11 files changed, 138 insertions, 157 deletions

diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index 0b394580d86..0cc20b35c1c 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -334,7 +334,7 @@ again:
 		if (freezing(current)) {
 			worker->working = 0;
 			spin_unlock_irq(&worker->lock);
-			refrigerator();
+			try_to_freeze();
 		} else {
 			spin_unlock_irq(&worker->lock);
 			if (!kthread_should_stop()) {
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3c2cbf7b666..27ebe61d3cc 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2364,7 +2364,7 @@ static inline u32 btrfs_file_extent_inline_item_len(struct extent_buffer *eb,
 	return btrfs_item_size(eb, e) - offset;
 }
 
-static inline struct btrfs_root *btrfs_sb(struct super_block *sb)
+static inline struct btrfs_fs_info *btrfs_sb(struct super_block *sb)
 {
 	return sb->s_fs_info;
 }
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 4c867112b4c..811d9f918b1 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -873,7 +873,8 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 
 #ifdef CONFIG_MIGRATION
 static int btree_migratepage(struct address_space *mapping,
-			struct page *newpage, struct page *page)
+			struct page *newpage, struct page *page,
+			enum migrate_mode mode)
 {
 	/*
 	 * we can't safely write a btree page from here,
@@ -888,7 +889,7 @@ static int btree_migratepage(struct address_space *mapping,
 	if (page_has_private(page) &&
 	    !try_to_release_page(page, GFP_KERNEL))
 		return -EAGAIN;
-	return migrate_page(mapping, newpage, page);
+	return migrate_page(mapping, newpage, page, mode);
 }
 #endif
 
@@ -1150,7 +1151,6 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 	root->orphan_item_inserted = 0;
 	root->orphan_cleanup_state = 0;
 
-	root->fs_info = fs_info;
 	root->objectid = objectid;
 	root->last_trans = 0;
 	root->highest_objectid = 0;
@@ -1224,6 +1224,14 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
 	return 0;
 }
 
+static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_root *root = kzalloc(sizeof(*root), GFP_NOFS);
+	if (root)
+		root->fs_info = fs_info;
+	return root;
+}
+
 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
 					 struct btrfs_fs_info *fs_info)
 {
@@ -1231,7 +1239,7 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
 	struct btrfs_root *tree_root = fs_info->tree_root;
 	struct extent_buffer *leaf;
 
-	root = kzalloc(sizeof(*root), GFP_NOFS);
+	root = btrfs_alloc_root(fs_info);
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 
@@ -1326,7 +1334,7 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
 	u32 blocksize;
 	int ret = 0;
 
-	root = kzalloc(sizeof(*root), GFP_NOFS);
+	root = btrfs_alloc_root(fs_info);
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 	if (location->offset == (u64)-1) {
@@ -1588,9 +1596,7 @@ static int cleaner_kthread(void *arg)
 			btrfs_run_defrag_inodes(root->fs_info);
 		}
 
-		if (freezing(current)) {
-			refrigerator();
-		} else {
+		if (!try_to_freeze()) {
 			set_current_state(TASK_INTERRUPTIBLE);
 			if (!kthread_should_stop())
 				schedule();
@@ -1644,9 +1650,7 @@ sleep:
 		wake_up_process(root->fs_info->cleaner_kthread);
 		mutex_unlock(&root->fs_info->transaction_kthread_mutex);
 
-		if (freezing(current)) {
-			refrigerator();
-		} else {
+		if (!try_to_freeze()) {
 			set_current_state(TASK_INTERRUPTIBLE);
 			if (!kthread_should_stop() &&
 			    !btrfs_transaction_blocked(root->fs_info))
@@ -1886,9 +1890,9 @@ static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
 }
 
