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-rw-r--r--fs/super.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/fs/super.c b/fs/super.c
index e9dc3c3fe159..d20d5b11dedf 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -112,9 +112,14 @@ static unsigned long super_cache_count(struct shrinker *shrink,
sb = container_of(shrink, struct super_block, s_shrink);
- if (!grab_super_passive(sb))
- return 0;
-
+ /*
+ * Don't call grab_super_passive as it is a potential
+ * scalability bottleneck. The counts could get updated
+ * between super_cache_count and super_cache_scan anyway.
+ * Call to super_cache_count with shrinker_rwsem held
+ * ensures the safety of call to list_lru_count_node() and
+ * s_op->nr_cached_objects().
+ */
if (sb->s_op && sb->s_op->nr_cached_objects)
total_objects = sb->s_op->nr_cached_objects(sb,
sc->nid);
@@ -125,7 +130,6 @@ static unsigned long super_cache_count(struct shrinker *shrink,
sc->nid);
total_objects = vfs_pressure_ratio(total_objects);
- drop_super(sb);
return total_objects;
}
@@ -276,10 +280,8 @@ void deactivate_locked_super(struct super_block *s)
struct file_system_type *fs = s->s_type;
if (atomic_dec_and_test(&s->s_active)) {
cleancache_invalidate_fs(s);
- fs->kill_sb(s);
-
- /* caches are now gone, we can safely kill the shrinker now */
unregister_shrinker(&s->s_shrink);
+ fs->kill_sb(s);
put_filesystem(fs);
put_super(s);
@@ -800,7 +802,10 @@ void emergency_remount(void)
static DEFINE_IDA(unnamed_dev_ida);
static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
-static int unnamed_dev_start = 0; /* don't bother trying below it */
+/* Many userspace utilities consider an FSID of 0 invalid.
+ * Always return at least 1 from get_anon_bdev.
+ */
+static int unnamed_dev_start = 1;
int get_anon_bdev(dev_t *p)
{