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: Mike Christie <mchri...@redhat.com>
---
drivers/target/target_core_user.c | 143 +++++++++++++++++++++++++++++++++-----
1 file changed, 124 insertions(+), 19 deletions(-)
diff --git a/drivers/target/target_core_user.c
b/drivers/target/target_core_user.c
index 92eb918..f49f765 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -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 @@ struct tcmu_cmd {
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 */
@@ -705,8 +752,8 @@ 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",
@@ -716,8 +763,8 @@ 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);
@@ -1072,7 +1119,7 @@ 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);
}
}
@@ -1179,6 +1226,7 @@ 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);
@@ -1323,7 +1371,7 @@ 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);
@@ -1384,7 +1432,7 @@ 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;
@@ -1466,6 +1514,7 @@ 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);
@@ -1642,6 +1691,11 @@ 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;
@@ -1651,7 +1705,7 @@ 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 */
@@ -1669,7 +1723,7 @@ 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;
@@ -1722,6 +1776,9 @@ 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;
@@ -1762,7 +1819,7 @@ 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 = {
@@ -1771,6 +1828,7 @@ enum {
{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}
};
@@ -1804,7 +1862,7 @@ 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)
@@ -1856,6 +1914,39 @@ 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;
}
@@ -1875,7 +1966,9 @@ 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;
}
@@ -1960,6 +2053,17 @@ 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),
@@ -2106,6 +2210,7 @@ static ssize_t tcmu_emulate_write_cache_store(struct
config_item *item,
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,
@@ -2139,7 +2244,7 @@ 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);
@@ -2187,7 +2292,7 @@ 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));
}
--
1.8.3.1
