Use new dax native zero page method for zeroing page if I/O is page
aligned. Otherwise fall back to direct_access() + memcpy().
This gets rid of one of the depenendency on block device in dax path.
Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
fs/dax.c | 53 +++++++++++++++++++++++------------------------------
1 file changed, 23 insertions(+), 30 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 35da144375a0..98ba3756163a 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1038,47 +1038,40 @@ static vm_fault_t dax_load_hole(struct xa_state *xas,
return ret;
}
-static bool dax_range_is_aligned(struct block_device *bdev,
- unsigned int offset, unsigned int length)
-{
- unsigned short sector_size = bdev_logical_block_size(bdev);
-
- if (!IS_ALIGNED(offset, sector_size))
- return false;
- if (!IS_ALIGNED(length, sector_size))
- return false;
-
- return true;
-}
-
int __dax_zero_page_range(struct block_device *bdev,
struct dax_device *dax_dev, sector_t sector,
unsigned int offset, unsigned int size)
{
- if (dax_range_is_aligned(bdev, offset, size)) {
- sector_t start_sector = sector + (offset >> 9);
+ pgoff_t pgoff;
+ long rc, id;
+ void *kaddr;
+ bool page_aligned = false;
- return blkdev_issue_zeroout(bdev, start_sector,
- size >> 9, GFP_NOFS, 0);
- } else {
- pgoff_t pgoff;
- long rc, id;
- void *kaddr;
- rc = bdev_dax_pgoff(bdev, sector, PAGE_SIZE, &pgoff);
- if (rc)
- return rc;
+ if (IS_ALIGNED(sector << SECTOR_SHIFT, PAGE_SIZE) &&
+ IS_ALIGNED(size, PAGE_SIZE))
+ page_aligned = true;
+
+ rc = bdev_dax_pgoff(bdev, sector, PAGE_SIZE, &pgoff);
+ if (rc)
+ return rc;
- id = dax_read_lock();
+ id = dax_read_lock();
+
+ if (page_aligned)
+ rc = dax_zero_page_range(dax_dev, pgoff, size >> PAGE_SHIFT);
+ else
rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr, NULL);
- if (rc < 0) {
- dax_read_unlock(id);
- return rc;
- }
+ if (rc < 0) {
+ dax_read_unlock(id);
+ return rc;
+ }
+
+ if (!page_aligned) {
memset(kaddr + offset, 0, size);
dax_flush(dax_dev, kaddr + offset, size);
- dax_read_unlock(id);
}
+ dax_read_unlock(id);
return 0;
}
EXPORT_SYMBOL_GPL(__dax_zero_page_range);
--
2.20.1
--
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