diff options
Diffstat (limited to 'fs/dax.c')
| -rw-r--r-- | fs/dax.c | 37 |
1 files changed, 37 insertions, 0 deletions
@@ -20,8 +20,45 @@ #include <linux/fs.h> #include <linux/genhd.h> #include <linux/mutex.h> +#include <linux/sched.h> #include <linux/uio.h> +int dax_clear_blocks(struct inode *inode, sector_t block, long size) +{ + struct block_device *bdev = inode->i_sb->s_bdev; + sector_t sector = block << (inode->i_blkbits - 9); + + might_sleep(); + do { + void *addr; + unsigned long pfn; + long count; + + count = bdev_direct_access(bdev, sector, &addr, &pfn, size); + if (count < 0) + return count; + BUG_ON(size < count); + while (count > 0) { + unsigned pgsz = PAGE_SIZE - offset_in_page(addr); + if (pgsz > count) + pgsz = count; + if (pgsz < PAGE_SIZE) + memset(addr, 0, pgsz); + else + clear_page(addr); + addr += pgsz; + size -= pgsz; + count -= pgsz; + BUG_ON(pgsz & 511); + sector += pgsz / 512; + cond_resched(); + } + } while (size); + + return 0; +} +EXPORT_SYMBOL_GPL(dax_clear_blocks); + static long dax_get_addr(struct buffer_head *bh, void **addr, unsigned blkbits) { unsigned long pfn; |