Re: [PATCH v6 3/7] fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero
From: "Darrick J. Wong" <djwong@kernel.org>
Date: 2021-05-25 22:17:23
Also in:
linux-fsdevel, lkml
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 <redacted> Reviewed-by: Ritesh Harjani <redacted>
Looks good now, Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D
quoted hunk ↗ jump to hunk
--- 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_tdiff --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