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-rw-r--r--include/linux/blkdev.h1
-rw-r--r--include/linux/genhd.h25
2 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 05667e6989f..5730043eb15 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -115,6 +115,7 @@ struct request {
void *elevator_private3;
struct gendisk *rq_disk;
+ struct hd_struct *part;
unsigned long start_time;
#ifdef CONFIG_BLK_CGROUP
unsigned long long start_time_ns;
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 13893aa2ac9..c0d5f6945c1 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -115,6 +115,7 @@ struct hd_struct {
#else
struct disk_stats dkstats;
#endif
+ atomic_t ref;
struct rcu_head rcu_head;
};
@@ -597,6 +598,7 @@ extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
sector_t len, int flags,
struct partition_meta_info
*info);
+extern void __delete_partition(struct hd_struct *);
extern void delete_partition(struct gendisk *, int);
extern void printk_all_partitions(void);
@@ -625,6 +627,29 @@ extern ssize_t part_fail_store(struct device *dev,
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) { }