[PATCH 10/13] block: convert the request_queue attrs to use ->seq_show

From: Christoph Hellwig
Date: Mon Sep 13 2021 - 01:53:33 EST

Trivial conversion to the seq_file based sysfs attributes.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/blk-sysfs.c | 209 ++++++++++++++++++++++-----------------
block/blk-throttle.c | 5 +-
block/blk.h | 2 +-
block/elevator.c | 21 ++--
include/linux/elevator.h | 2 +-
5 files changed, 134 insertions(+), 105 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 614d9d47de36b..ac57256db8710 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -20,14 +20,14 @@

struct queue_sysfs_entry {
struct attribute attr;
- ssize_t (*show)(struct request_queue *, char *);
+ int (*show)(struct request_queue *q, struct seq_file *sf);
ssize_t (*store)(struct request_queue *, const char *, size_t);
};

-static ssize_t
-queue_var_show(unsigned long var, char *page)
+static int queue_var_show(unsigned long var, struct seq_file *sf)
{
- return sprintf(page, "%lu\n", var);
+ seq_printf(sf, "%lu\n", var);
+ return 0;
}

static ssize_t
@@ -58,9 +58,9 @@ static ssize_t queue_var_store64(s64 *var, const char *page)
return 0;
}

-static ssize_t queue_requests_show(struct request_queue *q, char *page)
+static int queue_requests_show(struct request_queue *q, struct seq_file *sf)
{
- return queue_var_show(q->nr_requests, page);
+ return queue_var_show(q->nr_requests, sf);
}

static ssize_t
@@ -86,14 +86,14 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count)
return ret;
}

-static ssize_t queue_ra_show(struct request_queue *q, char *page)
+static int queue_ra_show(struct request_queue *q, struct seq_file *sf)
{
unsigned long ra_kb;

if (!q->disk)
return -EINVAL;
ra_kb = q->disk->bdi->ra_pages << (PAGE_SHIFT - 10);
- return queue_var_show(ra_kb, page);
+ return queue_var_show(ra_kb, sf);
}

static ssize_t
@@ -111,75 +111,83 @@ queue_ra_store(struct request_queue *q, const char *page, size_t count)
return ret;
}

-static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
+static int queue_max_sectors_show(struct request_queue *q, struct seq_file *sf)
{
int max_sectors_kb = queue_max_sectors(q) >> 1;

- return queue_var_show(max_sectors_kb, page);
+ return queue_var_show(max_sectors_kb, sf);
}

-static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
+static int queue_max_segments_show(struct request_queue *q, struct seq_file *sf)
{
- return queue_var_show(queue_max_segments(q), page);
+ return queue_var_show(queue_max_segments(q), sf);
}

-static ssize_t queue_max_discard_segments_show(struct request_queue *q,
- char *page)
+static int queue_max_discard_segments_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(queue_max_discard_segments(q), page);
+ return queue_var_show(queue_max_discard_segments(q), sf);
}

-static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
+static int queue_max_integrity_segments_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(q->limits.max_integrity_segments, page);
+ return queue_var_show(q->limits.max_integrity_segments, sf);
}

-static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
+static int queue_max_segment_size_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(queue_max_segment_size(q), page);
+ return queue_var_show(queue_max_segment_size(q), sf);
}

-static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
+static int queue_logical_block_size_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(queue_logical_block_size(q), page);
+ return queue_var_show(queue_logical_block_size(q), sf);
}

-static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
+static int queue_physical_block_size_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(queue_physical_block_size(q), page);
+ return queue_var_show(queue_physical_block_size(q), sf);
}

-static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page)
+static int queue_chunk_sectors_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(q->limits.chunk_sectors, page);
+ return queue_var_show(q->limits.chunk_sectors, sf);
}

-static ssize_t queue_io_min_show(struct request_queue *q, char *page)
+static int queue_io_min_show(struct request_queue *q, struct seq_file *sf)
{
- return queue_var_show(queue_io_min(q), page);
+ return queue_var_show(queue_io_min(q), sf);
}

