[PATCH V2 07/10] block, bfq: use standard file names for the proportional-share policy

[Paolo Valente]

Some of the files exposed in a cgroup by bfq, for the proportional
share policy, have the same meaning as the files owned by cfq (before
legacy blk was removed).

The old implementation of the cgroup interface didn't allow different
entities to create cgroup files with the same name (in the same
subsystem). So, for bfq, we had to add the prefix "bfq" to the names
of its cgroup files.

This commit renames the cgroup files of the bfq scheduler as those
exposed by cfq, and makes bfq willing to share these files with any
other future policy.

Signed-off-by: Angelo Ruocco <angeloruocco90@xxxxxxxxx>
Signed-off-by: Paolo Valente <paolo.valente@xxxxxxxxxx>
---
 block/bfq-cgroup.c | 94 +++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 69 insertions(+), 25 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index 038e418fa64f..0643147b2cbc 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -1055,50 +1055,67 @@ struct blkcg_policy blkcg_policy_bfq = {
 
 struct cftype bfq_blkcg_legacy_files[] = {
 	{
-		.name = "bfq.weight",
-		.flags = CFTYPE_NOT_ON_ROOT,
+		.name = "weight",
+		.owner_name = "bfq",
+		.flags = CFTYPE_NOT_ON_ROOT | CFTYPE_SHARES_FILE,
 		.seq_show = bfq_io_show_weight,
 		.write_u64 = bfq_io_set_weight_legacy,
 	},
 
 	/* statistics, covers only the tasks in the bfqg */
 	{
-		.name = "bfq.io_service_bytes",
+		.name = "io_service_bytes",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = (unsigned long)&blkcg_policy_bfq,
 		.seq_show_cft = blkg_print_stat_bytes,
 	},
 	{
-		.name = "bfq.io_serviced",
+		.name = "io_serviced",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = (unsigned long)&blkcg_policy_bfq,
 		.seq_show_cft = blkg_print_stat_ios,
 	},
 #ifdef CONFIG_DEBUG_BLK_CGROUP
 	{
-		.name = "bfq.time",
+		.name = "time",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.time),
 		.seq_show_cft = bfqg_print_stat,
 	},
 	{
-		.name = "bfq.sectors",
+		.name = "sectors",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.seq_show = bfqg_print_stat_sectors,
 	},
 	{
-		.name = "bfq.io_service_time",
+		.name = "io_service_time",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.service_time),
 		.seq_show_cft = bfqg_print_rwstat,
 	},
 	{
-		.name = "bfq.io_wait_time",
+		.name = "io_wait_time",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.wait_time),
 		.seq_show_cft = bfqg_print_rwstat,
 	},
 	{
-		.name = "bfq.io_merged",
+		.name = "io_merged",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.merged),
 		.seq_show_cft = bfqg_print_rwstat,
 	},
 	{
-		.name = "bfq.io_queued",
+		.name = "io_queued",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.queued),
 		.seq_show_cft = bfqg_print_rwstat,
 	},
@@ -1106,66 +1123,92 @@ struct cftype bfq_blkcg_legacy_files[] = {
 
 	/* the same statictics which cover the bfqg and its descendants */
 	{
-		.name = "bfq.io_service_bytes_recursive",
+		.name = "io_service_bytes_recursive",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = (unsigned long)&blkcg_policy_bfq,
 		.seq_show_cft = blkg_print_stat_bytes_recursive,
 	},
 	{
-		.name = "bfq.io_serviced_recursive",
+		.name = "io_serviced_recursive",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = (unsigned long)&blkcg_policy_bfq,
 		.seq_show_cft = blkg_print_stat_ios_recursive,
 	},
 #ifdef CONFIG_DEBUG_BLK_CGROUP
 	{
-		.name = "bfq.time_recursive",
+		.name = "time_recursive",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.time),
 		.seq_show_cft = bfqg_print_stat_recursive,
 	},
 	{
-		.name = "bfq.sectors_recursive",
+		.name = "sectors_recursive",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.seq_show = bfqg_print_stat_sectors_recursive,
 	},
 	{
-		.name = "bfq.io_service_time_recursive",
+		.name = "io_service_time_recursive",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.service_time),
 		.seq_show_cft = bfqg_print_rwstat_recursive,
 	},
 	{
-		.name = "bfq.io_wait_time_recursive",
+		.name = "io_wait_time_recursive",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.wait_time),
 		.seq_show_cft = bfqg_print_rwstat_recursive,
 	},
 	{
-		.name = "bfq.io_merged_recursive",
+		.name = "io_merged_recursive",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.merged),
 		.seq_show_cft = bfqg_print_rwstat_recursive,
 	},
 	{
-		.name = "bfq.io_queued_recursive",
+		.name = "io_queued_recursive",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.queued),
 		.seq_show_cft = bfqg_print_rwstat_recursive,
 	},
 	{
-		.name = "bfq.avg_queue_size",
+		.name = "avg_queue_size",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.seq_show = bfqg_print_avg_queue_size,
 	},
 	{
-		.name = "bfq.group_wait_time",
+		.name = "group_wait_time",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.group_wait_time),
 		.seq_show_cft = bfqg_print_stat,
 	},
 	{
-		.name = "bfq.idle_time",
+		.name = "idle_time",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.idle_time),
 		.seq_show_cft = bfqg_print_stat,
 	},
 	{
-		.name = "bfq.empty_time",
+		.name = "empty_time",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.empty_time),
 		.seq_show_cft = bfqg_print_stat,
 	},
 	{
-		.name = "bfq.dequeue",
+		.name = "dequeue",
+		.owner_name = "bfq",
+		.flags = CFTYPE_SHARES_FILE,
 		.private = offsetof(struct bfq_group, stats.dequeue),
 		.seq_show_cft = bfqg_print_stat,
 	},
@@ -1175,8 +1218,9 @@ struct cftype bfq_blkcg_legacy_files[] = {
 
 struct cftype bfq_blkg_files[] = {
 	{
-		.name = "bfq.weight",
-		.flags = CFTYPE_NOT_ON_ROOT,
+		.name = "weight",
+		.owner_name = "bfq",
+		.flags = CFTYPE_NOT_ON_ROOT | CFTYPE_SHARES_FILE,
 		.seq_show = bfq_io_show_weight,
 		.write = bfq_io_set_weight,
 	},
-- 
2.16.1