Squashed commit of the following:

commit 8ea9cff4af46e24c38020652cedeff72957354fb
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 01:29:24 2020 -0400

    remove remaining serializable aside hiding related

commit 99ccf06264db6319ece2a896a104031447447a5f
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 01:20:40 2020 -0400

    interactions: remove serializable

commit a63bef06a6962368f69cf83afbc3c44f2467618c
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 01:16:27 2020 -0400

    users: remove serializable

commit 8053229f6fab507c29a40f0e22dd9cab7971e34f
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 01:11:14 2020 -0400

    user_links: remove serializable

commit 9b058add825b0a876a91a1cf2b1b22dc34066e42
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 01:09:33 2020 -0400

    topics: remove serializable

commit cd9ea908c34f72c0120fca1c4d581540db60db98
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 01:05:23 2020 -0400

    tags: remove serializable

commit c7563fef8fc905c32a0727a4b104222227a6bafa
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 01:02:22 2020 -0400

    static_pages: remove serializable

commit 3da661bdd1aec74e4ac5b69ec21124bc1ebc6fb4
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 01:00:15 2020 -0400

    posts: remove serializable

commit 18a50a4e5bed1ab6e4e6c13c3051a21ae7e8fbb0
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 00:55:55 2020 -0400

    poll_votes: remove serializable

commit 7d946ef23d7b27877d4bf0fb6a4db4ae64a9ffab
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 00:51:49 2020 -0400

    galleries: remove serializable

commit d8c35a0934e5394b092b050e071abdada4bdb640
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 00:42:43 2020 -0400

    conversations: remove serializable

commit 079e6dca6c8064867f2c0f90f351ea83c0f12b75
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 00:38:28 2020 -0400

    comments: remove serializable

commit 00ae38bad566fb6badeccceac2e394e65ec9428e
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 00:37:15 2020 -0400

    commissions: remove serializable

commit b3c4a4b13671ca73c58080b090dd6165552c87d6
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 00:17:12 2020 -0400

    bans: remove serializable

commit 8be9fe913ff1f6264b899e96ee38fa52032b8bda
Author: byte[] <byteslice@airmail.cc>
Date:   Sun Sep 6 00:02:44 2020 -0400

    badges: remove serializable

commit 162adda185f705b9749774c4af8c7d8db0d89790
Author: byte[] <byteslice@airmail.cc>
Date:   Sat Sep 5 23:56:51 2020 -0400

    adverts: remove serializable

lib/philomena/adverts.ex

@@ -4,7 +4,6 @@ defmodule Philomena.Adverts do
   """
 
   import Ecto.Query, warn: false
-  alias Ecto.Multi
   alias Philomena.Repo
 
   alias Philomena.Adverts.Advert
@@ -74,7 +73,7 @@ defmodule Philomena.Adverts do
   def get_advert!(id), do: Repo.get!(Advert, id)
 
   @doc """
-  Creates a advert.
+  Creates an advert.
 
   ## Examples
 
@@ -86,24 +85,24 @@ defmodule Philomena.Adverts do
 
   """
   def create_advert(attrs \\ %{}) do
-    advert =
-      %Advert{}
-      |> Advert.save_changeset(attrs)
-      |> Uploader.analyze_upload(attrs)
+    %Advert{}
+    |> Advert.save_changeset(attrs)
+    |> Uploader.analyze_upload(attrs)
+    |> Repo.insert()
+    |> case do
+      {:ok, advert} ->
+        Uploader.persist_upload(advert)
+        Uploader.unpersist_old_upload(advert)
 
-    Multi.new()
-    |> Multi.insert(:advert, advert)
-    |> Multi.run(:after, fn _repo, %{advert: advert} ->
-      Uploader.persist_upload(advert)
-      Uploader.unpersist_old_upload(advert)
+        {:ok, advert}
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+      error ->
+        error
+    end
   end
 
   @doc """
-  Updates a advert.
+  Updates an advert.
 
   ## Examples
 
@@ -121,24 +120,24 @@ defmodule Philomena.Adverts do
   end
 
   def update_advert_image(%Advert{} = advert, attrs) do
-    advert =
-      advert
-      |> Advert.changeset(attrs)
-      |> Uploader.analyze_upload(attrs)
+    advert
+    |> Advert.changeset(attrs)
+    |> Uploader.analyze_upload(attrs)
+    |> Repo.update()
+    |> case do
+      {:ok, advert} ->
+        Uploader.persist_upload(advert)
+        Uploader.unpersist_old_upload(advert)
 
-    Multi.new()
-    |> Multi.update(:advert, advert)
-    |> Multi.run(:after, fn _repo, %{advert: advert} ->
-      Uploader.persist_upload(advert)
-      Uploader.unpersist_old_upload(advert)
+        {:ok, advert}
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+      error ->
+        error
+    end
   end
 
   @doc """
-  Deletes a Advert.
+  Deletes an Advert.
 
