Btrfs: Avoid orphan inodes cleanup during committing transaction

btrfs_lookup_dentry may trigger orphan cleanup, so it's not good
to call it while committing a transaction.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

2 files changed, 17 insertions, 16 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index a1a8db8c149d..3d6b33871afe 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -237,7 +237,6 @@ static noinline int create_subvol(struct btrfs_root *root,
         u64 objectid;
         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
         u64 index = 0;
-        unsigned long nr = 1;
 
         /*
          * 1 - inode item
@@ -342,24 +341,21 @@ static noinline int create_subvol(struct btrfs_root *root,
 
         d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 fail:
-        nr = trans->blocks_used;
         err = btrfs_commit_transaction(trans, root);
         if (err && !ret)
                 ret = err;
 
         btrfs_unreserve_metadata_space(root, 6);
-        btrfs_btree_balance_dirty(root, nr);
         return ret;
 }
 
 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
                            char *name, int namelen)
 {
+        struct inode *inode;
         struct btrfs_pending_snapshot *pending_snapshot;
         struct btrfs_trans_handle *trans;
-        int ret = 0;
-        int err;
-        unsigned long nr = 0;
+        int ret;
 
         if (!root->ref_cows)
                 return -EINVAL;
@@ -372,20 +368,20 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
          */
         ret = btrfs_reserve_metadata_space(root, 6);
         if (ret)
-                goto fail_unlock;
+                goto fail;
 
         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
         if (!pending_snapshot) {
                 ret = -ENOMEM;
                 btrfs_unreserve_metadata_space(root, 6);
-                goto fail_unlock;
+                goto fail;
         }
         pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
         if (!pending_snapshot->name) {
                 ret = -ENOMEM;
                 kfree(pending_snapshot);
                 btrfs_unreserve_metadata_space(root, 6);
-                goto fail_unlock;
+                goto fail;
         }
         memcpy(pending_snapshot->name, name, namelen);
         pending_snapshot->name[namelen] = '\0';
@@ -395,10 +391,19 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
         pending_snapshot->root = root;
         list_add(&pending_snapshot->list,
                  &trans->transaction->pending_snapshots);
-        err = btrfs_commit_transaction(trans, root);
+        ret = btrfs_commit_transaction(trans, root);
+        BUG_ON(ret);
+        btrfs_unreserve_metadata_space(root, 6);
 
-fail_unlock:
-        btrfs_btree_balance_dirty(root, nr);
+        inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
+        if (IS_ERR(inode)) {
+                ret = PTR_ERR(inode);
+                goto fail;
+        }
+        BUG_ON(!inode);
+        d_instantiate(dentry, inode);
+        ret = 0;
+fail:
         return ret;
 }
 
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index b7b22c344b66..728e8fe5d2cc 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -796,7 +796,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         memcpy(&pending->root_key, &key, sizeof(key));
 fail:
         kfree(new_root_item);
-        btrfs_unreserve_metadata_space(root, 6);
         return ret;
 }
 
@@ -808,7 +807,6 @@ static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info,
         u64 index = 0;
         struct btrfs_trans_handle *trans;
         struct inode *parent_inode;
-        struct inode *inode;
         struct btrfs_root *parent_root;
 
         parent_inode = pending->dentry->d_parent->d_inode;
@@ -840,8 +838,6 @@ static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info,
 
         BUG_ON(ret);
 
-        inode = btrfs_lookup_dentry(parent_inode, pending->dentry);
-        d_instantiate(pending->dentry, inode);
 fail:
         btrfs_end_transaction(trans, fs_info->fs_root);
         return ret;