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md/raid5: refactor raid5 "run"
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.. so that the code to create the private data structures is separate.
This will help with future code to change the level of an active
array.

Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown committed Mar 31, 2009
1 parent 34817e8 commit 91adb56
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Showing 2 changed files with 157 additions and 115 deletions.
267 changes: 152 additions & 115 deletions drivers/md/raid5.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4164,95 +4164,49 @@ static struct attribute_group raid5_attrs_group = {
.attrs = raid5_attrs,
};

static int run(mddev_t *mddev)
static raid5_conf_t *setup_conf(mddev_t *mddev)
{
raid5_conf_t *conf;
int raid_disk, memory;
mdk_rdev_t *rdev;
struct disk_info *disk;
int working_disks = 0;

if (mddev->level != 5 && mddev->level != 4 && mddev->level != 6) {
if (mddev->new_level != 5
&& mddev->new_level != 4
&& mddev->new_level != 6) {
printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
mdname(mddev), mddev->level);
return -EIO;
mdname(mddev), mddev->new_level);
return ERR_PTR(-EIO);
}
if ((mddev->level == 5 && !algorithm_valid_raid5(mddev->layout)) ||
(mddev->level == 6 && !algorithm_valid_raid6(mddev->layout))) {
if ((mddev->new_level == 5
&& !algorithm_valid_raid5(mddev->new_layout)) ||
(mddev->new_level == 6
&& !algorithm_valid_raid6(mddev->new_layout))) {
printk(KERN_ERR "raid5: %s: layout %d not supported\n",
mdname(mddev), mddev->layout);
return -EIO;
mdname(mddev), mddev->new_layout);
return ERR_PTR(-EIO);
}

if (mddev->chunk_size < PAGE_SIZE) {
printk(KERN_ERR "md/raid5: chunk_size must be at least "
"PAGE_SIZE but %d < %ld\n",
mddev->chunk_size, PAGE_SIZE);
return -EINVAL;
if (mddev->new_level == 6 && mddev->raid_disks < 4) {
printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
mdname(mddev), mddev->raid_disks);
return ERR_PTR(-EINVAL);
}

if (mddev->reshape_position != MaxSector) {
/* Check that we can continue the reshape.
* Currently only disks can change, it must
* increase, and we must be past the point where
* a stripe over-writes itself
*/
sector_t here_new, here_old;
int old_disks;
int max_degraded = (mddev->level == 5 ? 1 : 2);

if (mddev->new_level != mddev->level ||
mddev->new_layout != mddev->layout ||
mddev->new_chunk != mddev->chunk_size) {
printk(KERN_ERR "raid5: %s: unsupported reshape "
"required - aborting.\n",
mdname(mddev));
return -EINVAL;
}
if (mddev->delta_disks <= 0) {
printk(KERN_ERR "raid5: %s: unsupported reshape "
"(reduce disks) required - aborting.\n",
mdname(mddev));
return -EINVAL;
}
old_disks = mddev->raid_disks - mddev->delta_disks;
/* reshape_position must be on a new-stripe boundary, and one
* further up in new geometry must map after here in old
* geometry.
*/
here_new = mddev->reshape_position;
if (sector_div(here_new, (mddev->chunk_size>>9)*
(mddev->raid_disks - max_degraded))) {
printk(KERN_ERR "raid5: reshape_position not "
"on a stripe boundary\n");
return -EINVAL;
}
/* here_new is the stripe we will write to */
here_old = mddev->reshape_position;
sector_div(here_old, (mddev->chunk_size>>9)*
(old_disks-max_degraded));
/* here_old is the first stripe that we might need to read
* from */
if (here_new >= here_old) {
/* Reading from the same stripe as writing to - bad */
printk(KERN_ERR "raid5: reshape_position too early for "
"auto-recovery - aborting.\n");
return -EINVAL;
}
printk(KERN_INFO "raid5: reshape will continue\n");
/* OK, we should be able to continue; */
if (!mddev->new_chunk || mddev->new_chunk % PAGE_SIZE) {
printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
mddev->new_chunk, mdname(mddev));
return ERR_PTR(-EINVAL);
}


mddev->private = kzalloc(sizeof (raid5_conf_t), GFP_KERNEL);
if ((conf = mddev->private) == NULL)
conf = kzalloc(sizeof(raid5_conf_t), GFP_KERNEL);
if (conf == NULL)
goto abort;
if (mddev->reshape_position == MaxSector) {
conf->previous_raid_disks = conf->raid_disks = mddev->raid_disks;
} else {
conf->raid_disks = mddev->raid_disks;

