/*
* The msync() system call.
*/
-#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
#include <linux/mm.h>
#include <linux/mman.h>
-#include <linux/file.h>
+#include <linux/hugetlb.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 {
+ 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;
+ page = vm_normal_page(vma, addr, *pte);
+ if (!page)
+ continue;
+ 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().
+ */
+ if (vma->vm_flags & VM_HUGETLB)
+ 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).
- * 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
+ * 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
* 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 by _not_ starting I/O in MS_ASYNC we provide complete flexibility to
+ * 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)
+{
+ 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_mutex 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 = 0;
- int error = -EINVAL;
+ int unmapped_error, 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.
*/
- down_read(&mm->mmap_sem);
- vma = find_vma(mm, start);
+ vma = find_vma(current->mm, start);
+ unmapped_error = 0;
for (;;) {
- struct file *file;
-
/* Still start < end. */
error = -ENOMEM;
if (!vma)
- goto out_unlock;
+ goto out;
/* Here start < vma->vm_end. */
if (start < vma->vm_start) {
- start = vma->vm_start;
- if (start >= end)
- goto out_unlock;
unmapped_error = -ENOMEM;
+ start = vma->vm_start;
}
/* Here vma->vm_start <= start < vma->vm_end. */
- if ((flags & MS_INVALIDATE) &&
- (vma->vm_flags & VM_LOCKED)) {
- error = -EBUSY;
- goto out_unlock;
- }
- file = vma->vm_file;
- start = vma->vm_end;
- 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;
+ if (end <= vma->vm_end) {
+ if (start < end) {
+ error = msync_interval(vma, start, end, flags);
+ if (error)
+ goto out;
}
- vma = vma->vm_next;
+ error = unmapped_error;
+ goto out;
}
+ /* Here vma->vm_start <= start < vma->vm_end < end. */
+ error = msync_interval(vma, start, vma->vm_end, flags);
+ if (error)
+ goto out;
+ start = vma->vm_end;
+ vma = vma->vm_next;
}
-out_unlock:
- up_read(&mm->mmap_sem);
out:
- return error ? : unmapped_error;
+ up_read(¤t->mm->mmap_sem);
+ current->flags &= ~PF_SYNCWRITE;
+ return error;
}
git://git.onelab.eu / linux-2.6.git / blobdiff