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path: root/drivers/block/zram/zram_drv.c
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Diffstat (limited to 'drivers/block/zram/zram_drv.c')
-rw-r--r--drivers/block/zram/zram_drv.c90
1 files changed, 66 insertions, 24 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 33c5cc879f24..04ca65912638 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -316,11 +316,9 @@ static ssize_t idle_store(struct device *dev,
* See the comment in writeback_store.
*/
zram_slot_lock(zram, index);
- if (!zram_allocated(zram, index) ||
- zram_test_flag(zram, index, ZRAM_UNDER_WB))
- goto next;
- zram_set_flag(zram, index, ZRAM_IDLE);
-next:
+ if (zram_allocated(zram, index) &&
+ !zram_test_flag(zram, index, ZRAM_UNDER_WB))
+ zram_set_flag(zram, index, ZRAM_IDLE);
zram_slot_unlock(zram, index);
}
@@ -330,6 +328,41 @@ next:
}
#ifdef CONFIG_ZRAM_WRITEBACK
+static ssize_t writeback_limit_enable_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+ struct zram *zram = dev_to_zram(dev);
+ u64 val;
+ ssize_t ret = -EINVAL;
+
+ if (kstrtoull(buf, 10, &val))
+ return ret;
+
+ down_read(&zram->init_lock);
+ spin_lock(&zram->wb_limit_lock);
+ zram->wb_limit_enable = val;
+ spin_unlock(&zram->wb_limit_lock);
+ up_read(&zram->init_lock);
+ ret = len;
+
+ return ret;
+}
+
+static ssize_t writeback_limit_enable_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ bool val;
+ struct zram *zram = dev_to_zram(dev);
+
+ down_read(&zram->init_lock);
+ spin_lock(&zram->wb_limit_lock);
+ val = zram->wb_limit_enable;
+ spin_unlock(&zram->wb_limit_lock);
+ up_read(&zram->init_lock);
+
+ return scnprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+
static ssize_t writeback_limit_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
@@ -341,9 +374,9 @@ static ssize_t writeback_limit_store(struct device *dev,
return ret;
down_read(&zram->init_lock);
- atomic64_set(&zram->stats.bd_wb_limit, val);
- if (val == 0)
- zram->stop_writeback = false;
+ spin_lock(&zram->wb_limit_lock);
+ zram->bd_wb_limit = val;
+ spin_unlock(&zram->wb_limit_lock);
up_read(&zram->init_lock);
ret = len;
@@ -357,7 +390,9 @@ static ssize_t writeback_limit_show(struct device *dev,
struct zram *zram = dev_to_zram(dev);
down_read(&zram->init_lock);
- val = atomic64_read(&zram->stats.bd_wb_limit);
+ spin_lock(&zram->wb_limit_lock);
+ val = zram->bd_wb_limit;
+ spin_unlock(&zram->wb_limit_lock);
up_read(&zram->init_lock);
return scnprintf(buf, PAGE_SIZE, "%llu\n", val);
@@ -588,8 +623,8 @@ static int read_from_bdev_async(struct zram *zram, struct bio_vec *bvec,
return 1;
}
-#define HUGE_WRITEBACK 0x1
-#define IDLE_WRITEBACK 0x2
+#define HUGE_WRITEBACK 1
+#define IDLE_WRITEBACK 2
static ssize_t writeback_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
@@ -602,7 +637,7 @@ static ssize_t writeback_store(struct device *dev,
struct page *page;
ssize_t ret, sz;
char mode_buf[8];
- unsigned long mode = -1UL;
+ int mode = -1;
unsigned long blk_idx = 0;
sz = strscpy(mode_buf, buf, sizeof(mode_buf));
@@ -618,7 +653,7 @@ static ssize_t writeback_store(struct device *dev,
else if (!strcmp(mode_buf, "huge"))
mode = HUGE_WRITEBACK;
- if (mode == -1UL)
+ if (mode == -1)
return -EINVAL;
down_read(&zram->init_lock);
@@ -645,10 +680,13 @@ static ssize_t writeback_store(struct device *dev,
bvec.bv_len = PAGE_SIZE;
bvec.bv_offset = 0;
- if (zram->stop_writeback) {
+ spin_lock(&zram->wb_limit_lock);
+ if (zram->wb_limit_enable && !zram->bd_wb_limit) {
+ spin_unlock(&zram->wb_limit_lock);
ret = -EIO;
break;
}
+ spin_unlock(&zram->wb_limit_lock);
if (!blk_idx) {
blk_idx = alloc_block_bdev(zram);
@@ -667,10 +705,11 @@ static ssize_t writeback_store(struct device *dev,
zram_test_flag(zram, index, ZRAM_UNDER_WB))
goto next;
- if ((mode & IDLE_WRITEBACK &&
- !zram_test_flag(zram, index, ZRAM_IDLE)) &&
- (mode & HUGE_WRITEBACK &&
- !zram_test_flag(zram, index, ZRAM_HUGE)))
+ if (mode == IDLE_WRITEBACK &&
+ !zram_test_flag(zram, index, ZRAM_IDLE))
+ goto next;
+ if (mode == HUGE_WRITEBACK &&
+ !zram_test_flag(zram, index, ZRAM_HUGE))
goto next;
/*
* Clearing ZRAM_UNDER_WB is duty of caller.
@@ -732,11 +771,10 @@ static ssize_t writeback_store(struct device *dev,
zram_set_element(zram, index, blk_idx);
blk_idx = 0;
atomic64_inc(&zram->stats.pages_stored);
- if (atomic64_add_unless(&zram->stats.bd_wb_limit,
- -1 << (PAGE_SHIFT - 12), 0)) {
- if (atomic64_read(&zram->stats.bd_wb_limit) == 0)
- zram->stop_writeback = true;
- }
+ spin_lock(&zram->wb_limit_lock);
+ if (zram->wb_limit_enable && zram->bd_wb_limit > 0)
+ zram->bd_wb_limit -= 1UL << (PAGE_SHIFT - 12);
+ spin_unlock(&zram->wb_limit_lock);
next:
zram_slot_unlock(zram, index);
}
@@ -1812,6 +1850,7 @@ static DEVICE_ATTR_RW(comp_algorithm);
static DEVICE_ATTR_RW(backing_dev);
static DEVICE_ATTR_WO(writeback);
static DEVICE_ATTR_RW(writeback_limit);
+static DEVICE_ATTR_RW(writeback_limit_enable);
#endif
static struct attribute *zram_disk_attrs[] = {
@@ -1828,6 +1867,7 @@ static struct attribute *zram_disk_attrs[] = {
&dev_attr_backing_dev.attr,
&dev_attr_writeback.attr,
&dev_attr_writeback_limit.attr,
+ &dev_attr_writeback_limit_enable.attr,
#endif
&dev_attr_io_stat.attr,
&dev_attr_mm_stat.attr,
@@ -1867,7 +1907,9 @@ static int zram_add(void)
device_id = ret;
init_rwsem(&zram->init_lock);
-
+#ifdef CONFIG_ZRAM_WRITEBACK
+ spin_lock_init(&zram->wb_limit_lock);
+#endif
queue = blk_alloc_queue(GFP_KERNEL);
if (!queue) {
pr_err("Error allocating disk queue for device %d\n",