[PATCH v10 5/8] fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero
From: Shiyang Ruan <hidden>
Date: 2021-09-28 06:23:59
Also in:
linux-fsdevel, lkml, nvdimm
Subsystem:
filesystem direct access (dax), filesystems (vfs and infrastructure), the rest · Maintainers:
Dan Williams, Alexander Viro, Christian Brauner, Linus Torvalds
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_iomap_zero(). Signed-off-by: Shiyang Ruan <redacted> Reviewed-by: Ritesh Harjani <redacted> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> --- fs/dax.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index debe459680f2..5379de8ad0c7 100644
--- a/fs/dax.c
+++ b/fs/dax.c@@ -1212,6 +1212,7 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, s64 dax_iomap_zero(const struct iomap_iter *iter, loff_t pos, u64 length) { const struct iomap *iomap = &iter->iomap; + const struct iomap *srcmap = &iter->srcmap; sector_t sector = iomap_sector(iomap, pos & PAGE_MASK); pgoff_t pgoff; long rc, id;
@@ -1230,21 +1231,27 @@ s64 dax_iomap_zero(const struct iomap_iter *iter, loff_t pos, u64 length) id = dax_read_lock(); - if (page_aligned) + if (page_aligned) { rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1); - else - rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL); - if (rc < 0) { - dax_read_unlock(id); - return rc; + goto out; } - if (!page_aligned) { - memset(kaddr + offset, 0, size); + rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL); + if (rc < 0) + goto out; + memset(kaddr + offset, 0, size); + if (srcmap->addr != IOMAP_HOLE && srcmap->addr != iomap->addr) { + rc = dax_iomap_cow_copy(pos, size, PAGE_SIZE, srcmap, + kaddr); + if (rc < 0) + goto out; + dax_flush(iomap->dax_dev, kaddr, PAGE_SIZE); + } else dax_flush(iomap->dax_dev, kaddr + offset, size); - } + +out: dax_read_unlock(id); - return size; + return rc < 0 ? rc : size; } static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
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2.33.0