| Message ID | 20190416164154.30390-9-rgoldwyn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs dax support | expand |
On Tue, Apr 16, 2019 at 11:41:44AM -0500, Goldwyn Rodrigues wrote: > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > Change dax_iomap_pfn to return the address as well in order to > use it for performing a memcpy in case the type is IOMAP_DAX_COW. > > Question: > The sequence of bdev_dax_pgoff() and dax_direct_access() is > used multiple times to calculate address and pfn's. Would it make > sense to call it while calculating address as well to reduce code? > > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> > --- > fs/dax.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index 4b4ac51fbd16..45fc2e18969a 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -983,7 +983,7 @@ static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos) > } > > static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, > - pfn_t *pfnp) > + pfn_t *pfnp, void **addr) > { > const sector_t sector = dax_iomap_sector(iomap, pos); > pgoff_t pgoff; > @@ -995,7 +995,7 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, > return rc; > id = dax_read_lock(); > length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size), > - NULL, pfnp); > + addr, pfnp); > if (length < 0) { > rc = length; > goto out; > @@ -1280,6 +1280,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, > XA_STATE(xas, &mapping->i_pages, vmf->pgoff); > struct inode *inode = mapping->host; > unsigned long vaddr = vmf->address; > + void *addr; > loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; > struct iomap iomap = { 0 }; > unsigned flags = IOMAP_FAULT; > @@ -1369,16 +1370,23 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, > sync = dax_fault_is_synchronous(flags, vma, &iomap); > > switch (iomap.type) { > + case IOMAP_DAX_COW: > case IOMAP_MAPPED: > if (iomap.flags & IOMAP_F_NEW) { > count_vm_event(PGMAJFAULT); > count_memcg_event_mm(vma->vm_mm, PGMAJFAULT); > major = VM_FAULT_MAJOR; > } > - error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn); > + error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn, &addr); > if (error < 0) > goto error_finish_iomap; > > + if (iomap.type == IOMAP_DAX_COW) { > + if (iomap.inline_data) > + memcpy(addr, iomap.inline_data, PAGE_SIZE); Same memcpy_mcsafe question from my reply to patch 4 applies here. > + else > + memset(addr, 0, PAGE_SIZE); > + } > entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, > 0, write && !sync); > > @@ -1577,7 +1585,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, > > switch (iomap.type) { > case IOMAP_MAPPED: > - error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn); > + error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn, NULL); Same (unanswered) question from the v2 series -- doesn't a PMD fault also require handling IOMAP_DAX_COW? --D > if (error < 0) > goto finish_iomap; > > -- > 2.16.4 >
diff --git a/fs/dax.c b/fs/dax.c index 4b4ac51fbd16..45fc2e18969a 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -983,7 +983,7 @@ static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos) } static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, - pfn_t *pfnp) + pfn_t *pfnp, void **addr) { const sector_t sector = dax_iomap_sector(iomap, pos); pgoff_t pgoff; @@ -995,7 +995,7 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, return rc; id = dax_read_lock(); length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size), - NULL, pfnp); + addr, pfnp); if (length < 0) { rc = length; goto out; @@ -1280,6 +1280,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, XA_STATE(xas, &mapping->i_pages, vmf->pgoff); struct inode *inode = mapping->host; unsigned long vaddr = vmf->address; + void *addr; loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; struct iomap iomap = { 0 }; unsigned flags = IOMAP_FAULT; @@ -1369,16 +1370,23 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, sync = dax_fault_is_synchronous(flags, vma, &iomap); switch (iomap.type) { + case IOMAP_DAX_COW: case IOMAP_MAPPED: if (iomap.flags & IOMAP_F_NEW) { count_vm_event(PGMAJFAULT); count_memcg_event_mm(vma->vm_mm, PGMAJFAULT); major = VM_FAULT_MAJOR; } - error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn); + error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn, &addr); if (error < 0) goto error_finish_iomap; + if (iomap.type == IOMAP_DAX_COW) { + if (iomap.inline_data) + memcpy(addr, iomap.inline_data, PAGE_SIZE); + else + memset(addr, 0, PAGE_SIZE); + } entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, 0, write && !sync); @@ -1577,7 +1585,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, switch (iomap.type) { case IOMAP_MAPPED: - error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn); + error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn, NULL); if (error < 0) goto finish_iomap;