On Mon, Jun 4, 2018 at 10:47 PM, Souptick Joarder <jrdr.linux@xxxxxxxxx> 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")
>
> The aim is to change the return type of finish_fault()
> and handle_mm_fault() to vm_fault_t type. As part of
> that clean up return type of all other recursively called
> functions have been changed to vm_fault_t type.
>
> The places from where handle_mm_fault() is getting invoked
> will be change to vm_fault_t type but in a separate patch.
>
> vmf_error() is the newly introduce inline function
> in 4.17-rc6.
>
> Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
> Reviewed-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
> ---
> v2: Change patch title and fixed sparse warning.
>
> v3: Reviewed by Matthew Wilcox
>
> fs/userfaultfd.c | 6 +--
> include/linux/huge_mm.h | 10 +++--
> include/linux/hugetlb.h | 2 +-
> include/linux/mm.h | 14 +++----
> include/linux/oom.h | 2 +-
> include/linux/swapops.h | 5 ++-
> include/linux/userfaultfd_k.h | 5 ++-
> kernel/memremap.c | 2 +-
> mm/gup.c | 4 +-
> mm/huge_memory.c | 25 ++++++------
> mm/hugetlb.c | 29 +++++++-------
> mm/internal.h | 2 +-
> mm/khugepaged.c | 3 +-
> mm/memory.c | 90 ++++++++++++++++++++++---------------------
> mm/shmem.c | 17 ++++----
> 15 files changed, 110 insertions(+), 106 deletions(-)
>
> diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
> index cec550c..bf60c6a 100644
> --- a/fs/userfaultfd.c
> +++ b/fs/userfaultfd.c
> @@ -336,17 +336,15 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
> * fatal_signal_pending()s, and the mmap_sem must be released before
> * returning it.
> */
> -int handle_userfault(struct vm_fault *vmf, unsigned long reason)
> +vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
> {
> struct mm_struct *mm = vmf->vma->vm_mm;
> struct userfaultfd_ctx *ctx;
> struct userfaultfd_wait_queue uwq;
> - int ret;
> + vm_fault_t ret = VM_FAULT_SIGBUS;
> bool must_wait, return_to_userland;
> long blocking_state;
>
> - ret = VM_FAULT_SIGBUS;
> -
> /*
> * We don't do userfault handling for the final child pid update.
> *
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index a8a1262..8c4f0a6 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -3,10 +3,11 @@
> #define _LINUX_HUGE_MM_H
>
> #include <linux/sched/coredump.h>
> +#include <linux/mm_types.h>
>
> #include <linux/fs.h> /* only for vma_is_dax() */
>
> -extern int do_huge_pmd_anonymous_page(struct vm_fault *vmf);
> +extern vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf);
> extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
> pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
> struct vm_area_struct *vma);
> @@ -23,7 +24,7 @@ static inline void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
> }
> #endif
>
> -extern int do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd);
> +extern vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd);
> extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
> unsigned long addr,
> pmd_t *pmd,
> @@ -216,7 +217,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
> struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
> pud_t *pud, int flags);
>
> -extern int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
> +extern vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
>
> extern struct page *huge_zero_page;
>
> @@ -321,7 +322,8 @@ static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
> return NULL;
> }
>
> -static inline int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd)
> +static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf,
> + pmd_t orig_pmd)
> {
> return 0;
> }
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 36fa6a2..c779b2f 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -105,7 +105,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
> int hugetlb_report_node_meminfo(int, char *);
> void hugetlb_show_meminfo(void);
> unsigned long hugetlb_total_pages(void);
> -int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
> +vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
> unsigned long address, unsigned int flags);
> int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
> struct vm_area_struct *dst_vma,
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 02a616e..2971bff 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -694,10 +694,10 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
> return pte;
