diff --git a/plugins/coverbrowser.koplugin/bookinfomanager.lua b/plugins/coverbrowser.koplugin/bookinfomanager.lua
index bfa279467..6d19980f6 100644
--- a/plugins/coverbrowser.koplugin/bookinfomanager.lua
+++ b/plugins/coverbrowser.koplugin/bookinfomanager.lua
@@ -404,7 +404,6 @@ function BookInfoManager:extractBookInfo(filepath, cover_specs)
                 local spec_max_cover_h = cover_specs.max_cover_h
 
                 dbrow.cover_fetched = 'Y' -- we had a try at getting a cover
-                -- XXX make picdocument return a blitbuffer of the image
                 local cover_bb = document:getCoverPageImage()
                 if cover_bb then
                     dbrow.has_cover = 'Y'
@@ -455,6 +454,7 @@ function BookInfoManager:extractBookInfo(filepath, cover_specs)
     end
     self.set_stmt:step()
     self.set_stmt:clearbind():reset() -- get ready for next query
+    return loaded
 end
 
 function BookInfoManager:setBookInfoProperties(filepath, props)
@@ -626,6 +626,245 @@ function BookInfoManager:cleanUp()
     end
 end
 
+local function findFilesInDir(path, recursive)
+    local dirs = {path}
+    local files = {}
+    while #dirs ~= 0 do
+        local new_dirs = {}
+        -- handle each dir
+        for __, d in pairs(dirs) do
+            -- handle files in d
+            for f in lfs.dir(d) do
+                local fullpath = d.."/"..f
+                local attributes = lfs.attributes(fullpath)
+                if recursive and attributes.mode == "directory" and f ~= "." and f~=".." then
+                    table.insert(new_dirs, fullpath)
+                elseif attributes.mode == "file" and DocumentRegistry:hasProvider(fullpath) then
+                    table.insert(files, fullpath)
+                end
+            end
+        end
+        dirs = new_dirs
+    end
+    return files
+end
+
+-- Batch extraction
+function BookInfoManager:extractBooksInDirectory(path, cover_specs)
+    local Geom = require("ui/geometry")
+    local InfoMessage = require("ui/widget/infomessage")
+    local TopContainer = require("ui/widget/container/topcontainer")
+    local Trapper = require("ui/trapper")
+    local Screen = require("device").screen
+
+    local go_on = Trapper:confirm(_([[
+
+This will extract metadata and cover images for books in current directory.
+Once extraction has started, you can abort at any moment by taping on the screen.
+
+Cover images will be saved with the adequate size for the current display mode.
+If you later change display mode, they may need to be extracted again.
+
+This extraction may take time and use some battery power: you may wish to keep your device plugged in.
+]]) , _("Cancel"), _("Continue"))
+    if not go_on then
+        return
+    end
+
+    local recursive = Trapper:confirm(_([[
+
+Do you want to extract book information for books in sub-directories too?
+]]) , _("Here only"), _("Here and under"))
+
+    local refresh_existing = Trapper:confirm(_([[
+
+Do you want to refresh metadata and covers that have already been extracted?
+]]) , _("Don't refresh"), _("Refresh"))
+
+    local prune = Trapper:confirm(_([[
+
+If you have removed many books, or have renamed some directories, it is good to remove them from the cache database.
+
+Do you want to prune cache of removed books?
+]]) , _("Don't prune"), _("Prune"))
+
+    Trapper:clear()
+
+    local confirm_abort = function()
+        return Trapper:confirm(_("Do you want to abort extraction?"), _("Don't abort"), _("Abort"))
+    end
+
+    -- Cancel any background job, before we launch new ones
+    self:terminateBackgroundJobs()
+
+    local info, completed
+    if prune then
+        local summary
+        while true do
+            info = InfoMessage:new{text = _("Pruning cache of removed books…")}
+            UIManager:show(info)
+            UIManager:forceRePaint()
+            completed, summary = Trapper:dismissableRunInSubprocess(function()
+                return self:removeNonExistantEntries()
+            end, info)
+            if not completed then
+                if confirm_abort() then
+                    return
+                end
+            else
+                UIManager:close(info)
+                info = InfoMessage:new{text = summary}
+                UIManager:show(info)
+                UIManager:forceRePaint()
+                util.sleep(2) -- Let the user see that
+                break
+            end
+        end
+        UIManager:close(info)
+    end
+
+    local files
+    while true do
+        info = InfoMessage:new{text = _("Looking for books to index…")}
+        UIManager:show(info)
+        UIManager:forceRePaint()
+        completed, files = Trapper:dismissableRunInSubprocess(function()
+            local filepaths = findFilesInDir(path, recursive)
+            table.sort(filepaths)
+            return filepaths
+        end, info)
+        if not completed then
+            if confirm_abort() then
