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#ifndef _RAID10_H
#define _RAID10_H
struct mirror_info {
struct md_rdev *rdev, *replacement;
sector_t head_position;
int recovery_disabled; /* matches
* mddev->recovery_disabled
* when we shouldn't try
* recovering this device.
*/
};
struct r10conf {
struct mddev *mddev;
struct mirror_info *mirrors;
int raid_disks;
spinlock_t device_lock;
/* geometry */
int near_copies; /* number of copies laid out
* raid0 style */
int far_copies; /* number of copies laid out
* at large strides across drives
*/
int far_offset; /* far_copies are offset by 1
* stripe instead of many
*/
int copies; /* near_copies * far_copies.
* must be <= raid_disks
*/
sector_t stride; /* distance between far copies.
* This is size / far_copies unless
* far_offset, in which case it is
* 1 stripe.
*/
sector_t dev_sectors; /* temp copy of
* mddev->dev_sectors */
int chunk_shift; /* shift from chunks to sectors */
sector_t chunk_mask;
struct list_head retry_list;
/* queue pending writes and submit them on unplug */
struct bio_list pending_bio_list;
int pending_count;
spinlock_t resync_lock;
int nr_pending;
int nr_waiting;
int nr_queued;
int barrier;
sector_t next_resync;
int fullsync; /* set to 1 if a full sync is needed,
* (fresh device added).
* Cleared when a sync completes.
*/
int have_replacement; /* There is at least one
* replacement device.
*/
wait_queue_head_t wait_barrier;
mempool_t *r10bio_pool;
mempool_t *r10buf_pool;
struct page *tmppage;
/* When taking over an array from a different personality, we store
* the new thread here until we fully activate the array.
*/
struct md_thread *thread;
};
/*
* this is our 'private' RAID10 bio.
*
* it contains information about what kind of IO operations were started
* for this RAID10 operation, and about their status:
*/
struct r10bio {
atomic_t remaining; /* 'have we finished' count,
* used from IRQ handlers
*/
sector_t sector; /* virtual sector number */
int sectors;
unsigned long state;
struct mddev *mddev;
/*
* original bio going to /dev/mdx
*/
struct bio *master_bio;
/*
* if the IO is in READ direction, then this is where we read
*/
int read_slot;
struct list_head retry_list;
/*
* if the IO is in WRITE direction, then multiple bios are used,
* one for each copy.
* When resyncing we also use one for each copy.
* When reconstructing, we use 2 bios, one for read, one for write.
* We choose the number when they are allocated.
* We sometimes need an extra bio to write to the replacement.
*/
struct {
struct bio *bio;
union {
struct bio *repl_bio; /* used for resync and
* writes */
struct md_rdev *rdev; /* used for reads
* (read_slot >= 0) */
};
sector_t addr;
int devnum;
} devs[0];
};
/* when we get a read error on a read-only array, we redirect to another
* device without failing the first device, or trying to over-write to
* correct the read error. To keep track of bad blocks on a per-bio
* level, we store IO_BLOCKED in the appropriate 'bios' pointer
*/
#define IO_BLOCKED ((struct bio*)1)
/* When we successfully write to a known bad-block, we need to remove the
* bad-block marking which must be done from process context. So we record
* the success by setting devs[n].bio to IO_MADE_GOOD
*/
#define IO_MADE_GOOD ((struct bio *)2)
#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
/* bits for r10bio.state */
enum r10bio_state {
R10BIO_Uptodate,
R10BIO_IsSync,
R10BIO_IsRecover,
R10BIO_Degraded,
/* Set ReadError on bios that experience a read error
* so that raid10d knows what to do with them.
*/
R10BIO_ReadError,
/* If a write for this request means we can clear some
* known-bad-block records, we set this flag.
*/
R10BIO_MadeGood,
R10BIO_WriteError,
};
#endif
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