#include <linux/pagemap.h>
#include <linux/rmap.h>
#include <linux/module.h>
+#include <linux/delayacct.h>
#include <linux/init.h>
+#include <linux/writeback.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
pmd_clear(pmd);
pte_lock_deinit(page);
pte_free_tlb(tlb, page);
- dec_page_state(nr_page_table_pages);
+ dec_zone_page_state(page, NR_PAGETABLE);
tlb->mm->nr_ptes--;
}
pte_free(new);
} else {
mm->nr_ptes++;
- inc_page_state(nr_page_table_pages);
+ inc_zone_page_state(new, NR_PAGETABLE);
pmd_populate(mm, pmd, new);
}
spin_unlock(&mm->page_table_lock);
* and that the resulting page looks ok.
*/
if (unlikely(!pfn_valid(pfn))) {
- print_bad_pte(vma, pte, addr);
+ if (!(vma->vm_flags & VM_RESERVED))
+ print_bad_pte(vma, pte, addr);
return NULL;
}
/* pte contains position in swap or file, so copy. */
if (unlikely(!pte_present(pte))) {
if (!pte_file(pte)) {
- swap_duplicate(pte_to_swp_entry(pte));
+ swp_entry_t entry = pte_to_swp_entry(pte);
+
+ swap_duplicate(entry);
/* make sure dst_mm is on swapoff's mmlist. */
if (unlikely(list_empty(&dst_mm->mmlist))) {
spin_lock(&mmlist_lock);
&src_mm->mmlist);
spin_unlock(&mmlist_lock);
}
+ if (is_write_migration_entry(entry) &&
+ is_cow_mapping(vm_flags)) {
+ /*
+ * COW mappings require pages in both parent
+ * and child to be set to read.
+ */
+ make_migration_entry_read(&entry);
+ pte = swp_entry_to_pte(entry);
+ set_pte_at(src_mm, addr, src_pte, pte);
+ }
}
goto out_set_pte;
}
return -ENOMEM;
src_pte = pte_offset_map_nested(src_pmd, addr);
src_ptl = pte_lockptr(src_mm, src_pmd);
- spin_lock(src_ptl);
+ spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
do {
/*
mark_page_accessed(page);
file_rss--;
}
- page_remove_rmap(page);
+ page_remove_rmap(page, vma);
tlb_remove_page(tlb, page);
continue;
}
tlb_finish_mmu(tlb, address, end);
return end;
}
+EXPORT_SYMBOL(zap_page_range);
/*
* Do a quick page-table lookup for a single page.
continue;
}
+#ifdef CONFIG_XEN
+ if (vma && (vma->vm_flags & VM_FOREIGN)) {
+ struct page **map = vma->vm_private_data;
+ int offset = (start - vma->vm_start) >> PAGE_SHIFT;
+ if (map[offset] != NULL) {
+ if (pages) {
+ struct page *page = map[offset];
+
+ pages[i] = page;
+ get_page(page);
+ }
+ if (vmas)
+ vmas[i] = vma;
+ i++;
+ start += PAGE_SIZE;
+ len--;
+ continue;
+ }
+ }
+#endif
if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP))
|| !(vm_flags & vma->vm_flags))
return i ? : -EFAULT;
}
EXPORT_SYMBOL(remap_pfn_range);
+#ifdef CONFIG_XEN
+static inline int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ pte_fn_t fn, void *data)
+{
+ pte_t *pte;
+ int err;
+ struct page *pmd_page;
+ spinlock_t *ptl;
+
+ pte = (mm == &init_mm) ?
+ pte_alloc_kernel(pmd, addr) :
+ pte_alloc_map_lock(mm, pmd, addr, &ptl);
+ if (!pte)
+ return -ENOMEM;
+
+ BUG_ON(pmd_huge(*pmd));
+
+ pmd_page = pmd_page(*pmd);
+
+ do {
+ err = fn(pte, pmd_page, addr, data);
+ if (err)
+ break;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+
+ if (mm != &init_mm)
+ pte_unmap_unlock(pte-1, ptl);
+ return err;
+}
+
+static inline int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ pte_fn_t fn, void *data)
+{
+ pmd_t *pmd;
+ unsigned long next;
+ int err;
+
+ pmd = pmd_alloc(mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
+ do {
+ next = pmd_addr_end(addr, end);
+ err = apply_to_pte_range(mm, pmd, addr, next, fn, data);
+ if (err)
+ break;
+ } while (pmd++, addr = next, addr != end);
+ return err;
+}
+
+static inline int apply_to_pud_range(struct mm_struct *mm, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ pte_fn_t fn, void *data)
+{
+ pud_t *pud;
+ unsigned long next;
+ int err;
+
+ pud = pud_alloc(mm, pgd, addr);
+ if (!pud)
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+ err = apply_to_pmd_range(mm, pud, addr, next, fn, data);
+ if (err)
+ break;
+ } while (pud++, addr = next, addr != end);
+ return err;
+}
+
+/*
+ * Scan a region of virtual memory, filling in page tables as necessary
+ * and calling a provided function on each leaf page table.
