Christoph Hellwig
2021-Nov-09 08:32 UTC
[PATCH 17/29] fsdax: factor out a dax_memzero helper
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 at 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
On Tue, Nov 9, 2021 at 12:34 AM Christoph Hellwig <hch at lst.de> wrote:> > Factor out a helper for the "manual" zeroing of a DAX range to clean > up dax_iomap_zero a lot. >Small / optional fixup below: Reviewed-by: Dan Williams <dan.j.williams at intel.com>> Signed-off-by: Christoph Hellwig <hch at 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) {Technically this should be "> 0" because dax_direct_access() returns nr_available_pages @pgoff, but this isn't broken because dax_direct_access() converts the "zero pages available" case into -ERANGE.> + 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 >