Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (42 commits)
  Btrfs: hash the btree inode during  fill_super
  Btrfs: relocate file extents in clusters
  Btrfs: don't rename file into dummy directory
  Btrfs: check size of inode backref before adding hardlink
  Btrfs: fix releasepage to avoid unlocking extents we haven't locked
  Btrfs: Fix test_range_bit for whole file extents
  Btrfs: fix errors handling cached state in set/clear_extent_bit
  Btrfs: fix early enospc during balancing
  Btrfs: deal with NULL space info
  Btrfs: account for space used by the super mirrors
  Btrfs: fix extent entry threshold calculation
  Btrfs: remove dead code
  Btrfs: fix bitmap size tracking
  Btrfs: don't keep retrying a block group if we fail to allocate a cluster
  Btrfs: make balance code choose more wisely when relocating
  Btrfs: fix arithmetic error in clone ioctl
  Btrfs: add snapshot/subvolume destroy ioctl
  Btrfs: change how subvolumes are organized
  Btrfs: do not reuse objectid of deleted snapshot/subvol
  Btrfs: speed up snapshot dropping
  ...

1 files changed, 494 insertions, 169 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d154a3f365d5..e9b76bcd1c12 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -231,7 +231,8 @@ static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
         }
 
         ret = btrfs_drop_extents(trans, root, inode, start,
-                                 aligned_end, aligned_end, start, &hint_byte);
+                                 aligned_end, aligned_end, start,
+                                 &hint_byte, 1);
         BUG_ON(ret);
 
         if (isize > actual_end)
@@ -240,7 +241,7 @@ static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
                                    inline_len, compressed_size,
                                    compressed_pages);
         BUG_ON(ret);
-        btrfs_drop_extent_cache(inode, start, aligned_end, 0);
+        btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
         return 0;
 }
 
@@ -425,7 +426,7 @@ again:
                         extent_clear_unlock_delalloc(inode,
                                                      &BTRFS_I(inode)->io_tree,
                                                      start, end, NULL, 1, 0,
-                                                     0, 1, 1, 1);
+                                                     0, 1, 1, 1, 0);
                         ret = 0;
                         goto free_pages_out;
                 }
@@ -611,9 +612,9 @@ static noinline int submit_compressed_extents(struct inode *inode,
                 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
 
                 while (1) {
-                        spin_lock(&em_tree->lock);
+                        write_lock(&em_tree->lock);
                         ret = add_extent_mapping(em_tree, em);
-                        spin_unlock(&em_tree->lock);
+                        write_unlock(&em_tree->lock);
                         if (ret != -EEXIST) {
                                 free_extent_map(em);
                                 break;
@@ -640,7 +641,7 @@ static noinline int submit_compressed_extents(struct inode *inode,
                                              async_extent->start,
                                              async_extent->start +
                                              async_extent->ram_size - 1,
-                                             NULL, 1, 1, 0, 1, 1, 0);
+                                             NULL, 1, 1, 0, 1, 1, 0, 0);
 
                 ret = btrfs_submit_compressed_write(inode,
                                     async_extent->start,
@@ -713,7 +714,7 @@ static noinline int cow_file_range(struct inode *inode,
                         extent_clear_unlock_delalloc(inode,
                                                      &BTRFS_I(inode)->io_tree,
                                                      start, end, NULL, 1, 1,
-                                                     1, 1, 1, 1);
+                                                     1, 1, 1, 1, 0);
                         *nr_written = *nr_written +
                              (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
                         *page_started = 1;
@@ -725,6 +726,15 @@ static noinline int cow_file_range(struct inode *inode,
         BUG_ON(disk_num_bytes >
                btrfs_super_total_bytes(&root->fs_info->super_copy));
 
+
+        read_lock(&BTRFS_I(inode)->extent_tree.lock);
+        em = search_extent_mapping(&BTRFS_I(inode)->extent_tree,
+                                   start, num_bytes);
+        if (em) {
+                alloc_hint = em->block_start;
+                free_extent_map(em);
+        }
+        read_unlock(&BTRFS_I(inode)->extent_tree.lock);
         btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
 
         while (disk_num_bytes > 0) {
@@ -737,7 +747,6 @@ static noinline int cow_file_range(struct inode *inode,
                 em = alloc_extent_map(GFP_NOFS);
                 em->start = start;
                 em->orig_start = em->start;
-
                 ram_size = ins.offset;
                 em->len = ins.offset;
 
