mm: migration: avoid race between shift_arg_pages() and rmap_walk() during migration...

[safe/jmp/linux-2.6] / fs / drop_caches.c

diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index 4e47623..83c4f60 100644 (file)
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -12,40 +12,28 @@
 /* A global variable is a bit ugly, but it keeps the code simple */
 int sysctl_drop_caches;
 
-static void drop_pagecache_sb(struct super_block *sb)
+static void drop_pagecache_sb(struct super_block *sb, void *unused)
 {
-       struct inode *inode;
+       struct inode *inode, *toput_inode = NULL;
 
        spin_lock(&inode_lock);
        list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
-               if (inode->i_state & (I_FREEING|I_WILL_FREE))
+               if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW))
                        continue;
-               invalidate_inode_pages(inode->i_mapping);
+               if (inode->i_mapping->nrpages == 0)
+                       continue;
+               __iget(inode);
+               spin_unlock(&inode_lock);
+               invalidate_mapping_pages(inode->i_mapping, 0, -1);
+               iput(toput_inode);
+               toput_inode = inode;
+               spin_lock(&inode_lock);
        }
        spin_unlock(&inode_lock);
+       iput(toput_inode);
 }
 
-void drop_pagecache(void)
-{
-       struct super_block *sb;
-
-       spin_lock(&sb_lock);
-restart:
-       list_for_each_entry(sb, &super_blocks, s_list) {
-               sb->s_count++;
-               spin_unlock(&sb_lock);
-               down_read(&sb->s_umount);
-               if (sb->s_root)
-                       drop_pagecache_sb(sb);
-               up_read(&sb->s_umount);
-               spin_lock(&sb_lock);
-               if (__put_super_and_need_restart(sb))
-                       goto restart;
-       }
-       spin_unlock(&sb_lock);
-}
-
-void drop_slab(void)
+static void drop_slab(void)
 {
        int nr_objects;
 
@@ -55,12 +43,12 @@ void drop_slab(void)
 }
 
 int drop_caches_sysctl_handler(ctl_table *table, int write,
-       struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+       void __user *buffer, size_t *length, loff_t *ppos)
 {
-       proc_dointvec_minmax(table, write, file, buffer, length, ppos);
+       proc_dointvec_minmax(table, write, buffer, length, ppos);
        if (write) {
                if (sysctl_drop_caches & 1)
-                       drop_pagecache();
+                       iterate_supers(drop_pagecache_sb, NULL);
                if (sysctl_drop_caches & 2)
                        drop_slab();
        }