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Commit 80eb8761 authored by Mike Christie's avatar Mike Christie Committed by Nicholas Bellinger
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tcmu: allow max block and global max blocks to be settable 



Users might have a physical system to a target so they could
have a lot more than 2 gigs of memory they want to devote to
tcmu. OTOH, we could be running in a vm and so a 2 gig
global and 1 gig per dev limit might be too high. This patch
allows the user to specify the limits.

Signed-off-by: default avatarMike Christie <mchristi@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 9103575a

drivers/target/target_core_user.c

+124 −19
Original line number Diff line number Diff line
@@ -77,9 +77,13 @@ 
 * the total size is 256K * PAGE_SIZE.

 */

#define DATA_BLOCK_SIZE PAGE_SIZE

#define DATA_BLOCK_BITS (256 * 1024)

#define DATA_BLOCK_SHIFT PAGE_SHIFT

#define DATA_BLOCK_BITS_DEF (256 * 1024)

#define DATA_SIZE (DATA_BLOCK_BITS * DATA_BLOCK_SIZE)



#define TCMU_MBS_TO_BLOCKS(_mbs) (_mbs << (20 - DATA_BLOCK_SHIFT))

#define TCMU_BLOCKS_TO_MBS(_blocks) (_blocks >> (20 - DATA_BLOCK_SHIFT))



/* The total size of the ring is 8M + 256K * PAGE_SIZE */

#define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
@@ -87,7 +91,7 @@ 
 * Default number of global data blocks(512K * PAGE_SIZE)

 * when the unmap thread will be started.

 */

#define TCMU_GLOBAL_MAX_BLOCKS (512 * 1024)

#define TCMU_GLOBAL_MAX_BLOCKS_DEF (512 * 1024)



static u8 tcmu_kern_cmd_reply_supported;
@@ -131,13 +135,15 @@ struct tcmu_dev { 
	/* Must add data_off and mb_addr to get the address */

	size_t data_off;

	size_t data_size;

	uint32_t max_blocks;

	size_t ring_size;



	struct mutex cmdr_lock;

	struct list_head cmdr_queue;



	uint32_t dbi_max;

	uint32_t dbi_thresh;

	DECLARE_BITMAP(data_bitmap, DATA_BLOCK_BITS);

	unsigned long *data_bitmap;

	struct radix_tree_root data_blocks;



	struct idr commands;
@@ -198,10 +204,51 @@ static LIST_HEAD(root_udev); 
static DEFINE_SPINLOCK(timed_out_udevs_lock);

static LIST_HEAD(timed_out_udevs);



static struct kmem_cache *tcmu_cmd_cache;



static atomic_t global_db_count = ATOMIC_INIT(0);

static struct delayed_work tcmu_unmap_work;

static int tcmu_global_max_blocks = TCMU_GLOBAL_MAX_BLOCKS_DEF;



static struct kmem_cache *tcmu_cmd_cache;

static int tcmu_set_global_max_data_area(const char *str,

					 const struct kernel_param *kp)

{

	int ret, max_area_mb;



	ret = kstrtoint(str, 10, &max_area_mb);

	if (ret)

		return -EINVAL;



	if (max_area_mb <= 0) {

		pr_err("global_max_data_area must be larger than 0.\n");

		return -EINVAL;

	}



	tcmu_global_max_blocks = TCMU_MBS_TO_BLOCKS(max_area_mb);

	if (atomic_read(&global_db_count) > tcmu_global_max_blocks)

		schedule_delayed_work(&tcmu_unmap_work, 0);

	else

		cancel_delayed_work_sync(&tcmu_unmap_work);



	return 0;

}



static int tcmu_get_global_max_data_area(char *buffer,

					 const struct kernel_param *kp)

{

	return sprintf(buffer, "%d", TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));

}



static const struct kernel_param_ops tcmu_global_max_data_area_op = {

	.set = tcmu_set_global_max_data_area,

	.get = tcmu_get_global_max_data_area,

};



module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,

		S_IWUSR | S_IRUGO);

MODULE_PARM_DESC(global_max_data_area_mb,

		 "Max MBs allowed to be allocated to all the tcmu device's "

		 "data areas.");



/* multicast group */

enum tcmu_multicast_groups {
@@ -363,7 +410,7 @@ static inline bool tcmu_get_empty_block(struct tcmu_dev *udev, 
	page = radix_tree_lookup(&udev->data_blocks, dbi);

	if (!page) {

		if (atomic_add_return(1, &global_db_count) >

					TCMU_GLOBAL_MAX_BLOCKS)

				      tcmu_global_max_blocks)

			schedule_delayed_work(&tcmu_unmap_work, 0);



