2021-05-19 19:16:29

by Shiyang Ruan

Subject: [PATCH v6 3/7] fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero

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 <[email protected]>
Reviewed-by: Ritesh Harjani <[email protected]>
---
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 98531c53d613..baee584cb8ae 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1197,7 +1197,8 @@ 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;
@@ -1219,19 +1220,23 @@ 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(pos, size, PAGE_SIZE, srcmap,
+ kaddr);
+ 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 9023717c5188..fdaac4ba9b9d 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);
--
2.31.1

2021-05-25 23:00:59

by Darrick J. Wong

Subject: Re: [PATCH v6 3/7] fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero

On Wed, May 19, 2021 at 02:00:41PM +0800, 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 <[email protected]>
> Reviewed-by: Ritesh Harjani <[email protected]>

Looks good now,
Reviewed-by: Darrick J. Wong <[email protected]>

--D

> ---
> 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 98531c53d613..baee584cb8ae 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1197,7 +1197,8 @@ 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;
> @@ -1219,19 +1220,23 @@ 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(pos, size, PAGE_SIZE, srcmap,
> + kaddr);
> + 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 9023717c5188..fdaac4ba9b9d 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);
> --
> 2.31.1
>
>
>