// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2013 Shaohua Li * Copyright (C) 2014 Red Hat, Inc. * Copyright (C) 2015 Arrikto, Inc. * Copyright (C) 2017 Chinamobile, Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /** * DOC: Userspace I/O * Userspace I/O * ------------- * * Define a shared-memory interface for LIO to pass SCSI commands and * data to userspace for processing. This is to allow backends that * are too complex for in-kernel support to be possible. * * It uses the UIO framework to do a lot of the device-creation and * introspection work for us. * * See the .h file for how the ring is laid out. Note that while the * command ring is defined, the particulars of the data area are * not. Offset values in the command entry point to other locations * internal to the mmap-ed area. There is separate space outside the * command ring for data buffers. This leaves maximum flexibility for * moving buffer allocations, or even page flipping or other * allocation techniques, without altering the command ring layout. * * SECURITY: * The user process must be assumed to be malicious. There's no way to * prevent it breaking the command ring protocol if it wants, but in * order to prevent other issues we must only ever read *data* from * the shared memory area, not offsets or sizes. This applies to * command ring entries as well as the mailbox. Extra code needed for * this may have a 'UAM' comment. */ #define TCMU_TIME_OUT (30 * MSEC_PER_SEC) /* For mailbox plus cmd ring, the size is fixed 8MB */ #define MB_CMDR_SIZE (8 * 1024 * 1024) /* Offset of cmd ring is size of mailbox */ #define CMDR_OFF sizeof(struct tcmu_mailbox) #define CMDR_SIZE (MB_CMDR_SIZE - CMDR_OFF) /* * For data area, the default block size is PAGE_SIZE and * the default total size is 256K * PAGE_SIZE. */ #define DATA_PAGES_PER_BLK_DEF 1 #define DATA_AREA_PAGES_DEF (256 * 1024) #define TCMU_MBS_TO_PAGES(_mbs) ((size_t)_mbs << (20 - PAGE_SHIFT)) #define TCMU_PAGES_TO_MBS(_pages) (_pages >> (20 - PAGE_SHIFT)) /* * Default number of global data blocks(512K * PAGE_SIZE) * when the unmap thread will be started. */ #define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024) static u8 tcmu_kern_cmd_reply_supported; static u8 tcmu_netlink_blocked; static struct device *tcmu_root_device; struct tcmu_hba { u32 host_id; }; #define TCMU_CONFIG_LEN 256 static DEFINE_MUTEX(tcmu_nl_cmd_mutex); static LIST_HEAD(tcmu_nl_cmd_list); struct tcmu_dev; struct tcmu_nl_cmd { /* wake up thread waiting for reply */ struct completion complete; struct list_head nl_list; struct tcmu_dev *udev; int cmd; int status; }; struct tcmu_dev { struct list_head node; struct kref kref; struct se_device se_dev; struct se_dev_plug se_plug; char *name; struct se_hba *hba; #define TCMU_DEV_BIT_OPEN 0 #define TCMU_DEV_BIT_BROKEN 1 #define TCMU_DEV_BIT_BLOCKED 2 #define TCMU_DEV_BIT_TMR_NOTIFY 3 #define TCMU_DEV_BIT_PLUGGED 4 unsigned long flags; struct uio_info uio_info; struct inode *inode; uint64_t dev_size; struct tcmu_mailbox *mb_addr; void *cmdr; u32 cmdr_size; u32 cmdr_last_cleaned; /* Offset of data area from start of mb */ /* Must add data_off and mb_addr to get the address */ size_t data_off; int data_area_mb; uint32_t max_blocks; size_t mmap_pages; struct mutex cmdr_lock; struct list_head qfull_queue; struct list_head tmr_queue; uint32_t dbi_max; uint32_t dbi_thresh; unsigned long *data_bitmap; struct xarray data_pages; uint32_t data_pages_per_blk; uint32_t data_blk_size; struct xarray commands; struct timer_list cmd_timer; unsigned int cmd_time_out; struct list_head inflight_queue; struct timer_list qfull_timer; int qfull_time_out; struct list_head timedout_entry; struct tcmu_nl_cmd curr_nl_cmd; char dev_config[TCMU_CONFIG_LEN]; int nl_reply_supported; }; #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev) struct tcmu_cmd { struct se_cmd *se_cmd; struct tcmu_dev *tcmu_dev; struct list_head queue_entry; uint16_t cmd_id; /* Can't use se_cmd when cleaning up expired cmds, because if cmd has been completed then accessing se_cmd is off limits */ uint32_t dbi_cnt; uint32_t dbi_bidi_cnt; uint32_t dbi_cur; uint32_t *dbi; uint32_t data_len_bidi; unsigned long deadline; #define TCMU_CMD_BIT_EXPIRED 0 #define TCMU_CMD_BIT_KEEP_BUF 1 unsigned long flags; }; struct tcmu_tmr { struct list_head queue_entry; uint8_t tmr_type; uint32_t tmr_cmd_cnt; int16_t tmr_cmd_ids[]; }; /* * To avoid dead lock the mutex lock order should always be: * * mutex_lock(&root_udev_mutex); * ... * mutex_lock(&tcmu_dev->cmdr_lock); * mutex_unlock(&tcmu_dev->cmdr_lock); * ... * mutex_unlock(&root_udev_mutex); */ static DEFINE_MUTEX(root_udev_mutex); 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_page_count = ATOMIC_INIT(0); static struct delayed_work tcmu_unmap_work; static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF; 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_pages = TCMU_MBS_TO_PAGES(max_area_mb); if (atomic_read(&global_page_count) > tcmu_global_max_pages) 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\n", TCMU_PAGES_TO_MBS(tcmu_global_max_pages)); } 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."); static int tcmu_get_block_netlink(char *buffer, const struct kernel_param *kp) { return sprintf(buffer, "%s\n", tcmu_netlink_blocked ? "blocked" : "unblocked"); } static int tcmu_set_block_netlink(const char *str, const struct kernel_param *kp) { int ret; u8 val; ret = kstrtou8(str, 0, &val); if (ret < 0) return ret; if (val > 1) { pr_err("Invalid block netlink value %u\n", val); return -EINVAL; } tcmu_netlink_blocked = val; return 0; } static const struct kernel_param_ops tcmu_block_netlink_op = { .set = tcmu_set_block_netlink, .get = tcmu_get_block_netlink, }; module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO); MODULE_PARM_DESC(block_netlink, "Block new netlink commands."); static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd) { struct tcmu_dev *udev = nl_cmd->udev; if (!tcmu_netlink_blocked) { pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n"); return -EBUSY; } if (nl_cmd->cmd != TCMU_CMD_UNSPEC) { pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name); nl_cmd->status = -EINTR; list_del(&nl_cmd->nl_list); complete(&nl_cmd->complete); } return 0; } static int tcmu_set_reset_netlink(const char *str, const struct kernel_param *kp) { struct tcmu_nl_cmd *nl_cmd, *tmp_cmd; int ret; u8 val; ret = kstrtou8(str, 0, &val); if (ret < 0) return ret; if (val != 1) { pr_err("Invalid reset netlink value %u\n", val); return -EINVAL; } mutex_lock(&tcmu_nl_cmd_mutex); list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) { ret = tcmu_fail_netlink_cmd(nl_cmd); if (ret) break; } mutex_unlock(&tcmu_nl_cmd_mutex); return ret; } static const struct kernel_param_ops tcmu_reset_netlink_op = { .set = tcmu_set_reset_netlink, }; module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR); MODULE_PARM_DESC(reset_netlink, "Reset netlink commands."); /* multicast group */ enum tcmu_multicast_groups { TCMU_MCGRP_CONFIG, }; static const struct genl_multicast_group tcmu_mcgrps[] = { [TCMU_MCGRP_CONFIG] = { .name = "config", }, }; static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = { [TCMU_ATTR_DEVICE] = { .type = NLA_STRING }, [TCMU_ATTR_MINOR] = { .type = NLA_U32 }, [TCMU_ATTR_CMD_STATUS] = { .type = NLA_S32 }, [TCMU_ATTR_DEVICE_ID] = { .type = NLA_U32 }, [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 }, }; static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd) { struct tcmu_dev *udev = NULL; struct tcmu_nl_cmd *nl_cmd; int dev_id, rc, ret = 0; if (!info->attrs[TCMU_ATTR_CMD_STATUS] || !info->attrs[TCMU_ATTR_DEVICE_ID]) { printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n"); return -EINVAL; } dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]); rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]); mutex_lock(&tcmu_nl_cmd_mutex); list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) { if (nl_cmd->udev->se_dev.dev_index == dev_id) { udev = nl_cmd->udev; break; } } if (!udev) { pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n", completed_cmd, rc, dev_id); ret = -ENODEV; goto unlock; } list_del(&nl_cmd->nl_list); pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n", udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc, nl_cmd->status); if (nl_cmd->cmd != completed_cmd) { pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n", udev->name, completed_cmd, nl_cmd->cmd); ret = -EINVAL; goto unlock; } nl_cmd->status = rc; complete(&nl_cmd->complete); unlock: mutex_unlock(&tcmu_nl_cmd_mutex); return ret; } static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info) { return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE); } static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info) { return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE); } static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb, struct genl_info *info) { return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE); } static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info) { if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) { tcmu_kern_cmd_reply_supported = nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]); printk(KERN_INFO "tcmu daemon: command reply support %u.