block: add internal hd part table references
We can't use krefs since it's apparently restricted to very basic
reference counting.
This reverts commit e4a683c8.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 2ba2792..2d04681 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -115,8 +115,8 @@
#else
struct disk_stats dkstats;
#endif
+ atomic_t ref;
struct rcu_head rcu_head;
- struct kref ref;
};
#define GENHD_FL_REMOVABLE 1
@@ -584,7 +584,7 @@
sector_t len, int flags,
struct partition_meta_info
*info);
-extern void __delete_partition(struct kref *ref);
+extern void __delete_partition(struct hd_struct *);
extern void delete_partition(struct gendisk *, int);
extern void printk_all_partitions(void);
@@ -613,6 +613,29 @@
const char *buf, size_t count);
#endif /* CONFIG_FAIL_MAKE_REQUEST */
+static inline void hd_ref_init(struct hd_struct *part)
+{
+ atomic_set(&part->ref, 1);
+ smp_mb();
+}
+
+static inline void hd_struct_get(struct hd_struct *part)
+{
+ atomic_inc(&part->ref);
+ smp_mb__after_atomic_inc();
+}
+
+static inline int hd_struct_try_get(struct hd_struct *part)
+{
+ return atomic_inc_not_zero(&part->ref);
+}
+
+static inline void hd_struct_put(struct hd_struct *part)
+{
+ if (atomic_dec_and_test(&part->ref))
+ __delete_partition(part);
+}
+
#else /* CONFIG_BLOCK */
static inline void printk_all_partitions(void) { }