| Message ID | 1478233517-3571-14-git-send-email-jack@suse.cz (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Fri, Nov 04, 2016 at 05:25:09AM +0100, Jan Kara wrote: > We will need more information in the ->page_mkwrite() helper for DAX to > be able to fully finish faults there. Pass vm_fault structure to > do_page_mkwrite() and use it there so that information propagates > properly from upper layers. > > Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> > Signed-off-by: Jan Kara <jack@suse.cz> > --- > mm/memory.c | 19 +++++++------------ > 1 file changed, 7 insertions(+), 12 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index 4da66c984c2c..c89f99c270bc 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2038,20 +2038,14 @@ static gfp_t __get_fault_gfp_mask(struct vm_area_struct *vma) > * > * We do this without the lock held, so that it can sleep if it needs to. > */ > -static int do_page_mkwrite(struct vm_area_struct *vma, struct page *page, > - unsigned long address) > +static int do_page_mkwrite(struct vm_fault *vmf) > { > - struct vm_fault vmf; > int ret; > + struct page *page = vmf->page; > > - vmf.address = address; > - vmf.pgoff = page->index; > - vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; > - vmf.gfp_mask = __get_fault_gfp_mask(vma); > - vmf.page = page; > - vmf.cow_page = NULL; > + vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; This can be destructive: we loose rest of the flags here. It's probably okay in current state of the code, but may be should restore them before return from do_page_mkwrite()?
On Wed 16-11-16 01:40:23, Kirill A. Shutemov wrote: > On Fri, Nov 04, 2016 at 05:25:09AM +0100, Jan Kara wrote: > > We will need more information in the ->page_mkwrite() helper for DAX to > > be able to fully finish faults there. Pass vm_fault structure to > > do_page_mkwrite() and use it there so that information propagates > > properly from upper layers. > > > > Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> > > Signed-off-by: Jan Kara <jack@suse.cz> > > --- > > mm/memory.c | 19 +++++++------------ > > 1 file changed, 7 insertions(+), 12 deletions(-) > > > > diff --git a/mm/memory.c b/mm/memory.c > > index 4da66c984c2c..c89f99c270bc 100644 > > --- a/mm/memory.c > > +++ b/mm/memory.c > > @@ -2038,20 +2038,14 @@ static gfp_t __get_fault_gfp_mask(struct vm_area_struct *vma) > > * > > * We do this without the lock held, so that it can sleep if it needs to. > > */ > > -static int do_page_mkwrite(struct vm_area_struct *vma, struct page *page, > > - unsigned long address) > > +static int do_page_mkwrite(struct vm_fault *vmf) > > { > > - struct vm_fault vmf; > > int ret; > > + struct page *page = vmf->page; > > > > - vmf.address = address; > > - vmf.pgoff = page->index; > > - vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; > > - vmf.gfp_mask = __get_fault_gfp_mask(vma); > > - vmf.page = page; > > - vmf.cow_page = NULL; > > + vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; > > This can be destructive: we loose rest of the flags here. It's probably > okay in current state of the code, but may be should restore them before > return from do_page_mkwrite()? Yeah, probably makes sense as future-proofing. Changed. Honza
diff --git a/mm/memory.c b/mm/memory.c index 4da66c984c2c..c89f99c270bc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2038,20 +2038,14 @@ static gfp_t __get_fault_gfp_mask(struct vm_area_struct *vma) * * We do this without the lock held, so that it can sleep if it needs to. */ -static int do_page_mkwrite(struct vm_area_struct *vma, struct page *page, - unsigned long address) +static int do_page_mkwrite(struct vm_fault *vmf) { - struct vm_fault vmf; int ret; + struct page *page = vmf->page; - vmf.address = address; - vmf.pgoff = page->index; - vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; - vmf.gfp_mask = __get_fault_gfp_mask(vma); - vmf.page = page; - vmf.cow_page = NULL; + vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; - ret = vma->vm_ops->page_mkwrite(vma, &vmf); + ret = vmf->vma->vm_ops->page_mkwrite(vmf->vma, vmf); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) return ret; if (unlikely(!(ret & VM_FAULT_LOCKED))) { @@ -2327,7 +2321,8 @@ static int wp_page_shared(struct vm_fault *vmf, struct page *old_page) int tmp; pte_unmap_unlock(vmf->pte, vmf->ptl); - tmp = do_page_mkwrite(vma, old_page, vmf->address); + vmf->page = old_page; + tmp = do_page_mkwrite(vmf); if (unlikely(!tmp || (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { put_page(old_page); @@ -3292,7 +3287,7 @@ static int do_shared_fault(struct vm_fault *vmf) */ if (vma->vm_ops->page_mkwrite) { unlock_page(vmf->page); - tmp = do_page_mkwrite(vma, vmf->page, vmf->address); + tmp = do_page_mkwrite(vmf); if (unlikely(!tmp || (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { put_page(vmf->page);