-static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
+static int queue_io_opt_show(struct request_queue *q, struct seq_file *sf)
{
- return queue_var_show(queue_io_opt(q), page);
+ return queue_var_show(queue_io_opt(q), sf);
}

-static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
+static int queue_discard_granularity_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(q->limits.discard_granularity, page);
+ return queue_var_show(q->limits.discard_granularity, sf);
}

-static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
+static int queue_discard_max_hw_show(struct request_queue *q,
+ struct seq_file *sf)
{
-
- return sprintf(page, "%llu\n",
+ seq_printf(sf, "%llu\n",
(unsigned long long)q->limits.max_hw_discard_sectors << 9);
+ return 0;
}

-static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
+static int queue_discard_max_show(struct request_queue *q, struct seq_file *sf)
{
- return sprintf(page, "%llu\n",
- (unsigned long long)q->limits.max_discard_sectors << 9);
+ seq_printf(sf, "%llu\n",
+ (unsigned long long)q->limits.max_discard_sectors << 9);
+ return 0;
}

static ssize_t queue_discard_max_store(struct request_queue *q,
@@ -205,34 +213,41 @@ static ssize_t queue_discard_max_store(struct request_queue *q,
return ret;
}

-static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
+static int queue_discard_zeroes_data_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(0, page);
+ return queue_var_show(0, sf);
}

-static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
+static int queue_write_same_max_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return sprintf(page, "%llu\n",
+ seq_printf(sf, "%llu\n",
(unsigned long long)q->limits.max_write_same_sectors << 9);
+ return 0;
}

-static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
+static int queue_write_zeroes_max_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return sprintf(page, "%llu\n",
+ seq_printf(sf, "%llu\n",
(unsigned long long)q->limits.max_write_zeroes_sectors << 9);
+ return 0;
}

-static ssize_t queue_zone_write_granularity_show(struct request_queue *q,
- char *page)
+static int queue_zone_write_granularity_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(queue_zone_write_granularity(q), page);
+ return queue_var_show(queue_zone_write_granularity(q), sf);
}

-static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page)
+static int queue_zone_append_max_show(struct request_queue *q,
+ struct seq_file *sf)
{
unsigned long long max_sectors = q->limits.max_zone_append_sectors;

- return sprintf(page, "%llu\n", max_sectors << SECTOR_SHIFT);
+ seq_printf(sf, "%llu\n", max_sectors << SECTOR_SHIFT);
+ return 0;
}

static ssize_t
@@ -261,25 +276,27 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
return ret;
}

-static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
+static int queue_max_hw_sectors_show(struct request_queue *q,
+ struct seq_file *sf)
{
int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;

- return queue_var_show(max_hw_sectors_kb, page);
+ return queue_var_show(max_hw_sectors_kb, sf);
}

-static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page)
+static int queue_virt_boundary_mask_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(q->limits.virt_boundary_mask, page);
+ return queue_var_show(q->limits.virt_boundary_mask, sf);
}

#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
-static ssize_t \
-queue_##name##_show(struct request_queue *q, char *page) \
+static int \
+queue_##name##_show(struct request_queue *q, struct seq_file *sf) \
{ \
int bit; \
bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
- return queue_var_show(neg ? !bit : bit, page); \
+ return queue_var_show(neg ? !bit : bit, sf); \
} \
static ssize_t \
queue_##name##_store(struct request_queue *q, const char *page, size_t count) \
@@ -305,37 +322,43 @@ QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0);
#undef QUEUE_SYSFS_BIT_FNS

-static ssize_t queue_zoned_show(struct request_queue *q, char *page)
+static int queue_zoned_show(struct request_queue *q,
+ struct seq_file *sf)
{
switch (blk_queue_zoned_model(q)) {
case BLK_ZONED_HA:
- return sprintf(page, "host-aware\n");
+ seq_printf(sf, "host-aware\n");
+ return 0;
case BLK_ZONED_HM:
- return sprintf(page, "host-managed\n");
+ seq_printf(sf, "host-managed\n");
+ return 0;
default:
- return sprintf(page, "none\n");
+ seq_printf(sf, "none\n");
+ return 0;
}
}