 
-struct btrfs_root *open_ctree(struct super_block *sb,
-			      struct btrfs_fs_devices *fs_devices,
-			      char *options)
+int open_ctree(struct super_block *sb,
+	       struct btrfs_fs_devices *fs_devices,
+	       char *options)
 {
 	u32 sectorsize;
 	u32 nodesize;
@@ -1900,8 +1904,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	struct btrfs_key location;
 	struct buffer_head *bh;
 	struct btrfs_super_block *disk_super;
-	struct btrfs_root *tree_root = btrfs_sb(sb);
-	struct btrfs_fs_info *fs_info = tree_root->fs_info;
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	struct btrfs_root *tree_root;
 	struct btrfs_root *extent_root;
 	struct btrfs_root *csum_root;
 	struct btrfs_root *chunk_root;
@@ -1912,16 +1916,14 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	int num_backups_tried = 0;
 	int backup_index = 0;
 
-	extent_root = fs_info->extent_root =
-		kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
-	csum_root = fs_info->csum_root =
-		kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
-	chunk_root = fs_info->chunk_root =
-		kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
-	dev_root = fs_info->dev_root =
-		kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
+	tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info);
+	extent_root = fs_info->extent_root = btrfs_alloc_root(fs_info);
+	csum_root = fs_info->csum_root = btrfs_alloc_root(fs_info);
+	chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info);
+	dev_root = fs_info->dev_root = btrfs_alloc_root(fs_info);
 
-	if (!extent_root || !csum_root || !chunk_root || !dev_root) {
+	if (!tree_root || !extent_root || !csum_root ||
+	    !chunk_root || !dev_root) {
 		err = -ENOMEM;
 		goto fail;
 	}
@@ -2399,7 +2401,7 @@ retry_root_backup:
 		     btrfs_level_size(tree_root,
 				      btrfs_super_log_root_level(disk_super));
 
-		log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
+		log_tree_root = btrfs_alloc_root(fs_info);
 		if (!log_tree_root) {
 			err = -ENOMEM;
 			goto fail_trans_kthread;
@@ -2460,11 +2462,11 @@ retry_root_backup:
 
 		if (err) {
 			close_ctree(tree_root);
-			return ERR_PTR(err);
+			return err;
 		}
 	}
 
-	return tree_root;
+	return 0;
 
 fail_trans_kthread:
 	kthread_stop(fs_info->transaction_kthread);
@@ -2510,8 +2512,7 @@ fail_srcu:
 	cleanup_srcu_struct(&fs_info->subvol_srcu);
 fail:
 	btrfs_close_devices(fs_info->fs_devices);
-	free_fs_info(fs_info);
-	return ERR_PTR(err);
+	return err;
 
 recovery_tree_root:
 	if (!btrfs_test_opt(tree_root, RECOVERY))
@@ -3017,7 +3018,7 @@ int close_ctree(struct btrfs_root *root)
 		   (atomic_read(&fs_info->defrag_running) == 0));
 
 	/* clear out the rbtree of defraggable inodes */
-	btrfs_run_defrag_inodes(root->fs_info);
+	btrfs_run_defrag_inodes(fs_info);
 
 	/*
 	 * Here come 2 situations when btrfs is broken to flip readonly:
@@ -3046,8 +3047,8 @@ int close_ctree(struct btrfs_root *root)
 
 	btrfs_put_block_group_cache(fs_info);
 
-	kthread_stop(root->fs_info->transaction_kthread);
-	kthread_stop(root->fs_info->cleaner_kthread);
+	kthread_stop(fs_info->transaction_kthread);
+	kthread_stop(fs_info->cleaner_kthread);
 
 	fs_info->closing = 2;
 	smp_mb();
@@ -3065,14 +3066,14 @@ int close_ctree(struct btrfs_root *root)
 	free_extent_buffer(fs_info->extent_root->commit_root);
 	free_extent_buffer(fs_info->tree_root->node);
 	free_extent_buffer(fs_info->tree_root->commit_root);
-	free_extent_buffer(root->fs_info->chunk_root->node);
-	free_extent_buffer(root->fs_info->chunk_root->commit_root);
-	free_extent_buffer(root->fs_info->dev_root->node);
-	free_extent_buffer(root->fs_info->dev_root->commit_root);
-	free_extent_buffer(root->fs_info->csum_root->node);
-	free_extent_buffer(root->fs_info->csum_root->commit_root);
+	free_extent_buffer(fs_info->chunk_root->node);
+	free_extent_buffer(fs_info->chunk_root->commit_root);
+	free_extent_buffer(fs_info->dev_root->node);
+	free_extent_buffer(fs_info->dev_root->commit_root);
+	free_extent_buffer(fs_info->csum_root->node);
+	free_extent_buffer(fs_info->csum_root->commit_root);
 
