diff options
Diffstat (limited to 'drivers/block/zram/zram_drv.c')
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 1b697208d661..9a1e6ee4dbef 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -620,15 +620,19 @@ static int read_from_bdev_async(struct zram *zram, struct bio_vec *bvec, return 1; } +#define PAGE_WB_SIG "page_index=" + +#define PAGE_WRITEBACK 0 #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) { struct zram *zram = dev_to_zram(dev); unsigned long nr_pages = zram->disksize >> PAGE_SHIFT; - unsigned long index; + unsigned long index = 0; struct bio bio; struct bio_vec bio_vec; struct page *page; @@ -640,8 +644,17 @@ static ssize_t writeback_store(struct device *dev, mode = IDLE_WRITEBACK; else if (sysfs_streq(buf, "huge")) mode = HUGE_WRITEBACK; - else - return -EINVAL; + else { + if (strncmp(buf, PAGE_WB_SIG, sizeof(PAGE_WB_SIG) - 1)) + return -EINVAL; + + ret = kstrtol(buf + sizeof(PAGE_WB_SIG) - 1, 10, &index); + if (ret || index >= nr_pages) + return -EINVAL; + + nr_pages = 1; + mode = PAGE_WRITEBACK; + } down_read(&zram->init_lock); if (!init_done(zram)) { @@ -660,7 +673,7 @@ static ssize_t writeback_store(struct device *dev, goto release_init_lock; } - for (index = 0; index < nr_pages; index++) { + while (nr_pages--) { struct bio_vec bvec; bvec.bv_page = page; |