> }
>
> -int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
> +vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
> struct page *page);
> -int finish_fault(struct vm_fault *vmf);
> -int finish_mkwrite_fault(struct vm_fault *vmf);
> +vm_fault_t finish_fault(struct vm_fault *vmf);
> +vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);
> #endif
>
> /*
> @@ -1343,8 +1343,8 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
> int invalidate_inode_page(struct page *page);
>
> #ifdef CONFIG_MMU
> -extern int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
> - unsigned int flags);
> +extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
> + unsigned long address, unsigned int flags);
> extern int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
> unsigned long address, unsigned int fault_flags,
> bool *unlocked);
> @@ -1353,7 +1353,7 @@ void unmap_mapping_pages(struct address_space *mapping,
> void unmap_mapping_range(struct address_space *mapping,
> loff_t const holebegin, loff_t const holelen, int even_cows);
> #else
> -static inline int handle_mm_fault(struct vm_area_struct *vma,
> +static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
> unsigned long address, unsigned int flags)
> {
> /* should never happen if there's no MMU */
> @@ -2501,7 +2501,7 @@ static inline struct page *follow_page(struct vm_area_struct *vma,
> #define FOLL_COW 0x4000 /* internal GUP flag */
> #define FOLL_ANON 0x8000 /* don't do file mappings */
>
> -static inline int vm_fault_to_errno(int vm_fault, int foll_flags)
> +static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
> {
> if (vm_fault & VM_FAULT_OOM)
> return -ENOMEM;
> diff --git a/include/linux/oom.h b/include/linux/oom.h
> index 6adac11..9d30c15 100644
> --- a/include/linux/oom.h
> +++ b/include/linux/oom.h
> @@ -88,7 +88,7 @@ static inline bool mm_is_oom_victim(struct mm_struct *mm)
> *
> * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise.
> */
> -static inline int check_stable_address_space(struct mm_struct *mm)
> +static inline vm_fault_t check_stable_address_space(struct mm_struct *mm)
> {
> if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags)))
> return VM_FAULT_SIGBUS;
> diff --git a/include/linux/swapops.h b/include/linux/swapops.h
> index 1d3877c..9bc8ddb 100644
> --- a/include/linux/swapops.h
> +++ b/include/linux/swapops.h
> @@ -4,6 +4,7 @@
>
> #include <linux/radix-tree.h>
> #include <linux/bug.h>
> +#include <linux/mm_types.h>
>
> /*
> * swapcache pages are stored in the swapper_space radix tree. We want to
> @@ -134,7 +135,7 @@ static inline struct page *device_private_entry_to_page(swp_entry_t entry)
> return pfn_to_page(swp_offset(entry));
> }
>
> -int device_private_entry_fault(struct vm_area_struct *vma,
> +vm_fault_t device_private_entry_fault(struct vm_area_struct *vma,
> unsigned long addr,
> swp_entry_t entry,
> unsigned int flags,
> @@ -169,7 +170,7 @@ static inline struct page *device_private_entry_to_page(swp_entry_t entry)
> return NULL;
> }
>
> -static inline int device_private_entry_fault(struct vm_area_struct *vma,
> +static inline vm_fault_t device_private_entry_fault(struct vm_area_struct *vma,
> unsigned long addr,
> swp_entry_t entry,
> unsigned int flags,
> diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
> index f2f3b68..1f36c80 100644
> --- a/include/linux/userfaultfd_k.h
> +++ b/include/linux/userfaultfd_k.h
> @@ -28,7 +28,7 @@
> #define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
> #define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
>
> -extern int handle_userfault(struct vm_fault *vmf, unsigned long reason);
> +extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);
>
> extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
> unsigned long src_start, unsigned long len);
> @@ -75,7 +75,8 @@ extern void userfaultfd_unmap_complete(struct mm_struct *mm,
> #else /* CONFIG_USERFAULTFD */
>
> /* mm helpers */
> -static inline int handle_userfault(struct vm_fault *vmf, unsigned long reason)
> +static inline vm_fault_t handle_userfault(struct vm_fault *vmf,
> + unsigned long reason)
> {
> return VM_FAULT_SIGBUS;
> }
> diff --git a/kernel/memremap.c b/kernel/memremap.c
> index 895e6b7..d148d09 100644
> --- a/kernel/memremap.c
> +++ b/kernel/memremap.c
> @@ -214,7 +214,7 @@ static unsigned long order_at(struct resource *res, unsigned long pgoff)