-	btrfs_free_block_groups(root->fs_info);
+	btrfs_free_block_groups(fs_info);
 
 	del_fs_roots(fs_info);
 
@@ -3103,8 +3104,6 @@ int close_ctree(struct btrfs_root *root)
 	bdi_destroy(&fs_info->bdi);
 	cleanup_srcu_struct(&fs_info->subvol_srcu);
 
-	free_fs_info(fs_info);
-
 	return 0;
 }
 
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index c99d0a8f13f..e4bc4741319 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -46,9 +46,9 @@ struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 						   u64 bytenr, u32 blocksize);
 int clean_tree_block(struct btrfs_trans_handle *trans,
 		     struct btrfs_root *root, struct extent_buffer *buf);
-struct btrfs_root *open_ctree(struct super_block *sb,
-			      struct btrfs_fs_devices *fs_devices,
-			      char *options);
+int open_ctree(struct super_block *sb,
+	       struct btrfs_fs_devices *fs_devices,
+	       char *options);
 int close_ctree(struct btrfs_root *root);
 int write_ctree_super(struct btrfs_trans_handle *trans,
 		      struct btrfs_root *root, int max_mirrors);
diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 1b8dc33778f..5f77166fd01 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -67,7 +67,7 @@ static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
 				       u64 root_objectid, u32 generation,
 				       int check_generation)
 {
-	struct btrfs_fs_info *fs_info = btrfs_sb(sb)->fs_info;
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 	struct btrfs_root *root;
 	struct inode *inode;
 	struct btrfs_key key;
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 0f61e11a299..859ba2dd889 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1081,7 +1081,7 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
 again:
 	for (i = 0; i < num_pages; i++) {
 		pages[i] = find_or_create_page(inode->i_mapping, index + i,
-					       mask);
+					       mask | __GFP_WRITE);
 		if (!pages[i]) {
 			faili = i - 1;
 			err = -ENOMEM;
@@ -1136,7 +1136,8 @@ again:
 				     GFP_NOFS);
 	}
 	for (i = 0; i < num_pages; i++) {
-		clear_page_dirty_for_io(pages[i]);
+		if (clear_page_dirty_for_io(pages[i]))
+			account_page_redirty(pages[i]);
 		set_page_extent_mapped(pages[i]);
 		WARN_ON(!PageLocked(pages[i]));
 	}
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 5802b1473c3..c2f20594c9f 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -425,7 +425,7 @@ static void io_ctl_set_crc(struct io_ctl *io_ctl, int index)
 	}
 
 	if (index == 0)
-		offset = sizeof(u32) * io_ctl->num_pages;;
+		offset = sizeof(u32) * io_ctl->num_pages;
 
 	crc = btrfs_csum_data(io_ctl->root, io_ctl->orig + offset, crc,
 			      PAGE_CACHE_SIZE - offset);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7405753ec5d..32214fe0f7e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1944,7 +1944,7 @@ enum btrfs_orphan_cleanup_state {
 };
 
 /*
- * This is called in transaction commmit time. If there are no orphan
+ * This is called in transaction commit time. If there are no orphan
  * files in the subvolume, it removes orphan item and frees block_rsv
  * structure.
  */
@@ -4414,8 +4414,8 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 				     struct btrfs_root *root,
 				     struct inode *dir,
 				     const char *name, int name_len,
-				     u64 ref_objectid, u64 objectid, int mode,
-				     u64 *index)
+				     u64 ref_objectid, u64 objectid,
+				     umode_t mode, u64 *index)
 {
 	struct inode *inode;
 	struct btrfs_inode_item *inode_item;
@@ -4598,7 +4598,7 @@ static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
 }
 