@@ -747,9 +756,9 @@ static noinline int cow_file_range(struct inode *inode,
                 set_bit(EXTENT_FLAG_PINNED, &em->flags);
 
                 while (1) {
-                        spin_lock(&em_tree->lock);
+                        write_lock(&em_tree->lock);
                         ret = add_extent_mapping(em_tree, em);
-                        spin_unlock(&em_tree->lock);
+                        write_unlock(&em_tree->lock);
                         if (ret != -EEXIST) {
                                 free_extent_map(em);
                                 break;
@@ -776,11 +785,14 @@ static noinline int cow_file_range(struct inode *inode,
                 /* we're not doing compressed IO, don't unlock the first
                  * page (which the caller expects to stay locked), don't
                  * clear any dirty bits and don't set any writeback bits
+                 *
+                 * Do set the Private2 bit so we know this page was properly
+                 * setup for writepage
                  */
                 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
                                              start, start + ram_size - 1,
                                              locked_page, unlock, 1,
-                                             1, 0, 0, 0);
+                                             1, 0, 0, 0, 1);
                 disk_num_bytes -= cur_alloc_size;
                 num_bytes -= cur_alloc_size;
                 alloc_hint = ins.objectid + ins.offset;
@@ -853,7 +865,7 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
         int limit = 10 * 1024 * 1042;
 
         clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED |
-                         EXTENT_DELALLOC, 1, 0, GFP_NOFS);
+                         EXTENT_DELALLOC, 1, 0, NULL, GFP_NOFS);
         while (start < end) {
                 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
                 async_cow->inode = inode;
@@ -1080,9 +1092,9 @@ out_check:
                         em->bdev = root->fs_info->fs_devices->latest_bdev;
                         set_bit(EXTENT_FLAG_PINNED, &em->flags);
                         while (1) {
-                                spin_lock(&em_tree->lock);
+                                write_lock(&em_tree->lock);
                                 ret = add_extent_mapping(em_tree, em);
-                                spin_unlock(&em_tree->lock);
+                                write_unlock(&em_tree->lock);
                                 if (ret != -EEXIST) {
                                         free_extent_map(em);
                                         break;
@@ -1101,7 +1113,7 @@ out_check:
 
                 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
                                         cur_offset, cur_offset + num_bytes - 1,
-                                        locked_page, 1, 1, 1, 0, 0, 0);
+                                        locked_page, 1, 1, 1, 0, 0, 0, 1);
                 cur_offset = extent_end;
                 if (cur_offset > end)
                         break;
@@ -1374,10 +1386,8 @@ again:
         lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end, GFP_NOFS);
 
         /* already ordered? We're done */
-        if (test_range_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
-                             EXTENT_ORDERED, 0)) {
+        if (PagePrivate2(page))
                 goto out;
-        }
 
         ordered = btrfs_lookup_ordered_extent(inode, page_start);
         if (ordered) {
@@ -1413,11 +1423,9 @@ static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
         struct inode *inode = page->mapping->host;
         struct btrfs_writepage_fixup *fixup;
         struct btrfs_root *root = BTRFS_I(inode)->root;
-        int ret;
 
-        ret = test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
-                             EXTENT_ORDERED, 0);
-        if (ret)
+        /* this page is properly in the ordered list */
+        if (TestClearPagePrivate2(page))
                 return 0;
 
         if (PageChecked(page))
@@ -1455,9 +1463,19 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
         BUG_ON(!path);
 
         path->leave_spinning = 1;
+
+        /*
+         * we may be replacing one extent in the tree with another.
+         * The new extent is pinned in the extent map, and we don't want
+         * to drop it from the cache until it is completely in the btree.
+         *
+         * So, tell btrfs_drop_extents to leave this extent in the cache.
+         * the caller is expected to unpin it and allow it to be merged
+         * with the others.
+         */
         ret = btrfs_drop_extents(trans, root, inode, file_pos,
                                  file_pos + num_bytes, locked_end,
-                                 file_pos, &hint);
+                                 file_pos, &hint, 0);
         BUG_ON(ret);
 
         ins.objectid = inode->i_ino;
@@ -1485,7 +1503,6 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
         btrfs_mark_buffer_dirty(leaf);
 
         inode_add_bytes(inode, num_bytes);
-        btrfs_drop_extent_cache(inode, file_pos, file_pos + num_bytes - 1, 0);
 
         ins.objectid = disk_bytenr;
         ins.offset = disk_num_bytes;
@@ -1596,6 +1613,9 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
                                                 ordered_extent->len,
                                                 compressed, 0, 0,
                                                 BTRFS_FILE_EXTENT_REG);
+                unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
+                                   ordered_extent->file_offset,
+                                   ordered_extent->len);
                 BUG_ON(ret);
         }
         unlock_extent(io_tree, ordered_extent->file_offset,
@@ -1623,6 +1643,7 @@ nocow:
 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
                                 struct extent_state *state, int uptodate)
 {
+        ClearPagePrivate2(page);
         return btrfs_finish_ordered_io(page->mapping->host, start, end);
 }
 
@@ -1669,13 +1690,13 @@ static int btrfs_io_failed_hook(struct bio *failed_bio,
                 failrec->last_mirror = 0;
                 failrec->bio_flags = 0;
 
