#include <linux/vmalloc.h>
#include <linux/security.h>
#include <linux/memcontrol.h>
+#include <linux/syscalls.h>
#include "internal.h"
#define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
/*
- * Isolate one page from the LRU lists. If successful put it onto
- * the indicated list with elevated page count.
- *
- * Result:
- * -EBUSY: page not on LRU list
- * 0: page removed from LRU list and added to the specified list.
- */
-int isolate_lru_page(struct page *page, struct list_head *pagelist)
-{
- int ret = -EBUSY;
-
- if (PageLRU(page)) {
- struct zone *zone = page_zone(page);
-
- spin_lock_irq(&zone->lru_lock);
- if (PageLRU(page) && get_page_unless_zero(page)) {
- ret = 0;
- ClearPageLRU(page);
- if (PageActive(page))
- del_page_from_active_list(zone, page);
- else
- del_page_from_inactive_list(zone, page);
- list_add_tail(&page->lru, pagelist);
- }
- spin_unlock_irq(&zone->lru_lock);
- }
- return ret;
-}
-
-/*
* migrate_prep() needs to be called before we start compiling a list of pages
* to be migrated using isolate_lru_page().
*/
return 0;
}
-static inline void move_to_lru(struct page *page)
-{
- if (PageActive(page)) {
- /*
- * lru_cache_add_active checks that
- * the PG_active bit is off.
- */
- ClearPageActive(page);
- lru_cache_add_active(page);
- } else {
- lru_cache_add(page);
- }
- put_page(page);
-}
-
/*
- * Add isolated pages on the list back to the LRU.
+ * Add isolated pages on the list back to the LRU under page lock
+ * to avoid leaking evictable pages back onto unevictable list.
*
* returns the number of pages put back.
*/
list_for_each_entry_safe(page, page2, l, lru) {
list_del(&page->lru);
- move_to_lru(page);
+ dec_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+ putback_lru_page(page);
count++;
}
return count;
if (!is_migration_entry(entry) || migration_entry_to_page(entry) != old)
goto out;
- /*
- * Yes, ignore the return value from a GFP_ATOMIC mem_cgroup_charge.
- * Failure is not an option here: we're now expected to remove every
- * migration pte, and will cause crashes otherwise. Normally this
- * is not an issue: mem_cgroup_prepare_migration bumped up the old
- * page_cgroup count for safety, that's now attached to the new page,
- * so this charge should just be another incrementation of the count,
- * to keep in balance with rmap.c's mem_cgroup_uncharging. But if
- * there's been a force_empty, those reference counts may no longer
- * be reliable, and this charge can actually fail: oh well, we don't
- * make the situation any worse by proceeding as if it had succeeded.
- */
- mem_cgroup_charge(new, mm, GFP_ATOMIC);
-
get_page(new);
pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
if (is_write_migration_entry(entry))
static void remove_file_migration_ptes(struct page *old, struct page *new)
{
struct vm_area_struct *vma;
- struct address_space *mapping = page_mapping(new);
+ struct address_space *mapping = new->mapping;
struct prio_tree_iter iter;
pgoff_t pgoff = new->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
{
struct anon_vma *anon_vma;
struct vm_area_struct *vma;
- unsigned long mapping;
-
- mapping = (unsigned long)new->mapping;
-
- if (!mapping || (mapping & PAGE_MAPPING_ANON) == 0)
- return;
/*
* We hold the mmap_sem lock. So no need to call page_lock_anon_vma.
*/
- anon_vma = (struct anon_vma *) (mapping - PAGE_MAPPING_ANON);
+ anon_vma = page_anon_vma(new);
+ if (!anon_vma)
+ return;
+
spin_lock(&anon_vma->lock);
list_for_each_entry(vma, &anon_vma->head, anon_vma_node)
page = migration_entry_to_page(entry);
- get_page(page);
+ /*
+ * Once radix-tree replacement of page migration started, page_count
+ * *must* be zero. And, we don't want to call wait_on_page_locked()
+ * against a page without get_page().
+ * So, we use get_page_unless_zero(), here. Even failed, page fault
+ * will occur again.
+ */
+ if (!get_page_unless_zero(page))
+ goto out;
pte_unmap_unlock(ptep, ptl);
wait_on_page_locked(page);
put_page(page);
* The number of remaining references must be:
* 1 for anonymous pages without a mapping
* 2 for pages with a mapping
- * 3 for pages with a mapping and PagePrivate set.