 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
-			int mode, dev_t rdev)
+			umode_t mode, dev_t rdev)
 {
 	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(dir)->root;
@@ -4667,7 +4667,7 @@ out_unlock:
 }
 
 static int btrfs_create(struct inode *dir, struct dentry *dentry,
-			int mode, struct nameidata *nd)
+			umode_t mode, struct nameidata *nd)
 {
 	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(dir)->root;
@@ -4794,7 +4794,7 @@ fail:
 	return err;
 }
 
-static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode = NULL;
 	struct btrfs_trans_handle *trans;
@@ -6767,7 +6767,6 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
 static void btrfs_i_callback(struct rcu_head *head)
 {
 	struct inode *inode = container_of(head, struct inode, i_rcu);
-	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
 }
 
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 0b06a5ca8af..03bb62a9ee2 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -206,7 +206,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 		}
 	}
 
-	ret = mnt_want_write(file->f_path.mnt);
+	ret = mnt_want_write_file(file);
 	if (ret)
 		goto out_unlock;
 
@@ -271,7 +271,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 		inode->i_flags = i_oldflags;
 	}
 
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
  out_unlock:
 	mutex_unlock(&inode->i_mutex);
 	return ret;
@@ -286,14 +286,13 @@ static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 
 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 {
-	struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info;
-	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
 	struct btrfs_device *device;
 	struct request_queue *q;
 	struct fstrim_range range;
 	u64 minlen = ULLONG_MAX;
 	u64 num_devices = 0;
-	u64 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
+	u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 	int ret;
 
 	if (!capable(CAP_SYS_ADMIN))
@@ -322,7 +321,7 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 
 	range.len = min(range.len, total_bytes - range.start);
 	range.minlen = max(range.minlen, minlen);
-	ret = btrfs_trim_fs(root, &range);
+	ret = btrfs_trim_fs(fs_info->tree_root, &range);
 	if (ret < 0)
 		return ret;
 
@@ -1872,7 +1871,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 		goto out;
 	}
 
-	err = mnt_want_write(file->f_path.mnt);
+	err = mnt_want_write_file(file);
 	if (err)
 		goto out;
 
@@ -1988,7 +1987,7 @@ out_dput:
 	dput(dentry);
 out_unlock_dir:
 	mutex_unlock(&dir->i_mutex);
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 out:
 	kfree(vol_args);
 	return err;
@@ -2004,7 +2003,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
 	if (btrfs_root_readonly(root))
 		return -EROFS;
 
-	ret = mnt_want_write(file->f_path.mnt);
+	ret = mnt_want_write_file(file);
 	if (ret)
 		return ret;
 
@@ -2057,7 +2056,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
 		ret = -EINVAL;
 	}
 out:
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 	return ret;
 }
 
@@ -2234,7 +2233,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 	if (btrfs_root_readonly(root))
 		return -EROFS;
 
-	ret = mnt_want_write(file->f_path.mnt);
+	ret = mnt_want_write_file(file);
 	if (ret)
 		return ret;
 
@@ -2550,7 +2549,7 @@ out_unlock:
 out_fput:
 	fput(src_file);
 out_drop_write:
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 	return ret;
 }
 
@@ -2589,7 +2588,7 @@ static long btrfs_ioctl_trans_start(struct file *file)
 	if (btrfs_root_readonly(root))
 		goto out;
 
-	ret = mnt_want_write(file->f_path.mnt);
+	ret = mnt_want_write_file(file);
 	if (ret)
 		goto out;
 
@@ -2605,7 +2604,7 @@ static long btrfs_ioctl_trans_start(struct file *file)
 
 out_drop:
 	atomic_dec(&root->fs_info->open_ioctl_trans);
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 out:
 	return ret;
 }
@@ -2840,7 +2839,7 @@ long btrfs_ioctl_trans_end(struct file *file)
 
 	atomic_dec(&root->fs_info->open_ioctl_trans);
 