-                spin_lock(&em_tree->lock);
+                read_lock(&em_tree->lock);
                 em = lookup_extent_mapping(em_tree, start, failrec->len);
                 if (em->start > start || em->start + em->len < start) {
                         free_extent_map(em);
                         em = NULL;
                 }
-                spin_unlock(&em_tree->lock);
+                read_unlock(&em_tree->lock);
 
                 if (!em || IS_ERR(em)) {
                         kfree(failrec);
@@ -1794,7 +1815,7 @@ static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                 return 0;
 
         if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
-            test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1)) {
+            test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
                 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
                                   GFP_NOFS);
                 return 0;
@@ -2352,6 +2373,69 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
         return ret;
 }
 
+int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
+                        struct btrfs_root *root,
+                        struct inode *dir, u64 objectid,
+                        const char *name, int name_len)
+{
+        struct btrfs_path *path;
+        struct extent_buffer *leaf;
+        struct btrfs_dir_item *di;
+        struct btrfs_key key;
+        u64 index;
+        int ret;
+
+        path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+
+        di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
+                                   name, name_len, -1);
+        BUG_ON(!di || IS_ERR(di));
+
+        leaf = path->nodes[0];
+        btrfs_dir_item_key_to_cpu(leaf, di, &key);
+        WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
+        ret = btrfs_delete_one_dir_name(trans, root, path, di);
+        BUG_ON(ret);
+        btrfs_release_path(root, path);
+
+        ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
+                                 objectid, root->root_key.objectid,
+                                 dir->i_ino, &index, name, name_len);
+        if (ret < 0) {
+                BUG_ON(ret != -ENOENT);
+                di = btrfs_search_dir_index_item(root, path, dir->i_ino,
+                                                 name, name_len);
+                BUG_ON(!di || IS_ERR(di));
+
+                leaf = path->nodes[0];
+                btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+                btrfs_release_path(root, path);
+                index = key.offset;
+        }
+
+        di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
+                                         index, name, name_len, -1);
+        BUG_ON(!di || IS_ERR(di));
+
+        leaf = path->nodes[0];
+        btrfs_dir_item_key_to_cpu(leaf, di, &key);
+        WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
+        ret = btrfs_delete_one_dir_name(trans, root, path, di);
+        BUG_ON(ret);
+        btrfs_release_path(root, path);
+
+        btrfs_i_size_write(dir, dir->i_size - name_len * 2);
+        dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+        ret = btrfs_update_inode(trans, root, dir);
+        BUG_ON(ret);
+        dir->i_sb->s_dirt = 1;
+
+        btrfs_free_path(path);
+        return 0;
+}
+
 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 {
         struct inode *inode = dentry->d_inode;
@@ -2361,29 +2445,31 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
         struct btrfs_trans_handle *trans;
         unsigned long nr = 0;
 
-        /*
-         * the FIRST_FREE_OBJECTID check makes sure we don't try to rmdir
-         * the root of a subvolume or snapshot
-         */
         if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
-            inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) {
+            inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
                 return -ENOTEMPTY;
-        }
 
         trans = btrfs_start_transaction(root, 1);
         btrfs_set_trans_block_group(trans, dir);
 
+        if (unlikely(inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
+                err = btrfs_unlink_subvol(trans, root, dir,
+                                          BTRFS_I(inode)->location.objectid,
+                                          dentry->d_name.name,
+                                          dentry->d_name.len);
+                goto out;
+        }
+
         err = btrfs_orphan_add(trans, inode);
         if (err)
-                goto fail_trans;
+                goto out;
 
         /* now the directory is empty */
         err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
                                  dentry->d_name.name, dentry->d_name.len);
         if (!err)
                 btrfs_i_size_write(inode, 0);
-
-fail_trans:
+out:
         nr = trans->blocks_used;
         ret = btrfs_end_transaction_throttle(trans, root);
         btrfs_btree_balance_dirty(root, nr);
@@ -2935,7 +3021,7 @@ int btrfs_cont_expand(struct inode *inode, loff_t size)
                                                  cur_offset,
                                                  cur_offset + hole_size,
                                                  block_end,
-                                                 cur_offset, &hint_byte);
+                                                 cur_offset, &hint_byte, 1);
                         if (err)
                                 break;
                         err = btrfs_insert_file_extent(trans, root,
@@ -3003,6 +3089,11 @@ void btrfs_delete_inode(struct inode *inode)
         }
         btrfs_wait_ordered_range(inode, 0, (u64)-1);
 
+        if (inode->i_nlink > 0) {
+                BUG_ON(btrfs_root_refs(&root->root_item) != 0);
+                goto no_delete;
+        }
+
         btrfs_i_size_write(inode, 0);
         trans = btrfs_join_transaction(root, 1);
 
@@ -3070,29 +3161,67 @@ out_err:
  * is kind of like crossing a mount point.
  */
 static int fixup_tree_root_location(struct btrfs_root *root,
-                             struct btrfs_key *location,
-                             struct btrfs_root **sub_root,
-                             struct dentry *dentry)
+                                    struct inode *dir,
+                                    struct dentry *dentry,
+                                    struct btrfs_key *location,
+                                    struct btrfs_root **sub_root)
 {
-        struct btrfs_root_item *ri;
+        struct btrfs_path *path;
+        struct btrfs_root *new_root;
+        struct btrfs_root_ref *ref;
+        struct extent_buffer *leaf;
+        int ret;
+        int err = 0;
 
