From 7c7546ccf6463edbeee8d9aac6de7be1cd80d08a Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 26 Jun 2006 00:27:41 -0700 Subject: [PATCH] [PATCH] md: allow a linear array to have drives added while active Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/linear.c | 74 ++++++++++++++++++++++++++++++------- drivers/md/md.c | 15 +++++++- include/linux/raid/linear.h | 2 + 3 files changed, 76 insertions(+), 15 deletions(-) diff --git a/drivers/md/linear.c b/drivers/md/linear.c index 777585458c85..ff83c9b5979e 100644 --- a/drivers/md/linear.c +++ b/drivers/md/linear.c @@ -111,7 +111,7 @@ static int linear_issue_flush(request_queue_t *q, struct gendisk *disk, return ret; } -static int linear_run (mddev_t *mddev) +static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks) { linear_conf_t *conf; dev_info_t **table; @@ -121,20 +121,21 @@ static int linear_run (mddev_t *mddev) sector_t curr_offset; struct list_head *tmp; - conf = kzalloc (sizeof (*conf) + mddev->raid_disks*sizeof(dev_info_t), + conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(dev_info_t), GFP_KERNEL); if (!conf) - goto out; + return NULL; + mddev->private = conf; cnt = 0; - mddev->array_size = 0; + conf->array_size = 0; ITERATE_RDEV(mddev,rdev,tmp) { int j = rdev->raid_disk; dev_info_t *disk = conf->disks + j; - if (j < 0 || j > mddev->raid_disks || disk->rdev) { + if (j < 0 || j > raid_disks || disk->rdev) { printk("linear: disk numbering problem. Aborting!\n"); goto out; } @@ -152,11 +153,11 @@ static int linear_run (mddev_t *mddev) blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); disk->size = rdev->size; - mddev->array_size += rdev->size; + conf->array_size += rdev->size; cnt++; } - if (cnt != mddev->raid_disks) { + if (cnt != raid_disks) { printk("linear: not enough drives present. Aborting!\n"); goto out; } @@ -200,7 +201,7 @@ static int linear_run (mddev_t *mddev) unsigned round; unsigned long base; - sz = mddev->array_size >> conf->preshift; + sz = conf->array_size >> conf->preshift; sz += 1; /* force round-up */ base = conf->hash_spacing >> conf->preshift; round = sector_div(sz, base); @@ -247,14 +248,56 @@ static int linear_run (mddev_t *mddev) BUG_ON(table - conf->hash_table > nb_zone); + return conf; + +out: + kfree(conf); + return NULL; +} + +static int linear_run (mddev_t *mddev) +{ + linear_conf_t *conf; + + conf = linear_conf(mddev, mddev->raid_disks); + + if (!conf) + return 1; + mddev->private = conf; + mddev->array_size = conf->array_size; + blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec); mddev->queue->unplug_fn = linear_unplug; mddev->queue->issue_flush_fn = linear_issue_flush; return 0; +} -out: - kfree(conf); - return 1; +static int linear_add(mddev_t *mddev, mdk_rdev_t *rdev) +{ + /* Adding a drive to a linear array allows the array to grow. + * It is permitted if the new drive has a matching superblock + * already on it, with raid_disk equal to raid_disks. + * It is achieved by creating a new linear_private_data structure + * and swapping it in in-place of the current one. + * The current one is never freed until the array is stopped. + * This avoids races. + */ + linear_conf_t *newconf; + + if (rdev->raid_disk != mddev->raid_disks) + return -EINVAL; + + newconf = linear_conf(mddev,mddev->raid_disks+1); + + if (!newconf) + return -ENOMEM; + + newconf->prev = mddev_to_conf(mddev); + mddev->private = newconf; + mddev->raid_disks++; + mddev->array_size = newconf->array_size; + set_capacity(mddev->gendisk, mddev->array_size << 1); + return 0; } static int linear_stop (mddev_t *mddev) @@ -262,8 +305,12 @@ static int linear_stop (mddev_t *mddev) linear_conf_t *conf = mddev_to_conf(mddev); blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ - kfree(conf->hash_table); - kfree(conf); + do { + linear_conf_t *t = conf->prev; + kfree(conf->hash_table); + kfree(conf); + conf = t; + } while (conf); return 0; } @@ -360,6 +407,7 @@ static struct mdk_personality linear_personality = .run = linear_run, .stop = linear_stop, .status = linear_status, + .hot_add_disk = linear_add, }; static int __init linear_init (void) diff --git a/drivers/md/md.c b/drivers/md/md.c index a296edd7e1c3..2ce750d4be02 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -817,8 +817,8 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev) if (desc->state & (1<flags); - else if (desc->state & (1<raid_disk < mddev->raid_disks) { + else if (desc->state & (1<raid_disk < mddev->raid_disks */) { set_bit(In_sync, &rdev->flags); rdev->raid_disk = desc->raid_disk; } @@ -3359,6 +3359,17 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info) rdev->raid_disk = -1; err = bind_rdev_to_array(rdev, mddev); + if (!err && !mddev->pers->hot_remove_disk) { + /* If there is hot_add_disk but no hot_remove_disk + * then added disks for geometry changes, + * and should be added immediately. + */ + super_types[mddev->major_version]. + validate_super(mddev, rdev); + err = mddev->pers->hot_add_disk(mddev, rdev); + if (err) + unbind_rdev_from_array(rdev); + } if (err) export_rdev(rdev); diff --git a/include/linux/raid/linear.h b/include/linux/raid/linear.h index 7eaf290e10e7..ba15469daf11 100644 --- a/include/linux/raid/linear.h +++ b/include/linux/raid/linear.h @@ -13,8 +13,10 @@ typedef struct dev_info dev_info_t; struct linear_private_data { + struct linear_private_data *prev; /* earlier version */ dev_info_t **hash_table; sector_t hash_spacing; + sector_t array_size; int preshift; /* shift before dividing by hash_spacing */ dev_info_t disks[0]; }; -- 2.20.1