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 	return 0;
 }
 
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 61717a4eb14..3ce97b217cb 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -40,7 +40,6 @@
 #include <linux/magic.h>
 #include <linux/slab.h>
 #include <linux/cleancache.h>
-#include <linux/mnt_namespace.h>
 #include <linux/ratelimit.h>
 #include "compat.h"
 #include "delayed-inode.h"
@@ -148,13 +147,13 @@ void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 
 static void btrfs_put_super(struct super_block *sb)
 {
-	struct btrfs_root *root = btrfs_sb(sb);
-	int ret;
-
-	ret = close_ctree(root);
-	sb->s_fs_info = NULL;
-
-	(void)ret; /* FIXME: need to fix VFS to return error? */
+	(void)close_ctree(btrfs_sb(sb)->tree_root);
+	/* FIXME: need to fix VFS to return error? */
+	/* AV: return it _where_?  ->put_super() can be triggered by any number
+	 * of async events, up to and including delivery of SIGKILL to the
+	 * last process that kept it busy.  Or segfault in the aforementioned
+	 * process...  Whom would you report that to?
+	 */
 }
 
 enum {
@@ -542,7 +541,8 @@ out:
 static struct dentry *get_default_root(struct super_block *sb,
 				       u64 subvol_objectid)
 {
-	struct btrfs_root *root = sb->s_fs_info;
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	struct btrfs_root *root = fs_info->tree_root;
 	struct btrfs_root *new_root;
 	struct btrfs_dir_item *di;
 	struct btrfs_path *path;
@@ -572,7 +572,7 @@ static struct dentry *get_default_root(struct super_block *sb,
 	 * will mount by default if we haven't been given a specific subvolume
 	 * to mount.
 	 */
-	dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
+	dir_id = btrfs_super_root_dir(fs_info->super_copy);
 	di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
 	if (IS_ERR(di)) {
 		btrfs_free_path(path);
@@ -586,7 +586,7 @@ static struct dentry *get_default_root(struct super_block *sb,
 		 */
 		btrfs_free_path(path);
 		dir_id = BTRFS_FIRST_FREE_OBJECTID;
-		new_root = root->fs_info->fs_root;
+		new_root = fs_info->fs_root;
 		goto setup_root;
 	}
 
@@ -594,7 +594,7 @@ static struct dentry *get_default_root(struct super_block *sb,
 	btrfs_free_path(path);
 
 find_root:
-	new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
+	new_root = btrfs_read_fs_root_no_name(fs_info, &location);
 	if (IS_ERR(new_root))
 		return ERR_CAST(new_root);
 
@@ -630,7 +630,7 @@ static int btrfs_fill_super(struct super_block *sb,
 {
 	struct inode *inode;
 	struct dentry *root_dentry;
-	struct btrfs_root *tree_root;
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 	struct btrfs_key key;
 	int err;
 
@@ -645,18 +645,16 @@ static int btrfs_fill_super(struct super_block *sb,
 	sb->s_flags |= MS_POSIXACL;
 #endif
 
-	tree_root = open_ctree(sb, fs_devices, (char *)data);
-
-	if (IS_ERR(tree_root)) {
+	err = open_ctree(sb, fs_devices, (char *)data);
+	if (err) {
 		printk("btrfs: open_ctree failed\n");
-		return PTR_ERR(tree_root);
+		return err;
 	}
-	sb->s_fs_info = tree_root;
 
 	key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 	key.type = BTRFS_INODE_ITEM_KEY;
 	key.offset = 0;
-	inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
+	inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
 		goto fail_close;
@@ -673,23 +671,25 @@ static int btrfs_fill_super(struct super_block *sb,
 
 	save_mount_options(sb, data);
 	cleancache_init_fs(sb);
+	sb->s_flags |= MS_ACTIVE;
 	return 0;
 
 fail_close:
-	close_ctree(tree_root);
+	close_ctree(fs_info->tree_root);
 	return err;
 }
 
 int btrfs_sync_fs(struct super_block *sb, int wait)
 {
 	struct btrfs_trans_handle *trans;
-	struct btrfs_root *root = btrfs_sb(sb);
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	struct btrfs_root *root = fs_info->tree_root;
 	int ret;
 
 	trace_btrfs_sync_fs(wait);
 
 	if (!wait) {
-		filemap_flush(root->fs_info->btree_inode->i_mapping);
+		filemap_flush(fs_info->btree_inode->i_mapping);
 		return 0;
 	}
 