-        if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
-                return 0;
-        if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
-                return 0;
+        path = btrfs_alloc_path();
+        if (!path) {
+                err = -ENOMEM;
+                goto out;
+        }
 
-        *sub_root = btrfs_read_fs_root(root->fs_info, location,
-                                        dentry->d_name.name,
-                                        dentry->d_name.len);
-        if (IS_ERR(*sub_root))
-                return PTR_ERR(*sub_root);
+        err = -ENOENT;
+        ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
+                                  BTRFS_I(dir)->root->root_key.objectid,
+                                  location->objectid);
+        if (ret) {
+                if (ret < 0)
+                        err = ret;
+                goto out;
+        }
 
-        ri = &(*sub_root)->root_item;
-        location->objectid = btrfs_root_dirid(ri);
-        btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
-        location->offset = 0;
+        leaf = path->nodes[0];
+        ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
+        if (btrfs_root_ref_dirid(leaf, ref) != dir->i_ino ||
+            btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
+                goto out;
 
-        return 0;
+        ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
+                                   (unsigned long)(ref + 1),
+                                   dentry->d_name.len);
+        if (ret)
+                goto out;
+
+        btrfs_release_path(root->fs_info->tree_root, path);
+
+        new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
+        if (IS_ERR(new_root)) {
+                err = PTR_ERR(new_root);
+                goto out;
+        }
+
+        if (btrfs_root_refs(&new_root->root_item) == 0) {
+                err = -ENOENT;
+                goto out;
+        }
+
+        *sub_root = new_root;
+        location->objectid = btrfs_root_dirid(&new_root->root_item);
+        location->type = BTRFS_INODE_ITEM_KEY;
+        location->offset = 0;
+        err = 0;
+out:
+        btrfs_free_path(path);
+        return err;
 }
 
 static void inode_tree_add(struct inode *inode)
@@ -3101,11 +3230,13 @@ static void inode_tree_add(struct inode *inode)
         struct btrfs_inode *entry;
         struct rb_node **p;
         struct rb_node *parent;
-
 again:
         p = &root->inode_tree.rb_node;
         parent = NULL;
 
+        if (hlist_unhashed(&inode->i_hash))
+                return;
+
         spin_lock(&root->inode_lock);
         while (*p) {
                 parent = *p;
@@ -3132,13 +3263,87 @@ again:
 static void inode_tree_del(struct inode *inode)
 {
         struct btrfs_root *root = BTRFS_I(inode)->root;
+        int empty = 0;
 
         spin_lock(&root->inode_lock);
         if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
                 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
                 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
+                empty = RB_EMPTY_ROOT(&root->inode_tree);
         }
         spin_unlock(&root->inode_lock);
+
+        if (empty && btrfs_root_refs(&root->root_item) == 0) {
+                synchronize_srcu(&root->fs_info->subvol_srcu);
+                spin_lock(&root->inode_lock);
+                empty = RB_EMPTY_ROOT(&root->inode_tree);
+                spin_unlock(&root->inode_lock);
+                if (empty)
+                        btrfs_add_dead_root(root);
+        }
+}
+
+int btrfs_invalidate_inodes(struct btrfs_root *root)
+{
+        struct rb_node *node;
+        struct rb_node *prev;
+        struct btrfs_inode *entry;
+        struct inode *inode;
+        u64 objectid = 0;
+
+        WARN_ON(btrfs_root_refs(&root->root_item) != 0);
+
+        spin_lock(&root->inode_lock);
+again:
+        node = root->inode_tree.rb_node;
+        prev = NULL;
+        while (node) {
+                prev = node;
+                entry = rb_entry(node, struct btrfs_inode, rb_node);
+
+                if (objectid < entry->vfs_inode.i_ino)
+                        node = node->rb_left;
+                else if (objectid > entry->vfs_inode.i_ino)
+                        node = node->rb_right;
+                else
+                        break;
+        }
+        if (!node) {
+                while (prev) {
+                        entry = rb_entry(prev, struct btrfs_inode, rb_node);
+                        if (objectid <= entry->vfs_inode.i_ino) {
+                                node = prev;
+                                break;
+                        }
+                        prev = rb_next(prev);
+                }
+        }
+        while (node) {
+                entry = rb_entry(node, struct btrfs_inode, rb_node);
+                objectid = entry->vfs_inode.i_ino + 1;
+                inode = igrab(&entry->vfs_inode);
+                if (inode) {
+                        spin_unlock(&root->inode_lock);
+                        if (atomic_read(&inode->i_count) > 1)
+                                d_prune_aliases(inode);
+                        /*
+                         * btrfs_drop_inode will remove it from
+                         * the inode cache when its usage count
+                         * hits zero.
+                         */
+                        iput(inode);
+                        cond_resched();
+                        spin_lock(&root->inode_lock);
+                        goto again;
+                }
+
+                if (cond_resched_lock(&root->inode_lock))
+                        goto again;
+
+                node = rb_next(node);
+        }
+        spin_unlock(&root->inode_lock);
+        return 0;
 }
 
 static noinline void init_btrfs_i(struct inode *inode)
@@ -3225,15 +3430,41 @@ struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
         return inode;
 }
 
