/*
* The msync() system call.
*/
-#include <linux/slab.h>
-#include <linux/pagemap.h>
+#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/mman.h>
-#include <linux/hugetlb.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,
- unsigned long addr, unsigned long end)
-{
- pte_t *pte;
- spinlock_t *ptl;
- int progress = 0;
-
-again:
- pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
- do {
- unsigned long pfn;
- struct page *page;
-
- if (progress >= 64) {
- progress = 0;
- if (need_resched() || need_lockbreak(ptl))
- break;
- }
- progress++;
- if (!pte_present(*pte))
- continue;
- if (!pte_maybe_dirty(*pte))
- continue;
- pfn = pte_pfn(*pte);
- if (unlikely(!pfn_valid(pfn))) {
- print_bad_pte(vma, *pte, addr);
- continue;
- }
- page = pfn_to_page(pfn);
-
- if (ptep_clear_flush_dirty(vma, addr, pte) ||
- page_test_and_clear_dirty(page))
- 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;
-}
-
-static inline void msync_pmd_range(struct vm_area_struct *vma, pud_t *pud,
- unsigned long addr, unsigned long end)
-{
- pmd_t *pmd;
- unsigned long next;
-
- 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);
- } while (pmd++, addr = next, addr != end);
-}
-
-static inline void msync_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
- unsigned long addr, unsigned long end)
-{
- pud_t *pud;
- unsigned long next;
-
- 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);
- } while (pud++, addr = next, addr != end);
-}
-
-static void msync_page_range(struct vm_area_struct *vma,
- unsigned long addr, unsigned long end)
-{
- pgd_t *pgd;
- unsigned long next;
-
- /* 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().
- * Can't do anything with VM_RESERVED regions either.
- */
- if (vma->vm_flags & (VM_HUGETLB|VM_RESERVED))
- return;
-
- BUG_ON(addr >= end);
- pgd = pgd_offset(vma->vm_mm, addr);
- flush_cache_range(vma, addr, end);
- do {
- next = pgd_addr_end(addr, end);
- if (pgd_none_or_clear_bad(pgd))
- continue;
- msync_pud_range(vma, pgd, addr, next);
- } while (pgd++, addr = next, addr != end);
-}
-
/*
* MS_SYNC syncs the entire file - including mappings.
*
- * MS_ASYNC does not start I/O (it used to, up to 2.5.67). Instead, it just
- * marks the relevant pages dirty. The application may now run fsync() to
+ * MS_ASYNC does not start I/O (it used to, up to 2.5.67).
+ * Nor does it marks the relevant pages dirty (it used to up to 2.6.17).
+ * Now it doesn't do anything, since dirty pages are properly tracked.
+ *
+ * The application may now run fsync() to
* write out the dirty pages and wait on the writeout and check the result.
* Or the application may run fadvise(FADV_DONTNEED) against the fd to start
* async writeout immediately.
- * So my _not_ starting I/O in MS_ASYNC we provide complete flexibility to
+ * So by _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)
-{
- int ret = 0;
- struct file *file = vma->vm_file;
-
- if ((flags & MS_INVALIDATE) && (vma->vm_flags & VM_LOCKED))
- return -EBUSY;
-
- if (file && (vma->vm_flags & VM_SHARED)) {
- msync_page_range(vma, addr, end);
-
- if (flags & MS_SYNC) {
- struct address_space *mapping = file->f_mapping;
- int err;
-
- ret = filemap_fdatawrite(mapping);
- if (file->f_op && file->f_op->fsync) {
- /*
- * We don't take i_sem here because mmap_sem
- * is already held.
- */
- err = file->f_op->fsync(file,file->f_dentry,1);
- if (err && !ret)
- ret = err;
- }
- err = filemap_fdatawait(mapping);
- if (!ret)
- ret = err;
- }
- }
- return ret;
-}
-
asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
{
unsigned long end;
+ struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
- int unmapped_error, error = -EINVAL;
+ int unmapped_error = 0;
+ int error = -EINVAL;
- 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)
* If the interval [start,end) covers some unmapped address ranges,
* just ignore them, but return -ENOMEM at the end.
*/
- vma = find_vma(current->mm, start);
- unmapped_error = 0;
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, start);
for (;;) {
+ 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;
start = vma->vm_start;
+ if (start >= end)
+ goto out_unlock;
+ unmapped_error = -ENOMEM;
}
/* Here vma->vm_start <= start < vma->vm_end. */
- if (end <= vma->vm_end) {
- if (start < end) {
- error = msync_interval(vma, start, end, flags);
- if (error)
- goto out;
- }
- error = unmapped_error;
- goto out;
+ if ((flags & MS_INVALIDATE) &&
+ (vma->vm_flags & VM_LOCKED)) {
+ error = -EBUSY;
+ 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;
+ if ((flags & MS_SYNC) && file &&
+ (vma->vm_flags & VM_SHARED)) {
+ get_file(file);
+ up_read(&mm->mmap_sem);
+ error = do_fsync(file, 0);
+ fput(file);
+ if (error || start >= end)
+ goto out;
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, start);
+ } else {
+ if (start >= end) {
+ error = 0;
+ goto out_unlock;
+ }
+ vma = vma->vm_next;
+ }
}
+out_unlock:
+ up_read(&mm->mmap_sem);
out:
- up_read(¤t->mm->mmap_sem);
- current->flags &= ~PF_SYNCWRITE;
- return error;
+ return error ? : unmapped_error;
}
projects / linux.git / blobdiff