conf->raid_disks = mddev->raid_disks;
if (mddev->reshape_position == MaxSector)
conf->previous_raid_disks = mddev->raid_disks;
else
conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
}

conf->disks = kzalloc(conf->raid_disks * sizeof(struct disk_info),
GFP_KERNEL);
Expand All @@ -4264,13 +4218,12 @@ static int run(mddev_t *mddev)
if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
goto abort;

if (mddev->level == 6) {
if (mddev->new_level == 6) {
conf->spare_page = alloc_page(GFP_KERNEL);
if (!conf->spare_page)
goto abort;
}
spin_lock_init(&conf->device_lock);
mddev->queue->queue_lock = &conf->device_lock;
init_waitqueue_head(&conf->wait_for_stripe);
init_waitqueue_head(&conf->wait_for_overlap);
INIT_LIST_HEAD(&conf->handle_list);
Expand Down Expand Up @@ -4299,48 +4252,147 @@ static int run(mddev_t *mddev)
printk(KERN_INFO "raid5: device %s operational as raid"
" disk %d\n", bdevname(rdev->bdev,b),
raid_disk);
working_disks++;
} else
/* Cannot rely on bitmap to complete recovery */
conf->fullsync = 1;
}

/*
* 0 for a fully functional array, 1 or 2 for a degraded array.
*/
mddev->degraded = conf->raid_disks - working_disks;
conf->mddev = mddev;
conf->chunk_size = mddev->chunk_size;
conf->level = mddev->level;
conf->chunk_size = mddev->new_chunk;
conf->level = mddev->new_level;
if (conf->level == 6)
conf->max_degraded = 2;
else
conf->max_degraded = 1;
conf->algorithm = mddev->layout;
conf->algorithm = mddev->new_layout;
conf->max_nr_stripes = NR_STRIPES;
conf->expand_progress = mddev->reshape_position;

/* device size must be a multiple of chunk size */
mddev->dev_sectors &= ~(mddev->chunk_size / 512 - 1);
mddev->resync_max_sectors = mddev->dev_sectors;
memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
if (grow_stripes(conf, conf->max_nr_stripes)) {
printk(KERN_ERR
"raid5: couldn't allocate %dkB for buffers\n", memory);
goto abort;
} else
printk(KERN_INFO "raid5: allocated %dkB for %s\n",
memory, mdname(mddev));

if (conf->level == 6 && conf->raid_disks < 4) {
printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
mdname(mddev), conf->raid_disks);
conf->thread = md_register_thread(raid5d, mddev, "%s_raid5");
if (!conf->thread) {
printk(KERN_ERR
"raid5: couldn't allocate thread for %s\n",
mdname(mddev));
goto abort;
}
if (!conf->chunk_size || conf->chunk_size % 4) {
printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
conf->chunk_size, mdname(mddev));
goto abort;

return conf;

abort:
if (conf) {
shrink_stripes(conf);
safe_put_page(conf->spare_page);
kfree(conf->disks);
kfree(conf->stripe_hashtbl);
kfree(conf);
return ERR_PTR(-EIO);
} else
return ERR_PTR(-ENOMEM);
}

static int run(mddev_t *mddev)
{
raid5_conf_t *conf;
int working_disks = 0;
mdk_rdev_t *rdev;

if (mddev->reshape_position != MaxSector) {
/* Check that we can continue the reshape.
* Currently only disks can change, it must
* increase, and we must be past the point where
* a stripe over-writes itself
*/
sector_t here_new, here_old;
int old_disks;
int max_degraded = (mddev->level == 5 ? 1 : 2);