+ */
+int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
+ unsigned long size, pte_fn_t fn, void *data)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long end = addr + size;
+ int err;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset(mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = apply_to_pud_range(mm, pgd, addr, next, fn, data);
+ if (err)
+ break;
+ } while (pgd++, addr = next, addr != end);
+ return err;
+}
+EXPORT_SYMBOL_GPL(apply_to_page_range);
+#endif
+
/*
* handle_pte_fault chooses page fault handler according to an entry
* which was read non-atomically. Before making any commitment, on
{
struct page *old_page, *new_page;
pte_t entry;
- int ret = VM_FAULT_MINOR;
+ int reuse = 0, ret = VM_FAULT_MINOR;
+ struct page *dirty_page = NULL;
old_page = vm_normal_page(vma, address, orig_pte);
if (!old_page)
goto gotten;
- if (PageAnon(old_page) && !TestSetPageLocked(old_page)) {
- int reuse = can_share_swap_page(old_page);
- unlock_page(old_page);
- if (reuse) {
- flush_cache_page(vma, address, pte_pfn(orig_pte));
- entry = pte_mkyoung(orig_pte);
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- ptep_set_access_flags(vma, address, page_table, entry, 1);
- update_mmu_cache(vma, address, entry);
- lazy_mmu_prot_update(entry);
- ret |= VM_FAULT_WRITE;
- goto unlock;
+ /*
+ * Take out anonymous pages first, anonymous shared vmas are
+ * not dirty accountable.
+ */
+ if (PageAnon(old_page)) {
+ if (!TestSetPageLocked(old_page)) {
+ reuse = can_share_swap_page(old_page);
+ unlock_page(old_page);
+ }
+ } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
+ (VM_WRITE|VM_SHARED))) {
+ /*
+ * Only catch write-faults on shared writable pages,
+ * read-only shared pages can get COWed by
+ * get_user_pages(.write=1, .force=1).
+ */
+ if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
+ /*
+ * Notify the address space that the page is about to
+ * become writable so that it can prohibit this or wait
+ * for the page to get into an appropriate state.
+ *
+ * We do this without the lock held, so that it can
+ * sleep if it needs to.
+ */
+ page_cache_get(old_page);
+ pte_unmap_unlock(page_table, ptl);
+
+ if (vma->vm_ops->page_mkwrite(vma, old_page) < 0)
+ goto unwritable_page;
+
+ page_cache_release(old_page);
+
+ /*
+ * Since we dropped the lock we need to revalidate
+ * the PTE as someone else may have changed it. If
+ * they did, we just return, as we can count on the
+ * MMU to tell us if they didn't also make it writable.
+ */
+ page_table = pte_offset_map_lock(mm, pmd, address,
+ &ptl);
+ if (!pte_same(*page_table, orig_pte))
+ goto unlock;
}
+ dirty_page = old_page;
+ get_page(dirty_page);
+ reuse = 1;
+ }
+
+ if (reuse) {
+ flush_cache_page(vma, address, pte_pfn(orig_pte));
+ entry = pte_mkyoung(orig_pte);
+ entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ ptep_set_access_flags(vma, address, page_table, entry, 1);
+ update_mmu_cache(vma, address, entry);
+ lazy_mmu_prot_update(entry);
+ ret |= VM_FAULT_WRITE;
+ goto unlock;
}
/*
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
if (likely(pte_same(*page_table, orig_pte))) {
if (old_page) {
- page_remove_rmap(old_page);
+ page_remove_rmap(old_page, vma);
if (!PageAnon(old_page)) {
dec_mm_counter(mm, file_rss);
inc_mm_counter(mm, anon_rss);
flush_cache_page(vma, address, pte_pfn(orig_pte));
entry = mk_pte(new_page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- ptep_establish(vma, address, page_table, entry);
- update_mmu_cache(vma, address, entry);
lazy_mmu_prot_update(entry);
+ /*
+ * Clear the pte entry and flush it first, before updating the
+ * pte with the new entry. This will avoid a race condition
+ * seen in the presence of one thread doing SMC and another
+ * thread doing COW.
