dax: add dax_iomap_sector() helper function

To be able to correctly calculate the sector from a file position and a
struct iomap there is a complex little bit of logic that currently happens
in both dax_iomap_actor() and dax_iomap_fault().  This will need to be
repeated yet again in the DAX PMD fault handler when it is added, so break
it out into a helper function.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Ross Zwisler 2016-11-08 11:33:09 +11:00 committed by Dave Chinner
parent 11c59c92f4
commit 333ccc978e
1 changed files with 7 additions and 3 deletions

View File

@ -1030,6 +1030,11 @@ int dax_truncate_page(struct inode *inode, loff_t from, get_block_t get_block)
EXPORT_SYMBOL_GPL(dax_truncate_page);
#ifdef CONFIG_FS_IOMAP
static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
{
return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
}
static loff_t
dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct iomap *iomap)
@ -1055,8 +1060,7 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct blk_dax_ctl dax = { 0 };
ssize_t map_len;
dax.sector = iomap->blkno +
(((pos & PAGE_MASK) - iomap->offset) >> 9);
dax.sector = dax_iomap_sector(iomap, pos);
dax.size = (length + offset + PAGE_SIZE - 1) & PAGE_MASK;
map_len = dax_map_atomic(iomap->bdev, &dax);
if (map_len < 0) {
@ -1193,7 +1197,7 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
goto unlock_entry;
}
sector = iomap.blkno + (((pos & PAGE_MASK) - iomap.offset) >> 9);
sector = dax_iomap_sector(&iomap, pos);
if (vmf->cow_page) {
switch (iomap.type) {