Punch hole on a reflinked file needs dax_iomap_cow_copy() too.
Otherwise, data in not aligned area will be not correct. So, add the
CoW operation for not aligned case in dax_memzero().
Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
Reviewed-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
==
This patch changed a lot when rebasing to next-20220504 branch. Though it
has been tested by myself, I think it needs a re-review.
==
---
fs/dax.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 78e26204697b..b3aa863e9fec 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1220,17 +1220,27 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf,
}
#endif /* CONFIG_FS_DAX_PMD */
-static int dax_memzero(struct dax_device *dax_dev, pgoff_t pgoff,
- unsigned int offset, size_t size)
+static int dax_memzero(struct iomap_iter *iter, loff_t pos, size_t size)
{
+ const struct iomap *iomap = &iter->iomap;
+ const struct iomap *srcmap = iomap_iter_srcmap(iter);
+ unsigned offset = offset_in_page(pos);
+ pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);
void *kaddr;
long ret;
- ret = dax_direct_access(dax_dev, pgoff, 1, &kaddr, NULL);
- if (ret > 0) {
- memset(kaddr + offset, 0, size);
- dax_flush(dax_dev, kaddr + offset, size);
- }
+ ret = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
+ if (ret < 0)
+ return ret;
+ memset(kaddr + offset, 0, size);
+ if (srcmap->addr != iomap->addr) {
+ ret = dax_iomap_cow_copy(pos, size, PAGE_SIZE, srcmap,
+ kaddr);
+ if (ret < 0)
+ return ret;
+ dax_flush(iomap->dax_dev, kaddr, PAGE_SIZE);
+ } else
+ dax_flush(iomap->dax_dev, kaddr + offset, size);
return ret;
}
@@ -1257,7 +1267,7 @@ static s64 dax_zero_iter(struct iomap_iter *iter, bool *did_zero)
if (IS_ALIGNED(pos, PAGE_SIZE) && size == PAGE_SIZE)
rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
else
- rc = dax_memzero(iomap->dax_dev, pgoff, offset, size);
+ rc = dax_memzero(iter, pos, size);
dax_read_unlock(id);
if (rc < 0)
--
2.35.1
