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Diffstat (limited to 'mm/msync.c')
-rw-r--r--mm/msync.c93
1 files changed, 61 insertions, 32 deletions
diff --git a/mm/msync.c b/mm/msync.c
index 3563a56..8a66f5d 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -12,17 +12,20 @@
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/hugetlb.h>
+#include <linux/writeback.h>
+#include <linux/file.h>
#include <linux/syscalls.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
-static void msync_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
+static unsigned long msync_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end)
{
pte_t *pte;
spinlock_t *ptl;
int progress = 0;
+ unsigned long ret = 0;
again:
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
@@ -43,58 +46,64 @@ again:
if (!page)
continue;
if (ptep_clear_flush_dirty(vma, addr, pte) ||
- page_test_and_clear_dirty(page))
- set_page_dirty(page);
+ page_test_and_clear_dirty(page))
+ ret += set_page_dirty(page);
progress += 3;
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_unmap_unlock(pte - 1, ptl);
cond_resched();
if (addr != end)
goto again;
+ return ret;
}
-static inline void msync_pmd_range(struct vm_area_struct *vma, pud_t *pud,
- unsigned long addr, unsigned long end)
+static inline unsigned long msync_pmd_range(struct vm_area_struct *vma,
+ pud_t *pud, unsigned long addr, unsigned long end)
{
pmd_t *pmd;
unsigned long next;
+ unsigned long ret = 0;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none_or_clear_bad(pmd))
continue;
- msync_pte_range(vma, pmd, addr, next);
+ ret += msync_pte_range(vma, pmd, addr, next);
} while (pmd++, addr = next, addr != end);
+ return ret;
}
-static inline void msync_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
- unsigned long addr, unsigned long end)
+static inline unsigned long msync_pud_range(struct vm_area_struct *vma,
+ pgd_t *pgd, unsigned long addr, unsigned long end)
{
pud_t *pud;
unsigned long next;
+ unsigned long ret = 0;
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
continue;
- msync_pmd_range(vma, pud, addr, next);
+ ret += msync_pmd_range(vma, pud, addr, next);
} while (pud++, addr = next, addr != end);
+ return ret;
}
-static void msync_page_range(struct vm_area_struct *vma,
+static unsigned long msync_page_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end)
{
pgd_t *pgd;
unsigned long next;
+ unsigned long ret = 0;
/* For hugepages we can't go walking the page table normally,
* but that's ok, hugetlbfs is memory based, so we don't need
* to do anything more on an msync().
*/
if (vma->vm_flags & VM_HUGETLB)
- return;
+ return 0;
BUG_ON(addr >= end);
pgd = pgd_offset(vma->vm_mm, addr);
@@ -103,8 +112,9 @@ static void msync_page_range(struct vm_area_struct *vma,
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
- msync_pud_range(vma, pgd, addr, next);
+ ret += msync_pud_range(vma, pgd, addr, next);
} while (pgd++, addr = next, addr != end);
+ return ret;
}
/*
@@ -118,8 +128,9 @@ static void msync_page_range(struct vm_area_struct *vma,
* So my _not_ starting I/O in MS_ASYNC we provide complete flexibility to
* applications.
*/
-static int msync_interval(struct vm_area_struct *vma,
- unsigned long addr, unsigned long end, int flags)
+static int msync_interval(struct vm_area_struct *vma, unsigned long addr,
+ unsigned long end, int flags,
+ unsigned long *nr_pages_dirtied)
{
int ret = 0;
struct file *file = vma->vm_file;
@@ -128,7 +139,7 @@ static int msync_interval(struct vm_area_struct *vma,
return -EBUSY;
if (file && (vma->vm_flags & VM_SHARED)) {
- msync_page_range(vma, addr, end);
+ *nr_pages_dirtied = msync_page_range(vma, addr, end);
if (flags & MS_SYNC) {
struct address_space *mapping = file->f_mapping;
@@ -157,11 +168,8 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
unsigned long end;
struct vm_area_struct *vma;
int unmapped_error, error = -EINVAL;
+ int done = 0;
- if (flags & MS_SYNC)
- current->flags |= PF_SYNCWRITE;
-
- down_read(&current->mm->mmap_sem);
if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
goto out;
if (start & ~PAGE_MASK)
@@ -180,13 +188,19 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
* If the interval [start,end) covers some unmapped address ranges,
* just ignore them, but return -ENOMEM at the end.
*/
+ down_read(&current->mm->mmap_sem);
+ if (flags & MS_SYNC)
+ current->flags |= PF_SYNCWRITE;
vma = find_vma(current->mm, start);
unmapped_error = 0;
- for (;;) {
+ do {
+ unsigned long nr_pages_dirtied = 0;
+ struct file *file;
+
/* Still start < end. */
error = -ENOMEM;
if (!vma)
- goto out;
+ goto out_unlock;
/* Here start < vma->vm_end. */
if (start < vma->vm_start) {
unmapped_error = -ENOMEM;
@@ -195,22 +209,37 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
/* Here vma->vm_start <= start < vma->vm_end. */
if (end <= vma->vm_end) {
if (start < end) {
- error = msync_interval(vma, start, end, flags);
+ error = msync_interval(vma, start, end, flags,
+ &nr_pages_dirtied);
if (error)
- goto out;
+ goto out_unlock;
}
error = unmapped_error;
- goto out;
+ done = 1;
+ } else {
+ /* Here vma->vm_start <= start < vma->vm_end < end. */
+ error = msync_interval(vma, start, vma->vm_end, flags,
+ &nr_pages_dirtied);
+ if (error)
+ goto out_unlock;
}
- /* Here vma->vm_start <= start < vma->vm_end < end. */
- error = msync_interval(vma, start, vma->vm_end, flags);
- if (error)
- goto out;
+ file = vma->vm_file;
start = vma->vm_end;
- vma = vma->vm_next;
- }
-out:
- up_read(&current->mm->mmap_sem);
+ if ((flags & MS_ASYNC) && file && nr_pages_dirtied) {
+ get_file(file);
+ up_read(&current->mm->mmap_sem);
+ balance_dirty_pages_ratelimited_nr(file->f_mapping,
+ nr_pages_dirtied);
+ fput(file);
+ down_read(&current->mm->mmap_sem);
+ vma = find_vma(current->mm, start);
+ } else {
+ vma = vma->vm_next;
+ }
+ } while (!done);
+out_unlock:
current->flags &= ~PF_SYNCWRITE;
+ up_read(&current->mm->mmap_sem);
+out:
return error;
}
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