Hi,
On 11.5.2021 6.09, Shiyang Ruan wrote:
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@xxxxxxxxxxx>
Reviewed-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>
---
fs/dax.c | 25 +++++++++++++++----------
fs/iomap/buffered-io.c | 2 +-
include/linux/dax.h | 3 ++-
3 files changed, 18 insertions(+), 12 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index ef0e564e7904..ee9d28a79bfb 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1186,7 +1186,8 @@ 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;
@@ -1208,19 +1209,23 @@ s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
if (page_aligned)
rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
- else
+ else {
rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
- if (rc < 0) {
- dax_read_unlock(id);
- return rc;
- }
-
- if (!page_aligned) {
- memset(kaddr + offset, 0, size);
+ if (rc < 0)
+ goto out;
+ if (iomap->addr != srcmap->addr) {
+ rc = dax_iomap_cow_copy(offset, size, PAGE_SIZE, srcmap,
+ kaddr);
offset above is offset in page, think dax_iomap_cow_copy() expects
absolute pos
+ if (rc < 0)
+ goto out;
+ } else
+ memset(kaddr + offset, 0, size);
dax_flush(iomap->dax_dev, kaddr + offset, size);
}
+
+out:
dax_read_unlock(id);
- return size;
+ return rc < 0 ? rc : size;
}
static loff_t
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index f2cd2034a87b..2734955ea67f 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);