\n", tcmu_kern_cmd_reply_supported); } return 0; } static const struct genl_small_ops tcmu_genl_ops[] = { { .cmd = TCMU_CMD_SET_FEATURES, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .flags = GENL_ADMIN_PERM, .doit = tcmu_genl_set_features, }, { .cmd = TCMU_CMD_ADDED_DEVICE_DONE, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .flags = GENL_ADMIN_PERM, .doit = tcmu_genl_add_dev_done, }, { .cmd = TCMU_CMD_REMOVED_DEVICE_DONE, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .flags = GENL_ADMIN_PERM, .doit = tcmu_genl_rm_dev_done, }, { .cmd = TCMU_CMD_RECONFIG_DEVICE_DONE, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .flags = GENL_ADMIN_PERM, .doit = tcmu_genl_reconfig_dev_done, }, }; /* Our generic netlink family */ static struct genl_family tcmu_genl_family __ro_after_init = { .module = THIS_MODULE, .hdrsize = 0, .name = "TCM-USER", .version = 2, .maxattr = TCMU_ATTR_MAX, .policy = tcmu_attr_policy, .mcgrps = tcmu_mcgrps, .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps), .netnsok = true, .small_ops = tcmu_genl_ops, .n_small_ops = ARRAY_SIZE(tcmu_genl_ops), }; #define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index)) #define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0) #define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index)) #define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++]) static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len) { struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; uint32_t i; for (i = 0; i < len; i++) clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap); } static inline int tcmu_get_empty_block(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd, int prev_dbi, int length, int *iov_cnt) { XA_STATE(xas, &udev->data_pages, 0); struct page *page; int i, cnt, dbi, dpi; int page_cnt = DIV_ROUND_UP(length, PAGE_SIZE); dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh); if (dbi == udev->dbi_thresh) return -1; dpi = dbi * udev->data_pages_per_blk; /* Count the number of already allocated pages */ xas_set(&xas, dpi); rcu_read_lock(); for (cnt = 0; xas_next(&xas) && cnt < page_cnt;) cnt++; rcu_read_unlock(); for (i = cnt; i < page_cnt; i++) { /* try to get new page from the mm */ page = alloc_page(GFP_NOIO); if (!page) break; if (xa_store(&udev->data_pages, dpi + i, page, GFP_NOIO)) { __free_page(page); break; } } if (atomic_add_return(i - cnt, &global_page_count) > tcmu_global_max_pages) schedule_delayed_work(&tcmu_unmap_work, 0); if (i && dbi > udev->dbi_max) udev->dbi_max = dbi; set_bit(dbi, udev->data_bitmap); tcmu_cmd_set_dbi(tcmu_cmd, dbi); if (dbi != prev_dbi + 1) *iov_cnt += 1; return i == page_cnt ? dbi : -1; } static int tcmu_get_empty_blocks(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd, int length) { /* start value of dbi + 1 must not be a valid dbi */ int dbi = -2; int blk_data_len, iov_cnt = 0; uint32_t blk_size = udev->data_blk_size; for (; length > 0; length -= blk_size) { blk_data_len = min_t(uint32_t, length, blk_size); dbi = tcmu_get_empty_block(udev, tcmu_cmd, dbi, blk_data_len, &iov_cnt); if (dbi < 0) return -1; } return iov_cnt; } static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd) { kfree(tcmu_cmd->dbi); kmem_cache_free(tcmu_cmd_cache, tcmu_cmd); } static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd) { int i, len; struct se_cmd *se_cmd = cmd->se_cmd; uint32_t blk_size = cmd->tcmu_dev->data_blk_size; cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, blk_size); if (se_cmd->se_cmd_flags & SCF_BIDI) { BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents)); for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++) len += se_cmd->t_bidi_data_sg[i].length; cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, blk_size); cmd->dbi_cnt += cmd->dbi_bidi_cnt; cmd->data_len_bidi = len; } } static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd, struct iovec **iov, int prev_dbi, int len) { /* Get the next dbi */ int dbi = tcmu_cmd_get_dbi(cmd); /* Do not add more than udev->data_blk_size to iov */ len = min_t(int, len, udev->data_blk_size); /* * The following code will gather and map the blocks to the same iovec * when the blocks are all next to each other. */ if (dbi != prev_dbi + 1) { /* dbi is not next to previous dbi, so start new iov */ if (prev_dbi >= 0) (*iov)++; /* write offset relative to mb_addr */ (*iov)->iov_base = (void __user *) (udev->data_off + dbi * udev->data_blk_size); } (*iov)->iov_len += len; return dbi; } static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd, struct iovec **iov, int data_length) { /* start value of dbi + 1 must not be a valid dbi */ int dbi = -2; /* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */ for (; data_length > 0; data_length -= udev->data_blk_size) dbi = new_block_to_iov(udev, cmd, iov, dbi, data_length); } static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd) { struct se_device *se_dev = se_cmd->se_dev; struct tcmu_dev *udev = TCMU_DEV(se_dev); struct tcmu_cmd *tcmu_cmd; tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO); if (!tcmu_cmd) return NULL; INIT_LIST_HEAD(&tcmu_cmd->queue_entry); tcmu_cmd->se_cmd = se_cmd; tcmu_cmd->tcmu_dev = udev; tcmu_cmd_set_block_cnts(tcmu_cmd); tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t), GFP_NOIO); if (!tcmu_cmd->dbi) { kmem_cache_free(tcmu_cmd_cache, tcmu_cmd); return NULL; } return tcmu_cmd; } static inline void tcmu_flush_dcache_range(void *vaddr, size_t size) { unsigned long offset = offset_in_page(vaddr); void *start = vaddr - offset; size = round_up(size+offset, PAGE_SIZE); while (size) { flush_dcache_page(vmalloc_to_page(start)); start += PAGE_SIZE; size -= PAGE_SIZE; } } /* * Some ring helper functions. We don't assume size is a power of 2 so * we can't use circ_buf.h. */ static inline size_t spc_used(size_t head, size_t tail, size_t size) { int diff = head - tail; if (diff >= 0) return diff; else return size + diff; } static inline size_t spc_free(size_t head, size_t tail, size_t size) { /* Keep 1 byte unused or we can't tell full from empty */ return (size - spc_used(head, tail, size) - 1); } static inline size_t head_to_end(size_t head, size_t size) { return size - head; } #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size) #define TCMU_SG_TO_DATA_AREA 1 #define TCMU_DATA_AREA_TO_SG 2 static inline void tcmu_copy_data(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd, uint32_t direction, struct scatterlist *sg, unsigned int sg_nents, struct iovec **iov, size_t data_len) { /* start value of dbi + 1 must not be a valid dbi */ int dbi = -2; size_t page_remaining, cp_len; int page_cnt, page_inx, dpi; struct sg_mapping_iter sg_iter; unsigned int sg_flags; struct page *page; void *data_page_start, *data_addr; if (direction == TCMU_SG_TO_DATA_AREA) sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG; else sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG; sg_miter_start(&sg_iter, sg, sg_nents, sg_flags); while (data_len) { if (direction == TCMU_SG_TO_DATA_AREA) dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi, data_len); else dbi = tcmu_cmd_get_dbi(tcmu_cmd); page_cnt = DIV_ROUND_UP(data_len, PAGE_SIZE); if (page_cnt > udev->data_pages_per_blk) page_cnt = udev->data_pages_per_blk; dpi = dbi * udev->data_pages_per_blk; for (page_inx = 0; page_inx < page_cnt && data_len; page_inx++, dpi++) { page = xa_load(&udev->data_pages, dpi); if (direction == TCMU_DATA_AREA_TO_SG) flush_dcache_page(page); data_page_start = kmap_atomic(page); page_remaining = PAGE_SIZE; while (page_remaining && data_len) { if (!sg_miter_next(&sg_iter)) { /* set length to 0 to abort outer loop */ data_len = 0; pr_debug("%s: aborting data copy due to exhausted sg_list\n", __func__); break; } cp_len = min3(sg_iter.length, page_remaining, data_len); data_addr = data_page_start + PAGE_SIZE - page_remaining; if (direction == TCMU_SG_TO_DATA_AREA) memcpy(data_addr, sg_iter.addr, cp_len); else memcpy(sg_iter.addr, data_addr, cp_len); data_len -= cp_len; page_remaining -= cp_len; sg_iter.consumed = cp_len; } sg_miter_stop(&sg_iter); kunmap_atomic(data_page_start); if (direction == TCMU_SG_TO_DATA_AREA) flush_dcache_page(page); } } } static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd, struct iovec **iov) { struct se_cmd *se_cmd = tcmu_cmd->se_cmd; tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, se_cmd->t_data_sg, se_cmd->t_data_nents, iov, se_cmd->data_length); } static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd, bool bidi, uint32_t read_len) { struct se_cmd *se_cmd = tcmu_cmd->se_cmd; struct scatterlist *data_sg; unsigned int data_nents; if (!bidi) { data_sg = se_cmd->t_data_sg; data_nents = se_cmd->t_data_nents; } else { /* * For bidi case, the first count blocks are for Data-Out * buffer blocks, and before gathering the Data-In buffer * the Data-Out buffer blocks should be skipped. */ tcmu_cmd_set_dbi_cur(tcmu_cmd, tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt); data_sg = se_cmd->t_bidi_data_sg; data_nents = se_cmd->t_bidi_data_nents; } tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, data_sg, data_nents, NULL, read_len); } static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh) { return thresh - bitmap_weight(bitmap, thresh); } /* * We can't queue a command until we have space available on the cmd ring. * * Called with ring lock held. */ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size) { struct tcmu_mailbox *mb = udev->mb_addr; size_t space, cmd_needed; u32 cmd_head; tcmu_flush_dcache_range(mb, sizeof(*mb)); cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ /* * If cmd end-of-ring space is too small then we need space for a NOP plus * original cmd - cmds are internally contiguous. */ if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size) cmd_needed = cmd_size; else cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size); space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size); if (space < cmd_needed) { pr_debug("no cmd space: %u %u %u\n", cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size); return false; } return true; } /* * We have to allocate data buffers before we can queue a command. * Returns -1 on error (not enough