Add a sysfs entry to change stripe size.
Signed-off-by: Shaohua Li <shli@xxxxxxxxxxxx>
---
drivers/md/raid5.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 99 insertions(+), 12 deletions(-)
Index: linux/drivers/md/raid5.c
===================================================================
--- linux.orig/drivers/md/raid5.c 2014-07-23 14:09:55.112454432 +0800
+++ linux/drivers/md/raid5.c 2014-07-23 14:09:55.104454533 +0800
@@ -1911,10 +1911,10 @@ static void init_stripe_pointer(struct r
}
}
-static int grow_one_stripe(struct r5conf *conf, int hash)
+static int grow_one_stripe(struct r5conf *conf, int hash, gfp_t gfp)
{
struct stripe_head *sh;
- sh = kmem_cache_zalloc(conf->slab_cache, GFP_KERNEL);
+ sh = kmem_cache_zalloc(conf->slab_cache, gfp);
if (!sh)
return 0;
@@ -1937,7 +1937,7 @@ static int grow_one_stripe(struct r5conf
return 1;
}
-static int grow_stripes(struct r5conf *conf, int num)
+static int grow_stripes(struct r5conf *conf, int num, gfp_t gfp)
{
struct kmem_cache *sc;
int devs = max(conf->raid_disks, conf->previous_raid_disks);
@@ -1961,7 +1961,7 @@ static int grow_stripes(struct r5conf *c
conf->pool_size = devs;
hash = conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS;
while (num--) {
- if (!grow_one_stripe(conf, hash))
+ if (!grow_one_stripe(conf, hash, gfp))
return 1;
conf->max_nr_stripes++;
hash = (hash + 1) % NR_STRIPE_HASH_LOCKS;
@@ -5551,7 +5551,7 @@ raid5_set_cache_size(struct mddev *mddev
return err;
hash = conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS;
while (size > conf->max_nr_stripes) {
- if (grow_one_stripe(conf, hash))
+ if (grow_one_stripe(conf, hash, GFP_KERNEL))
conf->max_nr_stripes++;
else break;
hash = (hash + 1) % NR_STRIPE_HASH_LOCKS;
@@ -5743,12 +5743,97 @@ raid5_group_thread_cnt = __ATTR(group_th
raid5_show_group_thread_cnt,
raid5_store_group_thread_cnt);
+static ssize_t
+raid5_show_stripe_size(struct mddev *mddev, char *page)
+{
+ struct r5conf *conf = mddev->private;
+ if (conf)
+ return sprintf(page, "%ld\n", PAGE_SIZE << conf->stripe_size_order);
+ else
+ return 0;
+}
+
+static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu);
+static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu,
+ gfp_t gfp);
+static ssize_t
+raid5_store_stripe_size(struct mddev *mddev, const char *page, size_t len)
+{
+ struct r5conf *conf = mddev->private;
+ unsigned long new, chunk_size;
+ int err = 0;
+ int cpu;
+ int nr_stripes;
+
+ if (len >= PAGE_SIZE)
+ return -EINVAL;
+ if (!conf)
+ return -ENODEV;
+
+ if (kstrtoul(page, 10, &new))
+ return -EINVAL;
+
+ new = ilog2(new);
+ if (new == (PAGE_SIZE << conf->stripe_size_order))
+ return len;
+ chunk_size = conf->chunk_sectors * 512;
+ if ((1 << new) > chunk_size || (1 << new) < PAGE_SIZE)
+ return -EINVAL;
+ new -= PAGE_SHIFT;
+
+ mddev_suspend(mddev);
+
+ if (conf->worker_groups)
+ flush_workqueue(raid5_wq);
+
+ nr_stripes = conf->max_nr_stripes;
+ shrink_stripes(conf);
+ conf->max_nr_stripes = 0;
+
+ get_online_cpus();
+ for_each_possible_cpu(cpu) {
+ struct raid5_percpu *percpu;
+