+static struct inode *new_simple_dir(struct super_block *s,
+                                    struct btrfs_key *key,
+                                    struct btrfs_root *root)
+{
+        struct inode *inode = new_inode(s);
+
+        if (!inode)
+                return ERR_PTR(-ENOMEM);
+
+        init_btrfs_i(inode);
+
+        BTRFS_I(inode)->root = root;
+        memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
+        BTRFS_I(inode)->dummy_inode = 1;
+
+        inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
+        inode->i_op = &simple_dir_inode_operations;
+        inode->i_fop = &simple_dir_operations;
+        inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
+        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+
+        return inode;
+}
+
 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
 {
         struct inode *inode;
-        struct btrfs_inode *bi = BTRFS_I(dir);
-        struct btrfs_root *root = bi->root;
+        struct btrfs_root *root = BTRFS_I(dir)->root;
         struct btrfs_root *sub_root = root;
         struct btrfs_key location;
+        int index;
         int ret;
 
+        dentry->d_op = &btrfs_dentry_operations;
+
         if (dentry->d_name.len > BTRFS_NAME_LEN)
                 return ERR_PTR(-ENAMETOOLONG);
 
@@ -3242,29 +3473,50 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
         if (ret < 0)
                 return ERR_PTR(ret);
 
-        inode = NULL;
-        if (location.objectid) {
-                ret = fixup_tree_root_location(root, &location, &sub_root,
-                                                dentry);
-                if (ret < 0)
-                        return ERR_PTR(ret);
-                if (ret > 0)
-                        return ERR_PTR(-ENOENT);
+        if (location.objectid == 0)
+                return NULL;
+
+        if (location.type == BTRFS_INODE_ITEM_KEY) {
+                inode = btrfs_iget(dir->i_sb, &location, root);
+                return inode;
+        }
+
+        BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
+
+        index = srcu_read_lock(&root->fs_info->subvol_srcu);
+        ret = fixup_tree_root_location(root, dir, dentry,
+                                       &location, &sub_root);
+        if (ret < 0) {
+                if (ret != -ENOENT)
+                        inode = ERR_PTR(ret);
+                else
+                        inode = new_simple_dir(dir->i_sb, &location, sub_root);
+        } else {
                 inode = btrfs_iget(dir->i_sb, &location, sub_root);
-                if (IS_ERR(inode))
-                        return ERR_CAST(inode);
         }
+        srcu_read_unlock(&root->fs_info->subvol_srcu, index);
+
         return inode;
 }
 
+static int btrfs_dentry_delete(struct dentry *dentry)
+{
+        struct btrfs_root *root;
+
+        if (!dentry->d_inode)
+                return 0;
+
+        root = BTRFS_I(dentry->d_inode)->root;
+        if (btrfs_root_refs(&root->root_item) == 0)
+                return 1;
+        return 0;
+}
+
 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
                                    struct nameidata *nd)
 {
         struct inode *inode;
 
-        if (dentry->d_name.len > BTRFS_NAME_LEN)
-                return ERR_PTR(-ENAMETOOLONG);
-
         inode = btrfs_lookup_dentry(dir, dentry);
         if (IS_ERR(inode))
                 return ERR_CAST(inode);
@@ -3603,9 +3855,6 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
         if (ret != 0)
                 goto fail;
 
-        if (objectid > root->highest_inode)
-                root->highest_inode = objectid;
-
         inode->i_uid = current_fsuid();
 
         if (dir && (dir->i_mode & S_ISGID)) {
@@ -3673,26 +3922,35 @@ int btrfs_add_link(struct btrfs_trans_handle *trans,
                    struct inode *parent_inode, struct inode *inode,
                    const char *name, int name_len, int add_backref, u64 index)
 {
-        int ret;
+        int ret = 0;
         struct btrfs_key key;
         struct btrfs_root *root = BTRFS_I(parent_inode)->root;
 
-        key.objectid = inode->i_ino;
-        btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
-        key.offset = 0;
+        if (unlikely(inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
+                memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
+        } else {
+                key.objectid = inode->i_ino;
+                btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+                key.offset = 0;
+        }
+
+        if (unlikely(inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
+                ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
+                                         key.objectid, root->root_key.objectid,
+                                         parent_inode->i_ino,
+                                         index, name, name_len);
+        } else if (add_backref) {
+                ret = btrfs_insert_inode_ref(trans, root,
+                                             name, name_len, inode->i_ino,
+                                             parent_inode->i_ino, index);
+        }
 
