Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[~shefty/rdma-dev.git] / fs / btrfs / disk-io.c
index fb827d0d71811baff7aec0f49a2584f7eedbaf84..c547cca26a266e962bbb760c0616e0846439d81d 100644 (file)
@@ -28,6 +28,7 @@
 #include <linux/freezer.h>
 #include <linux/crc32c.h>
 #include <linux/slab.h>
+#include <linux/migrate.h>
 #include "compat.h"
 #include "ctree.h"
 #include "disk-io.h"
@@ -355,6 +356,8 @@ static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
        ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
                                             btrfs_header_generation(eb));
        BUG_ON(ret);
+       WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
+
        found_start = btrfs_header_bytenr(eb);
        if (found_start != start) {
                WARN_ON(1);
@@ -693,6 +696,29 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
                                   __btree_submit_bio_done);
 }
 
+static int btree_migratepage(struct address_space *mapping,
+                       struct page *newpage, struct page *page)
+{
+       /*
+        * we can't safely write a btree page from here,
+        * we haven't done the locking hook
+        */
+       if (PageDirty(page))
+               return -EAGAIN;
+       /*
+        * Buffers may be managed in a filesystem specific way.
+        * We must have no buffers or drop them.
+        */
+       if (page_has_private(page) &&
+           !try_to_release_page(page, GFP_KERNEL))
+               return -EAGAIN;
+#ifdef CONFIG_MIGRATION
+       return migrate_page(mapping, newpage, page);
+#else
+       return -ENOSYS;
+#endif
+}
+
 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 {
        struct extent_io_tree *tree;
@@ -707,8 +733,7 @@ static int btree_writepage(struct page *page, struct writeback_control *wbc)
        }
 
        redirty_page_for_writepage(wbc, page);
-       eb = btrfs_find_tree_block(root, page_offset(page),
-                                     PAGE_CACHE_SIZE);
+       eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
        WARN_ON(!eb);
 
        was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
@@ -799,6 +824,9 @@ static const struct address_space_operations btree_aops = {
        .releasepage    = btree_releasepage,
        .invalidatepage = btree_invalidatepage,
        .sync_page      = block_sync_page,
+#ifdef CONFIG_MIGRATION
+       .migratepage    = btree_migratepage,
+#endif
 };
 
 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
@@ -1538,10 +1566,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                                                 GFP_NOFS);
        struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),
                                                 GFP_NOFS);
-       struct btrfs_root *tree_root = kzalloc(sizeof(struct btrfs_root),
-                                              GFP_NOFS);
-       struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
-                                               GFP_NOFS);
+       struct btrfs_root *tree_root = btrfs_sb(sb);
+       struct btrfs_fs_info *fs_info = tree_root->fs_info;
        struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),
                                                GFP_NOFS);
        struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),