-static ssize_t queue_nr_zones_show(struct request_queue *q, char *page)
+static int queue_nr_zones_show(struct request_queue *q, struct seq_file *sf)
{
- return queue_var_show(blk_queue_nr_zones(q), page);
+ return queue_var_show(blk_queue_nr_zones(q), sf);
}

-static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page)
+static int queue_max_open_zones_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(queue_max_open_zones(q), page);
+ return queue_var_show(queue_max_open_zones(q), sf);
}

-static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page)
+static int queue_max_active_zones_show(struct request_queue *q,
+ struct seq_file *sf)
{
- return queue_var_show(queue_max_active_zones(q), page);
+ return queue_var_show(queue_max_active_zones(q), sf);
}

-static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
+static int queue_nomerges_show(struct request_queue *q, struct seq_file *sf)
{
return queue_var_show((blk_queue_nomerges(q) << 1) |
- blk_queue_noxmerges(q), page);
+ blk_queue_noxmerges(q), sf);
}

static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
@@ -357,12 +380,12 @@ static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
return ret;
}

-static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
+static int queue_rq_affinity_show(struct request_queue *q, struct seq_file *sf)
{
bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);

- return queue_var_show(set << force, page);
+ return queue_var_show(set << force, sf);
}

static ssize_t
@@ -390,7 +413,7 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
return ret;
}

-static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
+static int queue_poll_delay_show(struct request_queue *q, struct seq_file *sf)
{
int val;

@@ -399,7 +422,8 @@ static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
else
val = q->poll_nsec / 1000;

- return sprintf(page, "%d\n", val);
+ seq_printf(sf, "%d\n", val);
+ return 0;
}

static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
@@ -424,9 +448,9 @@ static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
return count;
}

-static ssize_t queue_poll_show(struct request_queue *q, char *page)
+static int queue_poll_show(struct request_queue *q, struct seq_file *sf)
{
- return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
+ return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), sf);
}

static ssize_t queue_poll_store(struct request_queue *q, const char *page,
@@ -454,9 +478,10 @@ static ssize_t queue_poll_store(struct request_queue *q, const char *page,
return ret;
}

-static ssize_t queue_io_timeout_show(struct request_queue *q, char *page)
+static int queue_io_timeout_show(struct request_queue *q, struct seq_file *sf)
{
- return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout));
+ seq_printf(sf, "%u\n", jiffies_to_msecs(q->rq_timeout));
+ return 0;
}

static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
@@ -474,12 +499,12 @@ static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
return count;
}

-static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
+static int queue_wb_lat_show(struct request_queue *q, struct seq_file *sf)
{
if (!wbt_rq_qos(q))
return -EINVAL;
-
- return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
+ seq_printf(sf, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
+ return 0;
}

static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
@@ -526,12 +551,13 @@ static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
return count;
}

-static ssize_t queue_wc_show(struct request_queue *q, char *page)
+static int queue_wc_show(struct request_queue *q, struct seq_file *sf)
{
if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
- return sprintf(page, "write back\n");
-
- return sprintf(page, "write through\n");
+ seq_printf(sf, "write back\n");
+ else
+ seq_printf(sf, "write through\n");
+ return 0;
}

static ssize_t queue_wc_store(struct request_queue *q, const char *page,
@@ -556,14 +582,15 @@ static ssize_t queue_wc_store(struct request_queue *q, const char *page,
return count;
}

-static ssize_t queue_fua_show(struct request_queue *q, char *page)
+static int queue_fua_show(struct request_queue *q, struct seq_file *sf)
{
- return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags));
+ seq_printf(sf, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags));
+ return 0;
}

-static ssize_t queue_dax_show(struct request_queue *q, char *page)
+static int queue_dax_show(struct request_queue *q, struct seq_file *sf)
{
- return queue_var_show(blk_queue_dax(q), page);
+ return queue_var_show(blk_queue_dax(q), sf);
}

#define QUEUE_RO_ENTRY(_prefix, _name) \
@@ -710,8 +737,8 @@ static struct attribute_group queue_attr_group = {

#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)