-        ret = btrfs_insert_dir_item(trans, root, name, name_len,
-                                    parent_inode->i_ino,
-                                    &key, btrfs_inode_type(inode),
-                                    index);
         if (ret == 0) {
-                if (add_backref) {
-                        ret = btrfs_insert_inode_ref(trans, root,
-                                                     name, name_len,
-                                                     inode->i_ino,
-                                                     parent_inode->i_ino,
-                                                     index);
-                }
+                ret = btrfs_insert_dir_item(trans, root, name, name_len,
+                                            parent_inode->i_ino, &key,
+                                            btrfs_inode_type(inode), index);
+                BUG_ON(ret);
+
                 btrfs_i_size_write(parent_inode, parent_inode->i_size +
                                    name_len * 2);
                 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
@@ -3875,18 +4133,16 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
 
         err = btrfs_add_nondir(trans, dentry, inode, 1, index);
 
-        if (err)
-                drop_inode = 1;
-
-        btrfs_update_inode_block_group(trans, dir);
-        err = btrfs_update_inode(trans, root, inode);
-
-        if (err)
+        if (err) {
                 drop_inode = 1;
+        } else {
+                btrfs_update_inode_block_group(trans, dir);
+                err = btrfs_update_inode(trans, root, inode);
+                BUG_ON(err);
+                btrfs_log_new_name(trans, inode, NULL, dentry->d_parent);
+        }
 
         nr = trans->blocks_used;
-
-        btrfs_log_new_name(trans, inode, NULL, dentry->d_parent);
         btrfs_end_transaction_throttle(trans, root);
 fail:
         if (drop_inode) {
@@ -4064,11 +4320,11 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
         int compressed;
 
 again:
-        spin_lock(&em_tree->lock);
+        read_lock(&em_tree->lock);
         em = lookup_extent_mapping(em_tree, start, len);
         if (em)
                 em->bdev = root->fs_info->fs_devices->latest_bdev;
-        spin_unlock(&em_tree->lock);
+        read_unlock(&em_tree->lock);
 
         if (em) {
                 if (em->start > start || em->start + em->len <= start)
@@ -4215,6 +4471,11 @@ again:
                                 map = kmap(page);
                                 read_extent_buffer(leaf, map + pg_offset, ptr,
                                                    copy_size);
+                                if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
+                                        memset(map + pg_offset + copy_size, 0,
+                                               PAGE_CACHE_SIZE - pg_offset -
+                                               copy_size);
+                                }
                                 kunmap(page);
                         }
                         flush_dcache_page(page);
@@ -4259,7 +4520,7 @@ insert:
         }
 
         err = 0;
-        spin_lock(&em_tree->lock);
+        write_lock(&em_tree->lock);
         ret = add_extent_mapping(em_tree, em);
         /* it is possible that someone inserted the extent into the tree
          * while we had the lock dropped.  It is also possible that
@@ -4299,7 +4560,7 @@ insert:
                         err = 0;
                 }
         }
-        spin_unlock(&em_tree->lock);
+        write_unlock(&em_tree->lock);
 out:
         if (path)
                 btrfs_free_path(path);
@@ -4398,13 +4659,21 @@ static void btrfs_invalidatepage(struct page *page, unsigned long offset)
         u64 page_start = page_offset(page);
         u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
 
+
+        /*
+         * we have the page locked, so new writeback can't start,
+         * and the dirty bit won't be cleared while we are here.
+         *
+         * Wait for IO on this page so that we can safely clear
+         * the PagePrivate2 bit and do ordered accounting
+         */
         wait_on_page_writeback(page);
+
         tree = &BTRFS_I(page->mapping->host)->io_tree;
         if (offset) {
                 btrfs_releasepage(page, GFP_NOFS);
                 return;
         }
-
         lock_extent(tree, page_start, page_end, GFP_NOFS);
         ordered = btrfs_lookup_ordered_extent(page->mapping->host,
                                            page_offset(page));
@@ -4415,16 +4684,21 @@ static void btrfs_invalidatepage(struct page *page, unsigned long offset)
                  */
                 clear_extent_bit(tree, page_start, page_end,
                                  EXTENT_DIRTY | EXTENT_DELALLOC |
-                                 EXTENT_LOCKED, 1, 0, GFP_NOFS);
-                btrfs_finish_ordered_io(page->mapping->host,
-                                        page_start, page_end);
+                                 EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS);
+                /*
+                 * whoever cleared the private bit is responsible
+                 * for the finish_ordered_io
+                 */
+                if (TestClearPagePrivate2(page)) {
+                        btrfs_finish_ordered_io(page->mapping->host,
+                                                page_start, page_end);
+                }
                 btrfs_put_ordered_extent(ordered);
                 lock_extent(tree, page_start, page_end, GFP_NOFS);
         }
         clear_extent_bit(tree, page_start, page_end,
-                 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
-                 EXTENT_ORDERED,
-                 1, 1, GFP_NOFS);
+                 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC,
+                 1, 1, NULL, GFP_NOFS);
         __btrfs_releasepage(page, GFP_NOFS);
 
