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path: root/drivers/md/bcache/sysfs.c
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Diffstat (limited to 'drivers/md/bcache/sysfs.c')
-rw-r--r--drivers/md/bcache/sysfs.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index f90f13616980..104c57cd666c 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -192,7 +192,7 @@ STORE(__cached_dev)
{
struct cached_dev *dc = container_of(kobj, struct cached_dev,
disk.kobj);
- unsigned v = size;
+ ssize_t v = size;
struct cache_set *c;
struct kobj_uevent_env *env;
@@ -227,7 +227,7 @@ STORE(__cached_dev)
bch_cached_dev_run(dc);
if (attr == &sysfs_cache_mode) {
- ssize_t v = bch_read_string_list(buf, bch_cache_modes + 1);
+ v = bch_read_string_list(buf, bch_cache_modes + 1);
if (v < 0)
return v;
@@ -615,8 +615,21 @@ STORE(__bch_cache_set)
bch_cache_accounting_clear(&c->accounting);
}
- if (attr == &sysfs_trigger_gc)
+ if (attr == &sysfs_trigger_gc) {
+ /*
+ * Garbage collection thread only works when sectors_to_gc < 0,
+ * when users write to sysfs entry trigger_gc, most of time
+ * they want to forcibly triger gargage collection. Here -1 is
+ * set to c->sectors_to_gc, to make gc_should_run() give a
+ * chance to permit gc thread to run. "give a chance" means
+ * before going into gc_should_run(), there is still chance
+ * that c->sectors_to_gc being set to other positive value. So
+ * writing sysfs entry trigger_gc won't always make sure gc
+ * thread takes effect.
+ */
+ atomic_set(&c->sectors_to_gc, -1);
wake_up_gc(c);
+ }
if (attr == &sysfs_prune_cache) {
struct shrink_control sc;