[PATCH 2/6] scsi: target: tcmu: Prepare for PAGE_SIZE != DATA_BLOCK_SIZE

Bodo Stroesser
2021-03-24T19:29:59Z

From: Bodo Stroesser <bstroesser@ts.fujitsu.com>

This patch renames some variables and definitions as a first
preparation for DATA_BLOCK_SIZE != PAGE_SIZE and adds the
new DATA_PAGES_PER_BLK definition containing the number of
pages per data block.
I also renamed tcmu_try_get_block_page() to
tcmu_try_get_data_page(), but kept name tcmu_get_block_page(),
since it will go away in a following patch, when there is only
one caller left.
The following patches will then add full support for
DATA_PAGES_PER_BLK != 1, which also means
DATA_BLOCK_SIZE = DATA_PAGES_PER_BLK * PAGE_SIZE

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
drivers/target/target_core_user.c | 82 +++++++++++++++++++--------------------
1 file changed, 41 insertions(+), 41 deletions(-)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 35975dd75dde..f42d38873aaf 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -71,17 +71,17 @@
* the total size is 256K * PAGE_SIZE.
*/
#define DATA_BLOCK_SIZE PAGE_SIZE
-#define DATA_BLOCK_SHIFT PAGE_SHIFT
+#define DATA_PAGES_PER_BLK 1
#define DATA_BLOCK_BITS_DEF (256 * 1024)

-#define TCMU_MBS_TO_BLOCKS(_mbs) (_mbs << (20 - DATA_BLOCK_SHIFT))
-#define TCMU_BLOCKS_TO_MBS(_blocks) (_blocks >> (20 - DATA_BLOCK_SHIFT))
+#define TCMU_MBS_TO_PAGES(_mbs) (_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_BLOCKS_DEF (512 * 1024)
+#define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024)

static u8 tcmu_kern_cmd_reply_supported;
static u8 tcmu_netlink_blocked;
@@ -149,7 +149,7 @@ struct tcmu_dev {
uint32_t dbi_max;
uint32_t dbi_thresh;
unsigned long *data_bitmap;
- struct xarray data_blocks;
+ struct xarray data_pages;

struct xarray commands;

@@ -219,9 +219,9 @@ static LIST_HEAD(timed_out_udevs);

static struct kmem_cache *tcmu_cmd_cache;

-static atomic_t global_db_count = ATOMIC_INIT(0);
+static atomic_t global_page_count = ATOMIC_INIT(0);
static struct delayed_work tcmu_unmap_work;
-static int tcmu_global_max_blocks = TCMU_GLOBAL_MAX_BLOCKS_DEF;
+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)
@@ -237,8 +237,8 @@ static int tcmu_set_global_max_data_area(const char *str,
return -EINVAL;
}

- tcmu_global_max_blocks = TCMU_MBS_TO_BLOCKS(max_area_mb);
- if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
+ 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);
@@ -249,7 +249,7 @@ static int tcmu_set_global_max_data_area(const char *str,
static int tcmu_get_global_max_data_area(char *buffer,
const struct kernel_param *kp)
{
- return sprintf(buffer, "%d\n", TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
+ 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 = {
@@ -510,10 +510,10 @@ static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
if (dbi == udev->dbi_thresh)
return -1;

- page = xa_load(&udev->data_blocks, dbi);
+ page = xa_load(&udev->data_pages, dbi);
if (!page) {
- if (atomic_add_return(1, &global_db_count) >
- tcmu_global_max_blocks)
+ if (atomic_add_return(1, &global_page_count) >
+ tcmu_global_max_pages)
schedule_delayed_work(&tcmu_unmap_work, 0);

/* try to get new page from the mm */
@@ -521,7 +521,7 @@ static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
if (!page)
goto err_alloc;

- if (xa_store(&udev->data_blocks, dbi, page, GFP_NOIO))
+ if (xa_store(&udev->data_pages, dbi, page, GFP_NOIO))
goto err_insert;
}

@@ -538,7 +538,7 @@ static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
err_insert:
__free_page(page);
err_alloc:
- atomic_dec(&global_db_count);
+ atomic_dec(&global_page_count);
return -1;
}

@@ -558,9 +558,9 @@ static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
}

static inline struct page *
-tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
+tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dpi)
{
- return xa_load(&udev->data_blocks, dbi);
+ return xa_load(&udev->data_pages, dpi);
}

static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
@@ -1454,7 +1454,7 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
if (free_space)
free_space = tcmu_run_tmr_queue(udev);

- if (atomic_read(&global_db_count) > tcmu_global_max_blocks &&
+ 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
@@ -1583,7 +1583,7 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);