+ */
+ ptep_clear_flush(vma, address, page_table);
+ set_pte_at(mm, address, page_table, entry);
+ update_mmu_cache(vma, address, entry);
lru_cache_add_active(new_page);
page_add_new_anon_rmap(new_page, vma, address);
page_cache_release(old_page);
unlock:
pte_unmap_unlock(page_table, ptl);
+ if (dirty_page) {
+ set_page_dirty_balance(dirty_page);
+ put_page(dirty_page);
+ }
return ret;
oom:
if (old_page)
page_cache_release(old_page);
return VM_FAULT_OOM;
+
+unwritable_page:
+ page_cache_release(old_page);
+ return VM_FAULT_SIGBUS;
}
/*
return 0;
}
-EXPORT_SYMBOL(vmtruncate_range);
+EXPORT_UNUSED_SYMBOL(vmtruncate_range); /* June 2006 */
/*
* Primitive swap readahead code. We simply read an aligned block of
goto out;
entry = pte_to_swp_entry(orig_pte);
-again:
+ if (is_migration_entry(entry)) {
+ migration_entry_wait(mm, pmd, address);
+ goto out;
+ }
+ delayacct_set_flag(DELAYACCT_PF_SWAPIN);
page = lookup_swap_cache(entry);
if (!page) {
swapin_readahead(entry, address, vma);
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
if (likely(pte_same(*page_table, orig_pte)))
ret = VM_FAULT_OOM;
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
goto unlock;
}
/* Had to read the page from swap area: Major fault */
ret = VM_FAULT_MAJOR;
- inc_page_state(pgmajfault);
+ count_vm_event(PGMAJFAULT);
grab_swap_token();
}
ret = VM_FAULT_OOM;
goto out;
}
+
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
mark_page_accessed(page);
lock_page(page);
- if (!PageSwapCache(page)) {
- /* Page migration has occured */
- unlock_page(page);
- page_cache_release(page);
- goto again;
- }
/*
* Back out if somebody else already faulted in this pte.
unsigned int sequence = 0;
int ret = VM_FAULT_MINOR;
int anon = 0;
+ struct page *dirty_page = NULL;
pte_unmap(page_table);
BUG_ON(vma->vm_flags & VM_PFNMAP);
/*
* Should we do an early C-O-W break?
*/
- if (write_access && !(vma->vm_flags & VM_SHARED)) {
- struct page *page;
+ if (write_access) {
+ if (!(vma->vm_flags & VM_SHARED)) {
+ struct page *page;
- if (unlikely(anon_vma_prepare(vma)))
- goto oom;
- page = alloc_page_vma(GFP_HIGHUSER, vma, address);
- if (!page)
- goto oom;
- copy_user_highpage(page, new_page, address);
- page_cache_release(new_page);
- new_page = page;
- anon = 1;
+ if (unlikely(anon_vma_prepare(vma)))
+ goto oom;
+ page = alloc_page_vma(GFP_HIGHUSER, vma, address);
+ if (!page)
+ goto oom;
+ copy_user_highpage(page, new_page, address);
+ page_cache_release(new_page);
+ new_page = page;
+ anon = 1;
+
+ } else {
+ /* if the page will be shareable, see if the backing
+ * address space wants to know that the page is about
+ * to become writable */
+ if (vma->vm_ops->page_mkwrite &&
+ vma->vm_ops->page_mkwrite(vma, new_page) < 0
+ ) {
+ page_cache_release(new_page);
+ return VM_FAULT_SIGBUS;
+ }
+ }
}
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
} else {
inc_mm_counter(mm, file_rss);
page_add_file_rmap(new_page);
+ if (write_access) {
+ dirty_page = new_page;
+ get_page(dirty_page);
+ }
}
} else {
/* One of our sibling threads was faster, back out. */
lazy_mmu_prot_update(entry);
unlock:
pte_unmap_unlock(page_table, ptl);
+ if (dirty_page) {
+ set_page_dirty_balance(dirty_page);
+ put_page(dirty_page);
+ }
return ret;
oom:
page_cache_release(new_page);
__set_current_state(TASK_RUNNING);
- inc_page_state(pgfault);
+ count_vm_event(PGFAULT);
if (unlikely(is_vm_hugetlb_page(vma)))
return hugetlb_fault(mm, vma, address, write_access);
git://git.onelab.eu / linux-2.6.git / blobdiff