> pgoff += 1UL << order, order = order_at((res), pgoff))
>
> #if IS_ENABLED(CONFIG_DEVICE_PRIVATE)
> -int device_private_entry_fault(struct vm_area_struct *vma,
> +vm_fault_t device_private_entry_fault(struct vm_area_struct *vma,
> unsigned long addr,
> swp_entry_t entry,
> unsigned int flags,
> diff --git a/mm/gup.c b/mm/gup.c
> index 541904a..e3a957e 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -481,7 +481,7 @@ static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma,
> unsigned long address, unsigned int *flags, int *nonblocking)
> {
> unsigned int fault_flags = 0;
> - int ret;
> + vm_fault_t ret;
>
> /* mlock all present pages, but do not fault in new pages */
> if ((*flags & (FOLL_POPULATE | FOLL_MLOCK)) == FOLL_MLOCK)
> @@ -802,7 +802,7 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
> bool *unlocked)
> {
> struct vm_area_struct *vma;
> - int ret, major = 0;
> + vm_fault_t ret, major = 0;
>
> if (unlocked)
> fault_flags |= FAULT_FLAG_ALLOW_RETRY;
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index a3a1815..82dc477 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -544,14 +544,14 @@ unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr,
> }
> EXPORT_SYMBOL_GPL(thp_get_unmapped_area);
>
> -static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page,
> - gfp_t gfp)
> +static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
> + struct page *page, gfp_t gfp)
> {
> struct vm_area_struct *vma = vmf->vma;
> struct mem_cgroup *memcg;
> pgtable_t pgtable;
> unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
> - int ret = 0;
> + vm_fault_t ret = 0;
>
> VM_BUG_ON_PAGE(!PageCompound(page), page);
>
> @@ -587,7 +587,7 @@ static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page,
>
> /* Deliver the page fault to userland */
> if (userfaultfd_missing(vma)) {
> - int ret;
> + vm_fault_t ret;
>
> spin_unlock(vmf->ptl);
> mem_cgroup_cancel_charge(page, memcg, true);
> @@ -666,7 +666,7 @@ static bool set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
> return true;
> }
>
> -int do_huge_pmd_anonymous_page(struct vm_fault *vmf)
> +vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> gfp_t gfp;
> @@ -685,7 +685,7 @@ int do_huge_pmd_anonymous_page(struct vm_fault *vmf)
> pgtable_t pgtable;
> struct page *zero_page;
> bool set;
> - int ret;
> + vm_fault_t ret;
> pgtable = pte_alloc_one(vma->vm_mm, haddr);
> if (unlikely(!pgtable))
> return VM_FAULT_OOM;
> @@ -1121,15 +1121,16 @@ void huge_pmd_set_accessed(struct vm_fault *vmf, pmd_t orig_pmd)
> spin_unlock(vmf->ptl);
> }
>
> -static int do_huge_pmd_wp_page_fallback(struct vm_fault *vmf, pmd_t orig_pmd,
> - struct page *page)
> +static vm_fault_t do_huge_pmd_wp_page_fallback(struct vm_fault *vmf,
> + pmd_t orig_pmd, struct page *page)
> {
> struct vm_area_struct *vma = vmf->vma;
> unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
> struct mem_cgroup *memcg;
> pgtable_t pgtable;
> pmd_t _pmd;
> - int ret = 0, i;
> + int i;
> + vm_fault_t ret = 0;
> struct page **pages;
> unsigned long mmun_start; /* For mmu_notifiers */
> unsigned long mmun_end; /* For mmu_notifiers */
> @@ -1239,7 +1240,7 @@ static int do_huge_pmd_wp_page_fallback(struct vm_fault *vmf, pmd_t orig_pmd,
> goto out;
> }
>
> -int do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
> +vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
> {
> struct vm_area_struct *vma = vmf->vma;
> struct page *page = NULL, *new_page;
> @@ -1248,7 +1249,7 @@ int do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
> unsigned long mmun_start; /* For mmu_notifiers */
> unsigned long mmun_end; /* For mmu_notifiers */
> gfp_t huge_gfp; /* for allocation and charge */
> - int ret = 0;
> + vm_fault_t ret = 0;
>
> vmf->ptl = pmd_lockptr(vma->vm_mm, vmf->pmd);
> VM_BUG_ON_VMA(!vma->anon_vma, vma);
> @@ -1459,7 +1460,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
> }
>
> /* NUMA hinting page fault entry point for trans huge pmds */
> -int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd)
> +vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd)
> {
> struct vm_area_struct *vma = vmf->vma;
> struct anon_vma *anon_vma = NULL;
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 2186791..d17b186 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -3499,14 +3499,15 @@ static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
> * cannot race with other handlers or page migration.