		/* try to get new page from the mm */
@@ -706,8 +753,8 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd, 
	/* try to check and get the data blocks as needed */

	space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);

	if ((space * DATA_BLOCK_SIZE) < data_needed) {

		unsigned long blocks_left = DATA_BLOCK_BITS - udev->dbi_thresh +

						space;

		unsigned long blocks_left =

				(udev->max_blocks - udev->dbi_thresh) + space;



		if (blocks_left < blocks_needed) {

			pr_debug("no data space: only %lu available, but ask for %zu\n",
@@ -717,8 +764,8 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd, 
		}



		udev->dbi_thresh += blocks_needed;

		if (udev->dbi_thresh > DATA_BLOCK_BITS)

			udev->dbi_thresh = DATA_BLOCK_BITS;

		if (udev->dbi_thresh > udev->max_blocks)

			udev->dbi_thresh = udev->max_blocks;

	}



	return tcmu_get_empty_blocks(udev, cmd);
@@ -1075,7 +1122,7 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) 
			 * reclaim blocks if needed.

			 */

			if (atomic_read(&global_db_count) >

			    TCMU_GLOBAL_MAX_BLOCKS)

			    tcmu_global_max_blocks)

				schedule_delayed_work(&tcmu_unmap_work, 0);

		}

	}
@@ -1194,6 +1241,7 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) 
	udev->cmd_time_out = TCMU_TIME_OUT;

	udev->qfull_time_out = -1;



	udev->max_blocks = DATA_BLOCK_BITS_DEF;

	mutex_init(&udev->cmdr_lock);



	INIT_LIST_HEAD(&udev->timedout_entry);
@@ -1335,7 +1383,7 @@ static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi) 


		/*

		 * Since this case is rare in page fault routine, here we

		 * will allow the global_db_count >= TCMU_GLOBAL_MAX_BLOCKS

		 * will allow the global_db_count >= tcmu_global_max_blocks

		 * to reduce possible page fault call trace.

		 */

		atomic_inc(&global_db_count);
@@ -1396,7 +1444,7 @@ static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma) 
	vma->vm_private_data = udev;



	/* Ensure the mmap is exactly the right size */

	if (vma_pages(vma) != (TCMU_RING_SIZE >> PAGE_SHIFT))

	if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))

		return -EINVAL;



	return 0;
@@ -1478,6 +1526,7 @@ static void tcmu_dev_kref_release(struct kref *kref) 
	WARN_ON(!all_expired);



	tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);

	kfree(udev->data_bitmap);

	mutex_unlock(&udev->cmdr_lock);



	call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
@@ -1654,6 +1703,11 @@ static int tcmu_configure_device(struct se_device *dev) 


	info = &udev->uio_info;



	udev->data_bitmap = kzalloc(BITS_TO_LONGS(udev->max_blocks) *

				    sizeof(unsigned long), GFP_KERNEL);

	if (!udev->data_bitmap)

		goto err_bitmap_alloc;



	udev->mb_addr = vzalloc(CMDR_SIZE);

	if (!udev->mb_addr) {

		ret = -ENOMEM;
@@ -1663,7 +1717,7 @@ static int tcmu_configure_device(struct se_device *dev) 
	/* mailbox fits in first part of CMDR space */

	udev->cmdr_size = CMDR_SIZE - CMDR_OFF;

	udev->data_off = CMDR_SIZE;

	udev->data_size = DATA_SIZE;

	udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;

	udev->dbi_thresh = 0; /* Default in Idle state */



	/* Initialise the mailbox of the ring buffer */
@@ -1681,7 +1735,7 @@ static int tcmu_configure_device(struct se_device *dev) 


	info->mem[0].name = "tcm-user command & data buffer";

	info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;

	info->mem[0].size = TCMU_RING_SIZE;

	info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;

	info->mem[0].memtype = UIO_MEM_NONE;



	info->irqcontrol = tcmu_irqcontrol;
@@ -1734,6 +1788,9 @@ static int tcmu_configure_device(struct se_device *dev) 
	vfree(udev->mb_addr);

	udev->mb_addr = NULL;

err_vzalloc:

	kfree(udev->data_bitmap);

	udev->data_bitmap = NULL;

err_bitmap_alloc:

	kfree(info->name);

	info->name = NULL;
@@ -1774,7 +1831,7 @@ static void tcmu_destroy_device(struct se_device *dev) 


enum {

	Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,

	Opt_nl_reply_supported, Opt_err,

	Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err,

};



static match_table_t tokens = {
@@ -1783,6 +1840,7 @@ static match_table_t tokens = { 
	{Opt_hw_block_size, "hw_block_size=%u"},