space) or number of needed iovs on success * * Called with ring lock held. */ static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd, int *iov_bidi_cnt) { int space, iov_cnt = 0, ret = 0; if (!cmd->dbi_cnt) goto wr_iov_cnts; /* try to check and get the data blocks as needed */ space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh); if (space < cmd->dbi_cnt) { unsigned long blocks_left = (udev->max_blocks - udev->dbi_thresh) + space; if (blocks_left < cmd->dbi_cnt) { pr_debug("no data space: only %lu available, but ask for %u\n", blocks_left * udev->data_blk_size, cmd->dbi_cnt * udev->data_blk_size); return -1; } udev->dbi_thresh += cmd->dbi_cnt; if (udev->dbi_thresh > udev->max_blocks) udev->dbi_thresh = udev->max_blocks; } iov_cnt = tcmu_get_empty_blocks(udev, cmd, cmd->se_cmd->data_length); if (iov_cnt < 0) return -1; if (cmd->dbi_bidi_cnt) { ret = tcmu_get_empty_blocks(udev, cmd, cmd->data_len_bidi); if (ret < 0) return -1; } wr_iov_cnts: *iov_bidi_cnt = ret; return iov_cnt + ret; } static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt) { return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]), sizeof(struct tcmu_cmd_entry)); } static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd, size_t base_command_size) { struct se_cmd *se_cmd = tcmu_cmd->se_cmd; size_t command_size; command_size = base_command_size + round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE); WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1)); return command_size; } static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo, struct timer_list *timer) { if (!tmo) return; tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo)); if (!timer_pending(timer)) mod_timer(timer, tcmu_cmd->deadline); pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd, tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC); } static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd) { struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; unsigned int tmo; /* * For backwards compat if qfull_time_out is not set use * cmd_time_out and if that's not set use the default time out. */ if (!udev->qfull_time_out) return -ETIMEDOUT; else if (udev->qfull_time_out > 0) tmo = udev->qfull_time_out; else if (udev->cmd_time_out) tmo = udev->cmd_time_out; else tmo = TCMU_TIME_OUT; tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer); list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue); pr_debug("adding cmd %p on dev %s to ring space wait queue\n", tcmu_cmd, udev->name); return 0; } static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size) { struct tcmu_cmd_entry_hdr *hdr; struct tcmu_mailbox *mb = udev->mb_addr; uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ /* Insert a PAD if end-of-ring space is too small */ if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) { size_t pad_size = head_to_end(cmd_head, udev->cmdr_size); hdr = udev->cmdr + cmd_head; tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD); tcmu_hdr_set_len(&hdr->len_op, pad_size); hdr->cmd_id = 0; /* not used for PAD */ hdr->kflags = 0; hdr->uflags = 0; tcmu_flush_dcache_range(hdr, sizeof(*hdr)); UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size); tcmu_flush_dcache_range(mb, sizeof(*mb)); cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ WARN_ON(cmd_head != 0); } return cmd_head; } static void tcmu_unplug_device(struct se_dev_plug *se_plug) { struct se_device *se_dev = se_plug->se_dev; struct tcmu_dev *udev = TCMU_DEV(se_dev); clear_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags); uio_event_notify(&udev->uio_info); } static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev) { struct tcmu_dev *udev = TCMU_DEV(se_dev); if (!test_and_set_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags)) return &udev->se_plug; return NULL; } /** * queue_cmd_ring - queue cmd to ring or internally * @tcmu_cmd: cmd to queue * @scsi_err: TCM error code if failure (-1) returned. * * Returns: * -1 we cannot queue internally or to the ring. * 0 success * 1 internally queued to wait for ring memory to free. */ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err) { struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; struct se_cmd *se_cmd = tcmu_cmd->se_cmd; size_t base_command_size, command_size; struct tcmu_mailbox *mb = udev->mb_addr; struct tcmu_cmd_entry *entry; struct iovec *iov; int iov_cnt, iov_bidi_cnt; uint32_t cmd_id, cmd_head; uint64_t cdb_off; uint32_t blk_size = udev->data_blk_size; /* size of data buffer needed */ size_t data_length = (size_t)tcmu_cmd->dbi_cnt * blk_size; *scsi_err = TCM_NO_SENSE; if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) { *scsi_err = TCM_LUN_BUSY; return -1; } if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) { *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; return -1; } if (!list_empty(&udev->qfull_queue)) goto queue; if (data_length > (size_t)udev->max_blocks * blk_size) { pr_warn("TCMU: Request of size %zu is too big for %zu data area\n", data_length, (size_t)udev->max_blocks * blk_size); *scsi_err = TCM_INVALID_CDB_FIELD; return -1; } iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt); if (iov_cnt < 0) goto free_and_queue; /* * Must be a certain minimum size for response sense info, but * also may be larger if the iov array is large. */ base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt); command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size); if (command_size > (udev->cmdr_size / 2)) { pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n", command_size, udev->cmdr_size); tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur); *scsi_err = TCM_INVALID_CDB_FIELD; return -1; } if (!is_ring_space_avail(udev, command_size)) /* * Don't leave commands partially setup because the unmap * thread might need the blocks to make forward progress. */ goto free_and_queue; if (xa_alloc(&udev->commands, &cmd_id, tcmu_cmd, XA_LIMIT(1, 0xffff), GFP_NOWAIT) < 0) { pr_err("tcmu: Could not allocate cmd id.\n"); tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt); *scsi_err = TCM_OUT_OF_RESOURCES; return -1; } tcmu_cmd->cmd_id = cmd_id; pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id, tcmu_cmd, udev->name); cmd_head = ring_insert_padding(udev, command_size); entry = udev->cmdr + cmd_head; memset(entry, 0, command_size); tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD); /* prepare iov list and copy data to data area if necessary */ tcmu_cmd_reset_dbi_cur(tcmu_cmd); iov = &entry->req.iov[0]; if (se_cmd->data_direction == DMA_TO_DEVICE || se_cmd->se_cmd_flags & SCF_BIDI) scatter_data_area(udev, tcmu_cmd, &iov); else tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length); entry->req.iov_cnt = iov_cnt - iov_bidi_cnt; /* Handle BIDI commands */ if (se_cmd->se_cmd_flags & SCF_BIDI) { iov++; tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi); entry->req.iov_bidi_cnt = iov_bidi_cnt; } tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer); entry->hdr.cmd_id = tcmu_cmd->cmd_id; tcmu_hdr_set_len(&entry->hdr.len_op, command_size); /* All offsets relative to mb_addr, not start of entry! */ cdb_off = CMDR_OFF + cmd_head + base_command_size; memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb)); entry->req.cdb_off = cdb_off; tcmu_flush_dcache_range(entry, command_size); UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size); tcmu_flush_dcache_range(mb, sizeof(*mb)); list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue); if (!test_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags)) uio_event_notify(&udev->uio_info); return 0; free_and_queue: tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur); tcmu_cmd_reset_dbi_cur(tcmu_cmd); queue: if (add_to_qfull_queue(tcmu_cmd)) { *scsi_err = TCM_OUT_OF_RESOURCES; return -1; } return 1; } /** * queue_tmr_ring - queue tmr info to ring or internally * @udev: related tcmu_dev * @tmr: tcmu_tmr containing tmr info to queue * * Returns: * 0 success * 1 internally queued to wait for ring memory to free. */ static int queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr) { struct tcmu_tmr_entry *entry; int cmd_size; int id_list_sz; struct tcmu_mailbox *mb = udev->mb_addr; uint32_t cmd_head; if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) goto out_free; id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt; cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE); if (!list_empty(&udev->tmr_queue) || !is_ring_space_avail(udev, cmd_size)) { list_add_tail(&tmr->queue_entry, &udev->tmr_queue); pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n", tmr, udev->name); return 1; } cmd_head = ring_insert_padding(udev, cmd_size); entry = udev->cmdr + cmd_head; memset(entry, 0, cmd_size); tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR); tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size); entry->tmr_type = tmr->tmr_type; entry->cmd_cnt = tmr->tmr_cmd_cnt; memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz); tcmu_flush_dcache_range(entry, cmd_size); UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size); tcmu_flush_dcache_range(mb, sizeof(*mb)); uio_event_notify(&udev->uio_info); out_free: kfree(tmr); return 0; } static sense_reason_t tcmu_queue_cmd(struct se_cmd *se_cmd) { struct se_device *se_dev = se_cmd->se_dev; struct tcmu_dev *udev = TCMU_DEV(se_dev); struct tcmu_cmd *tcmu_cmd; sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD; int ret = -1; tcmu_cmd = tcmu_alloc_cmd(se_cmd); if (!tcmu_cmd) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; mutex_lock(&udev->cmdr_lock); if (!