15 files changed, 572 insertions, 114 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 7845d1f7d1d9..b50bc4bd5c56 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -91,23 +91,10 @@ static inline int compressed_bio_size(struct btrfs_root *root,
 static struct bio *compressed_bio_alloc(struct block_device *bdev,
                                         u64 first_byte, gfp_t gfp_flags)
 {
-        struct bio *bio;
         int nr_vecs;
 
         nr_vecs = bio_get_nr_vecs(bdev);
-        bio = bio_alloc(gfp_flags, nr_vecs);
-
-        if (bio == NULL && (current->flags & PF_MEMALLOC)) {
-                while (!bio && (nr_vecs /= 2))
-                        bio = bio_alloc(gfp_flags, nr_vecs);
-        }
-
-        if (bio) {
-                bio->bi_size = 0;
-                bio->bi_bdev = bdev;
-                bio->bi_sector = first_byte >> 9;
-        }
-        return bio;
+        return btrfs_bio_alloc(bdev, first_byte >> 9, nr_vecs, gfp_flags);
 }
 
 static int check_compressed_csum(struct inode *inode,
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8db9234f6b41..af52f6d7a4d8 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -808,9 +808,9 @@ struct btrfs_block_group_cache {
         int extents_thresh;
         int free_extents;
         int total_bitmaps;
-        int ro:1;
-        int dirty:1;
-        int iref:1;
+        unsigned int ro:1;
+        unsigned int dirty:1;
+        unsigned int iref:1;
 
         int disk_cache_state;
 
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index fb827d0d7181..c547cca26a26 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -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),
diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 951ef09b82f4..6f0444473594 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -232,9 +232,85 @@ fail:
         return ERR_PTR(ret);
 }
 
+static int btrfs_get_name(struct dentry *parent, char *name,
+                          struct dentry *child)
+{
+        struct inode *inode = child->d_inode;
+        struct inode *dir = parent->d_inode;
+        struct btrfs_path *path;
+        struct btrfs_root *root = BTRFS_I(dir)->root;
+        struct btrfs_inode_ref *iref;
+        struct btrfs_root_ref *rref;
+        struct extent_buffer *leaf;
+        unsigned long name_ptr;
+        struct btrfs_key key;
+        int name_len;
+        int ret;
+
+        if (!dir || !inode)
+                return -EINVAL;
+
+        if (!S_ISDIR(dir->i_mode))
+                return -EINVAL;
+
+        path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+        path->leave_spinning = 1;
+
+        if (inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
+                key.objectid = BTRFS_I(inode)->root->root_key.objectid;
+                key.type = BTRFS_ROOT_BACKREF_KEY;
+                key.offset = (u64)-1;
+                root = root->fs_info->tree_root;
+        } else {
+                key.objectid = inode->i_ino;
+                key.offset = dir->i_ino;