@@ -703,10 +703,10 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
 	return ret;
 }
 
-static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
+static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 {
-	struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
-	struct btrfs_fs_info *info = root->fs_info;
+	struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
+	struct btrfs_root *root = info->tree_root;
 	char *compress_type;
 
 	if (btrfs_test_opt(root, DEGRADED))
@@ -771,23 +771,18 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 
 static int btrfs_test_super(struct super_block *s, void *data)
 {
-	struct btrfs_root *test_root = data;
-	struct btrfs_root *root = btrfs_sb(s);
+	struct btrfs_fs_info *p = data;
+	struct btrfs_fs_info *fs_info = btrfs_sb(s);
 
-	/*
-	 * If this super block is going away, return false as it
-	 * can't match as an existing super block.
-	 */
-	if (!atomic_read(&s->s_active))
-		return 0;
-	return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
+	return fs_info->fs_devices == p->fs_devices;
 }
 
 static int btrfs_set_super(struct super_block *s, void *data)
 {
-	s->s_fs_info = data;
-
-	return set_anon_super(s, data);
+	int err = set_anon_super(s, data);
+	if (!err)
+		s->s_fs_info = data;
+	return err;
 }
 
 /*
@@ -947,12 +942,6 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 	if (!fs_info)
 		return ERR_PTR(-ENOMEM);
 
-	fs_info->tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
-	if (!fs_info->tree_root) {
-		error = -ENOMEM;
-		goto error_fs_info;
-	}
-	fs_info->tree_root->fs_info = fs_info;
 	fs_info->fs_devices = fs_devices;
 
 	fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
@@ -972,43 +961,30 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 	}
 
 	bdev = fs_devices->latest_bdev;
-	s = sget(fs_type, btrfs_test_super, btrfs_set_super,
-		 fs_info->tree_root);
+	s = sget(fs_type, btrfs_test_super, btrfs_set_super, fs_info);
 	if (IS_ERR(s)) {
 		error = PTR_ERR(s);
 		goto error_close_devices;
 	}
 
 	if (s->s_root) {
-		if ((flags ^ s->s_flags) & MS_RDONLY) {
-			deactivate_locked_super(s);
-			error = -EBUSY;
-			goto error_close_devices;
-		}
-
 		btrfs_close_devices(fs_devices);
 		free_fs_info(fs_info);
+		if ((flags ^ s->s_flags) & MS_RDONLY)
+			error = -EBUSY;
 	} else {
 		char b[BDEVNAME_SIZE];
 
 		s->s_flags = flags | MS_NOSEC;
 		strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
-		btrfs_sb(s)->fs_info->bdev_holder = fs_type;
+		btrfs_sb(s)->bdev_holder = fs_type;
 		error = btrfs_fill_super(s, fs_devices, data,
 					 flags & MS_SILENT ? 1 : 0);
-		if (error) {
-			deactivate_locked_super(s);
-			return ERR_PTR(error);
-		}
-
-		s->s_flags |= MS_ACTIVE;
 	}
 
-	root = get_default_root(s, subvol_objectid);
-	if (IS_ERR(root)) {
+	root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
+	if (IS_ERR(root))
 		deactivate_locked_super(s);
-		return root;
-	}
 
 	return root;
 
@@ -1021,7 +997,8 @@ error_fs_info:
 
 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 {
-	struct btrfs_root *root = btrfs_sb(sb);
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	struct btrfs_root *root = fs_info->tree_root;
 	int ret;
 
 	ret = btrfs_parse_options(root, data);
@@ -1037,13 +1014,13 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 		ret =  btrfs_commit_super(root);
 		WARN_ON(ret);
 	} else {
-		if (root->fs_info->fs_devices->rw_devices == 0)
+		if (fs_info->fs_devices->rw_devices == 0)
 			return -EACCES;
 
-		if (btrfs_super_log_root(root->fs_info->super_copy) != 0)
+		if (btrfs_super_log_root(fs_info->super_copy) != 0)
 			return -EINVAL;
 
-		ret = btrfs_cleanup_fs_roots(root->fs_info);
+		ret = btrfs_cleanup_fs_roots(fs_info);
 		WARN_ON(ret);
 
 		/* recover relocation */
@@ -1212,18 +1189,18 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
 
 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
-	struct btrfs_root *root = btrfs_sb(dentry->d_sb);
-	struct btrfs_super_block *disk_super = root->fs_info->super_copy;
-	struct list_head *head = &root->fs_info->space_info;
+	struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
+	struct btrfs_super_block *disk_super = fs_info->super_copy;
+	struct list_head *head = &fs_info->space_info;
 	struct btrfs_space_info *found;
 	u64 total_used = 0;
 	u64 total_free_data = 0;
 	int bits = dentry->d_sb->s_blocksize_bits;
-	__be32 *fsid = (__be32 *)root->fs_info->fsid;
+	__be32 *fsid = (__be32 *)fs_info->fsid;
 	int ret;
 
 	/* holding chunk_muext to avoid allocating new chunks */
-	mutex_lock(&root->fs_info->chunk_mutex);
+	mutex_lock(&fs_info->chunk_mutex);
 	rcu_read_lock();
 	list_for_each_entry_rcu(found, head, list) {
 		if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
@@ -1242,14 +1219,14 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_bsize = dentry->d_sb->s_blocksize;
 	buf->f_type = BTRFS_SUPER_MAGIC;
 	buf->f_bavail = total_free_data;
-	ret = btrfs_calc_avail_data_space(root, &total_free_data);
+	ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
 	if (ret) {
-		mutex_unlock(&root->fs_info->chunk_mutex);
+		mutex_unlock(&fs_info->chunk_mutex);
 		return ret;
 	}
 	buf->f_bavail += total_free_data;
 	buf->f_bavail = buf->f_bavail >> bits;
-	mutex_unlock(&root->fs_info->chunk_mutex);
+	mutex_unlock(&fs_info->chunk_mutex);
 
 	/* We treat it as constant endianness (it doesn't matter _which_)
 	   because we want the fsid to come out the same whether mounted
@@ -1263,11 +1240,18 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	return 0;
 }
 
+static void btrfs_kill_super(struct super_block *sb)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	kill_anon_super(sb);
+	free_fs_info(fs_info);
+}
+
 static struct file_system_type btrfs_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "btrfs",
 	.mount		= btrfs_mount,
-	.kill_sb	= kill_anon_super,
+	.kill_sb	= btrfs_kill_super,
 	.fs_flags	= FS_REQUIRES_DEV,
 };
 
@@ -1301,17 +1285,17 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
 
 static int btrfs_freeze(struct super_block *sb)
 {
-	struct btrfs_root *root = btrfs_sb(sb);
-	mutex_lock(&root->fs_info->transaction_kthread_mutex);
-	mutex_lock(&root->fs_info->cleaner_mutex);
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	mutex_lock(&fs_info->transaction_kthread_mutex);
+	mutex_lock(&fs_info->cleaner_mutex);
 	return 0;
 }
 
 static int btrfs_unfreeze(struct super_block *sb)
 {
-	struct btrfs_root *root = btrfs_sb(sb);
-	mutex_unlock(&root->fs_info->cleaner_mutex);
-	mutex_unlock(&root->fs_info->transaction_kthread_mutex);
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	mutex_unlock(&fs_info->cleaner_mutex);
+	mutex_unlock(&fs_info->transaction_kthread_mutex);
 	return 0;
 }
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 7ffdb154dae..0b4e2af7954 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -708,8 +708,6 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 	u64 devid;
 	u64 transid;
 
-	mutex_lock(&uuid_mutex);
-
 	flags |= FMODE_EXCL;
 	bdev = blkdev_get_by_path(path, flags, holder);
 
@@ -718,6 +716,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 		goto error;
 	}
 
+	mutex_lock(&uuid_mutex);
 	ret = set_blocksize(bdev, 4096);
 	if (ret)
 		goto error_close;
@@ -739,9 +738,9 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 
 	brelse(bh);
 error_close:
+	mutex_unlock(&uuid_mutex);
 	blkdev_put(bdev, flags);
 error:
-	mutex_unlock(&uuid_mutex);
 	return ret;
 }