(se_cmd->transport_state & CMD_T_ABORTED)) ret = queue_cmd_ring(tcmu_cmd, &scsi_ret); if (ret < 0) tcmu_free_cmd(tcmu_cmd); else se_cmd->priv = tcmu_cmd; mutex_unlock(&udev->cmdr_lock); return scsi_ret; } static void tcmu_set_next_deadline(struct list_head *queue, struct timer_list *timer) { struct tcmu_cmd *cmd; if (!list_empty(queue)) { cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry); mod_timer(timer, cmd->deadline); } else del_timer(timer); } static int tcmu_tmr_type(enum tcm_tmreq_table tmf) { switch (tmf) { case TMR_ABORT_TASK: return TCMU_TMR_ABORT_TASK; case TMR_ABORT_TASK_SET: return TCMU_TMR_ABORT_TASK_SET; case TMR_CLEAR_ACA: return TCMU_TMR_CLEAR_ACA; case TMR_CLEAR_TASK_SET: return TCMU_TMR_CLEAR_TASK_SET; case TMR_LUN_RESET: return TCMU_TMR_LUN_RESET; case TMR_TARGET_WARM_RESET: return TCMU_TMR_TARGET_WARM_RESET; case TMR_TARGET_COLD_RESET: return TCMU_TMR_TARGET_COLD_RESET; case TMR_LUN_RESET_PRO: return TCMU_TMR_LUN_RESET_PRO; default: return TCMU_TMR_UNKNOWN; } } static void tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf, struct list_head *cmd_list) { int i = 0, cmd_cnt = 0; bool unqueued = false; uint16_t *cmd_ids = NULL; struct tcmu_cmd *cmd; struct se_cmd *se_cmd; struct tcmu_tmr *tmr; struct tcmu_dev *udev = TCMU_DEV(se_dev); mutex_lock(&udev->cmdr_lock); /* First we check for aborted commands in qfull_queue */ list_for_each_entry(se_cmd, cmd_list, state_list) { i++; if (!se_cmd->priv) continue; cmd = se_cmd->priv; /* Commands on qfull queue have no id yet */ if (cmd->cmd_id) { cmd_cnt++; continue; } pr_debug("Removing aborted command %p from queue on dev %s.\n", cmd, udev->name); list_del_init(&cmd->queue_entry); tcmu_free_cmd(cmd); se_cmd->priv = NULL; target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED); unqueued = true; } if (unqueued) tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer); if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags)) goto unlock; pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n", tcmu_tmr_type(tmf), udev->name, i, cmd_cnt); tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_NOIO); if (!tmr) goto unlock; tmr->tmr_type = tcmu_tmr_type(tmf); tmr->tmr_cmd_cnt = cmd_cnt; if (cmd_cnt != 0) { cmd_cnt = 0; list_for_each_entry(se_cmd, cmd_list, state_list) { if (!se_cmd->priv) continue; cmd = se_cmd->priv; if (cmd->cmd_id) tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id; } } queue_tmr_ring(udev, tmr); unlock: mutex_unlock(&udev->cmdr_lock); } static bool tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry, bool keep_buf) { struct se_cmd *se_cmd = cmd->se_cmd; struct tcmu_dev *udev = cmd->tcmu_dev; bool read_len_valid = false; bool ret = true; uint32_t read_len; /* * cmd has been completed already from timeout, just reclaim * data area space and free cmd */ if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) { WARN_ON_ONCE(se_cmd); goto out; } if (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) { pr_err("cmd_id %u already completed with KEEP_BUF, ring is broken\n", entry->hdr.cmd_id); set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags); ret = false; goto out; } list_del_init(&cmd->queue_entry); tcmu_cmd_reset_dbi_cur(cmd); if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) { pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n", cmd->se_cmd); entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION; goto done; } read_len = se_cmd->data_length; if (se_cmd->data_direction == DMA_FROM_DEVICE && (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) { read_len_valid = true; if (entry->rsp.read_len < read_len) read_len = entry->rsp.read_len; } if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) { transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer); if (!read_len_valid ) goto done; else se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL; } if (se_cmd->se_cmd_flags & SCF_BIDI) { /* Get Data-In buffer before clean up */ gather_data_area(udev, cmd, true, read_len); } else if (se_cmd->data_direction == DMA_FROM_DEVICE) { gather_data_area(udev, cmd, false, read_len); } else if (se_cmd->data_direction == DMA_TO_DEVICE) { /* TODO: */ } else if (se_cmd->data_direction != DMA_NONE) { pr_warn("TCMU: data direction was %d!\n", se_cmd->data_direction); } done: se_cmd->priv = NULL; if (read_len_valid) { pr_debug("read_len = %d\n", read_len); target_complete_cmd_with_length(cmd->se_cmd, entry->rsp.scsi_status, read_len); } else target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status); out: if (!keep_buf) { tcmu_cmd_free_data(cmd, cmd->dbi_cnt); tcmu_free_cmd(cmd); } else { /* * Keep this command after completion, since userspace still * needs the data buffer. Mark it with TCMU_CMD_BIT_KEEP_BUF * and reset potential TCMU_CMD_BIT_EXPIRED, so we don't accept * a second completion later. * Userspace can free the buffer later by writing the cmd_id * to new action attribute free_kept_buf. */ clear_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags); set_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags); } return ret; } static int tcmu_run_tmr_queue(struct tcmu_dev *udev) { struct tcmu_tmr *tmr, *tmp; LIST_HEAD(tmrs); if (list_empty(&udev->tmr_queue)) return 1; pr_debug("running %s's tmr queue\n", udev->name); list_splice_init(&udev->tmr_queue, &tmrs); list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) { list_del_init(&tmr->queue_entry); pr_debug("removing tmr %p on dev %s from queue\n", tmr, udev->name); if (queue_tmr_ring(udev, tmr)) { pr_debug("ran out of space during tmr queue run\n"); /* * tmr was requeued, so just put all tmrs back in * the queue */ list_splice_tail(&tmrs, &udev->tmr_queue); return 0; } } return 1; } static bool tcmu_handle_completions(struct tcmu_dev *udev) { struct tcmu_mailbox *mb; struct tcmu_cmd *cmd; bool free_space = false; if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) { pr_err("ring broken, not handling completions\n"); return false; } mb = udev->mb_addr; tcmu_flush_dcache_range(mb, sizeof(*mb)); while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) { struct tcmu_cmd_entry *entry = udev->cmdr + udev->cmdr_last_cleaned; bool keep_buf; /* * Flush max. up to end of cmd ring since current entry might * be a padding that is shorter than sizeof(*entry) */ size_t ring_left = head_to_end(udev->cmdr_last_cleaned, udev->cmdr_size); tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ? ring_left : sizeof(*entry)); free_space = true; if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD || tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) { UPDATE_HEAD(udev->cmdr_last_cleaned, tcmu_hdr_get_len(entry->hdr.len_op), udev->cmdr_size); continue; } WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD); keep_buf = !!(entry->hdr.uflags & TCMU_UFLAG_KEEP_BUF); if (keep_buf) cmd = xa_load(&udev->commands, entry->hdr.cmd_id); else cmd = xa_erase(&udev->commands, entry->hdr.cmd_id); if (!cmd) { pr_err("cmd_id %u not found, ring is broken\n", entry->hdr.cmd_id); set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags); return false; } if (!tcmu_handle_completion(cmd, entry, keep_buf)) break; UPDATE_HEAD(udev->cmdr_last_cleaned, tcmu_hdr_get_len(entry->hdr.len_op), udev->cmdr_size); } if (free_space) free_space = tcmu_run_tmr_queue(udev); if (atomic_read(&global_page_count) > tcmu_global_max_pages && xa_empty(&udev->commands) && list_empty(&udev->qfull_queue)) { /* * Allocated blocks exceeded global block limit, currently no * more pending or waiting commands so try to reclaim blocks. */ schedule_delayed_work(&tcmu_unmap_work, 0); } if (udev->cmd_time_out) tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer); return free_space; } static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd) { struct se_cmd *se_cmd; if (!time_after_eq(jiffies, cmd->deadline)) return; set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags); list_del_init(&cmd->queue_entry); se_cmd = cmd->se_cmd; se_cmd->priv = NULL; cmd->se_cmd = NULL; pr_debug("Timing out inflight cmd %u on dev %s.\n", cmd->cmd_id, cmd->tcmu_dev->name); target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION); } static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd) { struct se_cmd *se_cmd; if (!time_after_eq(jiffies, cmd->deadline)) return; pr_debug("Timing out queued cmd %p on dev %s.\n", cmd, cmd->tcmu_dev->name); list_del_init(&cmd->queue_entry); se_cmd = cmd->se_cmd; tcmu_free_cmd(cmd); se_cmd->priv = NULL; target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL); } static void tcmu_device_timedout(struct tcmu_dev *udev) { spin_lock(&timed_out_udevs_lock); if (list_empty(&udev->timedout_entry)) list_add_tail(&udev->timedout_entry, &timed_out_udevs); spin_unlock(&timed_out_udevs_lock); schedule_delayed_work(&tcmu_unmap_work, 0); } static void tcmu_cmd_timedout(struct timer_list *t) { struct tcmu_dev *udev = from_timer(udev, t, cmd_timer); pr_debug("%s cmd timeout has expired\n", udev->name); tcmu_device_timedout(udev); } static void tcmu_qfull_timedout(struct timer_list *t) { struct tcmu_dev *udev = from_timer(udev, t, qfull_timer); pr_debug("%s qfull timeout has expired\n", udev->name); tcmu_device_timedout(udev); } static int tcmu_attach_hba(struct se_hba *hba, u32 host_id) { struct tcmu_hba *tcmu_hba; tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL); if (!tcmu_hba) return -ENOMEM; tcmu_hba->host_id = host_id; hba->hba_ptr = tcmu_hba; return 0; } static void tcmu_detach_hba(struct se_hba *hba) { kfree(hba->hba_ptr); hba->hba_ptr = NULL; } static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) { struct tcmu_dev *udev; udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL); if (!udev) return NULL; kref_init(&udev->kref); udev->name = kstrdup(name, GFP_KERNEL); if (!udev->name) { kfree(udev); return NULL; } udev->hba = hba; udev->cmd_time_out = TCMU_TIME_OUT; udev->qfull_time_out = -1; udev->data_pages_per_blk = DATA_PAGES_PER_BLK_DEF; udev->max_blocks = DATA_AREA_PAGES_DEF / udev->data_pages_per_blk; udev->data_area_mb = TCMU_PAGES_TO_MBS(DATA_AREA_PAGES_DEF); mutex_init(&udev->cmdr_lock); INIT_LIST_HEAD(&udev->node); INIT_LIST_HEAD(&udev->timedout_entry); INIT_LIST_HEAD(&udev->qfull_queue); INIT_LIST_HEAD(&udev->tmr_queue); INIT_LIST_HEAD(&udev->inflight_queue); xa_init_flags(&udev->commands, XA_FLAGS_ALLOC1); timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0); timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0); xa_init(&udev->data_pages); return &udev->se_dev; } static void tcmu_dev_call_rcu(struct rcu_head *p) { struct se_device *dev = container_of(p, struct se_device, rcu_head); struct tcmu_dev *udev = TCMU_DEV(dev); kfree(udev->uio_info.name); kfree(udev->name); kfree(udev); } static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd) { if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) || test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) { kmem_cache_free(tcmu_cmd_cache, cmd); return 0; } return -EINVAL; } static u32 tcmu_blocks_release(struct tcmu_dev *udev, unsigned long first, unsigned long last) { struct page *page; unsigned long dpi; u32 pages_freed = 0; first = first * udev->data_pages_per_blk; last = (last + 1) * udev->data_pages_per_blk - 1; xa_for_each_range(&udev->data_pages, dpi, page, first, last) { xa_erase(&udev->data_pages, dpi); /* * While reaching here there may be page faults occurring on * the to-be-released pages. A race condition may occur if * unmap_mapping_range() is called before page faults on these * pages have completed; a valid but stale map is created. * * If another command subsequently runs and needs to extend * dbi_thresh, it may reuse the slot corresponding to the * previous page in data_bitmap. Though we will allocate a new * page for the slot in data_area, no page fault will happen * because we have a valid map. Therefore the command's data * will be lost. * * We lock and unlock pages that are to be released to ensure * all page faults have completed. This way * unmap_mapping_range() can ensure stale maps are cleanly * removed. */ lock_page(page); unlock_page(page); __free_page(page); pages_freed++; } atomic_sub(pages_freed, &global_page_count); return pages_freed; } static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev) { struct tcmu_tmr *tmr, *tmp; list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) { list_del_init(&tmr->queue_entry); kfree(tmr); } } static void tcmu_dev_kref_release(struct kref *kref) { struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref); struct se_device *dev = &udev->se_dev; struct tcmu_cmd *cmd; bool all_expired = true; unsigned long i; vfree(udev->mb_addr); udev->mb_addr = NULL; spin_lock_bh(&timed_out_udevs_lock); if (!list_empty(&udev->timedout_entry)) list_del(&udev->timedout_entry); spin_unlock_bh(&timed_out_udevs_lock); /* Upper layer should drain all requests before calling this */ mutex_lock(&udev->cmdr_lock); xa_for_each(&udev->commands, i, cmd) { if (tcmu_check_and_free_pending_cmd(cmd) != 0) all_expired = false; } /* There can be left over TMR cmds. Remove them. */ tcmu_remove_all_queued_tmr(udev); if (!list_empty(&udev->qfull_queue)) all_expired = false; xa_destroy(&udev->commands); WARN_ON(!all_expired); tcmu_blocks_release(udev, 0, udev->dbi_max); bitmap_free(udev->data_bitmap); mutex_unlock(&udev->cmdr_lock); pr_debug("dev_kref_release\n"); call_rcu(&dev->rcu_head, tcmu_dev_call_rcu); } static void run_qfull_queue(struct tcmu_dev *udev, bool fail) { struct tcmu_cmd *tcmu_cmd, *tmp_cmd; LIST_HEAD(cmds); sense_reason_t scsi_ret; int ret; if (list_empty(&udev->qfull_queue)) return; pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail); list_splice_init(&udev->qfull_queue, &cmds); list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) { list_del_init(&tcmu_cmd->queue_entry); pr_debug("removing cmd %p on dev %s from queue\n", tcmu_cmd, udev->name); if (fail) { /* * We were not able to even start the command, so * fail with busy to allow a retry in case runner * was only temporarily down. If the device is being * removed then LIO core will do the right thing and * fail the retry. */ tcmu_cmd->se_cmd->priv = NULL; target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY); tcmu_free_cmd(tcmu_cmd); continue; } ret = queue_cmd_ring(tcmu_cmd, &scsi_ret); if (ret < 0) { pr_debug("cmd %p on dev %s failed with %u\n", tcmu_cmd, udev->name, scsi_ret); /* * Ignore scsi_ret for now. target_complete_cmd * drops it. */ tcmu_cmd->se_cmd->priv = NULL; target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_CHECK_CONDITION); tcmu_free_cmd(tcmu_cmd); } else if (ret > 0) { pr_debug("ran out of space during cmdr queue run\n"); /* * cmd was requeued, so just put all cmds back in * the queue */ list_splice_tail(&cmds, &udev->qfull_queue); break; } } tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer); } static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on) { struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); mutex_lock(&udev->cmdr_lock); if (tcmu_handle_completions(udev)) run_qfull_queue(udev, false); mutex_unlock(&udev->cmdr_lock); return 0; } /* * mmap code from uio.c. Copied here because we want to hook mmap() * and this stuff must come along. */ static int tcmu_find_mem_index(struct vm_area_struct *vma) { struct tcmu_dev *udev = vma->vm_private_data; struct uio_info *info = &udev->uio_info; if (vma->vm_pgoff < MAX_UIO_MAPS) { if (info->mem[vma->vm_pgoff].size == 0) return -1; return (int)vma->vm_pgoff; } return -1; } static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi) { struct page *page; mutex_lock(&udev->cmdr_lock); page = xa_load(&udev->data_pages, dpi); if (likely(page)) { get_page(page); lock_page(page); mutex_unlock(&udev->cmdr_lock); return page; } /* * Userspace messed up and passed in a address not in the * data iov passed to it. */ pr_err("Invalid addr to data page mapping (dpi %u) on device %s\n", dpi, udev->name); mutex_unlock(&udev->cmdr_lock); return NULL; } static void tcmu_vma_open(struct vm_area_struct *vma) { struct tcmu_dev *udev = vma->vm_private_data; pr_debug("vma_open\n"); kref_get(&udev->kref); } static void tcmu_vma_close(struct vm_area_struct *vma) { struct tcmu_dev *udev = vma->vm_private_data; pr_debug("vma_close\n"); /* release ref from tcmu_vma_open */ kref_put(&udev->kref, tcmu_dev_kref_release); } static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf) { struct tcmu_dev *udev = vmf->vma->vm_private_data; struct uio_info *info = &udev->uio_info; struct page *page; unsigned long offset; void *addr; vm_fault_t ret = 0; int mi = tcmu_find_mem_index(vmf->vma); if (mi < 0) return VM_FAULT_SIGBUS; /* * We need to subtract mi because userspace uses offset = N*PAGE_SIZE * to use mem[N]. */ offset = (vmf->pgoff - mi) << PAGE_SHIFT; if (offset < udev->data_off) { /* For the vmalloc()ed cmd area pages */ addr = (void *)(unsigned long)info->mem[mi].addr + offset; page = vmalloc_to_page(addr); get_page(page); } else { uint32_t dpi; /* For the dynamically growing data area pages */ dpi = (offset - udev->data_off) / PAGE_SIZE; page = tcmu_try_get_data_page(udev, dpi); if (!page) return VM_FAULT_SIGBUS; ret = VM_FAULT_LOCKED; } vmf->page = page; return ret; } static const struct vm_operations_struct tcmu_vm_ops = { .open = tcmu_vma_open, .close = tcmu_vma_close, .fault = tcmu_vma_fault, }; static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma) { struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; vma->vm_ops = &tcmu_vm_ops; vma->vm_private_data = udev; /* Ensure the mmap is exactly the right size */ if (vma_pages(vma) != udev->mmap_pages) return -EINVAL; tcmu_vma_open(vma); return 0; } static int tcmu_open(struct uio_info *info, struct inode *inode) { struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); /* O_EXCL not supported for char devs, so fake it? */ if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags)) return -EBUSY; udev->inode = inode; pr_debug("open\n"); return 0; } static int tcmu_release(struct uio_info *info, struct inode *inode) { struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); struct tcmu_cmd *cmd; unsigned long i; bool freed = false; mutex_lock(&udev->cmdr_lock); xa_for_each(&udev->commands, i, cmd) { /* Cmds with KEEP_BUF set are no longer on the ring, but * userspace still holds the data buffer. If userspace closes * we implicitly free these cmds and buffers, since after new * open the (new ?) userspace cannot find the cmd in the ring * and thus never will release the buffer by writing cmd_id to * free_kept_buf action attribute. */ if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) continue; pr_debug("removing KEEP_BUF cmd %u on dev %s from ring\n", cmd->cmd_id, udev->name); freed = true; xa_erase(&udev->commands, i); tcmu_cmd_free_data(cmd, cmd->dbi_cnt); tcmu_free_cmd(cmd); } /* * We only freed data space, not ring space. Therefore we dont call * run_tmr_queue, but call run_qfull_queue if tmr_list is empty. */ if (freed && list_empty(&udev->tmr_queue)) run_qfull_queue(udev, false); mutex_unlock(&udev->cmdr_lock); clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags); pr_debug("close\n"); return 0; } static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd) { struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd; if (!tcmu_kern_cmd_reply_supported) return 0; if (udev->nl_reply_supported <= 0) return 0; mutex_lock(&tcmu_nl_cmd_mutex); if (tcmu_netlink_blocked) { mutex_unlock(&tcmu_nl_cmd_mutex); pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd, udev->name); return -EAGAIN; } if (nl_cmd->cmd != TCMU_CMD_UNSPEC) { mutex_unlock(&tcmu_nl_cmd_mutex); pr_warn("netlink cmd %d