+                return
+            end
+        elseif not files or #files == 0 then
+            UIManager:close(info)
+            info = InfoMessage:new{text = _("No book were found.")}
+            UIManager:show(info)
+            return
+        else
+            break
+        end
+    end
+    UIManager:close(info)
+
+    if refresh_existing then
+        info = InfoMessage:new{text = T(_("Found %1 books to index."), #files)}
+        UIManager:show(info)
+        UIManager:forceRePaint()
+        util.sleep(2) -- Let the user see that
+    else
+        local all_files = files
+        while true do
+            info = InfoMessage:new{text = T(_("Found %1 books.\nLooking for those not already present in cache database…"), #all_files)}
+            UIManager:show(info)
+            UIManager:forceRePaint()
+            util.sleep(2) -- Let the user see that
+            completed, files = Trapper:dismissableRunInSubprocess(function()
+                files = {}
+                for _, filepath in pairs(all_files) do
+                    local bookinfo = self:getBookInfo(filepath)
+                    local to_extract = not bookinfo
+                    if bookinfo and cover_specs and not bookinfo.ignore_cover then
+                        if bookinfo.cover_fetched then
+                            if bookinfo.has_cover and cover_specs.sizetag ~= bookinfo.cover_sizetag then
+                                if bookinfo.cover_sizetag ~= "M" then -- keep the bigger "M"
+                                    to_extract = true
+                                end
+                            end
+                        else
+                            to_extract = true
+                        end
+                    end
+                    if to_extract then
+                        table.insert(files, filepath)
+                    end
+                end
+                return files
+            end, info)
+            if not completed then
+                if confirm_abort() then
+                    return
+                end
+            elseif not files or #files == 0 then
+                UIManager:close(info)
+                info = InfoMessage:new{text = _("No books were found that need to be indexed.")}
+                UIManager:show(info)
+                return
+            else
+                break
+            end
+        end
+        UIManager:close(info)
+        info = InfoMessage:new{text = T(_("Found %1 books to index."), #files)}
+        UIManager:show(info)
+        UIManager:forceRePaint()
+        util.sleep(2) -- Let the user see that
+    end
+    UIManager:close(info)
+
+    local nb_files = #files
+    local nb_done = 0
+    local nb_success = 0
+    local i = 1
+
+    -- We use a little hack to InfoMessage for a consistent height and
+    -- fast refresh to avoid flicking
+    info = InfoMessage:new{text = "dummy"}
+    UIManager:show(info) -- but not yet painted
+    local info_max_seen_height = 0
+    local success
+
+    while i <= nb_files do
+        local filepath = files[i]
+        local filename = util.basename(filepath)
+
+        local orig_moved_offset = info.movable:getMovedOffset()
+        info:free()
+        info.text = T(_("Indexing %1 / %2…\n\n%3"), i, nb_files, filename)
+        info:init()
+        local text_widget = table.remove(info.movable[1][1], 3)
+        local text_widget_size = text_widget:getSize()
+        if text_widget_size.h > info_max_seen_height then
+            info_max_seen_height = text_widget_size.h
+        end
+        table.insert(info.movable[1][1], TopContainer:new{
+            dimen = Geom:new{
+                w = text_widget_size.w,
+                h = info_max_seen_height,
+            },
+            text_widget
+        })
+        info.movable:setMovedOffset(orig_moved_offset)
+        info:paintTo(Screen.bb, 0,0)
+        local d = info.movable[1].dimen
+        Screen.refreshUI(Screen, d.x, d.y, d.w, d.h)
+
+        completed, success = Trapper:dismissableRunInSubprocess(function()
+            return self:extractBookInfo(filepath, cover_specs)
+        end, info)
+        if not completed then
+            if confirm_abort() then
+                break
+            end
+            -- Recreate the infomessage that was dismissed
+            info = InfoMessage:new{text = "dummy"}
+            info.movable:setMovedOffset(orig_moved_offset)
+            UIManager:show(info) -- but not yet painted
+            -- don't increment i, re-process the one we interrupted
+        else
+            nb_done = nb_done + 1
+            if success then
+                nb_success = nb_success + 1
+            end
+            i = i + 1
+        end
+    end
+    UIManager:close(info)
+    info = InfoMessage:new{text = T(_("Processed %1 / %2 books.\n%3 extracted succesfully."), nb_done, nb_files, nb_success)}
+    UIManager:show(info)
+end
+
 BookInfoManager:init()
 