+ * 3 for pages with a mapping and PagePrivate/PagePrivate2 set.
*/
static int migrate_page_move_mapping(struct address_space *mapping,
struct page *newpage, struct page *page)
{
+ int expected_count;
void **pslot;
if (!mapping) {
return 0;
}
- write_lock_irq(&mapping->tree_lock);
+ spin_lock_irq(&mapping->tree_lock);
pslot = radix_tree_lookup_slot(&mapping->page_tree,
page_index(page));
- if (page_count(page) != 2 + !!PagePrivate(page) ||
+ expected_count = 2 + page_has_private(page);
+ if (page_count(page) != expected_count ||
(struct page *)radix_tree_deref_slot(pslot) != page) {
- write_unlock_irq(&mapping->tree_lock);
+ spin_unlock_irq(&mapping->tree_lock);
+ return -EAGAIN;
+ }
+
+ if (!page_freeze_refs(page, expected_count)) {
+ spin_unlock_irq(&mapping->tree_lock);
return -EAGAIN;
}
* Now we know that no one else is looking at the page.
*/
get_page(newpage); /* add cache reference */
-#ifdef CONFIG_SWAP
if (PageSwapCache(page)) {
SetPageSwapCache(newpage);
set_page_private(newpage, page_private(page));
}
-#endif
radix_tree_replace_slot(pslot, newpage);
+ page_unfreeze_refs(page, expected_count);
/*
* Drop cache reference from old page.
* We know this isn't the last reference.
*/
__dec_zone_page_state(page, NR_FILE_PAGES);
__inc_zone_page_state(newpage, NR_FILE_PAGES);
-
- write_unlock_irq(&mapping->tree_lock);
+ if (PageSwapBacked(page)) {
+ __dec_zone_page_state(page, NR_SHMEM);
+ __inc_zone_page_state(newpage, NR_SHMEM);
+ }
+ spin_unlock_irq(&mapping->tree_lock);
return 0;
}
*/
static void migrate_page_copy(struct page *newpage, struct page *page)
{
+ int anon;
+
copy_highpage(newpage, page);
if (PageError(page))
SetPageReferenced(newpage);
if (PageUptodate(page))
SetPageUptodate(newpage);
- if (PageActive(page))
+ if (TestClearPageActive(page)) {
+ VM_BUG_ON(PageUnevictable(page));
SetPageActive(newpage);
+ } else
+ unevictable_migrate_page(newpage, page);
if (PageChecked(page))
SetPageChecked(newpage);
if (PageMappedToDisk(page))
__set_page_dirty_nobuffers(newpage);
}
-#ifdef CONFIG_SWAP
+ mlock_migrate_page(newpage, page);
+
ClearPageSwapCache(page);
-#endif
- ClearPageActive(page);
ClearPagePrivate(page);
set_page_private(page, 0);
+ /* page->mapping contains a flag for PageAnon() */
+ anon = PageAnon(page);
page->mapping = NULL;
/*
/*
* Common logic to directly migrate a single page suitable for
- * pages that do not use PagePrivate.
+ * pages that do not use PagePrivate/PagePrivate2.
*
* Pages are locked upon entry and exit.
*/
remove_migration_ptes(page, page);
rc = mapping->a_ops->writepage(page, &wbc);
- if (rc < 0)
- /* I/O Error writing */
- return -EIO;
if (rc != AOP_WRITEPAGE_ACTIVATE)
/* unlocked. Relock */
lock_page(page);
- return -EAGAIN;
+ return (rc < 0) ? -EIO : -EAGAIN;
}
/*
* Buffers may be managed in a filesystem specific way.
* We must have no buffers or drop them.
*/
- if (PagePrivate(page) &&
+ if (page_has_private(page) &&
!try_to_release_page(page, GFP_KERNEL))
return -EAGAIN;
*
* The new page will have replaced the old page if this function
* is successful.
+ *
+ * Return value:
+ * < 0 - error code
+ * == 0 - success
*/
static int move_to_new_page(struct page *newpage, struct page *page)
{
* establishing additional references. We are the only one
* holding a reference to the new page at this point.