already executing on %s\n", nl_cmd->cmd, udev->name); return -EBUSY; } memset(nl_cmd, 0, sizeof(*nl_cmd)); nl_cmd->cmd = cmd; nl_cmd->udev = udev; init_completion(&nl_cmd->complete); INIT_LIST_HEAD(&nl_cmd->nl_list); list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list); mutex_unlock(&tcmu_nl_cmd_mutex); return 0; } static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev) { struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd; if (!tcmu_kern_cmd_reply_supported) return; if (udev->nl_reply_supported <= 0) return; mutex_lock(&tcmu_nl_cmd_mutex); list_del(&nl_cmd->nl_list); memset(nl_cmd, 0, sizeof(*nl_cmd)); mutex_unlock(&tcmu_nl_cmd_mutex); } static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev) { struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd; int ret; if (!tcmu_kern_cmd_reply_supported) return 0; if (udev->nl_reply_supported <= 0) return 0; pr_debug("sleeping for nl reply\n"); wait_for_completion(&nl_cmd->complete); mutex_lock(&tcmu_nl_cmd_mutex); nl_cmd->cmd = TCMU_CMD_UNSPEC; ret = nl_cmd->status; mutex_unlock(&tcmu_nl_cmd_mutex); return ret; } static int tcmu_netlink_event_init(struct tcmu_dev *udev, enum tcmu_genl_cmd cmd, struct sk_buff **buf, void **hdr) { struct sk_buff *skb; void *msg_header; int ret = -ENOMEM; skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); if (!skb) return ret; msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd); if (!msg_header) goto free_skb; ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name); if (ret < 0) goto free_skb; ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor); if (ret < 0) goto free_skb; ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index); if (ret < 0) goto free_skb; *buf = skb; *hdr = msg_header; return ret; free_skb: nlmsg_free(skb); return ret; } static int tcmu_netlink_event_send(struct tcmu_dev *udev, enum tcmu_genl_cmd cmd, struct sk_buff *skb, void *msg_header) { int ret; genlmsg_end(skb, msg_header); ret = tcmu_init_genl_cmd_reply(udev, cmd); if (ret) { nlmsg_free(skb); return ret; } ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0, TCMU_MCGRP_CONFIG, GFP_KERNEL); /* Wait during an add as the listener may not be up yet */ if (ret == 0 || (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE)) return tcmu_wait_genl_cmd_reply(udev); else tcmu_destroy_genl_cmd_reply(udev); return ret; } static int tcmu_send_dev_add_event(struct tcmu_dev *udev) { struct sk_buff *skb = NULL; void *msg_header = NULL; int ret = 0; ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb, &msg_header); if (ret < 0) return ret; return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb, msg_header); } static int tcmu_send_dev_remove_event(struct tcmu_dev *udev) { struct sk_buff *skb = NULL; void *msg_header = NULL; int ret = 0; ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE, &skb, &msg_header); if (ret < 0) return ret; return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE, skb, msg_header); } static int tcmu_update_uio_info(struct tcmu_dev *udev) { struct tcmu_hba *hba = udev->hba->hba_ptr; struct uio_info *info; char *str; info = &udev->uio_info; if (udev->dev_config[0]) str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id, udev->name, udev->dev_config); else str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id, udev->name); if (!str) return -ENOMEM; /* If the old string exists, free it */ kfree(info->name); info->name = str; return 0; } static int tcmu_configure_device(struct se_device *dev) { struct tcmu_dev *udev = TCMU_DEV(dev); struct uio_info *info; struct tcmu_mailbox *mb; size_t data_size; int ret = 0; ret = tcmu_update_uio_info(udev); if (ret) return ret; info = &udev->uio_info; mutex_lock(&udev->cmdr_lock); udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL); mutex_unlock(&udev->cmdr_lock); if (!udev->data_bitmap) { ret = -ENOMEM; goto err_bitmap_alloc; } mb = vzalloc(MB_CMDR_SIZE); if (!mb) { ret = -ENOMEM; goto err_vzalloc; } /* mailbox fits in first part of CMDR space */ udev->mb_addr = mb; udev->cmdr = (void *)mb + CMDR_OFF; udev->cmdr_size = CMDR_SIZE; udev->data_off = MB_CMDR_SIZE; data_size = TCMU_MBS_TO_PAGES(udev->data_area_mb) << PAGE_SHIFT; udev->mmap_pages = (data_size + MB_CMDR_SIZE) >> PAGE_SHIFT; udev->data_blk_size = udev->data_pages_per_blk * PAGE_SIZE; udev->dbi_thresh = 0; /* Default in Idle state */ /* Initialise the mailbox of the ring buffer */ mb->version = TCMU_MAILBOX_VERSION; mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC | TCMU_MAILBOX_FLAG_CAP_READ_LEN | TCMU_MAILBOX_FLAG_CAP_TMR | TCMU_MAILBOX_FLAG_CAP_KEEP_BUF; mb->cmdr_off = CMDR_OFF; mb->cmdr_size = udev->cmdr_size; WARN_ON(!PAGE_ALIGNED(udev->data_off)); WARN_ON(data_size % PAGE_SIZE); info->version = __stringify(TCMU_MAILBOX_VERSION); 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 = data_size + MB_CMDR_SIZE; info->mem[0].memtype = UIO_MEM_NONE; info->irqcontrol = tcmu_irqcontrol; info->irq = UIO_IRQ_CUSTOM; info->mmap = tcmu_mmap; info->open = tcmu_open; info->release = tcmu_release; ret = uio_register_device(tcmu_root_device, info); if (ret) goto err_register; /* User can set hw_block_size before enable the device */ if (dev->dev_attrib.hw_block_size == 0) dev->dev_attrib.hw_block_size = 512; /* Other attributes can be configured in userspace */ if (!dev->dev_attrib.hw_max_sectors) dev->dev_attrib.hw_max_sectors = 128; if (!dev->dev_attrib.emulate_write_cache) dev->dev_attrib.emulate_write_cache = 0; dev->dev_attrib.hw_queue_depth = 128; /* If user didn't explicitly disable netlink reply support, use * module scope setting. */ if (udev->nl_reply_supported >= 0) udev->nl_reply_supported = tcmu_kern_cmd_reply_supported; /* * Get a ref incase userspace does a close on the uio device before * LIO has initiated tcmu_free_device. */ kref_get(&udev->kref); ret = tcmu_send_dev_add_event(udev); if (ret) goto err_netlink; mutex_lock(&root_udev_mutex); list_add(&udev->node, &root_udev); mutex_unlock(&root_udev_mutex); return 0; err_netlink: kref_put(&udev->kref, tcmu_dev_kref_release); uio_unregister_device(&udev->uio_info); err_register: vfree(udev->mb_addr); udev->mb_addr = NULL; err_vzalloc: bitmap_free(udev->data_bitmap); udev->data_bitmap = NULL; err_bitmap_alloc: kfree(info->name); info->name = NULL; return ret; } static void tcmu_free_device(struct se_device *dev) { struct tcmu_dev *udev = TCMU_DEV(dev); /* release ref from init */ kref_put(&udev->kref, tcmu_dev_kref_release); } static void tcmu_destroy_device(struct se_device *dev) { struct tcmu_dev *udev = TCMU_DEV(dev); del_timer_sync(&udev->cmd_timer); del_timer_sync(&udev->qfull_timer); mutex_lock(&root_udev_mutex); list_del(&udev->node); mutex_unlock(&root_udev_mutex); tcmu_send_dev_remove_event(udev); uio_unregister_device(&udev->uio_info); /* release ref from configure */ kref_put(&udev->kref, tcmu_dev_kref_release); } static void tcmu_unblock_dev(struct tcmu_dev *udev) { mutex_lock(&udev->cmdr_lock); clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags); mutex_unlock(&udev->cmdr_lock); } static void tcmu_block_dev(struct tcmu_dev *udev) { mutex_lock(&udev->cmdr_lock); if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) goto unlock; /* complete IO that has executed successfully */ tcmu_handle_completions(udev); /* fail IO waiting to be queued */ run_qfull_queue(udev, true); unlock: mutex_unlock(&udev->cmdr_lock); } static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level) { struct tcmu_mailbox *mb; struct tcmu_cmd *cmd; unsigned long i; mutex_lock(&udev->cmdr_lock); xa_for_each(&udev->commands, i, cmd) { pr_debug("removing cmd %u on dev %s from ring %s\n", cmd->cmd_id, udev->name, test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ? "(is expired)" : (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags) ? "(is keep buffer)" : "")); xa_erase(&udev->commands, i); if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) && !test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) { WARN_ON(!cmd->se_cmd); list_del_init(&cmd->queue_entry); cmd->se_cmd->priv = NULL; if (err_level == 1) { /* * Userspace was not able to start the * command or it is retryable. */ target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY); } else { /* hard failure */ target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION); } } tcmu_cmd_free_data(cmd, cmd->dbi_cnt); tcmu_free_cmd(cmd); } mb = udev->mb_addr; tcmu_flush_dcache_range(mb, sizeof(*mb)); pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned, mb->cmd_tail, mb->cmd_head); udev->cmdr_last_cleaned = 0; mb->cmd_tail = 0; mb->cmd_head = 0; tcmu_flush_dcache_range(mb, sizeof(*mb)); clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags); del_timer(&udev->cmd_timer); /* * ring is empty and qfull queue never contains aborted commands. * So TMRs in tmr queue do not contain relevant cmd_ids. * After a ring reset userspace should do a fresh start, so * even LUN RESET message is no longer relevant. * Therefore remove all TMRs from qfull queue */ tcmu_remove_all_queued_tmr(udev); run_qfull_queue(udev, false); mutex_unlock(&udev->cmdr_lock); } enum { Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors, Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk, Opt_err, }; static match_table_t tokens = { {Opt_dev_config, "dev_config=%s"}, {Opt_dev_size, "dev_size=%s"}, {Opt_hw_block_size, "hw_block_size=%d"}, {Opt_hw_max_sectors, "hw_max_sectors=%d"}, {Opt_nl_reply_supported, "nl_reply_supported=%d"}, {Opt_max_data_area_mb, "max_data_area_mb=%d"}, {Opt_data_pages_per_blk, "data_pages_per_blk=%d"}, {Opt_err, NULL} }; static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib) { int val, ret; ret = match_int(arg, &val); if (ret < 0) { pr_err("match_int() failed for dev attrib. Error %d.