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-VuQAYsv1563Yd54FQh9/[email protected]>
---
fs/dax.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 982ccbb..7689ab0 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1023,6 +1023,11 @@ 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 inline 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)
@@ -1048,8 +1053,7 @@ 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) {
@@ -1186,7 +1190,7 @@ 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) {
--
2.7.4
Looks fine,
Reviewed-by: Christoph Hellwig <[email protected]>
On Fri 07-10-16 15:08:59, Ross Zwisler wrote:
> 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 <[email protected]>
Looks good. You can add:
Reviewed-by: Jan Kara <[email protected]>
Honza
> ---
> fs/dax.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/fs/dax.c b/fs/dax.c
> index 982ccbb..7689ab0 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1023,6 +1023,11 @@ 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 inline 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)
> @@ -1048,8 +1053,7 @@ 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) {
> @@ -1186,7 +1190,7 @@ 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) {
> --
> 2.7.4
>
>
--
Jan Kara <[email protected]>
SUSE Labs, CR
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