   ## Examples
 

lib/philomena/badges.ex

@@ -4,7 +4,6 @@ defmodule Philomena.Badges do
   """
 
   import Ecto.Query, warn: false
-  alias Ecto.Multi
   alias Philomena.Repo
 
   alias Philomena.Badges.Badge
@@ -52,20 +51,20 @@ defmodule Philomena.Badges do
 
   """
   def create_badge(attrs \\ %{}) do
-    badge =
-      %Badge{}
-      |> Badge.changeset(attrs)
-      |> Uploader.analyze_upload(attrs)
+    %Badge{}
+    |> Badge.changeset(attrs)
+    |> Uploader.analyze_upload(attrs)
+    |> Repo.insert()
+    |> case do
+      {:ok, badge} ->
+        Uploader.persist_upload(badge)
+        Uploader.unpersist_old_upload(badge)
 
-    Multi.new()
-    |> Multi.insert(:badge, badge)
-    |> Multi.run(:after, fn _repo, %{badge: badge} ->
-      Uploader.persist_upload(badge)
-      Uploader.unpersist_old_upload(badge)
+        {:ok, badge}
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+      error ->
+        error
+    end
   end
 
   @doc """
@@ -87,20 +86,20 @@ defmodule Philomena.Badges do
   end
 
   def update_badge_image(%Badge{} = badge, attrs) do
-    badge =
-      badge
-      |> Badge.changeset(attrs)
-      |> Uploader.analyze_upload(attrs)
+    badge
+    |> Badge.changeset(attrs)
+    |> Uploader.analyze_upload(attrs)
+    |> Repo.update()
+    |> case do
+      {:ok, badge} ->
+        Uploader.persist_upload(badge)
+        Uploader.unpersist_old_upload(badge)
 
-    Multi.new()
-    |> Multi.update(:badge, badge)
-    |> Multi.run(:after, fn _repo, %{badge: badge} ->
-      Uploader.persist_upload(badge)
-      Uploader.unpersist_old_upload(badge)
+        {:ok, badge}
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+      error ->
+        error
+    end
   end
 
   @doc """

lib/philomena/bans.ex

@@ -4,10 +4,9 @@ defmodule Philomena.Bans do
   """
 
   import Ecto.Query, warn: false
-  alias Ecto.Multi
   alias Philomena.Repo
 
-  alias Philomena.UserIps.UserIp
+  alias Philomena.UserIps
   alias Philomena.Bans.Fingerprint
 
   @doc """
@@ -244,40 +243,29 @@ defmodule Philomena.Bans do
 
   """
   def create_user(creator, attrs \\ %{}) do
-    user_ban =
-      %User{banning_user_id: creator.id}
-      |> User.save_changeset(attrs)
+    %User{banning_user_id: creator.id}
+    |> User.save_changeset(attrs)
+    |> Repo.insert()
+    |> case do
+      {:ok, user_ban} ->
+        ip = UserIps.get_ip_for_user(user_ban.user_id)
 
-    Multi.new()
-    |> Multi.insert(:user_ban, user_ban)
-    |> Multi.run(:auto_ip_ban, fn repo, %{user_ban: user_ban} ->
-      UserIp
-      |> where(user_id: ^user_ban.user_id)
-      |> order_by(desc: :updated_at)
-      |> limit(1)
-      |> select([u], u.ip)
-      |> Repo.one()
-      |> case do
-        nil ->
-          {:ok, nil}
-
-        ip ->
-          ip = masked_ip(ip)
+        if ip do
+          # Automatically create associated IP ban.
+          ip = UserIps.masked_ip(ip)
 
           %Subnet{banning_user_id: creator.id, specification: ip}
           |> Subnet.save_changeset(attrs)
-          |> repo.insert()
-      end
-    end)
-    |> Repo.isolated_transaction(:serializable)
+          |> Repo.insert()
+        end
+
+        {:ok, user_ban}
+
+      error ->
+        error
+    end
   end
 