if (mddev->new_level != mddev->level ||
mddev->new_layout != mddev->layout ||
mddev->new_chunk != mddev->chunk_size) {
printk(KERN_ERR "raid5: %s: unsupported reshape "
"required - aborting.\n",
mdname(mddev));
return -EINVAL;
}
if (mddev->delta_disks <= 0) {
printk(KERN_ERR "raid5: %s: unsupported reshape "
"(reduce disks) required - aborting.\n",
mdname(mddev));
return -EINVAL;
}
old_disks = mddev->raid_disks - mddev->delta_disks;
/* reshape_position must be on a new-stripe boundary, and one
* further up in new geometry must map after here in old
* geometry.
*/
here_new = mddev->reshape_position;
if (sector_div(here_new, (mddev->chunk_size>>9)*
(mddev->raid_disks - max_degraded))) {
printk(KERN_ERR "raid5: reshape_position not "
"on a stripe boundary\n");
return -EINVAL;
}
/* here_new is the stripe we will write to */
here_old = mddev->reshape_position;
sector_div(here_old, (mddev->chunk_size>>9)*
(old_disks-max_degraded));
/* here_old is the first stripe that we might need to read
* from */
if (here_new >= here_old) {
/* Reading from the same stripe as writing to - bad */
printk(KERN_ERR "raid5: reshape_position too early for "
"auto-recovery - aborting.\n");
return -EINVAL;
}
printk(KERN_INFO "raid5: reshape will continue\n");
/* OK, we should be able to continue; */
} else {
BUG_ON(mddev->level != mddev->new_level);
BUG_ON(mddev->layout != mddev->new_layout);
BUG_ON(mddev->chunk_size != mddev->new_chunk);
BUG_ON(mddev->delta_disks != 0);
}
conf = setup_conf(mddev);

if (conf == NULL)
return -EIO;
if (IS_ERR(conf))
return PTR_ERR(conf);

mddev->thread = conf->thread;
conf->thread = NULL;
mddev->private = conf;

/*
* 0 for a fully functional array, 1 or 2 for a degraded array.
*/
list_for_each_entry(rdev, &mddev->disks, same_set)
if (rdev->raid_disk >= 0 &&
test_bit(In_sync, &rdev->flags))
working_disks++;

mddev->degraded = conf->raid_disks - working_disks;

if (mddev->degraded > conf->max_degraded) {
printk(KERN_ERR "raid5: not enough operational devices for %s"
" (%d/%d failed)\n",
mdname(mddev), mddev->degraded, conf->raid_disks);
goto abort;
}

/* device size must be a multiple of chunk size */
mddev->dev_sectors &= ~(mddev->chunk_size / 512 - 1);
mddev->resync_max_sectors = mddev->dev_sectors;

if (mddev->degraded > 0 &&
mddev->recovery_cp != MaxSector) {
if (mddev->ok_start_degraded)
Expand All @@ -4356,27 +4408,6 @@ static int run(mddev_t *mddev)
}
}

{
mddev->thread = md_register_thread(raid5d, mddev, "%s_raid5");
if (!mddev->thread) {
printk(KERN_ERR
"raid5: couldn't allocate thread for %s\n",
mdname(mddev));
goto abort;
}
}
memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
conf->raid_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
if (grow_stripes(conf, conf->max_nr_stripes)) {
printk(KERN_ERR
"raid5: couldn't allocate %dkB for buffers\n", memory);
shrink_stripes(conf);
md_unregister_thread(mddev->thread);
goto abort;
} else
printk(KERN_INFO "raid5: allocated %dkB for %s\n",
memory, mdname(mddev));

if (mddev->degraded == 0)
printk("raid5: raid level %d set %s active with %d out of %d"
" devices, algorithm %d\n", conf->level, mdname(mddev),
Expand Down Expand Up @@ -4419,6 +4450,8 @@ static int run(mddev_t *mddev)
"raid5: failed to create sysfs attributes for %s\n",
mdname(mddev));

mddev->queue->queue_lock = &conf->device_lock;

mddev->queue->unplug_fn = raid5_unplug_device;
mddev->queue->backing_dev_info.congested_data = mddev;
mddev->queue->backing_dev_info.congested_fn = raid5_congested;
Expand All @@ -4430,7 +4463,11 @@ static int run(mddev_t *mddev)

return 0;
abort:
if (mddev->thread)
md_unregister_thread(mddev->thread);
mddev->thread = NULL;
if (conf) {
shrink_stripes(conf);
print_raid5_conf(conf);
safe_put_page(conf->spare_page);
kfree(conf->disks);
Expand Down
5 changes: 5 additions & 0 deletions drivers/md/raid5.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -386,6 +386,11 @@ struct raid5_private_data {
int pool_size; /* number of disks in stripeheads in pool */
spinlock_t device_lock;
struct disk_info *disks;

/* When taking over an array from a different personality, we store
* the new thread here until we fully activate the array.
*/
struct mdk_thread_s *thread;
};

typedef struct raid5_private_data raid5_conf_t;
Expand Down

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