0eb3ff12aa
Add in correct read-error handling for resync and read-only situations. When read-only, we don't over-write, so we need to mark the failed drive in the r10_bio so we don't re-try it. During resync, we always read all blocks, so if there is a read error, we simply over-write it with the good block that we found (assuming we found one). Note that the recovery case still isn't handled in an interesting way. There is nothing useful to do for the 2-copies case. If there are 3 or more copies, then we could try reading from one of the non-missing copies, but this is a bit complicated and very rarely would be used, so I'm leaving it for now. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
119 lines
2.9 KiB
C
119 lines
2.9 KiB
C
#ifndef _RAID10_H
|
|
#define _RAID10_H
|
|
|
|
#include <linux/raid/md.h>
|
|
|
|
typedef struct mirror_info mirror_info_t;
|
|
|
|
struct mirror_info {
|
|
mdk_rdev_t *rdev;
|
|
sector_t head_position;
|
|
};
|
|
|
|
typedef struct r10bio_s r10bio_t;
|
|
|
|
struct r10_private_data_s {
|
|
mddev_t *mddev;
|
|
mirror_info_t *mirrors;
|
|
int raid_disks;
|
|
int working_disks;
|
|
spinlock_t device_lock;
|
|
|
|
/* geometry */
|
|
int near_copies; /* number of copies layed out raid0 style */
|
|
int far_copies; /* number of copies layed out
|
|
* at large strides across drives
|
|
*/
|
|
int copies; /* near_copies * far_copies.
|
|
* must be <= raid_disks
|
|
*/
|
|
sector_t stride; /* distance between far copies.
|
|
* This is size / far_copies
|
|
*/
|
|
|
|
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;
|
|
|
|
|
|
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.
|
|
*/
|
|
|
|
wait_queue_head_t wait_barrier;
|
|
|
|
mempool_t *r10bio_pool;
|
|
mempool_t *r10buf_pool;
|
|
struct page *tmppage;
|
|
};
|
|
|
|
typedef struct r10_private_data_s 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) ((conf_t *) mddev->private)
|
|
|
|
/*
|
|
* 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_s {
|
|
atomic_t remaining; /* 'have we finished' count,
|
|
* used from IRQ handlers
|
|
*/
|
|
sector_t sector; /* virtual sector number */
|
|
int sectors;
|
|
unsigned long state;
|
|
mddev_t *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.
|
|
*/
|
|
struct {
|
|
struct bio *bio;
|
|
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)
|
|
|
|
/* bits for r10bio.state */
|
|
#define R10BIO_Uptodate 0
|
|
#define R10BIO_IsSync 1
|
|
#define R10BIO_IsRecover 2
|
|
#define R10BIO_Degraded 3
|
|
#endif
|