[PATCH 11/13] block: convert the elevator_queue attrs to use ->seq_show

Christoph Hellwig
2021-09-13T05:56:43Z

Trivial conversion to the seq_file based sysfs attributes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/bfq-iosched.c | 12 ++++++------
block/elevator.c | 21 ++++++++++++---------
block/kyber-iosched.c | 7 ++++---
block/mq-deadline.c | 5 +++--
include/linux/elevator.h | 2 +-
5 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index dd13c2bbc29c1..a72b4f90f3ba2 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -7092,9 +7092,9 @@ static int __init bfq_slab_setup(void)
return 0;
}

-static ssize_t bfq_var_show(unsigned int var, char *page)
+static void bfq_var_show(unsigned int var, struct seq_file *sf)
{
- return sprintf(page, "%u\n", var);
+ seq_printf(sf, "%u\n", var);
}

static int bfq_var_store(unsigned long *var, const char *page)
@@ -7109,7 +7109,7 @@ static int bfq_var_store(unsigned long *var, const char *page)
}

#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
-static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+static void __FUNC(struct elevator_queue *e, struct seq_file *sf) \
{ \
struct bfq_data *bfqd = e->elevator_data; \
u64 __data = __VAR; \
@@ -7117,7 +7117,7 @@ static ssize_t __FUNC(struct elevator_queue *e, char *page) \
__data = jiffies_to_msecs(__data); \
else if (__CONV == 2) \
__data = div_u64(__data, NSEC_PER_MSEC); \
- return bfq_var_show(__data, (page)); \
+ bfq_var_show(__data, (sf)); \
}
SHOW_FUNCTION(bfq_fifo_expire_sync_show, bfqd->bfq_fifo_expire[1], 2);
SHOW_FUNCTION(bfq_fifo_expire_async_show, bfqd->bfq_fifo_expire[0], 2);
@@ -7131,12 +7131,12 @@ SHOW_FUNCTION(bfq_low_latency_show, bfqd->low_latency, 0);
#undef SHOW_FUNCTION

#define USEC_SHOW_FUNCTION(__FUNC, __VAR) \
-static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+static void __FUNC(struct elevator_queue *e, struct seq_file *sf) \
{ \
struct bfq_data *bfqd = e->elevator_data; \
u64 __data = __VAR; \
__data = div_u64(__data, NSEC_PER_USEC); \
- return bfq_var_show(__data, (page)); \
+ bfq_var_show(__data, (sf)); \
}
USEC_SHOW_FUNCTION(bfq_slice_idle_us_show, bfqd->bfq_slice_idle);
#undef USEC_SHOW_FUNCTION
diff --git a/block/elevator.c b/block/elevator.c
index f068585f2f9b8..951bae559e5cb 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -442,21 +442,24 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq)

#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)

-static ssize_t
-elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
+static int elv_attr_seq_show(struct kobject *kobj, struct attribute *attr,
+ struct seq_file *sf)
{
struct elv_fs_entry *entry = to_elv(attr);
- struct elevator_queue *e;
- ssize_t error;
+ struct elevator_queue *e =
+ container_of(kobj, struct elevator_queue, kobj);

if (!entry->show)
return -EIO;

- e = container_of(kobj, struct elevator_queue, kobj);
mutex_lock(&e->sysfs_lock);
- error = e->type ? entry->show(e, page) : -ENOENT;
+ if (!e->type) {
+ mutex_unlock(&e->sysfs_lock);
+ return -ENOENT;
+ }
+ entry->show(e, sf);
mutex_unlock(&e->sysfs_lock);
- return error;
+ return 0;
}

static ssize_t
@@ -478,8 +481,8 @@ elv_attr_store(struct kobject *kobj, struct attribute *attr,
}

static const struct sysfs_ops elv_sysfs_ops = {
- .show = elv_attr_show,
- .store = elv_attr_store,
+ .seq_show = elv_attr_seq_show,
+ .store = elv_attr_store,
};

static struct kobj_type elv_ktype = {
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index 15a8be57203d6..633f9654b99b9 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -12,6 +12,7 @@
#include <linux/elevator.h>
#include <linux/module.h>
#include <linux/sbitmap.h>
+#include <linux/seq_file.h>

#include <trace/events/block.h>

@@ -857,12 +858,12 @@ static bool kyber_has_work(struct blk_mq_hw_ctx *hctx)
}

#define KYBER_LAT_SHOW_STORE(domain, name) \
-static ssize_t kyber_##name##_lat_show(struct elevator_queue *e, \
- char *page) \
+static void kyber_##name##_lat_show(struct elevator_queue *e, \
+ struct seq_file *sf) \
{ \
struct kyber_queue_data *kqd = e->elevator_data; \
\
- return sprintf(page, "%llu\n", kqd->latency_targets[domain]); \
+ seq_printf(sf, "%llu\n", kqd->latency_targets[domain]); \
} \
\
static ssize_t kyber_##name##_lat_store(struct elevator_queue *e, \
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 7f3c3932b723e..0e1fc6d3e5d64 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -17,6 +17,7 @@
#include <linux/compiler.h>
#include <linux/rbtree.h>
#include <linux/sbitmap.h>
+#include <linux/seq_file.h>

#include <trace/events/block.h>

@@ -800,11 +801,11 @@ static bool dd_has_work(struct blk_mq_hw_ctx *hctx)
* sysfs parts below
*/
#define SHOW_INT(__FUNC, __VAR) \
-static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+static void __FUNC(struct elevator_queue *e, struct seq_file *sf) \
{ \
struct deadline_data *dd = e->elevator_data; \
\
- return sysfs_emit(page, "%d\n", __VAR); \
+ seq_printf(sf, "%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]);
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index deecf7f9ff21a..ad5e4cb653a30 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -56,7 +56,7 @@ struct elevator_mq_ops {

struct elv_fs_entry {
struct attribute attr;
- ssize_t (*show)(struct elevator_queue *, char *);
+ void (*show)(struct elevator_queue *eq, struct seq_file *sf);
ssize_t (*store)(struct elevator_queue *, const char *, size_t);
};

--
2.30.2