                                \
 static ssize_t __FUNC(struct elevator_queue *e, char *page)            \
 {                                                                      \
        struct deadline_data *dd = e->elevator_data;                    \
-       int __data = __VAR;                                             \
-       if (__CONV)                                                     \
-               __data = jiffies_to_msecs(__data);                      \
-       return deadline_var_show(__data, (page));                       \
-}
-SHOW_FUNCTION(deadline_read_expire_show, dd->fifo_expire[DD_READ], 1);
-SHOW_FUNCTION(deadline_write_expire_show, dd->fifo_expire[DD_WRITE], 1);
-SHOW_FUNCTION(deadline_writes_starved_show, dd->writes_starved, 0);
-SHOW_FUNCTION(deadline_front_merges_show, dd->front_merges, 0);
-SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0);
-#undef SHOW_FUNCTION
+                                                                       \
+       return sysfs_emit(page, "%d\n", __VAR);                         \
+}
+#define SHOW_JIFFIES(__FUNC, __VAR) SHOW_INT(__FUNC, jiffies_to_msecs(__VAR))
+SHOW_JIFFIES(deadline_read_expire_show, dd->fifo_expire[DD_READ]);
+SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]);
+SHOW_INT(deadline_writes_starved_show, dd->writes_starved);
+SHOW_INT(deadline_front_merges_show, dd->front_merges);
+SHOW_INT(deadline_fifo_batch_show, dd->fifo_batch);
+#undef SHOW_INT
+#undef SHOW_JIFFIES
 
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)                        \
 static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)        \
 {                                                                      \
        struct deadline_data *dd = e->elevator_data;                    \
-       int __data;                                                     \
-       deadline_var_store(&__data, (page));                            \
+       int __data, __ret;                                              \
+                                                                       \
+       __ret = kstrtoint(page, 0, &__data);                            \
+       if (__ret < 0)                                                  \
+               return __ret;                                           \
        if (__data < (MIN))                                             \
                __data = (MIN);                                         \
        else if (__data > (MAX))                                        \
                __data = (MAX);                                         \
-       if (__CONV)                                                     \
-               *(__PTR) = msecs_to_jiffies(__data);                    \
-       else                                                            \
-               *(__PTR) = __data;                                      \
+       *(__PTR) = __CONV(__data);                                      \
        return count;                                                   \
 }
-STORE_FUNCTION(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX, 1);
-STORE_FUNCTION(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX, 1);
-STORE_FUNCTION(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX, 0);
-STORE_FUNCTION(deadline_front_merges_store, &dd->front_merges, 0, 1, 0);
-STORE_FUNCTION(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX, 0);
+#define STORE_INT(__FUNC, __PTR, MIN, MAX)                             \
+       STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, )
+#define STORE_JIFFIES(__FUNC, __PTR, MIN, MAX)                         \
+       STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, msecs_to_jiffies)
+STORE_JIFFIES(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX);
+STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX);
+STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX);
+STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1);
+STORE_INT(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX);
 #undef STORE_FUNCTION
+#undef STORE_INT
+#undef STORE_JIFFIES
 
 #define DD_ATTR(name) \
        __ATTR(name, 0644, deadline_##name##_show, deadline_##name##_store)