On 04/15/2016 07:45 PM, Bart Van Assche wrote:
On 04/04/2016 03:00 AM, Hannes Reinecke wrote:
Add a sysfs queue attribute 'zoned' to display the zone layout
for zoned devices.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
block/blk-sysfs.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index ff97091..748bb27 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -244,6 +244,43 @@ static ssize_t queue_max_hw_sectors_show(struct
request_queue *q, char *page)
return queue_var_show(max_hw_sectors_kb, (page));
}
+#ifdef CONFIG_BLK_DEV_ZONED
+static ssize_t queue_zoned_show(struct request_queue *q, char *page)
+{
+ struct rb_node *node;
+ struct blk_zone *zone;
+ ssize_t offset = 0, end = 0;
+ size_t size = 0, num = 0;
+ enum blk_zone_type type = BLK_ZONE_TYPE_UNKNOWN;
+
+ for (node = rb_first(&q->zones); node; node = rb_next(node)) {
+ zone = rb_entry(node, struct blk_zone, node);
+ if (zone->type != type ||
+ zone->len != size ||
+ end != zone->start) {
+ if (size != 0)
+ offset += sprintf(page + offset, "%zu\n", num);
+ /* We can only store one page ... */
+ if (offset + 42 > PAGE_SIZE) {
+ offset += sprintf(page + offset, "...\n");
+ return offset;
+ }
+ size = zone->len;
+ type = zone->type;
+ offset += sprintf(page + offset, "%zu %zu %d ",
+ zone->start, size, type);
+ num = 0;
+ end = zone->start + size;
+ } else
+ end += zone->len;
+ num++;
+ }
+ if (num > 0)
+ offset += sprintf(page + offset, "%zu\n", num);
+ return offset > 0 ? offset : -EINVAL;
+}
+#endif
+
#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
static ssize_t \
queue_show_##name(struct request_queue *q, char *page) \
@@ -468,6 +505,13 @@ static struct queue_sysfs_entry
queue_write_same_max_entry = {
.show = queue_write_same_max_show,
};
+#ifdef CONFIG_BLK_DEV_ZONED
+static struct queue_sysfs_entry queue_zoned_entry = {
+ .attr = {.name = "zoned", .mode = S_IRUGO },
+ .show = queue_zoned_show,
+};
+#endif
+
Hello Hannes,
Have you considered to move the above definitions into a new file? That
would allow to avoid two #ifdefs and to move the code that decides
whether or not the above code gets built into block/Makefile.
Well, it's just these few lines, so I thought it easier to put it into
the existing file.
But sure I can add a separate files for that.
Additionally, have you considered to create one sysfs directory per zone
instead of one sysfs attribute with all zone information? From
Documentation/filesystems/sysfs.txt: "Attributes should be ASCII text
files, preferably with only one value per file."
Yes, I have considered it.
But doing so would require me to add about 20k sysfs attributes.
For no apparent gain.
So I've settled on this condensed approach here.
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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