diff options
| -rw-r--r-- | mm/msync.c | 93 |
1 files changed, 61 insertions, 32 deletions
diff --git a/mm/msync.c b/mm/msync.c index 3563a56e1a51..8a66f5d5d4f0 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(¤t->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(¤t->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(¤t->mm->mmap_sem); + if ((flags & MS_ASYNC) && file && nr_pages_dirtied) { + get_file(file); + up_read(¤t->mm->mmap_sem); + balance_dirty_pages_ratelimited_nr(file->f_mapping, + nr_pages_dirtied); + fput(file); + down_read(¤t->mm->mmap_sem); + vma = find_vma(current->mm, start); + } else { + vma = vma->vm_next; + } + } while (!done); +out_unlock: current->flags &= ~PF_SYNCWRITE; + up_read(¤t->mm->mmap_sem); +out: return error; } |