-  defp masked_ip(%Postgrex.INET{address: {_1, _2, _3, _4}} = ip),
-    do: ip
-
-  defp masked_ip(%Postgrex.INET{address: {h1, h2, h3, h4, _5, _6, _7, _8}} = ip),
-    do: %{ip | address: {h1, h2, h3, h4, 0, 0, 0, 0}, netmask: 64}
-
   @doc """
   Updates a user.
 

lib/philomena/comments.ex

@@ -59,7 +59,7 @@ defmodule Philomena.Comments do
     |> Multi.run(:subscribe, fn _repo, _changes ->
       Images.create_subscription(image, attribution[:user])
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   def notify_comment(comment) do
@@ -117,7 +117,7 @@ defmodule Philomena.Comments do
         "edit_reason" => current_reason
       })
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   @doc """

lib/philomena/commissions.ex

@@ -9,19 +9,6 @@ defmodule Philomena.Commissions do
 
   alias Philomena.Commissions.Commission
 
-  @doc """
-  Returns the list of commissions.
-
-  ## Examples
-
-      iex> list_commissions()
-      [%Commission{}, ...]
-
-  """
-  def list_commissions do
-    Repo.all(Commission)
-  end
-
   @doc """
   Gets a single commission.
 
@@ -105,19 +92,6 @@ defmodule Philomena.Commissions do
 
   alias Philomena.Commissions.Item
 
-  @doc """
-  Returns the list of commission_items.
-
-  ## Examples
-
-      iex> list_commission_items()
-      [%Item{}, ...]
-
-  """
-  def list_commission_items do
-    Repo.all(Item)
-  end
-
   @doc """
   Gets a single item.
 
@@ -159,7 +133,7 @@ defmodule Philomena.Commissions do
     Multi.new()
     |> Multi.insert(:item, changeset)
     |> Multi.update_all(:commission, update, [])
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   @doc """
@@ -201,7 +175,7 @@ defmodule Philomena.Commissions do
     Multi.new()
     |> Multi.delete(:item, item)
     |> Multi.update_all(:commission, update, [])
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   @doc """

lib/philomena/conversations.ex

@@ -198,7 +198,7 @@ defmodule Philomena.Conversations do
     |> Multi.update_all(:conversation, conversation_query,
       set: [from_read: false, to_read: false, last_message_at: now]
     )
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   @doc """

lib/philomena/galleries.ex

@@ -14,19 +14,6 @@ defmodule Philomena.Galleries do
   alias Philomena.Notifications
   alias Philomena.Images
 
-  @doc """
-  Returns the list of galleries.
-
-  ## Examples
-
-      iex> list_galleries()
-      [%Gallery{}, ...]
-
-  """
-  def list_galleries do
-    Repo.all(Gallery)
-  end
-
   @doc """
   Gets a single gallery.
 
@@ -155,6 +142,15 @@ defmodule Philomena.Galleries do
 
   def add_image_to_gallery(gallery, image) do
     Multi.new()
+    |> Multi.run(:lock, fn repo, %{} ->
+      gallery =
+        Gallery
+        |> where(id: ^gallery.id)
+        |> lock("FOR UPDATE")
+        |> repo.one()
+
+      {:ok, gallery}
+    end)
     |> Multi.run(:interaction, fn repo, %{} ->
       position = (last_position(gallery.id) || -1) + 1
 
@@ -172,11 +168,20 @@ defmodule Philomena.Galleries do
 
       {:ok, count}
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   def remove_image_from_gallery(gallery, image) do
     Multi.new()
+    |> Multi.run(:lock, fn repo, %{} ->
+      gallery =
+        Gallery
+        |> where(id: ^gallery.id)
+        |> lock("FOR UPDATE")
+        |> repo.one()
+
+      {:ok, gallery}
+    end)
     |> Multi.run(:interaction, fn repo, %{} ->
       {count, nil} =
         Interaction
@@ -195,7 +200,7 @@ defmodule Philomena.Galleries do
 
       {:ok, count}
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   defp last_position(gallery_id) do

lib/philomena/images.ex

@@ -90,15 +90,12 @@ defmodule Philomena.Images do
     |> Multi.run(:subscribe, fn _repo, %{image: image} ->
       create_subscription(image, attribution[:user])
     end)
-    |> Multi.run(:after, fn _repo, %{image: image} ->
-      Uploader.persist_upload(image)
-      Uploader.unpersist_old_upload(image)
-
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
     |> case do
       {:ok, %{image: image}} = result ->
+        Uploader.persist_upload(image)
+        Uploader.unpersist_old_upload(image)
+
         repair_image(image)
         reindex_image(image)
         Tags.reindex_tags(image.added_tags)
@@ -135,21 +132,23 @@ defmodule Philomena.Images do
 