*/
- if (TestSetPageLocked(newpage))
+ if (!trylock_page(newpage))
BUG();
/* Prepare mapping for the new page.*/
newpage->index = page->index;
newpage->mapping = page->mapping;
+ if (PageSwapBacked(page))
+ SetPageSwapBacked(newpage);
mapping = page_mapping(page);
if (!mapping)
rc = fallback_migrate_page(mapping, newpage, page);
if (!rc) {
- mem_cgroup_page_migration(page, newpage);
remove_migration_ptes(page, newpage);
} else
newpage->mapping = NULL;
struct page *newpage = get_new_page(page, private, &result);
int rcu_locked = 0;
int charge = 0;
+ struct mem_cgroup *mem = NULL;
if (!newpage)
return -ENOMEM;
- if (page_count(page) == 1)
+ if (page_count(page) == 1) {
/* page was freed from under us. So we are done. */
goto move_newpage;
+ }
+ /* prepare cgroup just returns 0 or -ENOMEM */
rc = -EAGAIN;
- if (TestSetPageLocked(page)) {
+
+ if (!trylock_page(page)) {
if (!force)
goto move_newpage;
lock_page(page);
}
+ /* charge against new page */
+ charge = mem_cgroup_prepare_migration(page, &mem);
+ if (charge == -ENOMEM) {
+ rc = -ENOMEM;
+ goto unlock;
+ }
+ BUG_ON(charge);
+
if (PageWriteback(page)) {
if (!force)
- goto unlock;
+ goto uncharge;
wait_on_page_writeback(page);
}
/*
* free the metadata, so the page can be freed.
*/
if (!page->mapping) {
- if (!PageAnon(page) && PagePrivate(page)) {
+ if (!PageAnon(page) && page_has_private(page)) {
/*
* Go direct to try_to_free_buffers() here because
* a) that's what try_to_release_page() would do anyway
* needs to be effective.
*/
try_to_free_buffers(page);
+ goto rcu_unlock;
}
- goto rcu_unlock;
+ goto skip_unmap;
}
- charge = mem_cgroup_prepare_migration(page);
/* Establish migration ptes or remove ptes */
- try_to_unmap(page, 1);
+ try_to_unmap(page, TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
+skip_unmap:
if (!page_mapped(page))
rc = move_to_new_page(newpage, page);
- if (rc) {
+ if (rc)
remove_migration_ptes(page, page);
- if (charge)
- mem_cgroup_end_migration(page);
- } else if (charge)
- mem_cgroup_end_migration(newpage);
rcu_unlock:
if (rcu_locked)
rcu_read_unlock();
-
+uncharge:
+ if (!charge)
+ mem_cgroup_end_migration(mem, page, newpage);
unlock:
-
unlock_page(page);
if (rc != -EAGAIN) {
* restored.
*/
list_del(&page->lru);
- move_to_lru(page);
+ dec_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+ putback_lru_page(page);
}
move_newpage:
+
/*
* Move the new page to the LRU. If migration was not successful
* then this will free the page.
*/
- move_to_lru(newpage);
+ putback_lru_page(newpage);
+
if (result) {
if (rc)
*result = rc;
*result = &pm->status;
- return alloc_pages_node(pm->node,
+ return alloc_pages_exact_node(pm->node,
GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
}
* Move a set of pages as indicated in the pm array. The addr
* field must be set to the virtual address of the page to be moved
* and the node number must contain a valid target node.
+ * The pm array ends with node = MAX_NUMNODES.
*/
-static int do_move_pages(struct mm_struct *mm, struct page_to_node *pm,
- int migrate_all)
+static int do_move_page_to_node_array(struct mm_struct *mm,
+ struct page_to_node *pm,
+ int migrate_all)
{
int err;
struct page_to_node *pp;
/*
* Build a list of pages to migrate
*/
- migrate_prep();
for (pp = pm; pp->node != MAX_NUMNODES; pp++) {
struct vm_area_struct *vma;
struct page *page;
- /*
- * A valid page pointer that will not match any of the
- * pages that will be moved.
- */
- pp->page = ZERO_PAGE(0);
-
err = -EFAULT;
vma = find_vma(mm, pp->addr);
if (!vma || !vma_migratable(vma))
!migrate_all)
goto put_and_set;
- err = isolate_lru_page(page, &pagelist);
+ err = isolate_lru_page(page);
+ if (!err) {
+ list_add_tail(&page->lru, &pagelist);
+ inc_zone_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
+ }
put_and_set:
/*
* Either remove the duplicate refcount from
pp->status = err;
}
+ err = 0;
if (!list_empty(&pagelist))
err = migrate_pages(&pagelist, new_page_node,
(unsigned long)pm);
- else
- err = -ENOENT;
up_read(&mm->mmap_sem);
return err;
}
/*
- * Determine the nodes of a list of pages. The addr in the pm array
- * must have been set to the virtual address of which we want to determine
- * the node number.
