diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/genhd.h | 53 |
1 files changed, 39 insertions, 14 deletions
diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 0ff75329199..7fbba19e076 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -11,6 +11,7 @@ #include <linux/types.h> #include <linux/kdev_t.h> +#include <linux/rcupdate.h> #ifdef CONFIG_BLOCK @@ -100,6 +101,7 @@ struct hd_struct { #else struct disk_stats dkstats; #endif + struct rcu_head rcu_head; }; #define GENHD_FL_REMOVABLE 1 @@ -120,7 +122,14 @@ struct gendisk { * disks that can't be partitioned. */ char disk_name[32]; /* name of major driver */ - struct hd_struct **part; /* [indexed by minor - 1] */ + + /* Array of pointers to partitions indexed by partno - 1. + * Protected with matching bdev lock but stat and other + * non-critical accesses use RCU. Always access through + * helpers. + */ + struct hd_struct **__part; + struct block_device_operations *fops; struct request_queue *queue; void *private_data; @@ -171,25 +180,41 @@ static inline dev_t part_devt(struct hd_struct *part) return part->dev.devt; } +extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno); + +static inline void disk_put_part(struct hd_struct *part) +{ + if (likely(part)) + put_device(&part->dev); +} + +/* + * Smarter partition iterator without context limits. + */ +#define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */ +#define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */ + +struct disk_part_iter { + struct gendisk *disk; + struct hd_struct *part; + int idx; + unsigned int flags; +}; + +extern void disk_part_iter_init(struct disk_part_iter *piter, + struct gendisk *disk, unsigned int flags); +extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter); +extern void disk_part_iter_exit(struct disk_part_iter *piter); + +extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, + sector_t sector); + /* * Macros to operate on percpu disk statistics: * * The __ variants should only be called in critical sections. The full * variants disable/enable preemption. */ -static inline struct hd_struct *disk_map_sector(struct gendisk *gendiskp, - sector_t sector) -{ - struct hd_struct *part; - int i; - for (i = 0; i < disk_max_parts(gendiskp); i++) { - part = gendiskp->part[i]; - if (part && part->start_sect <= sector - && sector < part->start_sect + part->nr_sects) - return part; - } - return NULL; -} #ifdef CONFIG_SMP #define __disk_stat_add(gendiskp, field, addnd) \ |