vm_insert_mixed_mkwrite() has inefficiency when it
returns err, driver has to convert err to vm_fault_t
type. With new vmf_insert_mixed_mkwrite we can handle
this limitation.
As of now vm_insert_mixed_mkwrite() is only getting
invoked from fs/dax.c, so this change has to go first
in linus tree before changes in dax.
Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
---
include/linux/mm.h | 4 ++--
mm/memory.c | 15 +++++++++++----
2 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1ac1f06..9fe441c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2423,8 +2423,8 @@ int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn, pgprot_t pgprot);
int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn);
-int vm_insert_mixed_mkwrite(struct vm_area_struct *vma, unsigned long addr,
- pfn_t pfn);
+vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
+ unsigned long addr, pfn_t pfn);
int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
static inline vm_fault_t vmf_insert_page(struct vm_area_struct *vma,
diff --git a/mm/memory.c b/mm/memory.c
index 01f5464..721cfd5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1955,12 +1955,19 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
}
EXPORT_SYMBOL(vm_insert_mixed);
-int vm_insert_mixed_mkwrite(struct vm_area_struct *vma, unsigned long addr,
- pfn_t pfn)
+vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
+ unsigned long addr, pfn_t pfn)
{
- return __vm_insert_mixed(vma, addr, pfn, true);
+ int err;
+
+ err = __vm_insert_mixed(vma, addr, pfn, true);
+ if (err == -ENOMEM)
+ return VM_FAULT_OOM;
+ if (err < 0 && err != -EBUSY)
+ return VM_FAULT_SIGBUS;
+ return VM_FAULT_NOPAGE;
}
-EXPORT_SYMBOL(vm_insert_mixed_mkwrite);
+EXPORT_SYMBOL(vmf_insert_mixed_mkwrite);
/*
* maps a range of physical memory into the requested pages. the old
--
1.9.1
