md/raid10: prepare data structures for handling replacement.
Allow each slot in the RAID10 to have 2 devices, the want_replacement
and the replacement.
Also an r10bio to have 2 bios, and for resync/recovery allocate the
second bio if there are any replacement devices.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h
index 7facfdf..7c615613 100644
--- a/drivers/md/raid10.h
+++ b/drivers/md/raid10.h
@@ -2,7 +2,7 @@
#define _RAID10_H
struct mirror_info {
- struct md_rdev *rdev;
+ struct md_rdev *rdev, *replacement;
sector_t head_position;
int recovery_disabled; /* matches
* mddev->recovery_disabled
@@ -18,12 +18,13 @@
spinlock_t device_lock;
/* geometry */
- int near_copies; /* number of copies laid out raid0 style */
+ 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 far_offset; /* far_copies are offset by 1
+ * stripe instead of many
*/
int copies; /* near_copies * far_copies.
* must be <= raid_disks
@@ -34,10 +35,11 @@
* 1 stripe.
*/
- sector_t dev_sectors; /* temp copy of mddev->dev_sectors */
+ sector_t dev_sectors; /* temp copy of
+ * mddev->dev_sectors */
- int chunk_shift; /* shift from chunks to sectors */
- sector_t chunk_mask;
+ 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 */
@@ -45,20 +47,22 @@
int pending_count;
spinlock_t resync_lock;
- int nr_pending;
- int nr_waiting;
- int nr_queued;
- int barrier;
+ 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;
+ mempool_t *r10bio_pool;
+ mempool_t *r10buf_pool;
struct page *tmppage;
/* When taking over an array from a different personality, we store
@@ -98,11 +102,18 @@
* 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;
- sector_t addr;
- int devnum;
+ 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];
};
@@ -121,17 +132,19 @@
#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
/* bits for r10bio.state */
-#define R10BIO_Uptodate 0
-#define R10BIO_IsSync 1
-#define R10BIO_IsRecover 2
-#define R10BIO_Degraded 3
+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.
*/
-#define R10BIO_ReadError 4
+ R10BIO_ReadError,
/* If a write for this request means we can clear some
* known-bad-block records, we set this flag.
*/
-#define R10BIO_MadeGood 5
-#define R10BIO_WriteError 6
+ R10BIO_MadeGood,
+ R10BIO_WriteError,
+};
#endif