<p dir="ltr"></p>
<p dir="ltr">On 12-Jun-2018 2:21 AM, "Greg KH" <<a href="mailto:gregkh@linuxfoundation.org">gregkh@linuxfoundation.org</a>> wrote:<br>
><br>
> On Tue, Jun 12, 2018 at 02:00:47AM +0530, Souptick Joarder wrote:<br>
> > On Mon, May 21, 2018 at 11:39 PM, Souptick Joarder <<a href="mailto:jrdr.linux@gmail.com">jrdr.linux@gmail.com</a>> wrote:<br>
> > > Use new return type vm_fault_t for fault handler. For<br>
> > > now, this is just documenting that the function returns<br>
> > > a VM_FAULT value rather than an errno. Once all instances<br>
> > > are converted, vm_fault_t will become a distinct type.<br>
> > ><br>
> > > Ref-> commit 1c8f422059ae ("mm: change return type to<br>
> > > vm_fault_t") was added in 4.17-rc1 to introduce the new<br>
> > > typedef vm_fault_t. Currently we are making change to all<br>
> > > drivers to return vm_fault_t for page fault handlers. As<br>
> > > part of that lustre driver is also getting changed to<br>
> > > return vm_fault_t type.<br>
> > ><br>
> > > Signed-off-by: Souptick Joarder <<a href="mailto:jrdr.linux@gmail.com">jrdr.linux@gmail.com</a>><br>
> > > ---<br>
> > > v2: updated the change log<br>
> > ><br>
> > > v3: updated the change log<br>
> > ><br>
> > > drivers/staging/lustre/lustre/llite/llite_mmap.c | 35 ++++++++++++------------<br>
> > > 1 file changed, 18 insertions(+), 17 deletions(-)<br>
> > ><br>
> > > diff --git a/drivers/staging/lustre/lustre/llite/llite_mmap.c b/drivers/staging/lustre/lustre/llite/llite_mmap.c<br>
> > > index c0533bd..5b8fd10 100644<br>
> > > --- a/drivers/staging/lustre/lustre/llite/llite_mmap.c<br>
> > > +++ b/drivers/staging/lustre/lustre/llite/llite_mmap.c<br>
> > > @@ -231,7 +231,7 @@ static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,<br>
> > > return result;<br>
> > > }<br>
> > ><br>
> > > -static inline int to_fault_error(int result)<br>
> > > +static inline vm_fault_t to_fault_error(int result)<br>
> > > {<br>
> > > switch (result) {<br>
> > > case 0:<br>
> > > @@ -261,7 +261,7 @@ static inline int to_fault_error(int result)<br>
> > > * \retval VM_FAULT_ERROR on general error<br>
> > > * \retval NOPAGE_OOM not have memory for allocate new page<br>
> > > */<br>
> > > -static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)<br>
> > > +static vm_fault_t ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)<br>
> > > {<br>
> > > struct lu_env *env;<br>
> > > struct cl_io *io;<br>
> > > @@ -269,16 +269,16 @@ static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)<br>
> > > struct page *vmpage;<br>
> > > unsigned long ra_flags;<br>
> > > int result = 0;<br>
> > > - int fault_ret = 0;<br>
> > > + vm_fault_t fault_ret = 0;<br>
> > > u16 refcheck;<br>
> > ><br>
> > > env = cl_env_get(&refcheck);<br>
> > > if (IS_ERR(env))<br>
> > > - return PTR_ERR(env);<br>
> > > + return VM_FAULT_ERROR;<br>
> > ><br>
> > > io = ll_fault_io_init(env, vma, vmf->pgoff, &ra_flags);<br>
> > > if (IS_ERR(io)) {<br>
> > > - result = to_fault_error(PTR_ERR(io));<br>
