From 936ca80d3773bd9b6dda8a0dfd54425f9ec1be9d Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 14 Dec 2016 15:07:10 -0800 Subject: [PATCH] mm: trim __do_fault() arguments Use vm_fault structure to pass cow_page, page, and entry in and out of the function. That reduces number of __do_fault() arguments from 4 to 1. Link: http://lkml.kernel.org/r/1479460644-25076-6-git-send-email-jack@suse.cz Signed-off-by: Jan Kara Reviewed-by: Ross Zwisler Acked-by: Kirill A. Shutemov Cc: Dan Williams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 67 +++++++++++++++++++++++------------------------------ 1 file changed, 29 insertions(+), 38 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index cbc6d47fda73..78b81e8984df 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2844,26 +2844,22 @@ oom: * 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, struct page *cow_page, - struct page **page, void **entry) +static int __do_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; int ret; - vmf->cow_page = cow_page; - ret = vma->vm_ops->fault(vma, vmf); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) return ret; - if (ret & VM_FAULT_DAX_LOCKED) { - *entry = vmf->entry; + if (ret & VM_FAULT_DAX_LOCKED) return ret; - } if (unlikely(PageHWPoison(vmf->page))) { if (ret & VM_FAULT_LOCKED) unlock_page(vmf->page); put_page(vmf->page); + vmf->page = NULL; return VM_FAULT_HWPOISON; } @@ -2872,7 +2868,6 @@ static int __do_fault(struct vm_fault *vmf, struct page *cow_page, else VM_BUG_ON_PAGE(!PageLocked(vmf->page), vmf->page); - *page = vmf->page; return ret; } @@ -3208,7 +3203,6 @@ out: static int do_read_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; - struct page *fault_page; int ret = 0; /* @@ -3222,54 +3216,52 @@ static int do_read_fault(struct vm_fault *vmf) return ret; } - ret = __do_fault(vmf, NULL, &fault_page, NULL); + ret = __do_fault(vmf); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) return ret; - ret |= alloc_set_pte(vmf, NULL, fault_page); + ret |= alloc_set_pte(vmf, NULL, vmf->page); if (vmf->pte) pte_unmap_unlock(vmf->pte, vmf->ptl); - unlock_page(fault_page); + unlock_page(vmf->page); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) - put_page(fault_page); + put_page(vmf->page); return ret; } static int do_cow_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; - struct page *fault_page, *new_page; - void *fault_entry; struct mem_cgroup *memcg; int ret; if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM; - new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vmf->address); - if (!new_page) + vmf->cow_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vmf->address); + if (!vmf->cow_page) return VM_FAULT_OOM; - if (mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL, + if (mem_cgroup_try_charge(vmf->cow_page, vma->vm_mm, GFP_KERNEL, &memcg, false)) { - put_page(new_page); + put_page(vmf->cow_page); return VM_FAULT_OOM; } - ret = __do_fault(vmf, new_page, &fault_page, &fault_entry); + ret = __do_fault(vmf); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) goto uncharge_out; if (!(ret & VM_FAULT_DAX_LOCKED)) - copy_user_highpage(new_page, fault_page, vmf->address, vma); - __SetPageUptodate(new_page); + copy_user_highpage(vmf->cow_page, vmf->page, vmf->address, vma); + __SetPageUptodate(vmf->cow_page); - ret |= alloc_set_pte(vmf, memcg, new_page); + ret |= alloc_set_pte(vmf, memcg, vmf->cow_page); if (vmf->pte) pte_unmap_unlock(vmf->pte, vmf->ptl); if (!(ret & VM_FAULT_DAX_LOCKED)) { - unlock_page(fault_page); - put_page(fault_page); + unlock_page(vmf->page); + put_page(vmf->page); } else { dax_unlock_mapping_entry(vma->vm_file->f_mapping, vmf->pgoff); } @@ -3277,20 +3269,19 @@ static int do_cow_fault(struct vm_fault *vmf) goto uncharge_out; return ret; uncharge_out: - mem_cgroup_cancel_charge(new_page, memcg, false); - put_page(new_page); + mem_cgroup_cancel_charge(vmf->cow_page, memcg, false); + put_page(vmf->cow_page); return ret; } static int do_shared_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; - struct page *fault_page; struct address_space *mapping; int dirtied = 0; int ret, tmp; - ret = __do_fault(vmf, NULL, &fault_page, NULL); + ret = __do_fault(vmf); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) return ret; @@ -3299,26 +3290,26 @@ static int do_shared_fault(struct vm_fault *vmf) * about to become writable */ if (vma->vm_ops->page_mkwrite) { - unlock_page(fault_page); - tmp = do_page_mkwrite(vma, fault_page, vmf->address); + unlock_page(vmf->page); + tmp = do_page_mkwrite(vma, vmf->page, vmf->address); if (unlikely(!tmp || (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { - put_page(fault_page); + put_page(vmf->page); return tmp; } } - ret |= alloc_set_pte(vmf, NULL, fault_page); + ret |= alloc_set_pte(vmf, NULL, vmf->page); if (vmf->pte) pte_unmap_unlock(vmf->pte, vmf->ptl); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) { - unlock_page(fault_page); - put_page(fault_page); + unlock_page(vmf->page); + put_page(vmf->page); return ret; } - if (set_page_dirty(fault_page)) + if (set_page_dirty(vmf->page)) dirtied = 1; /* * Take a local copy of the address_space - page.mapping may be zeroed @@ -3326,8 +3317,8 @@ static int do_shared_fault(struct vm_fault *vmf) * pinned by vma->vm_file's reference. We rely on unlock_page()'s * release semantics to prevent the compiler from undoing this copying. */ - mapping = page_rmapping(fault_page); - unlock_page(fault_page); + mapping = page_rmapping(vmf->page); + unlock_page(vmf->page); if ((dirtied || vma->vm_ops->page_mkwrite) && mapping) { /* * Some device drivers do not set page.mapping but still -- 2.20.1