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>
diff --git a/fs/dax.c b/fs/dax.c
index fdbd7a1..7737954 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -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) {
