[PATCH v3 06/10] fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero

Shiyang Ruan
2021-03-19T01:54:02Z

Punch hole on a reflinked file needs dax_copy_edge() too. Otherwise,
data in not aligned area will be not correct. So, add the srcmap to
dax_iomap_zero() and replace memset() as dax_copy_edge().

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
---
fs/dax.c | 9 +++++++--
fs/iomap/buffered-io.c | 2 +-
include/linux/dax.h | 3 ++-
3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index cfe513eb111e..348297b38f76 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1174,7 +1174,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf,
}
#endif /* CONFIG_FS_DAX_PMD */

-s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
+s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
+ struct iomap *srcmap)
{
sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
pgoff_t pgoff;
@@ -1204,7 +1205,11 @@ s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
}

if (!page_aligned) {
- memset(kaddr + offset, 0, size);
+ if (iomap->addr != srcmap->addr)
+ dax_iomap_cow_copy(offset, size, PAGE_SIZE, srcmap,
+ kaddr, true);
+ else
+ memset(kaddr + offset, 0, size);
dax_flush(iomap->dax_dev, kaddr + offset, size);
}
dax_read_unlock(id);
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 16a1e82e3aeb..d754b1f1a05d 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -933,7 +933,7 @@ static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
s64 bytes;

if (IS_DAX(inode))
- bytes = dax_iomap_zero(pos, length, iomap);
+ bytes = dax_iomap_zero(pos, length, iomap, srcmap);
else
bytes = iomap_zero(inode, pos, length, iomap, srcmap);
if (bytes < 0)
diff --git a/include/linux/dax.h b/include/linux/dax.h
index b52f084aa643..3275e01ed33d 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -237,7 +237,8 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
-s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
+s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
+ struct iomap *srcmap);
static inline bool dax_mapping(struct address_space *mapping)
{
return mapping->host && IS_DAX(mapping->host);
--
2.30.1