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VM: make zap_page_range() callers that act on a single VMA use separate helper

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... and not rely on ->vm_next being there for them...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-03-05 14:14:20 -05:00
parent 6e8bb0193a
commit f5cc4eef99
1 changed files with 74 additions and 39 deletions
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97
mm/memory.c
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@ -1307,44 +1307,20 @@ static void unmap_page_range(struct mmu_gather *tlb,
mem_cgroup_uncharge_end();
}
/**
* unmap_vmas - unmap a range of memory covered by a list of vma's
* @tlb: address of the caller's struct mmu_gather
* @vma: the starting vma
* @start_addr: virtual address at which to start unmapping
* @end_addr: virtual address at which to end unmapping
* @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
* @details: details of nonlinear truncation or shared cache invalidation
*
* Unmap all pages in the vma list.
*
* Only addresses between `start' and `end' will be unmapped.
*
* The VMA list must be sorted in ascending virtual address order.
*
* unmap_vmas() assumes that the caller will flush the whole unmapped address
* range after unmap_vmas() returns. So the only responsibility here is to
* ensure that any thus-far unmapped pages are flushed before unmap_vmas()
* drops the lock and schedules.
*/
void unmap_vmas(struct mmu_gather *tlb,
static void unmap_single_vma(struct mmu_gather *tlb,
struct vm_area_struct *vma, unsigned long start_addr,
unsigned long end_addr, unsigned long *nr_accounted,
struct zap_details *details)
{
unsigned long start = start_addr;
struct mm_struct *mm = vma->vm_mm;
mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) {
unsigned long start = max(vma->vm_start, start_addr);
unsigned long end;
start = max(vma->vm_start, start_addr);
if (start >= vma->vm_end)
continue;
return;
end = min(vma->vm_end, end_addr);
if (end <= vma->vm_start)
continue;
return;
if (vma->vm_flags & VM_ACCOUNT)
*nr_accounted += (end - start) >> PAGE_SHIFT;
@ -1372,6 +1348,37 @@ void unmap_vmas(struct mmu_gather *tlb,
}
}
/**
* unmap_vmas - unmap a range of memory covered by a list of vma's
* @tlb: address of the caller's struct mmu_gather
* @vma: the starting vma
* @start_addr: virtual address at which to start unmapping
* @end_addr: virtual address at which to end unmapping
* @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
* @details: details of nonlinear truncation or shared cache invalidation
*
* Unmap all pages in the vma list.
*
* Only addresses between `start' and `end' will be unmapped.
*
* The VMA list must be sorted in ascending virtual address order.
*
* unmap_vmas() assumes that the caller will flush the whole unmapped address
* range after unmap_vmas() returns. So the only responsibility here is to
* ensure that any thus-far unmapped pages are flushed before unmap_vmas()
* drops the lock and schedules.
*/
void unmap_vmas(struct mmu_gather *tlb,
struct vm_area_struct *vma, unsigned long start_addr,
unsigned long end_addr, unsigned long *nr_accounted,
struct zap_details *details)
{
struct mm_struct *mm = vma->vm_mm;
mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next)
unmap_single_vma(tlb, vma, start_addr, end_addr, nr_accounted,
details);
mmu_notifier_invalidate_range_end(mm, start_addr, end_addr);
}
@ -1381,6 +1388,8 @@ void unmap_vmas(struct mmu_gather *tlb,
* @address: starting address of pages to zap
* @size: number of bytes to zap
* @details: details of nonlinear truncation or shared cache invalidation
*
* Caller must protect the VMA list
*/
void zap_page_range(struct vm_area_struct *vma, unsigned long address,
unsigned long size, struct zap_details *details)
@ -1397,6 +1406,32 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long address,
tlb_finish_mmu(&tlb, address, end);
}
/**
* zap_page_range_single - remove user pages in a given range
* @vma: vm_area_struct holding the applicable pages
* @address: starting address of pages to zap
* @size: number of bytes to zap
* @details: details of nonlinear truncation or shared cache invalidation
*
* The range must fit into one VMA.
*/
static void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
unsigned long size, struct zap_details *details)
{
struct mm_struct *mm = vma->vm_mm;
struct mmu_gather tlb;
unsigned long end = address + size;
unsigned long nr_accounted = 0;
lru_add_drain();
tlb_gather_mmu(&tlb, mm, 0);
update_hiwater_rss(mm);
mmu_notifier_invalidate_range_start(mm, address, end);
unmap_single_vma(&tlb, vma, address, end, &nr_accounted, details);
mmu_notifier_invalidate_range_end(mm, address, end);
tlb_finish_mmu(&tlb, address, end);
}
/**
* zap_vma_ptes - remove ptes mapping the vma
* @vma: vm_area_struct holding ptes to be zapped
@ -1415,7 +1450,7 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
if (address < vma->vm_start || address + size > vma->vm_end ||
!(vma->vm_flags & VM_PFNMAP))
return -1;
zap_page_range(vma, address, size, NULL);
zap_page_range_single(vma, address, size, NULL);
return 0;
}
EXPORT_SYMBOL_GPL(zap_vma_ptes);
@ -2762,7 +2797,7 @@ static void unmap_mapping_range_vma(struct vm_area_struct *vma,
unsigned long start_addr, unsigned long end_addr,
struct zap_details *details)
{
zap_page_range(vma, start_addr, end_addr - start_addr, details);
zap_page_range_single(vma, start_addr, end_addr - start_addr, details);
}
static inline void unmap_mapping_range_tree(struct prio_tree_root *root,