mm: extract do_pages_move() out of sys_move_pages()

To prepare the chunking, move the sys_move_pages() code that is used when
nodes!=NULL into do_pages_move().  And rename do_move_pages() into
do_move_page_to_node_array().

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/migrate.c b/mm/migrate.c
index a4c29081ebcea598530f4a0296eae589124886a4..11c6c56ec017e672fd058c0179a4c09ef8de291e 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -826,9 +826,11 @@ static struct page *new_page_node(struct page *p, unsigned long private,
  * 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;
@@ -905,6 +907,81 @@ set_status:
        return err;
 }
 
+/*
+ * 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 = NULL;
+       nodemask_t task_nodes;
+       int err = 0;
+       int i;
+
+       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 out;
+       }
+
+       pm = vmalloc((nr_pages + 1) * sizeof(struct page_to_node));
+       if (!pm) {
+               err = -ENOMEM;
+               goto out;
+       }
+
+       /*
+        * 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;
+
+               pm[i].addr = (unsigned long)p;
+               if (nodes) {
+                       int node;
+
+                       if (get_user(node, nodes + i))
+                               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[i].node = node;
+               } else
+                       pm[i].node = 0; /* anything to not match MAX_NUMNODES */
+       }
+       /* End marker */
+       pm[nr_pages].node = MAX_NUMNODES;
+
+       err = do_move_page_to_node_array(mm, pm, flags & MPOL_MF_MOVE_ALL);
+       if (err >= 0)
+               /* Return status information */
+               for (i = 0; i < nr_pages; i++)
+                       if (put_user(pm[i].status, status + i))
+                               err = -EFAULT;
+
+out_pm:
+       vfree(pm);
+out:
+       return err;
+}
+
 /*
  * Determine the nodes of an array of pages and store it in an array of status.
  */
@@ -963,12 +1040,9 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
                        const int __user *nodes,
                        int __user *status, int flags)
 {
-       int err = 0;
-       int i;
        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))
@@ -1000,75 +1074,21 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
            (current->uid != task->suid) && (current->uid != task->uid) &&
            !capable(CAP_SYS_NICE)) {
                err = -EPERM;
-               goto out2;
+               goto out;
        }
 
        err = security_task_movememory(task);
        if (err)
-               goto out2;
+               goto out;
 
-       if (!nodes) {
+       if (nodes) {
+               err = do_pages_move(mm, task, nr_pages, pages, nodes, status,
+                                   flags);
+       } else {
                err = do_pages_stat(mm, nr_pages, pages, status);
-               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;
-
-                       pm[i].node = node;
-               } else
-                       pm[i].node = 0; /* anything to not match MAX_NUMNODES */
-       }
-       /* End marker */
-       pm[nr_pages].node = MAX_NUMNODES;
-
-       err = do_move_pages(mm, pm, flags & MPOL_MF_MOVE_ALL);
-       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;
 }