+ percpu = per_cpu_ptr(conf->percpu, cpu);
+ free_scratch_buffer(conf, percpu);
+ }
+
+ conf->stripe_size_order = new;
+
+ conf->scribble_len = scribble_len(conf, conf->pool_size);
+ for_each_present_cpu(cpu) {
+ struct raid5_percpu *percpu;
+
+ percpu = per_cpu_ptr(conf->percpu, cpu);
+ err = alloc_scratch_buffer(conf, percpu, GFP_NOIO);
+ if (err)
+ break;
+ }
+
+ put_online_cpus();
+
+ if (!err)
+ err = grow_stripes(conf, nr_stripes, GFP_NOIO);
+
+ mddev_resume(mddev);
+
+ if (err)
+ return err;
+ return len;
+}
+static struct md_sysfs_entry
+raid5_stripe_size = __ATTR(stripe_size, S_IRUGO | S_IWUSR,
+ raid5_show_stripe_size,
+ raid5_store_stripe_size);
+
+
static struct attribute *raid5_attrs[] = {
&raid5_stripecache_size.attr,
&raid5_stripecache_active.attr,
&raid5_preread_bypass_threshold.attr,
&raid5_group_thread_cnt.attr,
&raid5_skip_copy.attr,
+ &raid5_stripe_size.attr,
NULL,
};
static struct attribute_group raid5_attrs_group = {
@@ -5840,7 +5925,8 @@ static void free_scratch_buffer(struct r
percpu->scribble = NULL;
}
-static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
+static int alloc_scratch_buffer(struct r5conf *conf,
+ struct raid5_percpu *percpu, gfp_t gfp)
{
bool sp_alloc_fail = false;
if (conf->level == 6 && !percpu->spare_pages) {
@@ -5848,12 +5934,12 @@ static int alloc_scratch_buffer(struct r
int i;
pages = kzalloc(sizeof(struct page *) * STRIPE_PAGES(conf),
- GFP_KERNEL);
+ gfp);
sp_alloc_fail = true;
if (pages) {
percpu->spare_pages = pages;
for (i = 0; i < STRIPE_PAGES(conf); i++) {
- pages[i] = alloc_page(GFP_KERNEL);
+ pages[i] = alloc_page(gfp);
if (!pages[i])
break;
}
@@ -5862,7 +5948,7 @@ static int alloc_scratch_buffer(struct r
}
}
if (!percpu->scribble)
- percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
+ percpu->scribble = kmalloc(conf->scribble_len, gfp);
if (!percpu->scribble || sp_alloc_fail) {
free_scratch_buffer(conf, percpu);
@@ -5912,7 +5998,7 @@ static int raid456_cpu_notify(struct not
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- if (alloc_scratch_buffer(conf, percpu)) {
+ if (alloc_scratch_buffer(conf, percpu, GFP_KERNEL)) {
pr_err("%s: failed memory allocation for cpu%ld\n",
__func__, cpu);
return notifier_from_errno(-ENOMEM);
@@ -5948,7 +6034,8 @@ static int raid5_alloc_percpu(struct r5c
get_online_cpus();
for_each_present_cpu(cpu) {
- err = alloc_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
+ err = alloc_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu),
+ GFP_KERNEL);
if (err) {
pr_err("%s: failed memory allocation for cpu%ld\n",
__func__, cpu);
@@ -6108,7 +6195,7 @@ static struct r5conf *setup_conf(struct
memory = conf->max_nr_stripes * (sizeof(struct stripe_head) +
max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
atomic_set(&conf->empty_inactive_list_nr, NR_STRIPE_HASH_LOCKS);
- if (grow_stripes(conf, NR_STRIPES)) {
+ if (grow_stripes(conf, NR_STRIPES, GFP_KERNEL)) {
printk(KERN_ERR
"md/raid:%s: couldn't allocate %dkB for buffers\n",
mdname(mddev), memory);
--
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