       {:ok, count}
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   def destroy_image(%Image{} = image) do
-    changeset = Image.remove_image_changeset(image)
+    image
+    |> Image.remove_image_changeset()
+    |> Repo.update()
+    |> case do
+      {:ok, image} ->
+        Uploader.unpersist_old_upload(image)
+        Hider.destroy_thumbnails(image)
 
-    Multi.new()
-    |> Multi.update(:image, changeset)
-    |> Multi.run(:remove_file, fn _repo, %{image: image} ->
-      Uploader.unpersist_old_upload(image)
-      Hider.destroy_thumbnails(image)
+        {:ok, image}
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+      error ->
+        error
+    end
   end
 
   def lock_comments(%Image{} = image, locked) do
@@ -201,20 +200,23 @@ defmodule Philomena.Images do
   defp queue(_mime_type), do: "images"
 
   def update_file(%Image{} = image, attrs) do
-    image =
-      image
-      |> Image.changeset(attrs)
-      |> Uploader.analyze_upload(attrs)
+    image
+    |> Image.changeset(attrs)
+    |> Uploader.analyze_upload(attrs)
+    |> Repo.update()
+    |> case do
+      {:ok, image} ->
+        Uploader.persist_upload(image)
+        Uploader.unpersist_old_upload(image)
 
-    Multi.new()
-    |> Multi.update(:image, image)
-    |> Multi.run(:after, fn _repo, %{image: image} ->
-      Uploader.persist_upload(image)
-      Uploader.unpersist_old_upload(image)
+        repair_image(image)
+        reindex_image(image)
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+        {:ok, image}
+
+      error ->
+        error
+    end
   end
 
   @doc """
@@ -261,7 +263,7 @@ defmodule Philomena.Images do
           {:ok, nil}
       end
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   def update_tags(%Image{} = image, attribution, attrs) do
@@ -324,7 +326,7 @@ defmodule Philomena.Images do
 
         {:ok, count}
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   defp tag_change_attributes(attribution, image, tag, added, user) do

lib/philomena/interactions.ex

@@ -128,7 +128,7 @@ defmodule Philomena.Interactions do
 
       {:ok, nil}
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   defp union_all_queries([query]),

lib/philomena/poll_votes.ex

@@ -44,6 +44,15 @@ defmodule Philomena.PollVotes do
     poll_votes = filter_options(user, poll, now, attrs)
 
     Multi.new()
+    |> Multi.run(:lock, fn repo, _ ->
+      poll =
+        Poll
+        |> where(id: ^poll.id)
+        |> lock("FOR UPDATE")
+        |> repo.one()
+
+      {:ok, poll}
+    end)
     |> Multi.run(:existing_votes, fn _repo, _changes ->
       # Don't proceed if any votes exist
       case voted?(poll, user) do
@@ -76,7 +85,7 @@ defmodule Philomena.PollVotes do
 
       {:ok, count}
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   defp filter_options(user, poll, now, %{"option_ids" => options}) when is_list(options) do

lib/philomena/posts.ex

@@ -88,7 +88,7 @@ defmodule Philomena.Posts do
     |> Multi.run(:subscribe, fn _repo, _changes ->
       Topics.create_subscription(topic, attributes[:user])
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   def notify_post(post) do
@@ -146,7 +146,7 @@ defmodule Philomena.Posts do
         "edit_reason" => current_reason
       })
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   @doc """

lib/philomena/static_pages.ex

@@ -61,7 +61,7 @@ defmodule Philomena.StaticPages do
       |> Version.changeset(attrs)
       |> repo.insert()
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   @doc """
@@ -88,7 +88,7 @@ defmodule Philomena.StaticPages do
     Multi.new()
     |> Multi.update(:static_page, static_page)
     |> Multi.insert(:version, version)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   @doc """

lib/philomena/tags.ex

@@ -4,7 +4,6 @@ defmodule Philomena.Tags do
   """
 
   import Ecto.Query, warn: false
-  alias Ecto.Multi
   alias Philomena.Repo
 
   alias Philomena.Elasticsearch
@@ -120,30 +119,34 @@ defmodule Philomena.Tags do
   end
 
   def update_tag_image(%Tag{} = tag, attrs) do
-    changeset = Uploader.analyze_upload(tag, attrs)
+    tag
+    |> Uploader.analyze_upload(attrs)
+    |> Repo.update()
+    |> case do
+      {:ok, tag} ->
+        Uploader.persist_upload(tag)
+        Uploader.unpersist_old_upload(tag)
 