> * Keep the pte_same checks anyway to make transition from the mutex easier.
> */
> -static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
> +static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
> unsigned long address, pte_t *ptep,
> struct page *pagecache_page, spinlock_t *ptl)
> {
> pte_t pte;
> struct hstate *h = hstate_vma(vma);
> struct page *old_page, *new_page;
> - int ret = 0, outside_reserve = 0;
> + int outside_reserve = 0;
> + vm_fault_t ret = 0;
> unsigned long mmun_start; /* For mmu_notifiers */
> unsigned long mmun_end; /* For mmu_notifiers */
>
> @@ -3570,8 +3571,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
> return 0;
> }
>
> - ret = (PTR_ERR(new_page) == -ENOMEM) ?
> - VM_FAULT_OOM : VM_FAULT_SIGBUS;
> + ret = vmf_error(PTR_ERR(new_page));
> goto out_release_old;
> }
>
> @@ -3675,12 +3675,13 @@ int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
> return 0;
> }
>
> -static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
> - struct address_space *mapping, pgoff_t idx,
> - unsigned long address, pte_t *ptep, unsigned int flags)
> +static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
> + struct vm_area_struct *vma,
> + struct address_space *mapping, pgoff_t idx,
> + unsigned long address, pte_t *ptep, unsigned int flags)
> {
> struct hstate *h = hstate_vma(vma);
> - int ret = VM_FAULT_SIGBUS;
> + vm_fault_t ret = VM_FAULT_SIGBUS;
> int anon_rmap = 0;
> unsigned long size;
> struct page *page;
> @@ -3742,11 +3743,7 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
>
> page = alloc_huge_page(vma, address, 0);
> if (IS_ERR(page)) {
> - ret = PTR_ERR(page);
> - if (ret == -ENOMEM)
> - ret = VM_FAULT_OOM;
> - else
> - ret = VM_FAULT_SIGBUS;
> + ret = vmf_error(PTR_ERR(page));
> goto out;
> }
> clear_huge_page(page, address, pages_per_huge_page(h));
> @@ -3870,12 +3867,12 @@ u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
> }
> #endif
>
> -int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
> +vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
> unsigned long address, unsigned int flags)
> {
> pte_t *ptep, entry;
> spinlock_t *ptl;
> - int ret;
> + vm_fault_t ret;
> u32 hash;
> pgoff_t idx;
> struct page *page = NULL;
> @@ -4206,7 +4203,7 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
> if (absent || is_swap_pte(huge_ptep_get(pte)) ||
> ((flags & FOLL_WRITE) &&
> !huge_pte_write(huge_ptep_get(pte)))) {
> - int ret;
> + vm_fault_t ret;
> unsigned int fault_flags = 0;
>
> if (pte)
> diff --git a/mm/internal.h b/mm/internal.h
> index 502d141..4044456 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -38,7 +38,7 @@
>
> void page_writeback_init(void);
>
> -int do_swap_page(struct vm_fault *vmf);
> +vm_fault_t do_swap_page(struct vm_fault *vmf);
>
> void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
> unsigned long floor, unsigned long ceiling);
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index d7b2a4b..778fd40 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -880,7 +880,8 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
> unsigned long address, pmd_t *pmd,
> int referenced)
> {
> - int swapped_in = 0, ret = 0;
> + int swapped_in = 0;
> + vm_fault_t ret = 0;
> struct vm_fault vmf = {
> .vma = vma,
> .address = address,
> diff --git a/mm/memory.c b/mm/memory.c
> index 01f5464..cee8245 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2360,9 +2360,9 @@ static gfp_t __get_fault_gfp_mask(struct vm_area_struct *vma)
> *
> * We do this without the lock held, so that it can sleep if it needs to.
