*/
#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/writeback.h>
+#include <linux/file.h>
#include <linux/syscalls.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
-/*
- * Called with mm->page_table_lock held to protect against other
- * threads/the swapper from ripping pte's out from under us.
- */
-
-static void sync_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;
- pte = pte_offset_map(pmd, addr);
+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;
- pfn = pte_pfn(*pte);
- if (!pfn_valid(pfn))
+ if (!pte_maybe_dirty(*pte))
continue;
- page = pfn_to_page(pfn);
- if (PageReserved(page))
+ 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);
+ page_test_and_clear_dirty(page))
+ ret += set_page_dirty(page);
+ progress += 3;
} while (pte++, addr += PAGE_SIZE, addr != end);
- pte_unmap(pte - 1);
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+ if (addr != end)
+ goto again;
+ return ret;
}
-static inline void sync_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;
- sync_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 sync_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;
- sync_pmd_range(vma, pud, addr, next);
+ ret += msync_pmd_range(vma, pud, addr, next);
} while (pud++, addr = next, addr != end);
+ return ret;
}
-static void sync_page_range(struct vm_area_struct *vma,
+static unsigned long msync_page_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end)
{
- struct mm_struct *mm = vma->vm_mm;
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 (is_vm_hugetlb_page(vma))
- return;
+ * to do anything more on an msync().
+ */
+ if (vma->vm_flags & VM_HUGETLB)
+ return 0;
BUG_ON(addr >= end);
- pgd = pgd_offset(mm, addr);
+ pgd = pgd_offset(vma->vm_mm, addr);
flush_cache_range(vma, addr, end);
- spin_lock(&mm->page_table_lock);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
- sync_pud_range(vma, pgd, addr, next);
+ ret += msync_pud_range(vma, pgd, addr, next);
} while (pgd++, addr = next, addr != end);
- spin_unlock(&mm->page_table_lock);
-}
-
-#ifdef CONFIG_PREEMPT
-static inline void filemap_sync(struct vm_area_struct *vma,
- unsigned long addr, unsigned long end)
-{
- const size_t chunk = 64 * 1024; /* bytes */
- unsigned long next;
-
- do {
- next = addr + chunk;
- if (next > end || next < addr)
- next = end;
- sync_page_range(vma, addr, next);
- cond_resched();
- } while (addr = next, addr != end);
-}
-#else
-static inline void filemap_sync(struct vm_area_struct *vma,
- unsigned long addr, unsigned long end)
-{
- sync_page_range(vma, addr, end);
+ return ret;
}
-#endif
/*
* MS_SYNC syncs the entire file - including mappings.
* 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)
+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;
if ((flags & MS_INVALIDATE) && (vma->vm_flags & VM_LOCKED))
return -EBUSY;
- if (file && (vma->vm_flags & VM_SHARED)) {
- filemap_sync(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;
+ if (file && (vma->vm_flags & VM_SHARED))
+ *nr_pages_dirtied = msync_page_range(vma, addr, end);
+ return 0;
}
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 unmapped_error = 0;
+ int 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)
* 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 (;;) {
- /* Still start < end. */
+ if (!vma) {
error = -ENOMEM;
- if (!vma)
- goto out;
+ goto out_unlock;
+ }
+ do {
+ unsigned long nr_pages_dirtied = 0;
+ struct file *file;
+
/* Here start < vma->vm_end. */
if (start < vma->vm_start) {
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);
+ 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 if ((flags & MS_SYNC) && file &&
+ (vma->vm_flags & VM_SHARED)) {
+ get_file(file);
+ up_read(¤t->mm->mmap_sem);
+ error = do_fsync(file, 0);
+ fput(file);
+ down_read(¤t->mm->mmap_sem);
+ if (error)
+ goto out_unlock;
+ vma = find_vma(current->mm, start);
+ } else {
+ vma = vma->vm_next;
+ }
+ } while (vma && !done);
+out_unlock:
current->flags &= ~PF_SYNCWRITE;
+ up_read(¤t->mm->mmap_sem);
+out:
return error;
}
git://git.onelab.eu / linux-2.6.git / blobdiff