@@ -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 @@ enum tcmu_multicast_groups {
#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 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
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 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
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 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
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 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
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 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
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 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
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 ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *pag
.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 @@ static int __init tcmu_module_init(void)
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);