\n", ret); return ret; } if (val <= 0) { pr_err("Invalid dev attrib value %d. Must be greater than zero.\n", val); return -EINVAL; } *dev_attrib = val; return 0; } static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg) { int val, ret; uint32_t pages_per_blk = udev->data_pages_per_blk; ret = match_int(arg, &val); if (ret < 0) { pr_err("match_int() failed for max_data_area_mb=. Error %d.\n", ret); return ret; } if (val <= 0) { pr_err("Invalid max_data_area %d.\n", val); return -EINVAL; } if (val > TCMU_PAGES_TO_MBS(tcmu_global_max_pages)) { pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n", val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages)); val = TCMU_PAGES_TO_MBS(tcmu_global_max_pages); } if (TCMU_MBS_TO_PAGES(val) < pages_per_blk) { pr_err("Invalid max_data_area %d (%zu pages): smaller than data_pages_per_blk (%u pages).\n", val, TCMU_MBS_TO_PAGES(val), pages_per_blk); return -EINVAL; } mutex_lock(&udev->cmdr_lock); if (udev->data_bitmap) { pr_err("Cannot set max_data_area_mb after it has been enabled.\n"); ret = -EINVAL; goto unlock; } udev->data_area_mb = val; udev->max_blocks = TCMU_MBS_TO_PAGES(val) / pages_per_blk; unlock: mutex_unlock(&udev->cmdr_lock); return ret; } static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg) { int val, ret; ret = match_int(arg, &val); if (ret < 0) { pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n", ret); return ret; } if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) { pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n", val, udev->data_area_mb, TCMU_MBS_TO_PAGES(udev->data_area_mb)); return -EINVAL; } mutex_lock(&udev->cmdr_lock); if (udev->data_bitmap) { pr_err("Cannot set data_pages_per_blk after it has been enabled.\n"); ret = -EINVAL; goto unlock; } udev->data_pages_per_blk = val; udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val; unlock: mutex_unlock(&udev->cmdr_lock); return ret; } static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, const char *page, ssize_t count) { struct tcmu_dev *udev = TCMU_DEV(dev); char *orig, *ptr, *opts; substring_t args[MAX_OPT_ARGS]; int ret = 0, token; opts = kstrdup(page, GFP_KERNEL); if (!opts) return -ENOMEM; orig = opts; while ((ptr = strsep(&opts, ",\n")) != NULL) { if (!*ptr) continue; token = match_token(ptr, tokens, args); switch (token) { case Opt_dev_config: if (match_strlcpy(udev->dev_config, &args[0], TCMU_CONFIG_LEN) == 0) { ret = -EINVAL; break; } pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config); break; case Opt_dev_size: ret = match_u64(&args[0], &udev->dev_size); if (ret < 0) pr_err("match_u64() failed for dev_size=. Error %d.\n", ret); break; case Opt_hw_block_size: ret = tcmu_set_dev_attrib(&args[0], &(dev->dev_attrib.hw_block_size)); break; case Opt_hw_max_sectors: ret = tcmu_set_dev_attrib(&args[0], &(dev->dev_attrib.hw_max_sectors)); break; case Opt_nl_reply_supported: ret = match_int(&args[0], &udev->nl_reply_supported); if (ret < 0) pr_err("match_int() failed for nl_reply_supported=. Error %d.\n", ret); break; case Opt_max_data_area_mb: ret = tcmu_set_max_blocks_param(udev, &args[0]); break; case Opt_data_pages_per_blk: ret = tcmu_set_data_pages_per_blk(udev, &args[0]); break; default: break; } if (ret) break; } kfree(orig); return (!ret) ? count : ret; } static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b) { struct tcmu_dev *udev = TCMU_DEV(dev); ssize_t bl = 0; bl = sprintf(b + bl, "Config: %s ", udev->dev_config[0] ? udev->dev_config : "NULL"); bl += sprintf(b + bl, "Size: %llu ", udev->dev_size); bl += sprintf(b + bl, "MaxDataAreaMB: %u ", udev->data_area_mb); bl += sprintf(b + bl, "DataPagesPerBlk: %u\n", udev->data_pages_per_blk); return bl; } static sector_t tcmu_get_blocks(struct se_device *dev) { struct tcmu_dev *udev = TCMU_DEV(dev); return div_u64(udev->dev_size - dev->dev_attrib.block_size, dev->dev_attrib.block_size); } static sense_reason_t tcmu_parse_cdb(struct se_cmd *cmd) { return passthrough_parse_cdb(cmd, tcmu_queue_cmd); } static ssize_t tcmu_cmd_time_out_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, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC); } static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page, size_t count) { struct se_dev_attrib *da = container_of(to_config_group(item), struct se_dev_attrib, da_group); struct tcmu_dev *udev = container_of(da->da_dev, struct tcmu_dev, se_dev); u32 val; int ret; if (da->da_dev->export_count) { pr_err("Unable to set tcmu cmd_time_out while exports exist\n"); return -EINVAL; } ret = kstrtou32(page, 0, &val); if (ret < 0) return ret; udev->cmd_time_out = val * MSEC_PER_SEC; return count; } CONFIGFS_ATTR(tcmu_, cmd_time_out); static ssize_t tcmu_qfull_time_out_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, "%ld\n", udev->qfull_time_out <= 0 ? udev->qfull_time_out : udev->qfull_time_out / MSEC_PER_SEC); } static ssize_t tcmu_qfull_time_out_store(struct config_item *item, const char *page, size_t count) { 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); s32 val; int ret; ret = kstrtos32(page, 0, &val); if (ret < 0) return ret; if (val >= 0) { udev->qfull_time_out = val * MSEC_PER_SEC; } else if (val == -1) { udev->qfull_time_out = val; } else { printk(KERN_ERR "Invalid qfull timeout value %d\n", val); return -EINVAL; } return count; } 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", udev->data_area_mb); } CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb); static ssize_t tcmu_data_pages_per_blk_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", udev->data_pages_per_blk); } CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk); static ssize_t tcmu_dev_config_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, "%s\n", udev->dev_config); } static int tcmu_send_dev_config_event(struct tcmu_dev *udev, const char *reconfig_data) { struct sk_buff *skb = NULL; void *msg_header = NULL; int ret = 0; ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE, &skb, &msg_header); if (ret < 0) return ret; ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data); if (ret < 0) { nlmsg_free(skb); return ret; } return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE, skb, msg_header); } static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page, size_t count) { 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); int ret, len; len = strlen(page); if (!len || len > TCMU_CONFIG_LEN - 1) return -EINVAL; /* Check if device has been configured before */ if (target_dev_configured(&udev->se_dev)) { ret = tcmu_send_dev_config_event(udev, page); if (ret) { pr_err("Unable to reconfigure device\n"); return ret; } strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN); ret = tcmu_update_uio_info(udev); if (ret) return ret; return count; } strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN); return count; } CONFIGFS_ATTR(tcmu_, dev_config); static ssize_t tcmu_dev_size_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, "%llu\n", udev->dev_size); } static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size) { struct sk_buff *skb = NULL; void *msg_header = NULL; int ret = 0; ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE, &skb, &msg_header); if (ret < 0) return ret; ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE, size, TCMU_ATTR_PAD); if (ret < 0) { nlmsg_free(skb); return ret; } return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE, skb, msg_header); } static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page, size_t count) { 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); u64 val; int ret; ret = kstrtou64(page, 0, &val); if (ret < 0) return ret; /* Check if device has been configured before */ if (target_dev_configured(&udev->se_dev)) { ret = tcmu_send_dev_size_event(udev, val); if (ret) { pr_err("Unable to reconfigure device\n"); return ret; } } udev->dev_size = val; return count; } CONFIGFS_ATTR(tcmu_, dev_size); static ssize_t tcmu_nl_reply_supported_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, "%d\n", udev->nl_reply_supported); } static ssize_t tcmu_nl_reply_supported_store(struct config_item *item, const char *page, size_t count) { 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); s8 val; int ret; ret = kstrtos8(page, 0, &val); if (ret < 0) return ret; udev->nl_reply_supported = val; return count; } CONFIGFS_ATTR(tcmu_, nl_reply_supported); static ssize_t tcmu_emulate_write_cache_show(struct config_item *item, char *page) { struct se_dev_attrib *da = container_of(to_config_group(item), struct se_dev_attrib, da_group); return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache); } static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val) { struct sk_buff *skb = NULL; void *msg_header = NULL; int ret = 0; ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE, &skb, &msg_header); if (ret < 0) return ret; ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val); if (ret < 0) { nlmsg_free(skb); return ret; } return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE, skb, msg_header); } static ssize_t tcmu_emulate_write_cache_store(struct config_item *item, const char *page, size_t count) { 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); u8 val; int ret; ret = kstrtou8(page, 0, &val); if (ret < 0) return ret; /* Check if device has been configured before */ if (target_dev_configured(&udev->se_dev)) { ret = tcmu_send_emulate_write_cache(udev, val); if (ret) { pr_err("Unable to reconfigure device\n"); return ret; } } da->emulate_write_cache = val; return count; } CONFIGFS_ATTR(tcmu_, emulate_write_cache); static ssize_t tcmu_tmr_notification_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, "%i\n", test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags)); } static ssize_t tcmu_tmr_notification_store(struct config_item *item, const char *page, size_t count) { 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); u8 val; int ret; ret = kstrtou8(page, 0, &val); if (ret < 0) return ret; if (val > 1) return -EINVAL; if (val) set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags); else clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags); return count; } CONFIGFS_ATTR(tcmu_, tmr_notification); static ssize_t tcmu_block_dev_show(struct config_item *item, char *page) { struct se_device *se_dev = container_of(to_config_group(item), struct se_device, dev_action_group); struct tcmu_dev *udev = TCMU_DEV(se_dev); if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) return snprintf(page, PAGE_SIZE, "%s\n", "blocked"); else return snprintf(page, PAGE_SIZE, "%s\n", "unblocked"); } static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page, size_t count) { struct se_device *se_dev = container_of(to_config_group(item), struct se_device, dev_action_group); struct tcmu_dev *udev = TCMU_DEV(se_dev); u8 val; int ret; if (!target_dev_configured(&udev->se_dev)) { pr_err("Device is not configured.