> */
> -static int do_page_mkwrite(struct vm_fault *vmf)
> +static vm_fault_t do_page_mkwrite(struct vm_fault *vmf)
> {
> - int ret;
> + vm_fault_t ret;
> struct page *page = vmf->page;
> unsigned int old_flags = vmf->flags;
>
> @@ -2466,7 +2466,7 @@ static inline void wp_page_reuse(struct vm_fault *vmf)
> * held to the old page, as well as updating the rmap.
> * - In any case, unlock the PTL and drop the reference we took to the old page.
> */
> -static int wp_page_copy(struct vm_fault *vmf)
> +static vm_fault_t wp_page_copy(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> struct mm_struct *mm = vma->vm_mm;
> @@ -2614,7 +2614,7 @@ static int wp_page_copy(struct vm_fault *vmf)
> * The function expects the page to be locked or other protection against
> * concurrent faults / writeback (such as DAX radix tree locks).
> */
> -int finish_mkwrite_fault(struct vm_fault *vmf)
> +vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf)
> {
> WARN_ON_ONCE(!(vmf->vma->vm_flags & VM_SHARED));
> vmf->pte = pte_offset_map_lock(vmf->vma->vm_mm, vmf->pmd, vmf->address,
> @@ -2635,12 +2635,12 @@ int finish_mkwrite_fault(struct vm_fault *vmf)
> * Handle write page faults for VM_MIXEDMAP or VM_PFNMAP for a VM_SHARED
> * mapping
> */
> -static int wp_pfn_shared(struct vm_fault *vmf)
> +static vm_fault_t wp_pfn_shared(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
>
> if (vma->vm_ops && vma->vm_ops->pfn_mkwrite) {
> - int ret;
> + vm_fault_t ret;
>
> pte_unmap_unlock(vmf->pte, vmf->ptl);
> vmf->flags |= FAULT_FLAG_MKWRITE;
> @@ -2653,7 +2653,7 @@ static int wp_pfn_shared(struct vm_fault *vmf)
> return VM_FAULT_WRITE;
> }
>
> -static int wp_page_shared(struct vm_fault *vmf)
> +static vm_fault_t wp_page_shared(struct vm_fault *vmf)
> __releases(vmf->ptl)
> {
> struct vm_area_struct *vma = vmf->vma;
> @@ -2661,7 +2661,7 @@ static int wp_page_shared(struct vm_fault *vmf)
> get_page(vmf->page);
>
> if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
> - int tmp;
> + vm_fault_t tmp;
>
> pte_unmap_unlock(vmf->pte, vmf->ptl);
> tmp = do_page_mkwrite(vmf);
> @@ -2704,7 +2704,7 @@ static int wp_page_shared(struct vm_fault *vmf)
> * but allow concurrent faults), with pte both mapped and locked.
> * We return with mmap_sem still held, but pte unmapped and unlocked.
