[PATCH 17/29] fsdax: factor out a dax_memzero helper

Christoph Hellwig
2021-11-09T08:34:00Z

Factor out a helper for the "manual" zeroing of a DAX range to clean
up dax_iomap_zero a lot.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/dax.c | 36 +++++++++++++++++++-----------------
1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index d7a923d152240..dc9ebeff850ab 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1121,34 +1121,36 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf,
}
#endif /* CONFIG_FS_DAX_PMD */

+static int dax_memzero(struct dax_device *dax_dev, pgoff_t pgoff,
+ unsigned int offset, size_t size)
+{
+ void *kaddr;
+ long rc;
+
+ rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr, NULL);
+ if (rc >= 0) {
+ memset(kaddr + offset, 0, size);
+ dax_flush(dax_dev, kaddr + offset, size);
+ }
+ return rc;
+}
+
s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
{
pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);
long rc, id;
- void *kaddr;
- bool page_aligned = false;
unsigned offset = offset_in_page(pos);
unsigned size = min_t(u64, PAGE_SIZE - offset, length);

- if (IS_ALIGNED(pos, PAGE_SIZE) && size == PAGE_SIZE)
- page_aligned = true;
-
id = dax_read_lock();
-
- if (page_aligned)
+ if (IS_ALIGNED(pos, PAGE_SIZE) && size == PAGE_SIZE)
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;
- }
-
- if (!page_aligned) {
- memset(kaddr + offset, 0, size);
- dax_flush(iomap->dax_dev, kaddr + offset, size);
- }
+ rc = dax_memzero(iomap->dax_dev, pgoff, offset, size);
dax_read_unlock(id);
+
+ if (rc < 0)
+ return rc;
return size;
}

--
2.30.2