\n"); return -EINVAL; } ret = kstrtou8(page, 0, &val); if (ret < 0) return ret; if (val > 1) { pr_err("Invalid block value %d\n", val); return -EINVAL; } if (!val) tcmu_unblock_dev(udev); else tcmu_block_dev(udev); return count; } CONFIGFS_ATTR(tcmu_, block_dev); static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page, size_t count) { struct se_device *se_dev = container_of(to_config_group(item), struct se_device, dev_action_group); struct tcmu_dev *udev = TCMU_DEV(se_dev); u8 val; int ret; if (!target_dev_configured(&udev->se_dev)) { pr_err("Device is not configured.\n"); return -EINVAL; } ret = kstrtou8(page, 0, &val); if (ret < 0) return ret; if (val != 1 && val != 2) { pr_err("Invalid reset ring value %d\n", val); return -EINVAL; } tcmu_reset_ring(udev, val); return count; } CONFIGFS_ATTR_WO(tcmu_, reset_ring); static ssize_t tcmu_free_kept_buf_store(struct config_item *item, const char *page, size_t count) { struct se_device *se_dev = container_of(to_config_group(item), struct se_device, dev_action_group); struct tcmu_dev *udev = TCMU_DEV(se_dev); struct tcmu_cmd *cmd; u16 cmd_id; int ret; if (!target_dev_configured(&udev->se_dev)) { pr_err("Device is not configured.\n"); return -EINVAL; } ret = kstrtou16(page, 0, &cmd_id); if (ret < 0) return ret; mutex_lock(&udev->cmdr_lock); { XA_STATE(xas, &udev->commands, cmd_id); xas_lock(&xas); cmd = xas_load(&xas); if (!cmd) { pr_err("free_kept_buf: cmd_id %d not found\n", cmd_id); count = -EINVAL; xas_unlock(&xas); goto out_unlock; } if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) { pr_err("free_kept_buf: cmd_id %d was not completed with KEEP_BUF\n", cmd_id); count = -EINVAL; xas_unlock(&xas); goto out_unlock; } xas_store(&xas, NULL); xas_unlock(&xas); } tcmu_cmd_free_data(cmd, cmd->dbi_cnt); tcmu_free_cmd(cmd); /* * We only freed data space, not ring space. Therefore we dont call * run_tmr_queue, but call run_qfull_queue if tmr_list is empty. */ if (list_empty(&udev->tmr_queue)) run_qfull_queue(udev, false); out_unlock: mutex_unlock(&udev->cmdr_lock); return count; } CONFIGFS_ATTR_WO(tcmu_, free_kept_buf); 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_data_pages_per_blk, &tcmu_attr_dev_config, &tcmu_attr_dev_size, &tcmu_attr_emulate_write_cache, &tcmu_attr_tmr_notification, &tcmu_attr_nl_reply_supported, NULL, }; static struct configfs_attribute **tcmu_attrs; static struct configfs_attribute *tcmu_action_attrs[] = { &tcmu_attr_block_dev, &tcmu_attr_reset_ring, &tcmu_attr_free_kept_buf, NULL, }; static struct target_backend_ops tcmu_ops = { .name = "user", .owner = THIS_MODULE, .transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH, .transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR | TRANSPORT_FLAG_PASSTHROUGH_ALUA, .attach_hba = tcmu_attach_hba, .detach_hba = tcmu_detach_hba, .alloc_device = tcmu_alloc_device, .configure_device = tcmu_configure_device, .destroy_device = tcmu_destroy_device, .free_device = tcmu_free_device, .unplug_device = tcmu_unplug_device, .plug_device = tcmu_plug_device, .parse_cdb = tcmu_parse_cdb, .tmr_notify = tcmu_tmr_notify, .set_configfs_dev_params = tcmu_set_configfs_dev_params, .show_configfs_dev_params = tcmu_show_configfs_dev_params, .get_device_type = sbc_get_device_type, .get_blocks = tcmu_get_blocks, .tb_dev_action_attrs = tcmu_action_attrs, }; static void find_free_blocks(void) { struct tcmu_dev *udev; loff_t off; u32 pages_freed, total_pages_freed = 0; u32 start, end, block, total_blocks_freed = 0; if (atomic_read(&global_page_count) <= tcmu_global_max_pages) return; mutex_lock(&root_udev_mutex); list_for_each_entry(udev, &root_udev, node) { mutex_lock(&udev->cmdr_lock); if (!target_dev_configured(&udev->se_dev)) { mutex_unlock(&udev->cmdr_lock); continue; } /* Try to complete the finished commands first */ if (tcmu_handle_completions(udev)) run_qfull_queue(udev, false); /* Skip the udevs in idle */ if (!udev->dbi_thresh) { mutex_unlock(&udev->cmdr_lock); continue; } end = udev->dbi_max + 1; block = find_last_bit(udev->data_bitmap, end); if (block == udev->dbi_max) { /* * The last bit is dbi_max, so it is not possible * reclaim any blocks. */ mutex_unlock(&udev->cmdr_lock); continue; } else if (block == end) { /* The current udev will goto idle state */ udev->dbi_thresh = start = 0; udev->dbi_max = 0; } else { udev->dbi_thresh = start = block + 1; udev->dbi_max = block; } /* * Release the block pages. * * Also note that since tcmu_vma_fault() gets an extra page * refcount, tcmu_blocks_release() won't free pages if pages * are mapped. This means it is safe to call * tcmu_blocks_release() before unmap_mapping_range() which * drops the refcount of any pages it unmaps and thus releases * them. */ pages_freed = tcmu_blocks_release(udev, start, end - 1); /* Here will truncate the data area from off */ off = udev->data_off + (loff_t)start * udev->data_blk_size; unmap_mapping_range(udev->inode->i_mapping, off, 0, 1); mutex_unlock(&udev->cmdr_lock); total_pages_freed += pages_freed; total_blocks_freed += end - start; pr_debug("Freed %u pages (total %u) from %u blocks (total %u) from %s.\n", pages_freed, total_pages_freed, end - start, total_blocks_freed, udev->name); } mutex_unlock(&root_udev_mutex); if (atomic_read(&global_page_count) > tcmu_global_max_pages) schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000)); } static void check_timedout_devices(void) { struct tcmu_dev *udev, *tmp_dev; struct tcmu_cmd *cmd, *tmp_cmd; LIST_HEAD(devs); spin_lock_bh(&timed_out_udevs_lock); list_splice_init(&timed_out_udevs, &devs); list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) { list_del_init(&udev->timedout_entry); spin_unlock_bh(&timed_out_udevs_lock); mutex_lock(&udev->cmdr_lock); /* * If cmd_time_out is disabled but qfull is set deadline * will only reflect the qfull timeout. Ignore it. */ if (udev->cmd_time_out) { list_for_each_entry_safe(cmd, tmp_cmd, &udev->inflight_queue, queue_entry) { tcmu_check_expired_ring_cmd(cmd); } tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer); } list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue, queue_entry) { tcmu_check_expired_queue_cmd(cmd); } tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer); mutex_unlock(&udev->cmdr_lock); spin_lock_bh(&timed_out_udevs_lock); } spin_unlock_bh(&timed_out_udevs_lock); } static void tcmu_unmap_work_fn(struct work_struct *work) { check_timedout_devices(); find_free_blocks(); } static int __init tcmu_module_init(void) { int ret, i, k, len = 0; BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0); INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn); tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache", sizeof(struct tcmu_cmd), __alignof__(struct tcmu_cmd), 0, NULL); if (!tcmu_cmd_cache) return -ENOMEM; tcmu_root_device = root_device_register("tcm_user"); if (IS_ERR(tcmu_root_device)) { ret = PTR_ERR(tcmu_root_device); goto out_free_cache; } ret = genl_register_family(&tcmu_genl_family); if (ret < 0) { goto out_unreg_device; } for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) len += sizeof(struct configfs_attribute *); for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++) len += sizeof(struct configfs_attribute *); for (i = 0; tcmu_attrib_attrs[i] != NULL; i++) len += sizeof(struct configfs_attribute *); len += sizeof(struct configfs_attribute *); tcmu_attrs = kzalloc(len, GFP_KERNEL); if (!tcmu_attrs) { ret = -ENOMEM; goto out_unreg_genl; } for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) tcmu_attrs[i] = passthrough_attrib_attrs[i]; for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++) tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k]; for (k = 0; tcmu_attrib_attrs[k] != NULL; k++) tcmu_attrs[i++] = tcmu_attrib_attrs[k]; tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs; ret = transport_backend_register(&tcmu_ops); if (ret) goto out_attrs; return 0; out_attrs: kfree(tcmu_attrs); out_unreg_genl: genl_unregister_family(&tcmu_genl_family); out_unreg_device: root_device_unregister(tcmu_root_device); out_free_cache: kmem_cache_destroy(tcmu_cmd_cache); return ret; } static void __exit tcmu_module_exit(void) { cancel_delayed_work_sync(&tcmu_unmap_work); target_backend_unregister(&tcmu_ops); kfree(tcmu_attrs); genl_unregister_family(&tcmu_genl_family); root_device_unregister(tcmu_root_device); kmem_cache_destroy(tcmu_cmd_cache); } MODULE_DESCRIPTION("TCM USER subsystem plugin"); MODULE_AUTHOR("Shaohua Li "); MODULE_AUTHOR("Andy Grover "); MODULE_LICENSE("GPL"); module_init(tcmu_module_init); module_exit(tcmu_module_exit);