+ * Migrate an array of page address onto an array of nodes and fill
+ * the corresponding array of status.
+ */
+static int do_pages_move(struct mm_struct *mm, struct task_struct *task,
+ unsigned long nr_pages,
+ const void __user * __user *pages,
+ const int __user *nodes,
+ int __user *status, int flags)
+{
+ struct page_to_node *pm;
+ nodemask_t task_nodes;
+ unsigned long chunk_nr_pages;
+ unsigned long chunk_start;
+ int err;
+
+ task_nodes = cpuset_mems_allowed(task);
+
+ err = -ENOMEM;
+ pm = (struct page_to_node *)__get_free_page(GFP_KERNEL);
+ if (!pm)
+ goto out;
+
+ migrate_prep();
+
+ /*
+ * Store a chunk of page_to_node array in a page,
+ * but keep the last one as a marker
+ */
+ chunk_nr_pages = (PAGE_SIZE / sizeof(struct page_to_node)) - 1;
+
+ for (chunk_start = 0;
+ chunk_start < nr_pages;
+ chunk_start += chunk_nr_pages) {
+ int j;
+
+ if (chunk_start + chunk_nr_pages > nr_pages)
+ chunk_nr_pages = nr_pages - chunk_start;
+
+ /* fill the chunk pm with addrs and nodes from user-space */
+ for (j = 0; j < chunk_nr_pages; j++) {
+ const void __user *p;
+ int node;
+
+ err = -EFAULT;
+ if (get_user(p, pages + j + chunk_start))
+ goto out_pm;
+ pm[j].addr = (unsigned long) p;
+
+ if (get_user(node, nodes + j + chunk_start))
+ goto out_pm;
+
+ err = -ENODEV;
+ if (!node_state(node, N_HIGH_MEMORY))
+ goto out_pm;
+
+ err = -EACCES;
+ if (!node_isset(node, task_nodes))
+ goto out_pm;
+
+ pm[j].node = node;
+ }
+
+ /* End marker for this chunk */
+ pm[chunk_nr_pages].node = MAX_NUMNODES;
+
+ /* Migrate this chunk */
+ err = do_move_page_to_node_array(mm, pm,
+ flags & MPOL_MF_MOVE_ALL);
+ if (err < 0)
+ goto out_pm;
+
+ /* Return status information */
+ for (j = 0; j < chunk_nr_pages; j++)
+ if (put_user(pm[j].status, status + j + chunk_start)) {
+ err = -EFAULT;
+ goto out_pm;
+ }
+ }
+ err = 0;
+
+out_pm:
+ free_page((unsigned long)pm);
+out:
+ return err;
+}
+
+/*
+ * Determine the nodes of an array of pages and store it in an array of status.
*/
-static int do_pages_stat(struct mm_struct *mm, struct page_to_node *pm)
+static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
+ const void __user **pages, int *status)
{
+ unsigned long i;
+
down_read(&mm->mmap_sem);
- for ( ; pm->node != MAX_NUMNODES; pm++) {
+ for (i = 0; i < nr_pages; i++) {
+ unsigned long addr = (unsigned long)(*pages);
struct vm_area_struct *vma;
struct page *page;
- int err;
+ int err = -EFAULT;
- err = -EFAULT;
- vma = find_vma(mm, pm->addr);
+ vma = find_vma(mm, addr);
if (!vma)
goto set_status;
- page = follow_page(vma, pm->addr, 0);
+ page = follow_page(vma, addr, 0);
err = PTR_ERR(page);
if (IS_ERR(page))
err = page_to_nid(page);
set_status:
- pm->status = err;
+ *status = err;
+
+ pages++;
+ status++;
}
up_read(&mm->mmap_sem);
- return 0;
+}
+
+/*
+ * Determine the nodes of a user array of pages and store it in
+ * a user array of status.
