[PATCH 42/44] btrfs: move fs_info init work into it's own helper function

[Josef Bacik <josef@toxicpanda.com>]

open_ctree mixes initialization of fs stuff and fs_info stuff, which
makes it confusing when doing things like adding the root leak
detection.  Make a separate function that init's all the static
structures inside of the fs_info needed for the fs to operate, and then
call that before we start setting up the fs_info to be mounted.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/disk-io.c | 164 +++++++++++++++++++++++----------------------
 1 file changed, 83 insertions(+), 81 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c7163229effc..6151c828a311 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2649,68 +2649,9 @@ static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
 	return ret;
 }
 
-int __cold open_ctree(struct super_block *sb,
-	       struct btrfs_fs_devices *fs_devices,
-	       char *options)
+static int init_fs_info(struct btrfs_fs_info *fs_info, struct super_block *sb)
 {
-	u32 sectorsize;
-	u32 nodesize;
-	u32 stripesize;
-	u64 generation;
-	u64 features;
-	u16 csum_type;
-	struct btrfs_key location;
-	struct buffer_head *bh;
-	struct btrfs_super_block *disk_super;
-	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
-	struct btrfs_root *tree_root;
-	struct btrfs_root *chunk_root;
 	int ret;
-	int err = -EINVAL;
-	int clear_free_space_tree = 0;
-	int level;
-
-	tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info,
-					BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
-	chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info,
-					BTRFS_CHUNK_TREE_OBJECTID, GFP_KERNEL);
-	if (!tree_root || !chunk_root) {
-		err = -ENOMEM;
-		goto fail;
-	}
-
-	ret = init_srcu_struct(&fs_info->subvol_srcu);
-	if (ret) {
-		err = ret;
-		goto fail;
-	}
-
-	ret = percpu_counter_init(&fs_info->dio_bytes, 0, GFP_KERNEL);
-	if (ret) {
-		err = ret;
-		goto fail_srcu;
-	}
-
-	ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
-	if (ret) {
-		err = ret;
-		goto fail_srcu;
-	}
-	fs_info->dirty_metadata_batch = PAGE_SIZE *
-					(1 + ilog2(nr_cpu_ids));
-
-	ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
-	if (ret) {
-		err = ret;
-		goto fail_srcu;
-	}
-
-	ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
-			GFP_KERNEL);
-	if (ret) {
-		err = ret;
-		goto fail_srcu;
-	}
 
 	INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
 	INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
@@ -2774,21 +2715,6 @@ int __cold open_ctree(struct super_block *sb,
 	INIT_LIST_HEAD(&fs_info->ordered_roots);
 	spin_lock_init(&fs_info->ordered_root_lock);
 
-	fs_info->btree_inode = new_inode(sb);
-	if (!fs_info->btree_inode) {
-		err = -ENOMEM;
-		goto fail_srcu;
-	}
-	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
-
-	fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
-					GFP_KERNEL);
-	if (!fs_info->delayed_root) {
-		err = -ENOMEM;
-		goto fail_iput;
-	}
-	btrfs_init_delayed_root(fs_info->delayed_root);
-
 	btrfs_init_scrub(fs_info);
 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 	fs_info->check_integrity_print_mask = 0;
@@ -2799,8 +2725,6 @@ int __cold open_ctree(struct super_block *sb,
 	sb->s_blocksize = BTRFS_BDEV_BLOCKSIZE;
 	sb->s_blocksize_bits = blksize_bits(BTRFS_BDEV_BLOCKSIZE);
 
-	btrfs_init_btree_inode(fs_info);
-
 	spin_lock_init(&fs_info->block_group_cache_lock);
 	fs_info->block_group_cache_tree = RB_ROOT;
 	fs_info->first_logical_byte = (u64)-1;
@@ -2845,12 +2769,91 @@ int __cold open_ctree(struct super_block *sb,
 
 	fs_info->send_in_progress = 0;
 
+	ret = init_srcu_struct(&fs_info->subvol_srcu);
+	if (ret)
+		return ret;
+
+	ret = percpu_counter_init(&fs_info->dio_bytes, 0, GFP_KERNEL);
+	if (ret)
+		goto fail;
+
+	ret = percpu_counter_init(&fs_info->dirty_metadata_bytes, 0, GFP_KERNEL);
+	if (ret)
+		goto fail;
+
+	fs_info->dirty_metadata_batch = PAGE_SIZE *
+					(1 + ilog2(nr_cpu_ids));
+
+	ret = percpu_counter_init(&fs_info->delalloc_bytes, 0, GFP_KERNEL);
+	if (ret)
+		goto fail;
+
+	ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0,
+			GFP_KERNEL);
+	if (ret)
+		goto fail;
+
+	fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
+					GFP_KERNEL);
+	if (!fs_info->delayed_root) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+	btrfs_init_delayed_root(fs_info->delayed_root);
+
 	ret = btrfs_alloc_stripe_hash_table(fs_info);
-	if (ret) {
-		err = ret;
-		goto fail_alloc;
+	if (ret)
+		goto fail;
+
+	return 0;
+fail:
+	cleanup_srcu_struct(&fs_info->subvol_srcu);
+	return ret;
+}
+
+int __cold open_ctree(struct super_block *sb,
+	       struct btrfs_fs_devices *fs_devices,
+	       char *options)
+{
+	u32 sectorsize;
+	u32 nodesize;
+	u32 stripesize;
+	u64 generation;
+	u64 features;
+	u16 csum_type;
+	struct btrfs_key location;
+	struct buffer_head *bh;
+	struct btrfs_super_block *disk_super;
+	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+	struct btrfs_root *tree_root;
+	struct btrfs_root *chunk_root;
+	int ret;
+	int err = -EINVAL;
+	int clear_free_space_tree = 0;
+	int level;
+
+	err = init_fs_info(fs_info, sb);
+	if (err)
+		goto fail;
+
+	/* These need to be init'ed before we start creating inodes and such. */
+	tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info,
+					BTRFS_ROOT_TREE_OBJECTID, GFP_KERNEL);
+	chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info,
+					BTRFS_CHUNK_TREE_OBJECTID, GFP_KERNEL);
+	if (!tree_root || !chunk_root) {
+		err = -ENOMEM;
+		goto fail_srcu;
 	}
 
+	fs_info->btree_inode = new_inode(sb);
+	if (!fs_info->btree_inode) {
+		err = -ENOMEM;
+		goto fail_srcu;
+	}
+	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
+	btrfs_init_btree_inode(fs_info);
+
 	invalidate_bdev(fs_devices->latest_bdev);
 
 	/*
@@ -3357,7 +3360,6 @@ int __cold open_ctree(struct super_block *sb,
 	btrfs_stop_all_workers(fs_info);
 	btrfs_free_block_groups(fs_info);
 fail_alloc:
-fail_iput:
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
 
 	iput(fs_info->btree_inode);
-- 
2.23.0