         ClearPageChecked(page);
@@ -4521,11 +4795,14 @@ again:
         }
         ClearPageChecked(page);
         set_page_dirty(page);
+        SetPageUptodate(page);
 
         BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 
 out_unlock:
+        if (!ret)
+                return VM_FAULT_LOCKED;
         unlock_page(page);
 out:
         return ret;
@@ -4594,11 +4871,11 @@ out:
  * create a new subvolume directory/inode (helper for the ioctl).
  */
 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
-                             struct btrfs_root *new_root, struct dentry *dentry,
+                             struct btrfs_root *new_root,
                              u64 new_dirid, u64 alloc_hint)
 {
         struct inode *inode;
-        int error;
+        int err;
         u64 index = 0;
 
         inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
@@ -4611,11 +4888,10 @@ int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
         inode->i_nlink = 1;
         btrfs_i_size_write(inode, 0);
 
-        error = btrfs_update_inode(trans, new_root, inode);
-        if (error)
-                return error;
+        err = btrfs_update_inode(trans, new_root, inode);
+        BUG_ON(err);
 
-        d_instantiate(dentry, inode);
+        iput(inode);
         return 0;
 }
 
@@ -4693,6 +4969,16 @@ void btrfs_destroy_inode(struct inode *inode)
         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
 }
 
+void btrfs_drop_inode(struct inode *inode)
+{
+        struct btrfs_root *root = BTRFS_I(inode)->root;
+
+        if (inode->i_nlink > 0 && btrfs_root_refs(&root->root_item) == 0)
+                generic_delete_inode(inode);
+        else
+                generic_drop_inode(inode);
+}
+
 static void init_once(void *foo)
 {
         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
@@ -4761,31 +5047,32 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 {
         struct btrfs_trans_handle *trans;
         struct btrfs_root *root = BTRFS_I(old_dir)->root;
+        struct btrfs_root *dest = BTRFS_I(new_dir)->root;
         struct inode *new_inode = new_dentry->d_inode;
         struct inode *old_inode = old_dentry->d_inode;
         struct timespec ctime = CURRENT_TIME;
         u64 index = 0;
+        u64 root_objectid;
         int ret;
 
-        /* we're not allowed to rename between subvolumes */
-        if (BTRFS_I(old_inode)->root->root_key.objectid !=
-            BTRFS_I(new_dir)->root->root_key.objectid)
+        if (new_dir->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
+                return -EPERM;
+
+        /* we only allow rename subvolume link between subvolumes */
+        if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
                 return -EXDEV;
 
-        if (S_ISDIR(old_inode->i_mode) && new_inode &&
-            new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
+        if (old_inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
+            (new_inode && new_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID))
                 return -ENOTEMPTY;
-        }
 
-        /* to rename a snapshot or subvolume, we need to juggle the
-         * backrefs.  This isn't coded yet
-         */
-        if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
-                return -EXDEV;
+        if (S_ISDIR(old_inode->i_mode) && new_inode &&
+            new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
+                return -ENOTEMPTY;
 
         ret = btrfs_check_metadata_free_space(root);
         if (ret)
-                goto out_unlock;
+                return ret;
 
         /*
          * we're using rename to replace one file with another.
@@ -4796,8 +5083,40 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
             old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
                 filemap_flush(old_inode->i_mapping);
 
+        /* close the racy window with snapshot create/destroy ioctl */
+        if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
+                down_read(&root->fs_info->subvol_sem);
+
         trans = btrfs_start_transaction(root, 1);
+        btrfs_set_trans_block_group(trans, new_dir);
+
+        if (dest != root)
+                btrfs_record_root_in_trans(trans, dest);
 
+        ret = btrfs_set_inode_index(new_dir, &index);
+        if (ret)
+                goto out_fail;
+
+        if (unlikely(old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
+                /* force full log commit if subvolume involved. */
+                root->fs_info->last_trans_log_full_commit = trans->transid;
+        } else {
+                ret = btrfs_insert_inode_ref(trans, dest,
+                                             new_dentry->d_name.name,
+                                             new_dentry->d_name.len,
+                                             old_inode->i_ino,
+                                             new_dir->i_ino, index);
+                if (ret)
+                        goto out_fail;
+                /*
+                 * this is an ugly little race, but the rename is required
+                 * to make sure that if we crash, the inode is either at the
+                 * old name or the new one.  pinning the log transaction lets
+                 * us make sure we don't allow a log commit to come in after
+                 * we unlink the name but before we add the new name back in.
+                 */
+                btrfs_pin_log_trans(root);
+        }
         /*
          * make sure the inode gets flushed if it is replacing
          * something.
@@ -4807,18 +5126,6 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
                 btrfs_add_ordered_operation(trans, root, old_inode);
         }
 
