[PATCH v8 05/22] Add vm_replace_mixed()
From: Matthew Wilcox <hidden>
Date: 2014-07-22 19:47:53
Also in:
linux-fsdevel, lkml
Subsystem:
memory management, memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
From: Matthew Wilcox <redacted> vm_insert_mixed() will fail if there is already a valid PTE at that location. The DAX code would rather replace the previous value with the new PTE. Signed-off-by: Matthew Wilcox <redacted> --- include/linux/mm.h | 8 ++++++-- mm/memory.c | 34 +++++++++++++++++++++------------- 2 files changed, 27 insertions(+), 15 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e04f531..8d1194c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -1958,8 +1958,12 @@ int remap_pfn_range(struct vm_area_struct *, unsigned long addr, int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *); int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn); -int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, - unsigned long pfn); +int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, bool replace); +#define vm_insert_mixed(vma, addr, pfn) \ + __vm_insert_mixed(vma, addr, pfn, false) +#define vm_replace_mixed(vma, addr, pfn) \ + __vm_insert_mixed(vma, addr, pfn, true) int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
diff --git a/mm/memory.c b/mm/memory.c
index 42bf429..cf06c97 100644
--- a/mm/memory.c
+++ b/mm/memory.c@@ -1476,7 +1476,7 @@ pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr, * pages reserved for the old functions anyway. */ static int insert_page(struct vm_area_struct *vma, unsigned long addr, - struct page *page, pgprot_t prot) + struct page *page, pgprot_t prot, bool replace) { struct mm_struct *mm = vma->vm_mm; int retval;
@@ -1492,8 +1492,12 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr, if (!pte) goto out; retval = -EBUSY; - if (!pte_none(*pte)) - goto out_unlock; + if (!pte_none(*pte)) { + if (!replace) + goto out_unlock; + VM_BUG_ON(!mutex_is_locked(&vma->vm_file->f_mapping->i_mmap_mutex)); + zap_page_range_single(vma, addr, PAGE_SIZE, NULL); + } /* Ok, finally just insert the thing.. */ get_page(page);
@@ -1549,12 +1553,12 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, BUG_ON(vma->vm_flags & VM_PFNMAP); vma->vm_flags |= VM_MIXEDMAP; } - return insert_page(vma, addr, page, vma->vm_page_prot); + return insert_page(vma, addr, page, vma->vm_page_prot, false); } EXPORT_SYMBOL(vm_insert_page); static int insert_pfn(struct vm_area_struct *vma, unsigned long addr, - unsigned long pfn, pgprot_t prot) + unsigned long pfn, pgprot_t prot, bool replace) { struct mm_struct *mm = vma->vm_mm; int retval;
@@ -1566,8 +1570,12 @@ static int insert_pfn(struct vm_area_struct *vma, unsigned long addr, if (!pte) goto out; retval = -EBUSY; - if (!pte_none(*pte)) - goto out_unlock; + if (!pte_none(*pte)) { + if (!replace) + goto out_unlock; + VM_BUG_ON(!mutex_is_locked(&vma->vm_file->f_mapping->i_mmap_mutex)); + zap_page_range_single(vma, addr, PAGE_SIZE, NULL); + } /* Ok, finally just insert the thing.. */ entry = pte_mkspecial(pfn_pte(pfn, prot));
@@ -1620,14 +1628,14 @@ int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, if (track_pfn_insert(vma, &pgprot, pfn)) return -EINVAL; - ret = insert_pfn(vma, addr, pfn, pgprot); + ret = insert_pfn(vma, addr, pfn, pgprot, false); return ret; } EXPORT_SYMBOL(vm_insert_pfn); -int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, - unsigned long pfn) +int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, bool replace) { BUG_ON(!(vma->vm_flags & VM_MIXEDMAP));
@@ -1645,11 +1653,11 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, struct page *page; page = pfn_to_page(pfn); - return insert_page(vma, addr, page, vma->vm_page_prot); + return insert_page(vma, addr, page, vma->vm_page_prot, replace); } - return insert_pfn(vma, addr, pfn, vma->vm_page_prot); + return insert_pfn(vma, addr, pfn, vma->vm_page_prot, replace); } -EXPORT_SYMBOL(vm_insert_mixed); +EXPORT_SYMBOL(__vm_insert_mixed); /* * maps a range of physical memory into the requested pages. the old
--
2.0.0
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