From 69335ef3bc5b766f34db2d688be1d35313138bca Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 23 Dec 2011 10:17:54 +1100 Subject: [PATCH] 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 --- drivers/md/raid10.c | 48 +++++++++++++++++++++++++++++------ drivers/md/raid10.h | 61 +++++++++++++++++++++++++++------------------ 2 files changed, 78 insertions(+), 31 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index f5088dda4dca..9722065022fa 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -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; diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h index 7facfdf841f4..7c615613c381 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 @@ 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