> > > + fault_ret = to_fault_error(PTR_ERR(io));<br>
> > > goto out;<br>
> > > }<br>
> > ><br>
> > > @@ -319,15 +319,15 @@ static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)<br>
> > > if (result != 0 && !(fault_ret & VM_FAULT_RETRY))<br>
> > > fault_ret |= to_fault_error(result);<br>
> > ><br>
> > > - CDEBUG(D_MMAP, "%s fault %d/%d\n", current->comm, fault_ret, result);<br>
> > > + CDEBUG(D_MMAP, "%s fault %x/%d\n", current->comm, fault_ret, result);<br>
> > > return fault_ret;<br>
> > > }<br>
> > ><br>
> > > -static int ll_fault(struct vm_fault *vmf)<br>
> > > +static vm_fault_t ll_fault(struct vm_fault *vmf)<br>
> > > {<br>
> > > int count = 0;<br>
> > > bool printed = false;<br>
> > > - int result;<br>
> > > + vm_fault_t result;<br>
> > > sigset_t set;<br>
> > ><br>
> > > /* Only SIGKILL and SIGTERM are allowed for fault/nopage/mkwrite<br>
> > > @@ -364,18 +364,19 @@ static int ll_fault(struct vm_fault *vmf)<br>
> > > return result;<br>
> > > }<br>
> > ><br>
> > > -static int ll_page_mkwrite(struct vm_fault *vmf)<br>
> > > +static vm_fault_t ll_page_mkwrite(struct vm_fault *vmf)<br>
> > > {<br>
> > > struct vm_area_struct *vma = vmf->vma;<br>
> > > int count = 0;<br>
> > > bool printed = false;<br>
> > > bool retry;<br>
> > > - int result;<br>
> > > + int err;<br>
> > > + vm_fault_t ret;<br>
> > ><br>
> > > file_update_time(vma->vm_file);<br>
> > > do {<br>
> > > retry = false;<br>
> > > - result = ll_page_mkwrite0(vma, vmf->page, &retry);<br>
> > > + err = ll_page_mkwrite0(vma, vmf->page, &retry);<br>
> > ><br>
> > > if (!printed && ++count > 16) {<br>
> > > const struct dentry *de = vma->vm_file->f_path.dentry;<br>
> > > @@ -387,25 +388,25 @@ static int ll_page_mkwrite(struct vm_fault *vmf)<br>
> > > }<br>
> > > } while (retry);<br>
> > ><br>
> > > - switch (result) {<br>
> > > + switch (err) {<br>
> > > case 0:<br>
> > > LASSERT(PageLocked(vmf->page));<br>
> > > - result = VM_FAULT_LOCKED;<br>
> > > + ret = VM_FAULT_LOCKED;<br>
> > > break;<br>
> > > case -ENODATA:<br>
> > > case -EAGAIN:<br>
> > > case -EFAULT:<br>
> > > - result = VM_FAULT_NOPAGE;<br>
> > > + ret = VM_FAULT_NOPAGE;<br>
> > > break;<br>
> > > case -ENOMEM:<br>
> > > - result = VM_FAULT_OOM;<br>
> > > + ret = VM_FAULT_OOM;<br>
> > > break;<br>
> > > default:<br>
> > > - result = VM_FAULT_SIGBUS;<br>
> > > + ret = VM_FAULT_SIGBUS;<br>
> > > break;<br>
> > > }<br>
> > ><br>
> > > - return result;<br>
> > > + return ret;<br>
> > > }<br>
> > ><br>
> > > /**<br>
> > > --<br>
> > > 1.9.1<br>
> > ><br>
> > <br>
> > If no further comment, we would like to get this patch in 4.18-rc-X.<br>
><br>
> Why? Is it a regression fix? That's all that is allowed after -rc1.</p>
<p dir="ltr">No, this is not regression fix. We need to get this into 4.18-rc-1. But mostly it can't make into linus tree in rc-1 :)<br>
><br>
> And have you tried applying it to Linus's current tree? :)</p>
<p dir="ltr">Last tested on 4.17-rc-6 and it worked fine. Let me verify in current tree.<br></p>
<p dir="ltr">><br>
> thanks,<br>
><br>
> greg k-h<br></p>