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#ifndef _MULTIPATH_H
#define _MULTIPATH_H
#include <linux/raid/md.h>
struct multipath_info {
int number;
int raid_disk;
kdev_t dev;
int sect_limit;
int head_position;
/*
* State bits:
*/
int operational;
int write_only;
int spare;
int used_slot;
};
struct multipath_private_data {
mddev_t *mddev;
struct multipath_info multipaths[MD_SB_DISKS];
int nr_disks;
int raid_disks;
int working_disks;
mdk_thread_t *thread;
struct multipath_info *spare;
md_spinlock_t device_lock;
/* buffer pool */
/* buffer_heads that we have pre-allocated have b_pprev -> &freebh
* and are linked into a stack using b_next
* multipath_bh that are pre-allocated have R1BH_PreAlloc set.
* All these variable are protected by device_lock
*/
struct buffer_head *freebh;
int freebh_cnt; /* how many are on the list */
struct multipath_bh *freer1;
struct multipath_bh *freebuf; /* each bh_req has a page allocated */
md_wait_queue_head_t wait_buffer;
/* for use when syncing multipaths: */
unsigned long start_active, start_ready,
start_pending, start_future;
int cnt_done, cnt_active, cnt_ready,
cnt_pending, cnt_future;
int phase;
int window;
md_wait_queue_head_t wait_done;
md_wait_queue_head_t wait_ready;
md_spinlock_t segment_lock;
};
typedef struct multipath_private_data multipath_conf_t;
/*
* this is the only point in the RAID code where we violate
* C type safety. mddev->private is an 'opaque' pointer.
*/
#define mddev_to_conf(mddev) ((multipath_conf_t *) mddev->private)
/*
* this is our 'private' 'collective' MULTIPATH buffer head.
* it contains information about what kind of IO operations were started
* for this MULTIPATH operation, and about their status:
*/
struct multipath_bh {
atomic_t remaining; /* 'have we finished' count,
* used from IRQ handlers
*/
int cmd;
unsigned long state;
mddev_t *mddev;
struct buffer_head *master_bh;
struct buffer_head *multipath_bh_list;
struct buffer_head bh_req;
struct multipath_bh *next_r1; /* next for retry or in free list */
};
/* bits for multipath_bh.state */
#define R1BH_Uptodate 1
#define R1BH_SyncPhase 2
#define R1BH_PreAlloc 3 /* this was pre-allocated, add to free list */
#endif
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