The following three sysfs files are created to display according feature
set information of bcache:
/sys/fs/bcache/<cache set UUID>/internal/feature_compat
/sys/fs/bcache/<cache set UUID>/internal/feature_ro_compat
/sys/fs/bcache/<cache set UUID>/internal/feature_incompat
is added by this patch, to display feature sets information of the cache
set.
Now only an incompat feature 'large_bucket' added in bcache, the sysfs
file content is:
[large_bucket]
string large_bucket means the running bcache drive supports incompat
feature 'large_bucket', the wrapping [] means the 'large_bucket' feature
is currently enabled on this cache set.
This patch is ready to display compat and ro_compat features, in future
once bcache code implements such feature sets, the according feature
strings will be displayed in their sysfs files too.
Signed-off-by: Coly Li <colyli@xxxxxxx>
---
Changlog:
v2: create single sysfs file for each feature set, suggested by Hannes.
v1: initial version.
drivers/md/bcache/Makefile | 2 +-
drivers/md/bcache/features.c | 53 ++++++++++++++++++++++++++++++++++++
drivers/md/bcache/features.h | 5 ++++
drivers/md/bcache/sysfs.c | 14 ++++++++++
4 files changed, 73 insertions(+), 1 deletion(-)
diff --git a/drivers/md/bcache/Makefile b/drivers/md/bcache/Makefile
index fd714628da6a..5b87e59676b8 100644
--- a/drivers/md/bcache/Makefile
+++ b/drivers/md/bcache/Makefile
@@ -4,4 +4,4 @@ obj-$(CONFIG_BCACHE) += bcache.o
bcache-y := alloc.o bset.o btree.o closure.o debug.o extents.o\
io.o journal.o movinggc.o request.o stats.o super.o sysfs.o trace.o\
- util.o writeback.o
+ util.o writeback.o features.o
diff --git a/drivers/md/bcache/features.c b/drivers/md/bcache/features.c
index ba53944bb390..4442df48d28c 100644
--- a/drivers/md/bcache/features.c
+++ b/drivers/md/bcache/features.c
@@ -8,6 +8,7 @@
*/
#include <linux/bcache.h>
#include "bcache.h"
+#include "features.h"
struct feature {
int compat;
@@ -20,3 +21,55 @@ static struct feature feature_list[] = {
"large_bucket"},
{0, 0, 0 },
};
+
+#define compose_feature_string(type) \
+({ \
+ struct feature *f; \
+ bool first = true; \
+ \
+ for (f = &feature_list[0]; f->compat != 0; f++) { \
+ if (f->compat != BCH_FEATURE_ ## type) \
+ continue; \
+ if (BCH_HAS_ ## type ## _FEATURE(&c->sb, f->mask)) { \
+ if (first) { \
+ out += snprintf(out, buf + size - out, \
+ "["); \
+ } else { \
+ out += snprintf(out, buf + size - out, \
+ " ["); \
+ } \
+ } else if (!first) { \
+ out += snprintf(out, buf + size - out, " "); \
+ } \
+ \
+ out += snprintf(out, buf + size - out, "%s", f->string);\
+ \
+ if (BCH_HAS_ ## type ## _FEATURE(&c->sb, f->mask)) \
+ out += snprintf(out, buf + size - out, "]"); \
+ \
+ first = false; \
+ } \
+ if (!first) \
+ out += snprintf(out, buf + size - out, "\n"); \
+})
+
+int bch_print_cache_set_feature_compat(struct cache_set *c, char *buf, int size)
+{
+ char *out = buf;
+ compose_feature_string(COMPAT);
+ return out - buf;
+}
+
+int bch_print_cache_set_feature_ro_compat(struct cache_set *c, char *buf, int size)
+{
+ char *out = buf;
+ compose_feature_string(RO_COMPAT);
+ return out - buf;
+}
+
+int bch_print_cache_set_feature_incompat(struct cache_set *c, char *buf, int size)
+{
+ char *out = buf;
+ compose_feature_string(INCOMPAT);
+ return out - buf;
+}
diff --git a/drivers/md/bcache/features.h b/drivers/md/bcache/features.h
index dca052cf5203..a1653c478041 100644
--- a/drivers/md/bcache/features.h
+++ b/drivers/md/bcache/features.h
@@ -78,4 +78,9 @@ static inline void bch_clear_feature_##name(struct cache_sb *sb) \
}
BCH_FEATURE_INCOMPAT_FUNCS(large_bucket, LARGE_BUCKET);
+
+int bch_print_cache_set_feature_compat(struct cache_set *c, char *buf, int size);
+int bch_print_cache_set_feature_ro_compat(struct cache_set *c, char *buf, int size);
+int bch_print_cache_set_feature_incompat(struct cache_set *c, char *buf, int size);
+
#endif
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 0dadec5a78f6..ac06c0bc3c0a 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -11,6 +11,7 @@
#include "btree.h"
#include "request.h"
#include "writeback.h"
+#include "features.h"
#include <linux/blkdev.h>
#include <linux/sort.h>
@@ -88,6 +89,9 @@ read_attribute(btree_used_percent);
read_attribute(average_key_size);
read_attribute(dirty_data);
read_attribute(bset_tree_stats);
+read_attribute(feature_compat);
+read_attribute(feature_ro_compat);
+read_attribute(feature_incompat);
read_attribute(state);
read_attribute(cache_read_races);
@@ -779,6 +783,13 @@ SHOW(__bch_cache_set)
if (attr == &sysfs_bset_tree_stats)
return bch_bset_print_stats(c, buf);
+ if (attr == &sysfs_feature_compat)
+ return bch_print_cache_set_feature_compat(c, buf, PAGE_SIZE);
+ if (attr == &sysfs_feature_ro_compat)
+ return bch_print_cache_set_feature_ro_compat(c, buf, PAGE_SIZE);
+ if (attr == &sysfs_feature_incompat)
+ return bch_print_cache_set_feature_incompat(c, buf, PAGE_SIZE);
+
return 0;
}
SHOW_LOCKED(bch_cache_set)
@@ -987,6 +998,9 @@ static struct attribute *bch_cache_set_internal_files[] = {
&sysfs_io_disable,
&sysfs_cutoff_writeback,
&sysfs_cutoff_writeback_sync,
+ &sysfs_feature_compat,
+ &sysfs_feature_ro_compat,
+ &sysfs_feature_incompat,
NULL
};
KTYPE(bch_cache_set_internal);
--
2.26.2
