Re: [PATCH] powerpc: platform: cell: spufs: Change return type to vm_fault_t
From: Matthew Wilcox <willy@infradead.org>
Date: 2018-04-17 20:47:20
On Wed, Apr 18, 2018 at 12:50:38AM +0530, Souptick Joarder 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.
Reference id -> 1c8f422059ae ("mm: change return type to
vm_fault_t")
Previously vm_insert_pfn() returns err but driver returns
VM_FAULT_NOPAGE as default. The new function vmf_insert_pfn()
will replace this inefficiency by returning correct VM_FAULT_*
type.
vmf_handle_error is a inline wrapper function which
will convert error number to vm_fault_t type err.I think you sent the wrong version of this one ... The commit message should mention that we're fixing a minor bug, that the error from vm_insert_pfn() was being ignored and the effect of this is likely to be only felt in OOM situations.
quoted hunk ↗ jump to hunk
@@ -256,11 +257,11 @@ static ssize_t spufs_attr_write(struct file *file, const char __user *buf, vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot); pfn = (ctx->spu->local_store_phys + offset) >> PAGE_SHIFT; } - vm_insert_pfn(vma, vmf->address, pfn); + ret = vmf_insert_pfn(vma, vmf->address, pfn); spu_release(ctx); - return VM_FAULT_NOPAGE; + return ret; }
I thought I said not to introduce vmf_handle_error(), because it's too trivial and obfuscates what's actually going on.
-static int spufs_ps_fault(struct vm_fault *vmf,
+static inline vm_fault_t vmf_handle_error(int err)
+{
+ return VM_FAULT_NOPAGE;
+}
+Re-reading spufs_ps_fault(), I wouldn't change anything inside it. Just change its return type to vm_fault_t and call it done.