Btrfs: fix some metadata enospc issues

We weren't reserving metadata space for rename, rmdir and unlink, which could
cause problems.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 31 insertions, 5 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d8393ddc72a3..bb7fd8072802 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2488,7 +2488,19 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 
         root = BTRFS_I(dir)->root;
 
+        /*
+         * 5 items for unlink inode
+         * 1 for orphan
+         */
+        ret = btrfs_reserve_metadata_space(root, 6);
+        if (ret)
+                return ret;
+
         trans = btrfs_start_transaction(root, 1);
+        if (IS_ERR(trans)) {
+                btrfs_unreserve_metadata_space(root, 6);
+                return PTR_ERR(trans);
+        }
 
         btrfs_set_trans_block_group(trans, dir);
 
@@ -2503,6 +2515,7 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
         nr = trans->blocks_used;
 
         btrfs_end_transaction_throttle(trans, root);
+        btrfs_unreserve_metadata_space(root, 6);
         btrfs_btree_balance_dirty(root, nr);
         return ret;
 }
@@ -2583,7 +2596,16 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
             inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
                 return -ENOTEMPTY;
 
+        ret = btrfs_reserve_metadata_space(root, 5);
+        if (ret)
+                return ret;
+
         trans = btrfs_start_transaction(root, 1);
+        if (IS_ERR(trans)) {
+                btrfs_unreserve_metadata_space(root, 5);
+                return PTR_ERR(trans);
+        }
+
         btrfs_set_trans_block_group(trans, dir);
 
         if (unlikely(inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
@@ -2606,6 +2628,7 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 out:
         nr = trans->blocks_used;
         ret = btrfs_end_transaction_throttle(trans, root);
+        btrfs_unreserve_metadata_space(root, 5);
         btrfs_btree_balance_dirty(root, nr);
 
         if (ret && !err)
@@ -5297,11 +5320,14 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
                 return -ENOTEMPTY;
 
         /*
-         * 2 items for dir items
-         * 1 item for orphan entry
-         * 1 item for ref
+         * We want to reserve the absolute worst case amount of items.  So if
+         * both inodes are subvols and we need to unlink them then that would
+         * require 4 item modifications, but if they are both normal inodes it
+         * would require 5 item modifications, so we'll assume their normal
+         * inodes.  So 5 * 2 is 10, plus 1 for the new link, so 11 total items
+         * should cover the worst case number of items we'll modify.
          */
-        ret = btrfs_reserve_metadata_space(root, 4);
+        ret = btrfs_reserve_metadata_space(root, 11);
         if (ret)
                 return ret;
 
@@ -5417,7 +5443,7 @@ out_fail:
         if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
                 up_read(&root->fs_info->subvol_sem);
 
-        btrfs_unreserve_metadata_space(root, 4);
+        btrfs_unreserve_metadata_space(root, 11);
         return ret;
 }