-        /*
-         * this is an ugly little race, but the rename is required to make
-         * sure that if we crash, the inode is either at the old name
-         * or the new one.  pinning the log transaction lets us make sure
-         * we don't allow a log commit to come in after we unlink the
-         * name but before we add the new name back in.
-         */
-        btrfs_pin_log_trans(root);
-
-        btrfs_set_trans_block_group(trans, new_dir);
-
-        btrfs_inc_nlink(old_dentry->d_inode);
         old_dir->i_ctime = old_dir->i_mtime = ctime;
         new_dir->i_ctime = new_dir->i_mtime = ctime;
         old_inode->i_ctime = ctime;
@@ -4826,47 +5133,58 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
         if (old_dentry->d_parent != new_dentry->d_parent)
                 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
 
-        ret = btrfs_unlink_inode(trans, root, old_dir, old_dentry->d_inode,
-                                 old_dentry->d_name.name,
-                                 old_dentry->d_name.len);
-        if (ret)
-                goto out_fail;
+        if (unlikely(old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
+                root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
+                ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
+                                        old_dentry->d_name.name,
+                                        old_dentry->d_name.len);
+        } else {
+                btrfs_inc_nlink(old_dentry->d_inode);
+                ret = btrfs_unlink_inode(trans, root, old_dir,
+                                         old_dentry->d_inode,
+                                         old_dentry->d_name.name,
+                                         old_dentry->d_name.len);
+        }
+        BUG_ON(ret);
 
         if (new_inode) {
                 new_inode->i_ctime = CURRENT_TIME;
-                ret = btrfs_unlink_inode(trans, root, new_dir,
-                                         new_dentry->d_inode,
-                                         new_dentry->d_name.name,
-                                         new_dentry->d_name.len);
-                if (ret)
-                        goto out_fail;
+                if (unlikely(new_inode->i_ino ==
+                             BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
+                        root_objectid = BTRFS_I(new_inode)->location.objectid;
+                        ret = btrfs_unlink_subvol(trans, dest, new_dir,
+                                                root_objectid,
+                                                new_dentry->d_name.name,
+                                                new_dentry->d_name.len);
+                        BUG_ON(new_inode->i_nlink == 0);
+                } else {
+                        ret = btrfs_unlink_inode(trans, dest, new_dir,
+                                                 new_dentry->d_inode,
+                                                 new_dentry->d_name.name,
+                                                 new_dentry->d_name.len);
+                }
+                BUG_ON(ret);
                 if (new_inode->i_nlink == 0) {
                         ret = btrfs_orphan_add(trans, new_dentry->d_inode);
-                        if (ret)
-                                goto out_fail;
+                        BUG_ON(ret);
                 }
-
         }
-        ret = btrfs_set_inode_index(new_dir, &index);
-        if (ret)
-                goto out_fail;
 
-        ret = btrfs_add_link(trans, new_dentry->d_parent->d_inode,
-                             old_inode, new_dentry->d_name.name,
-                             new_dentry->d_name.len, 1, index);
-        if (ret)
-                goto out_fail;
+        ret = btrfs_add_link(trans, new_dir, old_inode,
+                             new_dentry->d_name.name,
+                             new_dentry->d_name.len, 0, index);
+        BUG_ON(ret);
 
-        btrfs_log_new_name(trans, old_inode, old_dir,
-                                       new_dentry->d_parent);
+        if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
+                btrfs_log_new_name(trans, old_inode, old_dir,
+                                   new_dentry->d_parent);
+                btrfs_end_log_trans(root);
+        }
 out_fail:
-
-        /* this btrfs_end_log_trans just allows the current
-         * log-sub transaction to complete
-         */
-        btrfs_end_log_trans(root);
         btrfs_end_transaction_throttle(trans, root);
-out_unlock:
+
+        if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
+                up_read(&root->fs_info->subvol_sem);
         return ret;
 }
 
@@ -5058,6 +5376,8 @@ static int prealloc_file_range(struct btrfs_trans_handle *trans,
                                                   0, 0, 0,
                                                   BTRFS_FILE_EXTENT_PREALLOC);
                 BUG_ON(ret);
+                btrfs_drop_extent_cache(inode, cur_offset,
+                                        cur_offset + ins.offset -1, 0);
                 num_bytes -= ins.offset;
                 cur_offset += ins.offset;
                 alloc_hint = ins.objectid + ins.offset;
@@ -5223,6 +5543,7 @@ static const struct inode_operations btrfs_dir_ro_inode_operations = {
         .lookup         = btrfs_lookup,
         .permission     = btrfs_permission,
 };
+
 static struct file_operations btrfs_dir_file_operations = {
         .llseek         = generic_file_llseek,
         .read           = generic_read_dir,
@@ -5310,3 +5631,7 @@ static const struct inode_operations btrfs_symlink_inode_operations = {
         .listxattr      = btrfs_listxattr,
         .removexattr    = btrfs_removexattr,
 };
+
+struct dentry_operations btrfs_dentry_operations = {
+        .d_delete       = btrfs_dentry_delete,
+};