-static ssize_t
-queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
+static int queue_attr_seq_show(struct kobject *kobj, struct attribute *attr,
+ struct seq_file *sf)
{
struct queue_sysfs_entry *entry = to_queue(attr);
struct request_queue *q =
@@ -721,7 +748,7 @@ queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
if (!entry->show)
return -EIO;
mutex_lock(&q->sysfs_lock);
- res = entry->show(q, page);
+ res = entry->show(q, sf);
mutex_unlock(&q->sysfs_lock);
return res;
}
@@ -837,8 +864,8 @@ static void blk_release_queue(struct kobject *kobj)
}

static const struct sysfs_ops queue_sysfs_ops = {
- .show = queue_attr_show,
- .store = queue_attr_store,
+ .seq_show = queue_attr_seq_show,
+ .store = queue_attr_store,
};

struct kobj_type blk_queue_ktype = {
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 7c4e7993ba970..579d31f0269bf 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -2496,11 +2496,12 @@ void blk_throtl_register_queue(struct request_queue *q)
}

#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
-ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page)
+int blk_throtl_sample_time_show(struct request_queue *q, struct seq_file *sf)
{
if (!q->td)
return -EINVAL;
- return sprintf(page, "%u\n", jiffies_to_msecs(q->td->throtl_slice));
+ seq_printf(sf, "%u\n", jiffies_to_msecs(q->td->throtl_slice));
+ return 0;
}

ssize_t blk_throtl_sample_time_store(struct request_queue *q,
diff --git a/block/blk.h b/block/blk.h
index 7d2a0ba7ed21d..69b9b6b3b2169 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -300,7 +300,7 @@ static inline void blk_throtl_charge_bio_split(struct bio *bio) { }
static inline bool blk_throtl_bio(struct bio *bio) { return false; }
#endif /* CONFIG_BLK_DEV_THROTTLING */
#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
-extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
+int blk_throtl_sample_time_show(struct request_queue *q, struct seq_file *sf);
extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
const char *page, size_t count);
extern void blk_throtl_bio_endio(struct bio *bio);
diff --git a/block/elevator.c b/block/elevator.c
index ff45d8388f487..f068585f2f9b8 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -782,39 +782,40 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
return ret;
}

-ssize_t elv_iosched_show(struct request_queue *q, char *name)
+int elv_iosched_show(struct request_queue *q, struct seq_file *sf)
{
struct elevator_queue *e = q->elevator;
struct elevator_type *elv = NULL;
struct elevator_type *__e;
- int len = 0;

- if (!queue_is_mq(q))
- return sprintf(name, "none\n");
+ if (!queue_is_mq(q)) {
+ seq_printf(sf, "none\n");
+ return 0;
+ }

if (!q->elevator)
- len += sprintf(name+len, "[none] ");
+ seq_printf(sf, "[none] ");
else
elv = e->type;

spin_lock(&elv_list_lock);
list_for_each_entry(__e, &elv_list, list) {
if (elv && elevator_match(elv, __e->elevator_name, 0)) {
- len += sprintf(name+len, "[%s] ", elv->elevator_name);
+ seq_printf(sf, "[%s] ", elv->elevator_name);
continue;
}
if (elv_support_iosched(q) &&
elevator_match(__e, __e->elevator_name,
q->required_elevator_features))
- len += sprintf(name+len, "%s ", __e->elevator_name);
+ seq_printf(sf, "%s ", __e->elevator_name);
}
spin_unlock(&elv_list_lock);

if (q->elevator)
- len += sprintf(name+len, "none");
+ seq_printf(sf, "none");

- len += sprintf(len+name, "\n");
- return len;
+ seq_printf(sf, "\n");
+ return 0;
}

struct request *elv_rb_former_request(struct request_queue *q,
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index ef9ceead3db13..deecf7f9ff21a 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -132,7 +132,7 @@ extern void elv_unregister(struct elevator_type *);
/*
* io scheduler sysfs switching
*/
-extern ssize_t elv_iosched_show(struct request_queue *, char *);
+int elv_iosched_show(struct request_queue *q, struct seq_file *sf);
extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t);

extern bool elv_bio_merge_ok(struct request *, struct bio *);
--
2.30.2