From 80eb876138a1adc7d30831ce275ea744c050d97e Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Tue, 28 Nov 2017 12:40:41 -0600 Subject: [PATCH] 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: Mike Christie Signed-off-by: Nicholas Bellinger --- 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 c6a0c31..bac08bc 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 @@ 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 @@ err_register: 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)); } -- 2.7.4