-    Multi.new()
-    |> Multi.update(:tag, changeset)
-    |> Multi.run(:update_file, fn _repo, %{tag: tag} ->
-      Uploader.persist_upload(tag)
-      Uploader.unpersist_old_upload(tag)
+        {:ok, tag}
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+      error ->
+        error
+    end
   end
 
   def remove_tag_image(%Tag{} = tag) do
-    changeset = Tag.remove_image_changeset(tag)
+    tag
+    |> Tag.remove_image_changeset()
+    |> Repo.update()
+    |> case do
+      {:ok, tag} ->
+        Uploader.unpersist_old_upload(tag)
 
-    Multi.new()
-    |> Multi.update(:tag, changeset)
-    |> Multi.run(:remove_file, fn _repo, %{tag: tag} ->
-      Uploader.unpersist_old_upload(tag)
+        {:ok, tag}
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+      error ->
+        error
+    end
   end
 
   @doc """

lib/philomena/topics.ex

@@ -70,7 +70,7 @@ defmodule Philomena.Topics do
     |> Multi.run(:subscribe, fn _repo, %{topic: topic} ->
       create_subscription(topic, attribution[:user])
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   def notify_topic(topic) do
@@ -239,7 +239,7 @@ defmodule Philomena.Topics do
 
       {:ok, count}
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   def hide_topic(topic, deletion_reason, user) do

lib/philomena/user_ips.ex

@@ -8,19 +8,6 @@ defmodule Philomena.UserIps do
 
   alias Philomena.UserIps.UserIp
 
-  @doc """
-  Returns the list of user_ips.
-
-  ## Examples
-
-      iex> list_user_ips()
-      [%UserIp{}, ...]
-
-  """
-  def list_user_ips do
-    Repo.all(UserIp)
-  end
-
   @doc """
   Gets a single user_ip.
 
@@ -37,6 +24,31 @@ defmodule Philomena.UserIps do
   """
   def get_user_ip!(id), do: Repo.get!(UserIp, id)
 
+  @doc """
+  Gets this user's most recent IP address, if the user has one
+  recorded.
+  """
+  def get_ip_for_user(user_id) do
+    UserIp
+    |> where(user_id: ^user_id)
+    |> order_by(desc: :updated_at)
+    |> limit(1)
+    |> select([u], u.ip)
+    |> Repo.one()
+  end
+
+  @doc """
+  Sets the appropriate netmask for correctly banning an IPv6-enabled
+  client per RFC4941. IPv4 addresses are not changed.
+  """
+  def masked_ip(%Postgrex.INET{address: {_1, _2, _3, _4}} = ip) do
+    ip
+  end
+
+  def masked_ip(%Postgrex.INET{address: {h1, h2, h3, h4, _5, _6, _7, _8}} = ip) do
+    %{ip | address: {h1, h2, h3, h4, 0, 0, 0, 0}, netmask: 64}
+  end
+
   @doc """
   Creates a user_ip.
 

lib/philomena/user_links.ex

@@ -106,7 +106,7 @@ defmodule Philomena.UserLinks do
           {:ok, nil}
       end
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   def reject_user_link(%UserLink{} = user_link) do

lib/philomena/users.ex

@@ -515,7 +515,7 @@ defmodule Philomena.Users do
     |> Multi.run(:unsubscribe, fn _repo, %{user: user} ->
       unsubscribe_restricted_actors(user)
     end)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
   end
 
   defp clean_roles(nil), do: []
@@ -562,30 +562,34 @@ defmodule Philomena.Users do
   end
 
   def update_avatar(%User{} = user, attrs) do
-    changeset = Uploader.analyze_upload(user, attrs)
+    user
+    |> Uploader.analyze_upload(attrs)
+    |> Repo.update()
+    |> case do
+      {:ok, user} ->
+        Uploader.persist_upload(user)
+        Uploader.unpersist_old_upload(user)
 
-    Multi.new()
-    |> Multi.update(:user, changeset)
-    |> Multi.run(:update_file, fn _repo, %{user: user} ->
-      Uploader.persist_upload(user)
-      Uploader.unpersist_old_upload(user)
+        {:ok, user}
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+      error ->
+        error
+    end
   end
 
   def remove_avatar(%User{} = user) do
-    changeset = User.remove_avatar_changeset(user)
+    user
+    |> User.remove_avatar_changeset()
+    |> Repo.update()
+    |> case do
+      {:ok, user} ->
+        Uploader.unpersist_old_upload(user)
 