- xa_init(&udev->data_blocks);
+ xa_init(&udev->data_pages);

return &udev->se_dev;
}
@@ -1617,7 +1617,7 @@ static void tcmu_blocks_release(struct xarray *blocks, unsigned long first,
xas_for_each(&xas, page, last) {
xas_store(&xas, NULL);
__free_page(page);
- atomic_dec(&global_db_count);
+ atomic_dec(&global_page_count);
}
xas_unlock(&xas);
}
@@ -1661,7 +1661,7 @@ static void tcmu_dev_kref_release(struct kref *kref)
xa_destroy(&udev->commands);
WARN_ON(!all_expired);

- tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max);
+ tcmu_blocks_release(&udev->data_pages, 0, udev->dbi_max);
bitmap_free(udev->data_bitmap);
mutex_unlock(&udev->cmdr_lock);

@@ -1759,12 +1759,12 @@ 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)
+static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
{
struct page *page;

mutex_lock(&udev->cmdr_lock);
- page = tcmu_get_block_page(udev, dbi);
+ page = tcmu_get_block_page(udev, dpi);
if (likely(page)) {
mutex_unlock(&udev->cmdr_lock);
return page;
@@ -1774,12 +1774,11 @@ static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
* Userspace messed up and passed in a address not in the
* data iov passed to it.
*/
- pr_err("Invalid addr to data block mapping (dbi %u) on device %s\n",
- dbi, udev->name);
- page = NULL;
+ pr_err("Invalid addr to data page mapping (dpi %u) on device %s\n",
+ dpi, udev->name);
mutex_unlock(&udev->cmdr_lock);

- return page;
+ return NULL;
}

static void tcmu_vma_open(struct vm_area_struct *vma)
@@ -1824,11 +1823,11 @@ static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
addr = (void *)(unsigned long)info->mem[mi].addr + offset;
page = vmalloc_to_page(addr);
} else {
- uint32_t dbi;
+ uint32_t dpi;

/* For the dynamically growing data area pages */
- dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE;
- page = tcmu_try_get_block_page(udev, dbi);
+ dpi = (offset - udev->data_off) / PAGE_SIZE;
+ page = tcmu_try_get_data_page(udev, dpi);
if (!page)
return VM_FAULT_SIGBUS;
}
@@ -2344,7 +2343,7 @@ static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)

static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
{
- int val, ret;
+ int val, ret, blks;

ret = match_int(arg, &val);
if (ret < 0) {
@@ -2353,7 +2352,8 @@ static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
return ret;
}

- if (val <= 0) {
+ blks = TCMU_MBS_TO_PAGES(val) / DATA_PAGES_PER_BLK;
+ if (blks <= 0) {
pr_err("Invalid max_data_area %d.\n", val);
return -EINVAL;
}
@@ -2365,11 +2365,11 @@ static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
goto unlock;
}

- udev->max_blocks = TCMU_MBS_TO_BLOCKS(val);
- if (udev->max_blocks > tcmu_global_max_blocks) {
+ udev->max_blocks = blks;
+ if (udev->max_blocks * DATA_PAGES_PER_BLK > tcmu_global_max_pages) {
pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
- val, TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
- udev->max_blocks = tcmu_global_max_blocks;
+ val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
+ udev->max_blocks = tcmu_global_max_pages / DATA_PAGES_PER_BLK;
}

unlock:
@@ -2449,7 +2449,7 @@ static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
udev->dev_config[0] ? udev->dev_config : "NULL");
bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",
- TCMU_BLOCKS_TO_MBS(udev->max_blocks));
+ TCMU_PAGES_TO_MBS(udev->max_blocks * DATA_PAGES_PER_BLK));

return bl;
}
@@ -2544,7 +2544,7 @@ static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);

return snprintf(page, PAGE_SIZE, "%u\n",
- TCMU_BLOCKS_TO_MBS(udev->max_blocks));
+ TCMU_PAGES_TO_MBS(udev->max_blocks * DATA_PAGES_PER_BLK));
}
CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);

@@ -2904,7 +2904,7 @@ static void find_free_blocks(void)
loff_t off;
u32 start, end, block, total_freed = 0;

- if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)
+ if (atomic_read(&global_page_count) <= tcmu_global_max_pages)
return;

mutex_lock(&root_udev_mutex);
@@ -2949,7 +2949,7 @@ static void find_free_blocks(void)
unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);

/* Release the block pages */
- tcmu_blocks_release(&udev->data_blocks, start, end - 1);
+ tcmu_blocks_release(&udev->data_pages, start, end - 1);
mutex_unlock(&udev->cmdr_lock);

total_freed += end - start;
@@ -2958,7 +2958,7 @@ static void find_free_blocks(void)
}
mutex_unlock(&root_udev_mutex);

- if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
+ if (atomic_read(&global_page_count) > tcmu_global_max_pages)
schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
}

--
2.12.3