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 <[email protected]> --- 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