> */
> -static int do_wp_page(struct vm_fault *vmf)
> +static vm_fault_t do_wp_page(struct vm_fault *vmf)
> __releases(vmf->ptl)
> {
> struct vm_area_struct *vma = vmf->vma;
> @@ -2880,7 +2880,7 @@ void unmap_mapping_range(struct address_space *mapping,
> * We return with the mmap_sem locked or unlocked in the same cases
> * as does filemap_fault().
> */
> -int do_swap_page(struct vm_fault *vmf)
> +vm_fault_t do_swap_page(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> struct page *page = NULL, *swapcache;
> @@ -2889,7 +2889,7 @@ int do_swap_page(struct vm_fault *vmf)
> pte_t pte;
> int locked;
> int exclusive = 0;
> - int ret = 0;
> + vm_fault_t ret = 0;
>
> if (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, vmf->orig_pte))
> goto out;
> @@ -3100,12 +3100,12 @@ int do_swap_page(struct vm_fault *vmf)
> * but allow concurrent faults), and pte mapped but not yet locked.
> * We return with mmap_sem still held, but pte unmapped and unlocked.
> */
> -static int do_anonymous_page(struct vm_fault *vmf)
> +static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> struct mem_cgroup *memcg;
> struct page *page;
> - int ret = 0;
> + vm_fault_t ret = 0;
> pte_t entry;
>
> /* File mapping without ->vm_ops ? */
> @@ -3214,10 +3214,10 @@ static int do_anonymous_page(struct vm_fault *vmf)
> * released depending on flags and vma->vm_ops->fault() return value.
> * See filemap_fault() and __lock_page_retry().
> */
> -static int __do_fault(struct vm_fault *vmf)
> +static vm_fault_t __do_fault(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> - int ret;
> + vm_fault_t ret;
>
> ret = vma->vm_ops->fault(vmf);
> if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY |
> @@ -3251,7 +3251,7 @@ static int pmd_devmap_trans_unstable(pmd_t *pmd)
> return pmd_devmap(*pmd) || pmd_trans_unstable(pmd);
> }
>
> -static int pte_alloc_one_map(struct vm_fault *vmf)
> +static vm_fault_t pte_alloc_one_map(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
>
> @@ -3327,13 +3327,14 @@ static void deposit_prealloc_pte(struct vm_fault *vmf)
> vmf->prealloc_pte = NULL;
> }
>
> -static int do_set_pmd(struct vm_fault *vmf, struct page *page)
> +static vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
> {
> struct vm_area_struct *vma = vmf->vma;
> bool write = vmf->flags & FAULT_FLAG_WRITE;
> unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
> pmd_t entry;
> - int i, ret;
> + int i;
> + vm_fault_t ret;
>
> if (!transhuge_vma_suitable(vma, haddr))
> return VM_FAULT_FALLBACK;
> @@ -3383,7 +3384,7 @@ static int do_set_pmd(struct vm_fault *vmf, struct page *page)
> return ret;
> }
> #else
> -static int do_set_pmd(struct vm_fault *vmf, struct page *page)
> +static vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
> {
> BUILD_BUG();
> return 0;
> @@ -3404,13 +3405,13 @@ static int do_set_pmd(struct vm_fault *vmf, struct page *page)
> * Target users are page handler itself and implementations of
> * vm_ops->map_pages.
> */
> -int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
> +vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
> struct page *page)
> {
> struct vm_area_struct *vma = vmf->vma;
> bool write = vmf->flags & FAULT_FLAG_WRITE;
> pte_t entry;
> - int ret;
> + vm_fault_t ret;
>
> if (pmd_none(*vmf->pmd) && PageTransCompound(page) &&
> IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) {
> @@ -3469,10 +3470,10 @@ int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
> * The function expects the page to be locked and on success it consumes a
> * reference of a page being mapped (for the PTE which maps it).
> */
> -int finish_fault(struct vm_fault *vmf)
> +vm_fault_t finish_fault(struct vm_fault *vmf)
> {
> struct page *page;
> - int ret = 0;
> + vm_fault_t ret = 0;
>
> /* Did we COW the page? */
> if ((vmf->flags & FAULT_FLAG_WRITE) &&
> @@ -3558,12 +3559,13 @@ static int __init fault_around_debugfs(void)
> * (and therefore to page order). This way it's easier to guarantee
> * that we don't cross page table boundaries.
> */
> -static int do_fault_around(struct vm_fault *vmf)
> +static vm_fault_t do_fault_around(struct vm_fault *vmf)
> {
> unsigned long address = vmf->address, nr_pages, mask;
> pgoff_t start_pgoff = vmf->pgoff;
> pgoff_t end_pgoff;
> - int off, ret = 0;
> + int off;
> + vm_fault_t ret = 0;
>
> nr_pages = READ_ONCE(fault_around_bytes) >> PAGE_SHIFT;
> mask = ~(nr_pages * PAGE_SIZE - 1) & PAGE_MASK;
> @@ -3613,10 +3615,10 @@ static int do_fault_around(struct vm_fault *vmf)
> return ret;
> }
>
> -static int do_read_fault(struct vm_fault *vmf)
> +static vm_fault_t do_read_fault(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> - int ret = 0;
> + vm_fault_t ret = 0;
>
> /*
> * Let's call ->map_pages() first and use ->fault() as fallback
> @@ -3640,10 +3642,10 @@ static int do_read_fault(struct vm_fault *vmf)
> return ret;
> }
>
> -static int do_cow_fault(struct vm_fault *vmf)
> +static vm_fault_t do_cow_fault(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> - int ret;
> + vm_fault_t ret;
>
> if (unlikely(anon_vma_prepare(vma)))
> return VM_FAULT_OOM;
> @@ -3679,10 +3681,10 @@ static int do_cow_fault(struct vm_fault *vmf)
> return ret;
> }
>
> -static int do_shared_fault(struct vm_fault *vmf)
> +static vm_fault_t do_shared_fault(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> - int ret, tmp;
> + vm_fault_t ret, tmp;
>
> ret = __do_fault(vmf);
> if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
> @@ -3720,10 +3722,10 @@ static int do_shared_fault(struct vm_fault *vmf)
> * The mmap_sem may have been released depending on flags and our
> * return value. See filemap_fault() and __lock_page_or_retry().
> */
> -static int do_fault(struct vm_fault *vmf)
> +static vm_fault_t do_fault(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> - int ret;
> + vm_fault_t ret;
>
> /* The VMA was not fully populated on mmap() or missing VM_DONTEXPAND */
> if (!vma->vm_ops->fault)
> @@ -3758,7 +3760,7 @@ static int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
> return mpol_misplaced(page, vma, addr);
> }
>
> -static int do_numa_page(struct vm_fault *vmf)
> +static vm_fault_t do_numa_page(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> struct page *page = NULL;
> @@ -3848,7 +3850,7 @@ static int do_numa_page(struct vm_fault *vmf)
> return 0;
> }
>
> -static inline int create_huge_pmd(struct vm_fault *vmf)
> +static inline vm_fault_t create_huge_pmd(struct vm_fault *vmf)
> {
> if (vma_is_anonymous(vmf->vma))
> return do_huge_pmd_anonymous_page(vmf);
> @@ -3858,7 +3860,7 @@ static inline int create_huge_pmd(struct vm_fault *vmf)
> }
>
> /* `inline' is required to avoid gcc 4.1.2 build error */
> -static inline int wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd)
> +static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd)
> {
> if (vma_is_anonymous(vmf->vma))
> return do_huge_pmd_wp_page(vmf, orig_pmd);
> @@ -3877,7 +3879,7 @@ static inline bool vma_is_accessible(struct vm_area_struct *vma)
> return vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE);
> }
>
> -static int create_huge_pud(struct vm_fault *vmf)
> +static vm_fault_t create_huge_pud(struct vm_fault *vmf)
> {
> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> /* No support for anonymous transparent PUD pages yet */
> @@ -3889,7 +3891,7 @@ static int create_huge_pud(struct vm_fault *vmf)
> return VM_FAULT_FALLBACK;
> }
>
> -static int wp_huge_pud(struct vm_fault *vmf, pud_t orig_pud)
> +static vm_fault_t wp_huge_pud(struct vm_fault *vmf, pud_t orig_pud)
> {
> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> /* No support for anonymous transparent PUD pages yet */
> @@ -3916,7 +3918,7 @@ static int wp_huge_pud(struct vm_fault *vmf, pud_t orig_pud)
> * The mmap_sem may have been released depending on flags and our return value.