+ */
+static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
+ const void __user * __user *pages,
+ int __user *status)
+{
+#define DO_PAGES_STAT_CHUNK_NR 16
+ const void __user *chunk_pages[DO_PAGES_STAT_CHUNK_NR];
+ int chunk_status[DO_PAGES_STAT_CHUNK_NR];
+ unsigned long i, chunk_nr = DO_PAGES_STAT_CHUNK_NR;
+ int err;
+
+ for (i = 0; i < nr_pages; i += chunk_nr) {
+ if (chunk_nr > nr_pages - i)
+ chunk_nr = nr_pages - i;
+
+ err = copy_from_user(chunk_pages, &pages[i],
+ chunk_nr * sizeof(*chunk_pages));
+ if (err) {
+ err = -EFAULT;
+ goto out;
+ }
+
+ do_pages_stat_array(mm, chunk_nr, chunk_pages, chunk_status);
+
+ err = copy_to_user(&status[i], chunk_status,
+ chunk_nr * sizeof(*chunk_status));
+ if (err) {
+ err = -EFAULT;
+ goto out;
+ }
+ }
+ err = 0;
+
+out:
+ return err;
}
/*
* Move a list of pages in the address space of the currently executing
* process.
*/
-asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
- const void __user * __user *pages,
- const int __user *nodes,
- int __user *status, int flags)
+SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages,
+ const void __user * __user *, pages,
+ const int __user *, nodes,
+ int __user *, status, int, flags)
{
- int err = 0;
- int i;
+ const struct cred *cred = current_cred(), *tcred;
struct task_struct *task;
- nodemask_t task_nodes;
struct mm_struct *mm;
- struct page_to_node *pm = NULL;
+ int err;
/* Check flags */
if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL))
* capabilities, superuser privileges or the same
* userid as the target process.
*/
- if ((current->euid != task->suid) && (current->euid != task->uid) &&
- (current->uid != task->suid) && (current->uid != task->uid) &&
+ rcu_read_lock();
+ tcred = __task_cred(task);
+ if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
+ cred->uid != tcred->suid && cred->uid != tcred->uid &&
!capable(CAP_SYS_NICE)) {
+ rcu_read_unlock();
err = -EPERM;
- goto out2;
+ goto out;
}
+ rcu_read_unlock();
err = security_task_movememory(task);
if (err)
- goto out2;
-
-
- task_nodes = cpuset_mems_allowed(task);
-
- /* Limit nr_pages so that the multiplication may not overflow */
- if (nr_pages >= ULONG_MAX / sizeof(struct page_to_node) - 1) {
- err = -E2BIG;
- goto out2;
- }
-
- pm = vmalloc((nr_pages + 1) * sizeof(struct page_to_node));
- if (!pm) {
- err = -ENOMEM;
- goto out2;
- }
-
- /*
- * Get parameters from user space and initialize the pm
- * array. Return various errors if the user did something wrong.
- */
- for (i = 0; i < nr_pages; i++) {
- const void __user *p;
-
- err = -EFAULT;
- if (get_user(p, pages + i))
- goto out;
-
- pm[i].addr = (unsigned long)p;
- if (nodes) {
- int node;
-
- if (get_user(node, nodes + i))
- goto out;
-
- err = -ENODEV;
- if (!node_state(node, N_HIGH_MEMORY))
- goto out;
-
- err = -EACCES;
- if (!node_isset(node, task_nodes))
- goto out;
+ goto out;
- pm[i].node = node;
- } else
- pm[i].node = 0; /* anything to not match MAX_NUMNODES */
+ if (nodes) {
+ err = do_pages_move(mm, task, nr_pages, pages, nodes, status,
+ flags);
+ } else {
+ err = do_pages_stat(mm, nr_pages, pages, status);
}
- /* End marker */
- pm[nr_pages].node = MAX_NUMNODES;
-
- if (nodes)
- err = do_move_pages(mm, pm, flags & MPOL_MF_MOVE_ALL);
- else
- err = do_pages_stat(mm, pm);
-
- if (err >= 0)
- /* Return status information */
- for (i = 0; i < nr_pages; i++)
- if (put_user(pm[i].status, status + i))
- err = -EFAULT;
out:
- vfree(pm);
-out2:
mmput(mm);
return err;
}
-#endif
/*
* Call migration functions in the vma_ops that may prepare
struct vm_area_struct *vma;
int err = 0;
- for(vma = mm->mmap; vma->vm_next && !err; vma = vma->vm_next) {
+ for (vma = mm->mmap; vma && !err; vma = vma->vm_next) {
if (vma->vm_ops && vma->vm_ops->migrate) {
err = vma->vm_ops->migrate(vma, to, from, flags);
if (err)
}
return err;
}
+#endif
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff