From 98c7089c769048f941bd5c5285287f8fc301f8b1 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 01:00:31 -0500
Subject: btrfs: preparation to fixing mount/umount race

We need fs_info and root to live until the moment when the victim
superblock leaves the list, so we need to postpone free_fs_info()
until after ->put_super().  The call is buried in close_ctree(),
though, so we need to lift it into the callers (including
btrfs_put_super()) first.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/disk-io.c | 3 +--
 fs/btrfs/super.c   | 6 +++++-
 2 files changed, 6 insertions(+), 3 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f99a099a7747..dcb5d949b543 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2424,6 +2424,7 @@ retry_root_backup:
 		up_read(&fs_info->cleanup_work_sem);
 		if (err) {
 			close_ctree(tree_root);
+			free_fs_info(fs_info);
 			return ERR_PTR(err);
 		}
 	}
@@ -3059,8 +3060,6 @@ 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/super.c b/fs/btrfs/super.c
index ae488aa1966a..a3f435e58987 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -151,6 +151,7 @@ static void btrfs_put_super(struct super_block *sb)
 	int ret;
 
 	ret = close_ctree(root);
+	free_fs_info(root->fs_info);
 	sb->s_fs_info = NULL;
 
 	(void)ret; /* FIXME: need to fix VFS to return error? */
@@ -589,6 +590,7 @@ 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;
 	struct btrfs_key key;
 	int err;
 
@@ -609,12 +611,13 @@ static int btrfs_fill_super(struct super_block *sb,
 		printk("btrfs: open_ctree failed\n");
 		return PTR_ERR(tree_root);
 	}
+	fs_info = tree_root->fs_info;
 	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;
@@ -635,6 +638,7 @@ static int btrfs_fill_super(struct super_block *sb,
 
 fail_close:
 	close_ctree(tree_root);
+	free_fs_info(fs_info);
 	return err;
 }
 
-- 
cgit v1.2.1


From aea52e19dd2085617dd7d247afb76a90cf2ea40c Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 01:22:46 -0500
Subject: btrfs: get ->kill_sb() of its own

... and move free_fs_info() to that, out of ->put_super().  Do NOT
set ->s_fs_info to NULL in the latter; we need it for sget() to
be able to see and wait for fs in the middle of umount if we get a
mount/umount race.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/super.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index a3f435e58987..eca48624a4f0 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -147,14 +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);
-	free_fs_info(root->fs_info);
-	sb->s_fs_info = NULL;
-
-	(void)ret; /* FIXME: need to fix VFS to return error? */
+	(void)close_ctree(btrfs_sb(sb));
+	/* 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 {
@@ -1223,11 +1222,21 @@ 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 = NULL;
+	if (sb->s_root)
+		fs_info = btrfs_sb(sb)->fs_info;
+	kill_anon_super(sb);
+	if (fs_info)
+		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,
 };
 
-- 
cgit v1.2.1


From 6de1d09d9677dce7a04ef485d426821159ab7de9 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 01:29:09 -0500
Subject: btrfs: fix mount/umount race

Do *NOT* skip doomed superblocks in btrfs_test_super(); we want
sget() to wait for their shutdown to complete.  Since we don't
mutilate ->s_fs_info in ->put_super() anymore (or free what it
used to point to until the superblock is past being findable
by sget()), we can just DTRT there and report a match.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/super.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index eca48624a4f0..b9fd62a0fca2 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -733,20 +733,15 @@ static int btrfs_test_super(struct super_block *s, void *data)
 	struct btrfs_root *test_root = data;
 	struct btrfs_root *root = 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;
 }
 
 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;
 }
 
 /*
-- 
cgit v1.2.1


From 10f6327b5d26660e06120ba17cff993cb616b1d2 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 15:05:22 -0500
Subject: btrfs: fix a deadlock in btrfs_scan_one_device()

pathname resolution under a global mutex, taken on some paths in ->mount()
is a Bad Idea(tm) - think what happens if said pathname resolution triggers
automount of some btrfs instance and walks into attempt to grab the same
mutex.  Deadlock - we are waiting for daemon to finish walking the path,
daemon is waiting for us to release the mutex...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/volumes.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f4b839fd3c9d..96bb3c0a79b0 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -706,8 +706,6 @@ 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);
 
@@ -716,6 +714,7 @@ 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;
@@ -737,9 +736,9 @@ 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;
 }
 
-- 
cgit v1.2.1


From 2eb34cd368b3e5cef960ae9d9971a037cd6fa9d3 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 00:32:06 -0500
Subject: btrfs: sanitizing ->fs_info, part 1

take assignment of ->fs_info to callers of __setup_root()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/disk-io.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index dcb5d949b543..04eba10af825 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1142,7 +1142,6 @@ 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;
@@ -1193,6 +1192,7 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
 	u32 blocksize;
 	u64 generation;
 
+	root->fs_info = fs_info;
 	__setup_root(tree_root->nodesize, tree_root->leafsize,
 		     tree_root->sectorsize, tree_root->stripesize,
 		     root, fs_info, objectid);
@@ -1227,6 +1227,7 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 
+	root->fs_info = fs_info;
 	__setup_root(tree_root->nodesize, tree_root->leafsize,
 		     tree_root->sectorsize, tree_root->stripesize,
 		     root, fs_info, BTRFS_TREE_LOG_OBJECTID);
@@ -1330,6 +1331,7 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
 		goto out;
 	}
 
+	root->fs_info = fs_info;
 	__setup_root(tree_root->nodesize, tree_root->leafsize,
 		     tree_root->sectorsize, tree_root->stripesize,
 		     root, fs_info, location->objectid);
@@ -2055,6 +2057,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	init_waitqueue_head(&fs_info->transaction_blocked_wait);
 	init_waitqueue_head(&fs_info->async_submit_wait);
 
+	tree_root->fs_info = fs_info;
 	__setup_root(4096, 4096, 4096, 4096, tree_root,
 		     fs_info, BTRFS_ROOT_TREE_OBJECTID);
 
@@ -2247,6 +2250,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 				     btrfs_super_chunk_root_level(disk_super));
 	generation = btrfs_super_chunk_root_generation(disk_super);
 
+	chunk_root->fs_info = fs_info;
 	__setup_root(nodesize, leafsize, sectorsize, stripesize,
 		     chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
 
@@ -2373,6 +2377,7 @@ retry_root_backup:
 			goto fail_trans_kthread;
 		}
 
+		log_tree_root->fs_info = fs_info;
 		__setup_root(nodesize, leafsize, sectorsize, stripesize,
 			     log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 
-- 
cgit v1.2.1


From 1233f546ec29ac32424327baf6ae5df81e3d9eae Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 00:34:00 -0500
Subject: btrfs: sanitizing ->fs_info, part 2

lift assignment to callers of find_and_setup_root()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/disk-io.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 04eba10af825..b8dae517f80c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1192,7 +1192,6 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
 	u32 blocksize;
 	u64 generation;
 
-	root->fs_info = fs_info;
 	__setup_root(tree_root->nodesize, tree_root->leafsize,
 		     tree_root->sectorsize, tree_root->stripesize,
 		     root, fs_info, objectid);
@@ -1322,6 +1321,7 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 	if (location->offset == (u64)-1) {
+		root->fs_info = fs_info;
 		ret = find_and_setup_root(tree_root, fs_info,
 					  location->objectid, root);
 		if (ret) {
@@ -2300,18 +2300,21 @@ retry_root_backup:
 	btrfs_set_root_node(&tree_root->root_item, tree_root->node);
 	tree_root->commit_root = btrfs_root_node(tree_root);
 
+	extent_root->fs_info = fs_info;
 	ret = find_and_setup_root(tree_root, fs_info,
 				  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 	if (ret)
 		goto recovery_tree_root;
 	extent_root->track_dirty = 1;
 
+	dev_root->fs_info = fs_info;
 	ret = find_and_setup_root(tree_root, fs_info,
 				  BTRFS_DEV_TREE_OBJECTID, dev_root);
 	if (ret)
 		goto recovery_tree_root;
 	dev_root->track_dirty = 1;
 
+	csum_root->fs_info = fs_info;
 	ret = find_and_setup_root(tree_root, fs_info,
 				  BTRFS_CSUM_TREE_OBJECTID, csum_root);
 	if (ret)
-- 
cgit v1.2.1


From 38a77db49ad8f78369dcdfb693b8e5a818a60104 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 00:38:54 -0500
Subject: btrfs: sanitizing ->fs_info, part 3

move assignments to ->fs_info in open_ctree() up, to the place
just after the original allocations.  Assignment for tree_root
becomes a no-op - we'd obtained fs_info from tree_root->fs_info
in the first place.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/disk-io.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b8dae517f80c..06480fcf0fb3 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1320,8 +1320,8 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
 	root = kzalloc(sizeof(*root), GFP_NOFS);
 	if (!root)
 		return ERR_PTR(-ENOMEM);
+	root->fs_info = fs_info;
 	if (location->offset == (u64)-1) {
-		root->fs_info = fs_info;
 		ret = find_and_setup_root(tree_root, fs_info,
 					  location->objectid, root);
 		if (ret) {
@@ -1331,7 +1331,6 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
 		goto out;
 	}
 
-	root->fs_info = fs_info;
 	__setup_root(tree_root->nodesize, tree_root->leafsize,
 		     tree_root->sectorsize, tree_root->stripesize,
 		     root, fs_info, location->objectid);
@@ -1914,6 +1913,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 		err = -ENOMEM;
 		goto fail;
 	}
+	chunk_root->fs_info = fs_info;
+	extent_root->fs_info = fs_info;
+	dev_root->fs_info = fs_info;
+	csum_root->fs_info = fs_info;
 
 	ret = init_srcu_struct(&fs_info->subvol_srcu);
 	if (ret) {
@@ -2057,7 +2060,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	init_waitqueue_head(&fs_info->transaction_blocked_wait);
 	init_waitqueue_head(&fs_info->async_submit_wait);
 
-	tree_root->fs_info = fs_info;
 	__setup_root(4096, 4096, 4096, 4096, tree_root,
 		     fs_info, BTRFS_ROOT_TREE_OBJECTID);
 
@@ -2250,7 +2252,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 				     btrfs_super_chunk_root_level(disk_super));
 	generation = btrfs_super_chunk_root_generation(disk_super);
 
-	chunk_root->fs_info = fs_info;
 	__setup_root(nodesize, leafsize, sectorsize, stripesize,
 		     chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
 
@@ -2300,21 +2301,18 @@ retry_root_backup:
 	btrfs_set_root_node(&tree_root->root_item, tree_root->node);
 	tree_root->commit_root = btrfs_root_node(tree_root);
 
-	extent_root->fs_info = fs_info;
 	ret = find_and_setup_root(tree_root, fs_info,
 				  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
 	if (ret)
 		goto recovery_tree_root;
 	extent_root->track_dirty = 1;
 
-	dev_root->fs_info = fs_info;
 	ret = find_and_setup_root(tree_root, fs_info,
 				  BTRFS_DEV_TREE_OBJECTID, dev_root);
 	if (ret)
 		goto recovery_tree_root;
 	dev_root->track_dirty = 1;
 
-	csum_root->fs_info = fs_info;
 	ret = find_and_setup_root(tree_root, fs_info,
 				  BTRFS_CSUM_TREE_OBJECTID, csum_root);
 	if (ret)
-- 
cgit v1.2.1


From 6f07e42ee6fcc252a210781d7262f4051e9fd8f6 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 00:46:16 -0500
Subject: btrfs: sanitizing ->fs_info, part 4

A new helper: btrfs_alloc_root(fs_info); allocates btrfs_root
and sets ->fs_info.  All places allocating the suckers converted
to it.  At that point we *never* reassign ->fs_info of btrfs_root;
it's set before anyone sees the address of newly allocated
struct btrfs_root and never assigned anywhere else.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/disk-io.c | 33 +++++++++++++++------------------
 fs/btrfs/disk-io.h |  2 ++
 fs/btrfs/super.c   |  3 +--
 3 files changed, 18 insertions(+), 20 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 06480fcf0fb3..ee846ce58846 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1215,6 +1215,14 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
 	return 0;
 }
 
+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)
 {
@@ -1222,11 +1230,10 @@ 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);
 
-	root->fs_info = fs_info;
 	__setup_root(tree_root->nodesize, tree_root->leafsize,
 		     tree_root->sectorsize, tree_root->stripesize,
 		     root, fs_info, BTRFS_TREE_LOG_OBJECTID);
@@ -1317,10 +1324,9 @@ 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);
-	root->fs_info = fs_info;
 	if (location->offset == (u64)-1) {
 		ret = find_and_setup_root(tree_root, fs_info,
 					  location->objectid, root);
@@ -1900,23 +1906,15 @@ 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);
+	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) {
 		err = -ENOMEM;
 		goto fail;
 	}
-	chunk_root->fs_info = fs_info;
-	extent_root->fs_info = fs_info;
-	dev_root->fs_info = fs_info;
-	csum_root->fs_info = fs_info;
 
 	ret = init_srcu_struct(&fs_info->subvol_srcu);
 	if (ret) {
@@ -2372,13 +2370,12 @@ 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;
 		}
 
-		log_tree_root->fs_info = fs_info;
 		__setup_root(nodesize, leafsize, sectorsize, stripesize,
 			     log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
 
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index c99d0a8f13fa..2bb5f59ddf95 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -86,6 +86,8 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 		       struct btrfs_root *root);
 
+struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info);
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 void btrfs_init_lockdep(void);
 void btrfs_set_buffer_lockdep_class(u64 objectid,
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index b9fd62a0fca2..e9f876a1655b 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -901,12 +901,11 @@ 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);
+	fs_info->tree_root = btrfs_alloc_root(fs_info);
 	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);
-- 
cgit v1.2.1


From e3029d9fd426c8f582210ba35551ae5506218345 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 00:56:18 -0500
Subject: btrfs: sanitizing ->fs_info, part 5

close_ctree() uses a weird mix of accesses to root->fs_info and
its value at the beginning of function stored in local variable.
Since ->fs_info *never* changes, let's just use the local variable
to avoid confusion.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/disk-io.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ee846ce58846..9308c7f13c17 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2982,7 +2982,7 @@ 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:
@@ -3011,8 +3011,8 @@ 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();
@@ -3030,14 +3030,14 @@ 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);
-
-	btrfs_free_block_groups(root->fs_info);
+	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(fs_info);
 
 	del_fs_roots(fs_info);
 
-- 
cgit v1.2.1


From ad2b2c802be2d3e8ed8364fef5ffaddabe448219 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 01:10:02 -0500
Subject: btrfs: make open_ctree() return int

It returns either ERR_PTR(-ve) or sb->s_fs_info.  The latter can
be found by caller just as well, TYVM, no need to return it.  Just
return -ve or 0...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/disk-io.c | 12 ++++++------
 fs/btrfs/disk-io.h |  6 +++---
 fs/btrfs/super.c   |  8 ++++----
 3 files changed, 13 insertions(+), 13 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9308c7f13c17..78247522c693 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1880,9 +1880,9 @@ 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;
@@ -2428,11 +2428,11 @@ retry_root_backup:
 		if (err) {
 			close_ctree(tree_root);
 			free_fs_info(fs_info);
-			return ERR_PTR(err);
+			return err;
 		}
 	}
 
-	return tree_root;
+	return 0;
 
 fail_trans_kthread:
 	kthread_stop(fs_info->transaction_kthread);
@@ -2479,7 +2479,7 @@ fail_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))
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 2bb5f59ddf95..6f5f48778b00 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/super.c b/fs/btrfs/super.c
index e9f876a1655b..56e007fd6702 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -604,12 +604,12 @@ 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;
 	}
+	tree_root = sb->s_fs_info;
 	fs_info = tree_root->fs_info;
 	sb->s_fs_info = tree_root;
 
-- 
cgit v1.2.1


From 29db78aa0ac82319b764b87a1c5030d74523e296 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 01:12:38 -0500
Subject: btrfs: kill pointless reassignment of ->s_fs_info in
 btrfs_fill_super()

We do not (fortunately) modify ->s_fs_info of superblock on the fly in
btrfs_fill_super(); apparent assignment is a no-op.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/super.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 56e007fd6702..a381f9f9b0c2 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -588,8 +588,8 @@ 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;
+	struct btrfs_root *tree_root = sb->s_fs_info;
+	struct btrfs_fs_info *fs_info = tree_root->fs_info;
 	struct btrfs_key key;
 	int err;
 
@@ -609,9 +609,6 @@ static int btrfs_fill_super(struct super_block *sb,
 		printk("btrfs: open_ctree failed\n");
 		return err;
 	}
-	tree_root = sb->s_fs_info;
-	fs_info = tree_root->fs_info;
-	sb->s_fs_info = tree_root;
 
 	key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 	key.type = BTRFS_INODE_ITEM_KEY;
-- 
cgit v1.2.1


From be7e0950def403e90b5295ff2192c39967bf2aec Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 01:40:05 -0500
Subject: btrfs: merge free_fs_info() calls on fill_super failures

... all the way up into btrfs_mount().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/disk-io.c | 2 --
 fs/btrfs/super.c   | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 78247522c693..b6d11eb4e430 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2427,7 +2427,6 @@ retry_root_backup:
 		up_read(&fs_info->cleanup_work_sem);
 		if (err) {
 			close_ctree(tree_root);
-			free_fs_info(fs_info);
 			return err;
 		}
 	}
@@ -2478,7 +2477,6 @@ fail_srcu:
 	cleanup_srcu_struct(&fs_info->subvol_srcu);
 fail:
 	btrfs_close_devices(fs_info->fs_devices);
-	free_fs_info(fs_info);
 	return err;
 
 recovery_tree_root:
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index a381f9f9b0c2..8901b6c85260 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -634,7 +634,6 @@ static int btrfs_fill_super(struct super_block *sb,
 
 fail_close:
 	close_ctree(tree_root);
-	free_fs_info(fs_info);
 	return err;
 }
 
@@ -947,6 +946,7 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 		error = btrfs_fill_super(s, fs_devices, data,
 					 flags & MS_SILENT ? 1 : 0);
 		if (error) {
+			free_fs_info(fs_info);
 			deactivate_locked_super(s);
 			return ERR_PTR(error);
 		}
-- 
cgit v1.2.1


From d22ca7de770e2a683eac000ba4db5a95e2f4c969 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 01:46:50 -0500
Subject: btrfs: make free_fs_info() call ->kill_sb() unconditional

... and don't bother with it after btrfs_fill_super() failure -
->kill_sb() (unlike ->put_super()) will be called even if we
have not got non-NULL ->s_root.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/super.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8901b6c85260..f628a6a79ca6 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -946,7 +946,6 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 		error = btrfs_fill_super(s, fs_devices, data,
 					 flags & MS_SILENT ? 1 : 0);
 		if (error) {
-			free_fs_info(fs_info);
 			deactivate_locked_super(s);
 			return ERR_PTR(error);
 		}
@@ -1215,12 +1214,9 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 static void btrfs_kill_super(struct super_block *sb)
 {
-	struct btrfs_fs_info *fs_info = NULL;
-	if (sb->s_root)
-		fs_info = btrfs_sb(sb)->fs_info;
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb)->fs_info;
 	kill_anon_super(sb);
-	if (fs_info)
-		free_fs_info(fs_info);
+	free_fs_info(fs_info);
 }
 
 static struct file_system_type btrfs_fs_type = {
-- 
cgit v1.2.1


From 59553edf110e5576d91be9dd5bd53d110e0d0290 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 01:56:28 -0500
Subject: btrfs: consolidate failure exits in btrfs_mount() a bit

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/super.c | 21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f628a6a79ca6..15c8ae571e40 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -630,6 +630,7 @@ 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:
@@ -929,14 +930,10 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 	}
 
 	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];
 
@@ -945,19 +942,11 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 		btrfs_sb(s)->fs_info->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;
 
-- 
cgit v1.2.1


From 815745cf3e46681241ad8025602ffbf2a452d514 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 15:40:49 -0500
Subject: btrfs: let ->s_fs_info point to fs_info, not root...

the latter can be obtained from the former (by looking as ->tree_root)
just as cheaply as we currently are doing the other way round.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/ctree.h   |  2 +-
 fs/btrfs/disk-io.c |  4 +--
 fs/btrfs/export.c  |  2 +-
 fs/btrfs/ioctl.c   |  7 +++--
 fs/btrfs/super.c   | 75 +++++++++++++++++++++++++++---------------------------
 5 files changed, 45 insertions(+), 45 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 67385033323d..dbb999a38272 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2196,7 +2196,7 @@ 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 b6d11eb4e430..f7d8b9ba519b 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1894,8 +1894,8 @@ int 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 = fs_info->tree_root;
 	struct btrfs_root *extent_root;
 	struct btrfs_root *csum_root;
 	struct btrfs_root *chunk_root;
diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 1b8dc33778f9..5f77166fd01c 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/ioctl.c b/fs/btrfs/ioctl.c
index 5441ff1480fd..0c55f8f38091 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -276,14 +276,13 @@ 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))
@@ -312,7 +311,7 @@ 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;
 
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 15c8ae571e40..305adf6dc09a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -147,7 +147,7 @@ void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 
 static void btrfs_put_super(struct super_block *sb)
 {
-	(void)close_ctree(btrfs_sb(sb));
+	(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
@@ -500,7 +500,8 @@ 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;
@@ -530,7 +531,7 @@ 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);
@@ -544,7 +545,7 @@ 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;
 	}
 
@@ -552,7 +553,7 @@ 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);
 
@@ -588,8 +589,7 @@ static int btrfs_fill_super(struct super_block *sb,
 {
 	struct inode *inode;
 	struct dentry *root_dentry;
-	struct btrfs_root *tree_root = sb->s_fs_info;
-	struct btrfs_fs_info *fs_info = tree_root->fs_info;
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 	struct btrfs_key key;
 	int err;
 
@@ -634,20 +634,21 @@ static int btrfs_fill_super(struct super_block *sb,
 	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;
 	}
 
@@ -663,8 +664,8 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
 
 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 {
-	struct btrfs_root *root = btrfs_sb(dentry->d_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))
@@ -727,10 +728,10 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 
 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);
 
-	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)
@@ -922,8 +923,7 @@ 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;
@@ -939,7 +939,7 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 
 		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);
 	}
@@ -959,7 +959,8 @@ 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);
@@ -975,13 +976,13 @@ 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 */
@@ -1150,18 +1151,18 @@ 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) {
@@ -1180,14 +1181,14 @@ 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
@@ -1203,7 +1204,7 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 static void btrfs_kill_super(struct super_block *sb)
 {
-	struct btrfs_fs_info *fs_info = btrfs_sb(sb)->fs_info;
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 	kill_anon_super(sb);
 	free_fs_info(fs_info);
 }
@@ -1246,17 +1247,17 @@ 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;
 }
 
-- 
cgit v1.2.1


From f84a8bd60e3ee49eacc9ba824babf149ba3dad7e Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 17 Nov 2011 15:57:57 -0500
Subject: btrfs: take allocation of ->tree_root into open_ctree()

now that we don't need it for sget() anymore...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/disk-io.c | 8 +++++---
 fs/btrfs/disk-io.h | 2 --
 fs/btrfs/super.c   | 5 -----
 3 files changed, 5 insertions(+), 10 deletions(-)

(limited to 'fs/btrfs')

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f7d8b9ba519b..dd71be875939 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1215,7 +1215,7 @@ static int find_and_setup_root(struct btrfs_root *tree_root,
 	return 0;
 }
 
-struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info)
+static struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_root *root = kzalloc(sizeof(*root), GFP_NOFS);
 	if (root)
@@ -1895,7 +1895,7 @@ int open_ctree(struct super_block *sb,
 	struct buffer_head *bh;
 	struct btrfs_super_block *disk_super;
 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
-	struct btrfs_root *tree_root = fs_info->tree_root;
+	struct btrfs_root *tree_root;
 	struct btrfs_root *extent_root;
 	struct btrfs_root *csum_root;
 	struct btrfs_root *chunk_root;
@@ -1906,12 +1906,14 @@ int open_ctree(struct super_block *sb,
 	int num_backups_tried = 0;
 	int backup_index = 0;
 
+	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;
 	}
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 6f5f48778b00..e4bc4741319b 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -86,8 +86,6 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 		       struct btrfs_root *root);
 
-struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info);
-
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 void btrfs_init_lockdep(void);
 void btrfs_set_buffer_lockdep_class(u64 objectid,
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 305adf6dc09a..044652ee7ef5 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -899,11 +899,6 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 	if (!fs_info)
 		return ERR_PTR(-ENOMEM);
 
-	fs_info->tree_root = btrfs_alloc_root(fs_info);
-	if (!fs_info->tree_root) {
-		error = -ENOMEM;
-		goto error_fs_info;
-	}
 	fs_info->fs_devices = fs_devices;
 
 	fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
-- 
cgit v1.2.1