	{Opt_hw_max_sectors, "hw_max_sectors=%u"},

	{Opt_nl_reply_supported, "nl_reply_supported=%d"},

	{Opt_max_data_area_mb, "max_data_area_mb=%u"},

	{Opt_err, NULL}

};
@@ -1816,7 +1874,7 @@ static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, 
	struct tcmu_dev *udev = TCMU_DEV(dev);

	char *orig, *ptr, *opts, *arg_p;

	substring_t args[MAX_OPT_ARGS];

	int ret = 0, token;

	int ret = 0, token, tmpval;



	opts = kstrdup(page, GFP_KERNEL);

	if (!opts)
@@ -1868,6 +1926,39 @@ static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, 
			if (ret < 0)

				pr_err("kstrtoint() failed for nl_reply_supported=\n");

			break;

		case Opt_max_data_area_mb:

			if (dev->export_count) {

				pr_err("Unable to set max_data_area_mb while exports exist\n");

				ret = -EINVAL;

				break;

			}



			arg_p = match_strdup(&args[0]);

			if (!arg_p) {

				ret = -ENOMEM;

				break;

			}

			ret = kstrtoint(arg_p, 0, &tmpval);

			kfree(arg_p);

			if (ret < 0) {

				pr_err("kstrtoint() failed for max_data_area_mb=\n");

				break;

			}



			if (tmpval <= 0) {

				pr_err("Invalid max_data_area %d\n", tmpval);

				ret = -EINVAL;

				break;

			}



			udev->max_blocks = TCMU_MBS_TO_BLOCKS(tmpval);

			if (udev->max_blocks > tcmu_global_max_blocks) {

				pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",

				       tmpval,

				       TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));

				udev->max_blocks = tcmu_global_max_blocks;

			}

			break;

		default:

			break;

		}
@@ -1887,7 +1978,9 @@ static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b) 


	bl = sprintf(b + bl, "Config: %s ",

		     udev->dev_config[0] ? udev->dev_config : "NULL");

	bl += sprintf(b + bl, "Size: %zu\n", udev->dev_size);

	bl += sprintf(b + bl, "Size: %zu ", udev->dev_size);

	bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",

		      TCMU_BLOCKS_TO_MBS(udev->max_blocks));



	return bl;

}
@@ -1973,6 +2066,17 @@ static ssize_t tcmu_qfull_time_out_store(struct config_item *item, 
}

CONFIGFS_ATTR(tcmu_, qfull_time_out);



static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)

{

	struct se_dev_attrib *da = container_of(to_config_group(item),

						struct se_dev_attrib, da_group);

	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);



	return snprintf(page, PAGE_SIZE, "%u\n",

			TCMU_BLOCKS_TO_MBS(udev->max_blocks));

}

CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);



static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)

{

	struct se_dev_attrib *da = container_of(to_config_group(item),
@@ -2119,6 +2223,7 @@ CONFIGFS_ATTR(tcmu_, emulate_write_cache); 
static struct configfs_attribute *tcmu_attrib_attrs[] = {

	&tcmu_attr_cmd_time_out,

	&tcmu_attr_qfull_time_out,

	&tcmu_attr_max_data_area_mb,

	&tcmu_attr_dev_config,

	&tcmu_attr_dev_size,

	&tcmu_attr_emulate_write_cache,
@@ -2152,7 +2257,7 @@ static void find_free_blocks(void) 
	loff_t off;

	u32 start, end, block, total_freed = 0;



	if (atomic_read(&global_db_count) <= TCMU_GLOBAL_MAX_BLOCKS)

	if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)

		return;



	mutex_lock(&root_udev_mutex);
@@ -2200,7 +2305,7 @@ static void find_free_blocks(void) 
	}

	mutex_unlock(&root_udev_mutex);



	if (atomic_read(&global_db_count) > TCMU_GLOBAL_MAX_BLOCKS)

	if (atomic_read(&global_db_count) > tcmu_global_max_blocks)

		schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));

}