-    Multi.new()
-    |> Multi.update(:user, changeset)
-    |> Multi.run(:remove_file, fn _repo, %{user: user} ->
-      Uploader.unpersist_old_upload(user)
+        {:ok, user}
 
-      {:ok, nil}
-    end)
-    |> Repo.isolated_transaction(:serializable)
+      error ->
+        error
+    end
   end
 
   def update_name(user, user_params) do
@@ -597,7 +601,7 @@ defmodule Philomena.Users do
     Multi.new()
     |> Multi.insert(:name_change, name_change)
     |> Multi.update(:account, account)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
     |> case do
       {:ok, %{account: %{name: new_name}}} = result ->
         spawn(fn ->

lib/philomena_web/controllers/admin/badge_controller.ex

@@ -25,7 +25,7 @@ defmodule PhilomenaWeb.Admin.BadgeController do
 
   def create(conn, %{"badge" => badge_params}) do
     case Badges.create_badge(badge_params) do
-      {:ok, %{badge: _badge}} ->
+      {:ok, _badge} ->
         conn
         |> put_flash(:info, "Badge created successfully.")
         |> redirect(to: Routes.admin_badge_path(conn, :index))

lib/philomena_web/controllers/image/destroy_controller.ex

@@ -12,7 +12,7 @@ defmodule PhilomenaWeb.Image.DestroyController do
     image = conn.assigns.image
 
     case Images.destroy_image(image) do
-      {:ok, %{image: image}} ->
+      {:ok, image} ->
         conn
         |> put_flash(:info, "Image contents destroyed.")
         |> redirect(to: Routes.image_path(conn, :show, image))

lib/philomena_web/controllers/image/fave_controller.ex

@@ -27,7 +27,7 @@ defmodule PhilomenaWeb.Image.FaveController do
     )
     |> Multi.append(ImageVotes.delete_vote_transaction(image, user))
     |> Multi.append(ImageVotes.create_vote_transaction(image, user, true))
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
     |> case do
       {:ok, _result} ->
         image =
@@ -49,7 +49,7 @@ defmodule PhilomenaWeb.Image.FaveController do
     image = conn.assigns.image
 
     ImageFaves.delete_fave_transaction(image, user)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
     |> case do
       {:ok, _result} ->
         image =

lib/philomena_web/controllers/image/file_controller.ex

@@ -11,10 +11,7 @@ defmodule PhilomenaWeb.Image.FileController do
 
   def update(conn, %{"image" => image_params}) do
     case Images.update_file(conn.assigns.image, image_params) do
-      {:ok, %{image: image}} ->
-        Images.repair_image(image)
-        Images.reindex_image(image)
-
+      {:ok, image} ->
         conn
         |> put_flash(:info, "Successfully updated file.")
         |> redirect(to: Routes.image_path(conn, :show, image))

lib/philomena_web/controllers/image/tamper_controller.ex

@@ -18,7 +18,7 @@ defmodule PhilomenaWeb.Image.TamperController do
 
     {:ok, _result} =
       ImageVotes.delete_vote_transaction(image, user)
-      |> Repo.isolated_transaction(:serializable)
+      |> Repo.transaction()
 
     Images.reindex_image(image)
 

lib/philomena_web/controllers/image/vote_controller.ex

@@ -25,7 +25,7 @@ defmodule PhilomenaWeb.Image.VoteController do
       ImageVotes.delete_vote_transaction(image, user),
       ImageVotes.create_vote_transaction(image, user, params["up"] == true)
     )
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
     |> case do
       {:ok, _result} ->
         image =
@@ -47,7 +47,7 @@ defmodule PhilomenaWeb.Image.VoteController do
     image = conn.assigns.image
 
     ImageVotes.delete_vote_transaction(image, user)
-    |> Repo.isolated_transaction(:serializable)
+    |> Repo.transaction()
     |> case do
       {:ok, _result} ->
         image =

lib/philomena_web/controllers/tag/image_controller.ex

@@ -20,7 +20,7 @@ defmodule PhilomenaWeb.Tag.ImageController do
 
   def update(conn, %{"tag" => tag_params}) do
     case Tags.update_tag_image(conn.assigns.tag, tag_params) do
-      {:ok, %{tag: tag}} ->
+      {:ok, tag} ->
         conn
         |> put_flash(:info, "Tag image successfully updated.")
         |> redirect(to: Routes.tag_path(conn, :show, tag))