Commit 69335ef3 authored by NeilBrown's avatar NeilBrown

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: default avatarNeilBrown <neilb@suse.de>
parent 3a6de292
......@@ -73,7 +73,8 @@ static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
struct r10conf *conf = data;
int size = offsetof(struct r10bio, devs[conf->copies]);
/* allocate a r10bio with room for raid_disks entries in the bios array */
/* allocate a r10bio with room for raid_disks entries in the
* bios array */
return kzalloc(size, gfp_flags);
}
......@@ -123,12 +124,19 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
if (!bio)
goto out_free_bio;
r10_bio->devs[j].bio = bio;
if (!conf->have_replacement)
continue;
bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
if (!bio)
goto out_free_bio;
r10_bio->devs[j].repl_bio = bio;
}
/*
* Allocate RESYNC_PAGES data pages and attach them
* where needed.
*/
for (j = 0 ; j < nalloc; j++) {
struct bio *rbio = r10_bio->devs[j].repl_bio;
bio = r10_bio->devs[j].bio;
for (i = 0; i < RESYNC_PAGES; i++) {
if (j == 1 && !test_bit(MD_RECOVERY_SYNC,
......@@ -143,6 +151,8 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
goto out_free_pages;
bio->bi_io_vec[i].bv_page = page;
if (rbio)
rbio->bi_io_vec[i].bv_page = page;
}
}
......@@ -156,8 +166,11 @@ out_free_pages:
safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
j = -1;
out_free_bio:
while ( ++j < nalloc )
while (++j < nalloc) {
bio_put(r10_bio->devs[j].bio);
if (r10_bio->devs[j].repl_bio)
bio_put(r10_bio->devs[j].repl_bio);
}
r10bio_pool_free(r10_bio, conf);
return NULL;
}
......@@ -178,6 +191,9 @@ static void r10buf_pool_free(void *__r10_bio, void *data)
}
bio_put(bio);
}
bio = r10bio->devs[j].repl_bio;
if (bio)
bio_put(bio);
}
r10bio_pool_free(r10bio, conf);
}
......@@ -191,6 +207,10 @@ static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio)
if (!BIO_SPECIAL(*bio))
bio_put(*bio);
*bio = NULL;
bio = &r10_bio->devs[i].repl_bio;
if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio))
bio_put(*bio);
*bio = NULL;
}
}
......@@ -275,19 +295,27 @@ static inline void update_head_pos(int slot, struct r10bio *r10_bio)
* Find the disk number which triggered given bio
*/
static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio,
struct bio *bio, int *slotp)
struct bio *bio, int *slotp, int *replp)
{
int slot;
int repl = 0;
for (slot = 0; slot < conf->copies; slot++)
for (slot = 0; slot < conf->copies; slot++) {
if (r10_bio->devs[slot].bio == bio)
break;
if (r10_bio->devs[slot].repl_bio == bio) {
repl = 1;
break;
}
}
BUG_ON(slot == conf->copies);
update_head_pos(slot, r10_bio);
if (slotp)
*slotp = slot;
if (replp)
*replp = repl;
return r10_bio->devs[slot].devnum;
}
......@@ -368,7 +396,7 @@ static void raid10_end_write_request(struct bio *bio, int error)
struct r10conf *conf = r10_bio->mddev->private;
int slot;
dev = find_bio_disk(conf, r10_bio, bio, &slot);
dev = find_bio_disk(conf, r10_bio, bio, &slot, NULL);
/*
* this branch is our 'one mirror IO has finished' event handler:
......@@ -1025,6 +1053,7 @@ read_again:
*/
plugged = mddev_check_plugged(mddev);
r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
raid10_find_phys(conf, r10_bio);
retry_write:
blocked_rdev = NULL;
......@@ -1431,7 +1460,7 @@ static void end_sync_read(struct bio *bio, int error)
struct r10conf *conf = r10_bio->mddev->private;
int d;
d = find_bio_disk(conf, r10_bio, bio, NULL);
d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
if (test_bit(BIO_UPTODATE, &bio->bi_flags))
set_bit(R10BIO_Uptodate, &r10_bio->state);
......@@ -1493,7 +1522,7 @@ static void end_sync_write(struct bio *bio, int error)
int bad_sectors;
int slot;
d = find_bio_disk(conf, r10_bio, bio, &slot);
d = find_bio_disk(conf, r10_bio, bio, &slot, NULL);
if (!uptodate) {
set_bit(WriteErrorSeen, &conf->mirrors[d].rdev->flags);
......@@ -2271,9 +2300,14 @@ static void raid10d(struct mddev *mddev)
static int init_resync(struct r10conf *conf)
{
int buffs;
int i;
buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
BUG_ON(conf->r10buf_pool);
conf->have_replacement = 0;
for (i = 0; i < conf->raid_disks; i++)
if (conf->mirrors[i].replacement)
conf->have_replacement = 1;
conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
if (!conf->r10buf_pool)
return -ENOMEM;
......
......@@ -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 @@ struct r10conf {
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 @@ struct r10conf {
* 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 @@ struct r10conf {
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 @@ struct r10bio {
* 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 @@ struct r10bio {
#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
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