diff options
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/target_core_user.c | 464 |
1 files changed, 336 insertions, 128 deletions
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 02cf543a888d..0b29e4f00bce 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -31,6 +31,8 @@ #include <linux/bitops.h> #include <linux/highmem.h> #include <linux/configfs.h> +#include <linux/mutex.h> +#include <linux/kthread.h> #include <net/genetlink.h> #include <scsi/scsi_common.h> #include <scsi/scsi_proto.h> @@ -67,17 +69,24 @@ #define TCMU_TIME_OUT (30 * MSEC_PER_SEC) -/* For cmd area, the size is fixed 2M */ -#define CMDR_SIZE (2 * 1024 * 1024) +/* For cmd area, the size is fixed 8MB */ +#define CMDR_SIZE (8 * 1024 * 1024) -/* For data area, the size is fixed 32M */ -#define DATA_BLOCK_BITS (8 * 1024) -#define DATA_BLOCK_SIZE 4096 +/* + * For data area, the block size is PAGE_SIZE and + * the total size is 256K * PAGE_SIZE. + */ +#define DATA_BLOCK_SIZE PAGE_SIZE +#define DATA_BLOCK_BITS (256 * 1024) #define DATA_SIZE (DATA_BLOCK_BITS * DATA_BLOCK_SIZE) +#define DATA_BLOCK_INIT_BITS 128 -/* The ring buffer size is 34M */ +/* The total size of the ring is 8M + 256K * PAGE_SIZE */ #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE) +/* Default maximum of the global data blocks(512K * PAGE_SIZE) */ +#define TCMU_GLOBAL_MAX_BLOCKS (512 * 1024) + static struct device *tcmu_root_device; struct tcmu_hba { @@ -87,6 +96,8 @@ struct tcmu_hba { #define TCMU_CONFIG_LEN 256 struct tcmu_dev { + struct list_head node; + struct se_device se_dev; char *name; @@ -98,6 +109,8 @@ struct tcmu_dev { struct uio_info uio_info; + struct inode *inode; + struct tcmu_mailbox *mb_addr; size_t dev_size; u32 cmdr_size; @@ -108,10 +121,11 @@ struct tcmu_dev { size_t data_size; wait_queue_head_t wait_cmdr; - /* TODO should this be a mutex? */ - spinlock_t cmdr_lock; + struct mutex cmdr_lock; + bool waiting_global; uint32_t dbi_max; + uint32_t dbi_thresh; DECLARE_BITMAP(data_bitmap, DATA_BLOCK_BITS); struct radix_tree_root data_blocks; @@ -146,6 +160,13 @@ struct tcmu_cmd { unsigned long flags; }; +static struct task_struct *unmap_thread; +static wait_queue_head_t unmap_wait; +static DEFINE_MUTEX(root_udev_mutex); +static LIST_HEAD(root_udev); + +static atomic_t global_db_count = ATOMIC_INIT(0); + static struct kmem_cache *tcmu_cmd_cache; /* multicast group */ @@ -174,48 +195,78 @@ static struct genl_family tcmu_genl_family __ro_after_init = { #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) +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 < tcmu_cmd->dbi_cnt; i++) + for (i = 0; i < len; i++) clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap); } -static int tcmu_get_empty_block(struct tcmu_dev *udev, void **addr) +static inline bool tcmu_get_empty_block(struct tcmu_dev *udev, + struct tcmu_cmd *tcmu_cmd) { - void *p; - uint32_t dbi; - int ret; + struct page *page; + int ret, dbi; - dbi = find_first_zero_bit(udev->data_bitmap, DATA_BLOCK_BITS); - if (dbi > udev->dbi_max) - udev->dbi_max = dbi; + dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh); + if (dbi == udev->dbi_thresh) + return false; - set_bit(dbi, udev->data_bitmap); + page = radix_tree_lookup(&udev->data_blocks, dbi); + if (!page) { - p = radix_tree_lookup(&udev->data_blocks, dbi); - if (!p) { - p = kzalloc(DATA_BLOCK_SIZE, GFP_ATOMIC); - if (!p) { - clear_bit(dbi, udev->data_bitmap); - return -ENOMEM; + if (atomic_add_return(1, &global_db_count) > + TCMU_GLOBAL_MAX_BLOCKS) { + atomic_dec(&global_db_count); + return false; } - ret = radix_tree_insert(&udev->data_blocks, dbi, p); + /* try to get new page from the mm */ + page = alloc_page(GFP_KERNEL); + if (!page) + return false; + + ret = radix_tree_insert(&udev->data_blocks, dbi, page); if (ret) { - kfree(p); - clear_bit(dbi, udev->data_bitmap); - return ret; + __free_page(page); + return false; } + } - *addr = p; - return dbi; + if (dbi > udev->dbi_max) + udev->dbi_max = dbi; + + set_bit(dbi, udev->data_bitmap); + tcmu_cmd_set_dbi(tcmu_cmd, dbi); + + return true; } -static void *tcmu_get_block_addr(struct tcmu_dev *udev, uint32_t dbi) +static bool tcmu_get_empty_blocks(struct tcmu_dev *udev, + struct tcmu_cmd *tcmu_cmd) +{ + int i; + + udev->waiting_global = false; + + for (i = tcmu_cmd->dbi_cur; i < tcmu_cmd->dbi_cnt; i++) { + if (!tcmu_get_empty_block(udev, tcmu_cmd)) + goto err; + } + return true; + +err: + udev->waiting_global = true; + /* Try to wake up the unmap thread */ + wake_up(&unmap_wait); + return false; +} + +static inline struct page * +tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi) { return radix_tree_lookup(&udev->data_blocks, dbi); } @@ -355,7 +406,7 @@ static inline size_t iov_tail(struct tcmu_dev *udev, struct iovec *iov) return (size_t)iov->iov_base + iov->iov_len; } -static int alloc_and_scatter_data_area(struct tcmu_dev *udev, +static int scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd, struct scatterlist *data_sg, unsigned int data_nents, struct iovec **iov, int *iov_cnt, bool copy_data) @@ -365,19 +416,20 @@ static int alloc_and_scatter_data_area(struct tcmu_dev *udev, void *from, *to = NULL; size_t copy_bytes, to_offset, offset; struct scatterlist *sg; + struct page *page; for_each_sg(data_sg, sg, data_nents, i) { int sg_remaining = sg->length; from = kmap_atomic(sg_page(sg)) + sg->offset; while (sg_remaining > 0) { if (block_remaining == 0) { + if (to) + kunmap_atomic(to); + block_remaining = DATA_BLOCK_SIZE; - dbi = tcmu_get_empty_block(udev, &to); - if (dbi < 0) { - kunmap_atomic(from - sg->offset); - return dbi; - } - tcmu_cmd_set_dbi(tcmu_cmd, dbi); + dbi = tcmu_cmd_get_dbi(tcmu_cmd); + page = tcmu_get_block_page(udev, dbi); + to = kmap_atomic(page); } copy_bytes = min_t(size_t, sg_remaining, @@ -405,6 +457,8 @@ static int alloc_and_scatter_data_area(struct tcmu_dev *udev, } kunmap_atomic(from - sg->offset); } + if (to) + kunmap_atomic(to); return 0; } @@ -415,9 +469,10 @@ static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd, struct se_cmd *se_cmd = cmd->se_cmd; int i, dbi; int block_remaining = 0; - void *from, *to; + void *from = NULL, *to; size_t copy_bytes, offset; struct scatterlist *sg, *data_sg; + struct page *page; unsigned int data_nents; uint32_t count = 0; @@ -444,9 +499,13 @@ static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd, to = kmap_atomic(sg_page(sg)) + sg->offset; while (sg_remaining > 0) { if (block_remaining == 0) { + if (from) + kunmap_atomic(from); + block_remaining = DATA_BLOCK_SIZE; dbi = tcmu_cmd_get_dbi(cmd); - from = tcmu_get_block_addr(udev, dbi); + page = tcmu_get_block_page(udev, dbi); + from = kmap_atomic(page); } copy_bytes = min_t(size_t, sg_remaining, block_remaining); @@ -461,12 +520,13 @@ static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd, } kunmap_atomic(to - sg->offset); } + if (from) + kunmap_atomic(from); } -static inline size_t spc_bitmap_free(unsigned long *bitmap) +static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh) { - return DATA_BLOCK_SIZE * (DATA_BLOCK_BITS - - bitmap_weight(bitmap, DATA_BLOCK_BITS)); + return DATA_BLOCK_SIZE * (thresh - bitmap_weight(bitmap, thresh)); } /* @@ -475,9 +535,12 @@ static inline size_t spc_bitmap_free(unsigned long *bitmap) * * Called with ring lock held. */ -static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t data_needed) +static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd, + size_t cmd_size, size_t data_needed) { struct tcmu_mailbox *mb = udev->mb_addr; + uint32_t blocks_needed = (data_needed + DATA_BLOCK_SIZE - 1) + / DATA_BLOCK_SIZE; size_t space, cmd_needed; u32 cmd_head; @@ -501,13 +564,41 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d return false; } - space = spc_bitmap_free(udev->data_bitmap); + /* try to check and get the data blocks as needed */ + space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh); if (space < data_needed) { - pr_debug("no data space: only %zu available, but ask for %zu\n", - space, data_needed); - return false; + unsigned long blocks_left = DATA_BLOCK_BITS - udev->dbi_thresh; + unsigned long grow; + + if (blocks_left < blocks_needed) { + pr_debug("no data space: only %lu available, but ask for %zu\n", + blocks_left * DATA_BLOCK_SIZE, + data_needed); + return false; + } + + /* Try to expand the thresh */ + if (!udev->dbi_thresh) { + /* From idle state */ + uint32_t init_thresh = DATA_BLOCK_INIT_BITS; + + udev->dbi_thresh = max(blocks_needed, init_thresh); + } else { + /* + * Grow the data area by max(blocks needed, + * dbi_thresh / 2), but limited to the max + * DATA_BLOCK_BITS size. + */ + grow = max(blocks_needed, udev->dbi_thresh / 2); + udev->dbi_thresh += grow; + if (udev->dbi_thresh > DATA_BLOCK_BITS) + udev->dbi_thresh = DATA_BLOCK_BITS; + } } + if (!tcmu_get_empty_blocks(udev, cmd)) + return false; + return true; } @@ -544,7 +635,7 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1)); - spin_lock_irq(&udev->cmdr_lock); + mutex_lock(&udev->cmdr_lock); mb = udev->mb_addr; cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ @@ -553,18 +644,18 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu " "cmd ring/data area\n", command_size, data_length, udev->cmdr_size, udev->data_size); - spin_unlock_irq(&udev->cmdr_lock); + mutex_unlock(&udev->cmdr_lock); return TCM_INVALID_CDB_FIELD; } - while (!is_ring_space_avail(udev, command_size, data_length)) { + while (!is_ring_space_avail(udev, tcmu_cmd, command_size, data_length)) { int ret; DEFINE_WAIT(__wait); prepare_to_wait(&udev->wait_cmdr, &__wait, TASK_INTERRUPTIBLE); pr_debug("sleeping for ring space\n"); - spin_unlock_irq(&udev->cmdr_lock); + mutex_unlock(&udev->cmdr_lock); if (udev->cmd_time_out) ret = schedule_timeout( msecs_to_jiffies(udev->cmd_time_out)); @@ -576,7 +667,7 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } - spin_lock_irq(&udev->cmdr_lock); + mutex_lock(&udev->cmdr_lock); /* We dropped cmdr_lock, cmd_head is stale */ cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ @@ -609,15 +700,18 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) entry->hdr.uflags = 0; /* Handle allocating space from the data area */ + tcmu_cmd_reset_dbi_cur(tcmu_cmd); iov = &entry->req.iov[0]; iov_cnt = 0; copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE || se_cmd->se_cmd_flags & SCF_BIDI); - ret = alloc_and_scatter_data_area(udev, tcmu_cmd, - se_cmd->t_data_sg, se_cmd->t_data_nents, - &iov, &iov_cnt, copy_to_data_area); + ret = scatter_data_area(udev, tcmu_cmd, se_cmd->t_data_sg, + se_cmd->t_data_nents, &iov, &iov_cnt, + copy_to_data_area); if (ret) { - spin_unlock_irq(&udev->cmdr_lock); + tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt); + mutex_unlock(&udev->cmdr_lock); + pr_err("tcmu: alloc and scatter data failed\n"); return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } @@ -628,12 +722,14 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) if (se_cmd->se_cmd_flags & SCF_BIDI) { iov_cnt = 0; iov++; - ret = alloc_and_scatter_data_area(udev, tcmu_cmd, + ret = scatter_data_area(udev, tcmu_cmd, se_cmd->t_bidi_data_sg, se_cmd->t_bidi_data_nents, &iov, &iov_cnt, false); if (ret) { - spin_unlock_irq(&udev->cmdr_lock); + tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt); + mutex_unlock(&udev->cmdr_lock); + pr_err("tcmu: alloc and scatter bidi data failed\n"); return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } @@ -648,8 +744,7 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size); tcmu_flush_dcache_range(mb, sizeof(*mb)); - - spin_unlock_irq(&udev->cmdr_lock); + mutex_unlock(&udev->cmdr_lock); /* TODO: only if FLUSH and FUA? */ uio_event_notify(&udev->uio_info); @@ -723,14 +818,13 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry * out: cmd->se_cmd = NULL; - tcmu_cmd_free_data(cmd); + tcmu_cmd_free_data(cmd, cmd->dbi_cnt); tcmu_free_cmd(cmd); } static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) { struct tcmu_mailbox *mb; - unsigned long flags; int handled = 0; if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) { @@ -738,8 +832,6 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) return 0; } - spin_lock_irqsave(&udev->cmdr_lock, flags); - mb = udev->mb_addr; tcmu_flush_dcache_range(mb, sizeof(*mb)); @@ -780,8 +872,6 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) if (mb->cmd_tail == mb->cmd_head) del_timer(&udev->timeout); /* no more pending cmds */ - spin_unlock_irqrestore(&udev->cmdr_lock, flags); - wake_up(&udev->wait_cmdr); return handled; @@ -808,16 +898,14 @@ static void tcmu_device_timedout(unsigned long data) { struct tcmu_dev *udev = (struct tcmu_dev *)data; unsigned long flags; - int handled; - - handled = tcmu_handle_completions(udev); - - pr_warn("%d completions handled from timeout\n", handled); spin_lock_irqsave(&udev->commands_lock, flags); idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL); spin_unlock_irqrestore(&udev->commands_lock, flags); + /* Try to wake up the ummap thread */ + wake_up(&unmap_wait); + /* * We don't need to wakeup threads on wait_cmdr since they have their * own timeout. @@ -862,7 +950,7 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) udev->cmd_time_out = TCMU_TIME_OUT; init_waitqueue_head(&udev->wait_cmdr); - spin_lock_init(&udev->cmdr_lock); + mutex_init(&udev->cmdr_lock); idr_init(&udev->commands); spin_lock_init(&udev->commands_lock); @@ -877,59 +965,13 @@ static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on) { struct tcmu_dev *tcmu_dev = container_of(info, struct tcmu_dev, uio_info); + mutex_lock(&tcmu_dev->cmdr_lock); tcmu_handle_completions(tcmu_dev); + mutex_unlock(&tcmu_dev->cmdr_lock); return 0; } -static void tcmu_blocks_release(struct tcmu_dev *udev, bool release_pending) -{ - uint32_t dbi, end; - void *addr; - - spin_lock_irq(&udev->cmdr_lock); - - end = udev->dbi_max + 1; - - /* try to release all unused blocks */ - dbi = find_first_zero_bit(udev->data_bitmap, end); - if (dbi >= end) { - spin_unlock_irq(&udev->cmdr_lock); - return; - } - do { - addr = radix_tree_delete(&udev->data_blocks, dbi); - kfree(addr); - - dbi = find_next_zero_bit(udev->data_bitmap, end, dbi + 1); - } while (dbi < end); - - if (!release_pending) - return; - - /* try to release all pending blocks */ - dbi = find_first_bit(udev->data_bitmap, end); - if (dbi >= end) { - spin_unlock_irq(&udev->cmdr_lock); - return; - } - do { - addr = radix_tree_delete(&udev->data_blocks, dbi); - kfree(addr); - - dbi = find_next_bit(udev->data_bitmap, end, dbi + 1); - } while (dbi < end); - - spin_unlock_irq(&udev->cmdr_lock); -} - -static void tcmu_vma_close(struct vm_area_struct *vma) -{ - struct tcmu_dev *udev = vma->vm_private_data; - - tcmu_blocks_release(udev, false); -} - /* * mmap code from uio.c. Copied here because we want to hook mmap() * and this stuff must come along. @@ -947,6 +989,60 @@ static int tcmu_find_mem_index(struct vm_area_struct *vma) return -1; } +static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi) +{ + struct page *page; + int ret; + + mutex_lock(&udev->cmdr_lock); + page = tcmu_get_block_page(udev, dbi); + if (likely(page)) { + mutex_unlock(&udev->cmdr_lock); + return page; + } + + /* + * Normally it shouldn't be here: + * Only when the userspace has touched the blocks which + * are out of the tcmu_cmd's data iov[], and will return + * one zeroed page. + */ + pr_warn("Block(%u) out of cmd's iov[] has been touched!\n", dbi); + pr_warn("Mostly it will be a bug of userspace, please have a check!\n"); + + if (dbi >= udev->dbi_thresh) { + /* Extern the udev->dbi_thresh to dbi + 1 */ + udev->dbi_thresh = dbi + 1; + udev->dbi_max = dbi; + } + + page = radix_tree_lookup(&udev->data_blocks, dbi); + if (!page) { + page = alloc_page(GFP_KERNEL | __GFP_ZERO); + if (!page) { + mutex_unlock(&udev->cmdr_lock); + return NULL; + } + + ret = radix_tree_insert(&udev->data_blocks, dbi, page); + if (ret) { + mutex_unlock(&udev->cmdr_lock); + __free_page(page); + return NULL; + } + + /* + * Since this case is rare in page fault routine, here we + * will allow the global_db_count >= TCMU_GLOBAL_MAX_BLOCKS + * to reduce possible page fault call trace. + */ + atomic_inc(&global_db_count); + } + mutex_unlock(&udev->cmdr_lock); + + return page; +} + static int tcmu_vma_fault(struct vm_fault *vmf) { struct tcmu_dev *udev = vmf->vma->vm_private_data; @@ -970,14 +1066,13 @@ static int tcmu_vma_fault(struct vm_fault *vmf) addr = (void *)(unsigned long)info->mem[mi].addr + offset; page = vmalloc_to_page(addr); } else { - /* For the dynamically growing data area pages */ uint32_t dbi; + /* For the dynamically growing data area pages */ dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE; - addr = tcmu_get_block_addr(udev, dbi); - if (!addr) + page = tcmu_try_get_block_page(udev, dbi); + if (!page) return VM_FAULT_NOPAGE; - page = virt_to_page(addr); } get_page(page); @@ -986,7 +1081,6 @@ static int tcmu_vma_fault(struct vm_fault *vmf) } static const struct vm_operations_struct tcmu_vm_ops = { - .close = tcmu_vma_close, .fault = tcmu_vma_fault, }; @@ -1014,6 +1108,8 @@ static int tcmu_open(struct uio_info *info, struct inode *inode) if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags)) return -EBUSY; + udev->inode = inode; + pr_debug("open\n"); return 0; @@ -1104,6 +1200,8 @@ static int tcmu_configure_device(struct se_device *dev) udev->cmdr_size = CMDR_SIZE - CMDR_OFF; udev->data_off = CMDR_SIZE; udev->data_size = DATA_SIZE; + udev->dbi_thresh = 0; /* Default in Idle state */ + udev->waiting_global = false; /* Initialise the mailbox of the ring buffer */ mb = udev->mb_addr; @@ -1116,7 +1214,7 @@ static int tcmu_configure_device(struct se_device *dev) WARN_ON(udev->data_size % PAGE_SIZE); WARN_ON(udev->data_size % DATA_BLOCK_SIZE); - INIT_RADIX_TREE(&udev->data_blocks, GFP_ATOMIC); + INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL); info->version = __stringify(TCMU_MAILBOX_VERSION); @@ -1149,6 +1247,10 @@ static int tcmu_configure_device(struct se_device *dev) 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: @@ -1183,6 +1285,23 @@ static bool tcmu_dev_configured(struct tcmu_dev *udev) return udev->uio_info.uio_dev ? true : false; } +static void tcmu_blocks_release(struct tcmu_dev *udev) +{ + int i; + struct page *page; + + /* Try to release all block pages */ + mutex_lock(&udev->cmdr_lock); + for (i = 0; i <= udev->dbi_max; i++) { + page = radix_tree_delete(&udev->data_blocks, i); + if (page) { + __free_page(page); + atomic_dec(&global_db_count); + } + } + mutex_unlock(&udev->cmdr_lock); +} + static void tcmu_free_device(struct se_device *dev) { struct tcmu_dev *udev = TCMU_DEV(dev); @@ -1192,6 +1311,10 @@ static void tcmu_free_device(struct se_device *dev) del_timer_sync(&udev->timeout); + mutex_lock(&root_udev_mutex); + list_del(&udev->node); + mutex_unlock(&root_udev_mutex); + vfree(udev->mb_addr); /* Upper layer should drain all requests before calling this */ @@ -1204,7 +1327,7 @@ static void tcmu_free_device(struct se_device *dev) spin_unlock_irq(&udev->commands_lock); WARN_ON(!all_expired); - tcmu_blocks_release(udev, true); + tcmu_blocks_release(udev); if (tcmu_dev_configured(udev)) { tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE, udev->uio_info.name, @@ -1392,6 +1515,81 @@ static struct target_backend_ops tcmu_ops = { .tb_dev_attrib_attrs = NULL, }; +static int unmap_thread_fn(void *data) +{ + struct tcmu_dev *udev; + loff_t off; + uint32_t start, end, block; + struct page *page; + int i; + + while (1) { + DEFINE_WAIT(__wait); + + prepare_to_wait(&unmap_wait, &__wait, TASK_INTERRUPTIBLE); + schedule(); + finish_wait(&unmap_wait, &__wait); + + mutex_lock(&root_udev_mutex); + list_for_each_entry(udev, &root_udev, node) { + mutex_lock(&udev->cmdr_lock); + + /* Try to complete the finished commands first */ + tcmu_handle_completions(udev); + + /* Skip the udevs waiting the global pool or in idle */ + if (udev->waiting_global || !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 there is + * no need to shrink 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; + } + + /* Here will truncate the data area from off */ + off = udev->data_off + start * DATA_BLOCK_SIZE; + unmap_mapping_range(udev->inode->i_mapping, off, 0, 1); + + /* Release the block pages */ + for (i = start; i < end; i++) { + page = radix_tree_delete(&udev->data_blocks, i); + if (page) { + __free_page(page); + atomic_dec(&global_db_count); + } + } + mutex_unlock(&udev->cmdr_lock); + } + + /* + * Try to wake up the udevs who are waiting + * for the global data pool. + */ + list_for_each_entry(udev, &root_udev, node) { + if (udev->waiting_global) + wake_up(&udev->wait_cmdr); + } + mutex_unlock(&root_udev_mutex); + } + + return 0; +} + static int __init tcmu_module_init(void) { int ret, i, len = 0; @@ -1437,8 +1635,17 @@ static int __init tcmu_module_init(void) if (ret) goto out_attrs; + init_waitqueue_head(&unmap_wait); + unmap_thread = kthread_run(unmap_thread_fn, NULL, "tcmu_unmap"); + if (IS_ERR(unmap_thread)) { + ret = PTR_ERR(unmap_thread); + goto out_unreg_transport; + } + return 0; +out_unreg_transport: + target_backend_unregister(&tcmu_ops); out_attrs: kfree(tcmu_attrs); out_unreg_genl: @@ -1453,6 +1660,7 @@ out_free_cache: static void __exit tcmu_module_exit(void) { + kthread_stop(unmap_thread); target_backend_unregister(&tcmu_ops); kfree(tcmu_attrs); genl_unregister_family(&tcmu_genl_family); |