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authorTejun Heo <tj@kernel.org>2008-08-25 19:56:15 +0900
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 08:56:08 +0200
commit540eed5637b766bb1e881ef744c42617760b4815 (patch)
tree8bdf54967a8290f780216f767291623e67ee7e9b /include/linux
parent074a7aca7afa6f230104e8e65eba3420263714a5 (diff)
block: make partition array dynamic
disk->__part used to be statically allocated to the maximum possible number of partitions. This patch makes partition array allocation dynamic. The added overhead is minimal as only real change is one memory dereference changed to RCU one. This saves both a bit of memory and cpu cycles iterating through unoccupied slots and makes increasing partition limit easier. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/genhd.h19
1 files changed, 18 insertions, 1 deletions
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index c90e1b4fbe5..ecf649c3dee 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -113,6 +113,21 @@ struct hd_struct {
#define GENHD_FL_UP 16
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32
+#define BLK_SCSI_MAX_CMDS (256)
+#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
+
+struct blk_scsi_cmd_filter {
+ unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
+ unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
+ struct kobject kobj;
+};
+
+struct disk_part_tbl {
+ struct rcu_head rcu_head;
+ int len;
+ struct hd_struct *part[];
+};
+
struct gendisk {
/* major, first_minor, minors and ext_minors are input
* parameters only, don't use directly. Use disk_devt() and
@@ -131,7 +146,7 @@ struct gendisk {
* non-critical accesses use RCU. Always access through
* helpers.
*/
- struct hd_struct **__part;
+ struct disk_part_tbl *part_tbl;
struct hd_struct part0;
struct block_device_operations *fops;
@@ -149,6 +164,7 @@ struct gendisk {
#ifdef CONFIG_BLK_DEV_INTEGRITY
struct blk_integrity *integrity;
#endif
+ int node_id;
};
static inline struct gendisk *part_to_disk(struct hd_struct *part)
@@ -503,6 +519,7 @@ extern void blk_free_devt(dev_t devt);
extern dev_t blk_lookup_devt(const char *name, int partno);
extern char *disk_name (struct gendisk *hd, int partno, char *buf);
+extern int disk_expand_part_tbl(struct gendisk *disk, int target);
extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
extern int __must_check add_partition(struct gendisk *, int, sector_t, sector_t, int);
extern void delete_partition(struct gendisk *, int);