[lustre-devel] [PATCH v3] staging: lustre: Change return type to vm_fault_t
Greg KH
gregkh at linuxfoundation.org
Mon Jun 11 13:50:58 PDT 2018
On Tue, Jun 12, 2018 at 02:00:47AM +0530, Souptick Joarder wrote:
> On Mon, May 21, 2018 at 11:39 PM, Souptick Joarder <jrdr.linux at gmail.com> wrote:
> > Use new return type vm_fault_t for fault handler. For
> > now, this is just documenting that the function returns
> > a VM_FAULT value rather than an errno. Once all instances
> > are converted, vm_fault_t will become a distinct type.
> >
> > Ref-> commit 1c8f422059ae ("mm: change return type to
> > vm_fault_t") was added in 4.17-rc1 to introduce the new
> > typedef vm_fault_t. Currently we are making change to all
> > drivers to return vm_fault_t for page fault handlers. As
> > part of that lustre driver is also getting changed to
> > return vm_fault_t type.
> >
> > Signed-off-by: Souptick Joarder <jrdr.linux at gmail.com>
> > ---
> > v2: updated the change log
> >
> > v3: updated the change log
> >
> > drivers/staging/lustre/lustre/llite/llite_mmap.c | 35 ++++++++++++------------
> > 1 file changed, 18 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/staging/lustre/lustre/llite/llite_mmap.c b/drivers/staging/lustre/lustre/llite/llite_mmap.c
> > index c0533bd..5b8fd10 100644
> > --- a/drivers/staging/lustre/lustre/llite/llite_mmap.c
> > +++ b/drivers/staging/lustre/lustre/llite/llite_mmap.c
> > @@ -231,7 +231,7 @@ static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
> > return result;
> > }
> >
> > -static inline int to_fault_error(int result)
> > +static inline vm_fault_t to_fault_error(int result)
> > {
> > switch (result) {
> > case 0:
> > @@ -261,7 +261,7 @@ static inline int to_fault_error(int result)
> > * \retval VM_FAULT_ERROR on general error
> > * \retval NOPAGE_OOM not have memory for allocate new page
> > */
> > -static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
> > +static vm_fault_t ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
> > {
> > struct lu_env *env;
> > struct cl_io *io;
> > @@ -269,16 +269,16 @@ static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
> > struct page *vmpage;
> > unsigned long ra_flags;
> > int result = 0;
> > - int fault_ret = 0;
> > + vm_fault_t fault_ret = 0;
> > u16 refcheck;
> >
> > env = cl_env_get(&refcheck);
> > if (IS_ERR(env))
> > - return PTR_ERR(env);
> > + return VM_FAULT_ERROR;
> >
> > io = ll_fault_io_init(env, vma, vmf->pgoff, &ra_flags);
> > if (IS_ERR(io)) {
> > - result = to_fault_error(PTR_ERR(io));
> > + fault_ret = to_fault_error(PTR_ERR(io));
> > goto out;
> > }
> >
> > @@ -319,15 +319,15 @@ static int ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
> > if (result != 0 && !(fault_ret & VM_FAULT_RETRY))
> > fault_ret |= to_fault_error(result);
> >
> > - CDEBUG(D_MMAP, "%s fault %d/%d\n", current->comm, fault_ret, result);
> > + CDEBUG(D_MMAP, "%s fault %x/%d\n", current->comm, fault_ret, result);
> > return fault_ret;
> > }
> >
> > -static int ll_fault(struct vm_fault *vmf)
> > +static vm_fault_t ll_fault(struct vm_fault *vmf)
> > {
> > int count = 0;
> > bool printed = false;
> > - int result;
> > + vm_fault_t result;
> > sigset_t set;
> >
> > /* Only SIGKILL and SIGTERM are allowed for fault/nopage/mkwrite
> > @@ -364,18 +364,19 @@ static int ll_fault(struct vm_fault *vmf)
> > return result;
> > }
> >
> > -static int ll_page_mkwrite(struct vm_fault *vmf)
> > +static vm_fault_t ll_page_mkwrite(struct vm_fault *vmf)
> > {
> > struct vm_area_struct *vma = vmf->vma;
> > int count = 0;
> > bool printed = false;
> > bool retry;
> > - int result;
> > + int err;
> > + vm_fault_t ret;
> >
> > file_update_time(vma->vm_file);
> > do {
> > retry = false;
> > - result = ll_page_mkwrite0(vma, vmf->page, &retry);
> > + err = ll_page_mkwrite0(vma, vmf->page, &retry);
> >
> > if (!printed && ++count > 16) {
> > const struct dentry *de = vma->vm_file->f_path.dentry;
> > @@ -387,25 +388,25 @@ static int ll_page_mkwrite(struct vm_fault *vmf)
> > }
> > } while (retry);
> >
> > - switch (result) {
> > + switch (err) {
> > case 0:
> > LASSERT(PageLocked(vmf->page));
> > - result = VM_FAULT_LOCKED;
> > + ret = VM_FAULT_LOCKED;
> > break;
> > case -ENODATA:
> > case -EAGAIN:
> > case -EFAULT:
> > - result = VM_FAULT_NOPAGE;
> > + ret = VM_FAULT_NOPAGE;
> > break;
> > case -ENOMEM:
> > - result = VM_FAULT_OOM;
> > + ret = VM_FAULT_OOM;
> > break;
> > default:
> > - result = VM_FAULT_SIGBUS;
> > + ret = VM_FAULT_SIGBUS;
> > break;
> > }
> >
> > - return result;
> > + return ret;
> > }
> >
> > /**
> > --
> > 1.9.1
> >
>
> If no further comment, we would like to get this patch in 4.18-rc-X.
Why? Is it a regression fix? That's all that is allowed after -rc1.
And have you tried applying it to Linus's current tree? :)
thanks,
greg k-h
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