> * See filemap_fault() and __lock_page_or_retry().
> */
> -static int handle_pte_fault(struct vm_fault *vmf)
> +static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
> {
> pte_t entry;
>
> @@ -4004,8 +4006,8 @@ static int handle_pte_fault(struct vm_fault *vmf)
> * The mmap_sem may have been released depending on flags and our
> * return value. See filemap_fault() and __lock_page_or_retry().
> */
> -static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
> - unsigned int flags)
> +static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
> + unsigned long address, unsigned int flags)
> {
> struct vm_fault vmf = {
> .vma = vma,
> @@ -4018,7 +4020,7 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
> struct mm_struct *mm = vma->vm_mm;
> pgd_t *pgd;
> p4d_t *p4d;
> - int ret;
> + vm_fault_t ret;
>
> pgd = pgd_offset(mm, address);
> p4d = p4d_alloc(mm, pgd, address);
> @@ -4093,10 +4095,10 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
> * The mmap_sem may have been released depending on flags and our
> * return value. See filemap_fault() and __lock_page_or_retry().
> */
> -int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
> +vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
> unsigned int flags)
> {
> - int ret;
> + vm_fault_t ret;
>
> __set_current_state(TASK_RUNNING);
>
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 9d6c7e5..af05c35 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -123,7 +123,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
> static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
> struct page **pagep, enum sgp_type sgp,
> gfp_t gfp, struct vm_area_struct *vma,
> - struct vm_fault *vmf, int *fault_type);
> + struct vm_fault *vmf, vm_fault_t *fault_type);
>
> int shmem_getpage(struct inode *inode, pgoff_t index,
> struct page **pagep, enum sgp_type sgp)
> @@ -1604,7 +1604,8 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
> */
> static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
> struct page **pagep, enum sgp_type sgp, gfp_t gfp,
> - struct vm_area_struct *vma, struct vm_fault *vmf, int *fault_type)
> + struct vm_area_struct *vma, struct vm_fault *vmf,
> + vm_fault_t *fault_type)
> {
> struct address_space *mapping = inode->i_mapping;
> struct shmem_inode_info *info = SHMEM_I(inode);
> @@ -1931,14 +1932,14 @@ static int synchronous_wake_function(wait_queue_entry_t *wait, unsigned mode, in
> return ret;
> }
>
> -static int shmem_fault(struct vm_fault *vmf)
> +static vm_fault_t shmem_fault(struct vm_fault *vmf)
> {
> struct vm_area_struct *vma = vmf->vma;
> struct inode *inode = file_inode(vma->vm_file);
> gfp_t gfp = mapping_gfp_mask(inode->i_mapping);
> enum sgp_type sgp;
> - int error;
> - int ret = VM_FAULT_LOCKED;
> + int err;
> + vm_fault_t ret = VM_FAULT_LOCKED;
>
> /*
> * Trinity finds that probing a hole which tmpfs is punching can
> @@ -2006,10 +2007,10 @@ static int shmem_fault(struct vm_fault *vmf)
> else if (vma->vm_flags & VM_HUGEPAGE)
> sgp = SGP_HUGE;
>
> - error = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp,
> + err = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp,
> gfp, vma, vmf, &ret);
> - if (error)
> - return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS);
> + if (err)
> + ret = vmf_error(err);
> return ret;
> }
>
> --
> 1.9.1
>
Any further comment on this patch ?