 return BookInfoManager
diff --git a/plugins/coverbrowser.koplugin/covermenu.lua b/plugins/coverbrowser.koplugin/covermenu.lua
index 08e7a72c5..4bf01d41e 100644
--- a/plugins/coverbrowser.koplugin/covermenu.lua
+++ b/plugins/coverbrowser.koplugin/covermenu.lua
@@ -28,6 +28,12 @@ local BookInfoManager = require("bookinfomanager")
 -- not found item to self.items_to_update for us to update() them
 -- regularly.
 
+-- Store these as local, to be set by some object and re-used by
+-- another object (as we plug the methods below to different objects,
+-- we can't store them in 'self' if we want another one to use it)
+local current_path = nil
+local current_cover_specs = false
+
 -- Simple holder of methods that will replace those
 -- in the real Menu class or instance
 local CoverMenu = {}
@@ -76,6 +82,10 @@ function CoverMenu:updateItems(select_number)
     -- Specific UI building implementation (defined in some other module)
     self:_updateItemsBuildUI()
 
+    -- Set the local variables with the things we know
+    current_path = self.path
+    current_cover_specs = self.cover_specs
+
     -- As done in Menu:updateItems()
     if self.item_group[1] then
         if not Device:isTouchDevice() then
@@ -476,4 +486,43 @@ function CoverMenu:onSwipe(arg, ges_ev)
     end
 end
 
+function CoverMenu:tapPlus()
+    -- Call original function: it will create a ButtonDialogTitle
+    -- and store it as self.file_dialog, and UIManager:show() it.
+    CoverMenu._FileManager_tapPlus_orig(self)
+
+    -- Remember some of this original ButtonDialogTitle properties
+    local orig_title = self.file_dialog.title
+    local orig_title_align = self.file_dialog.title_align
+    local orig_buttons = self.file_dialog.buttons
+    -- Close original ButtonDialogTitle (it has not yet been painted
+    -- on screen, so we won't see it)
+    UIManager:close(self.file_dialog)
+
+    -- Add a new button to original buttons set
+    table.insert(orig_buttons, {}) -- separator
+    table.insert(orig_buttons, {
+        {
+            text = _("Extract and cache book information"),
+            callback = function()
+                UIManager:close(self.file_dialog)
+                local Trapper = require("ui/trapper")
+                Trapper:wrap(function()
+                    BookInfoManager:extractBooksInDirectory(current_path, current_cover_specs)
+                end)
+            end,
+        },
+    })
+
+    -- Create the new ButtonDialogTitle, and let UIManager show it
+    local ButtonDialogTitle = require("ui/widget/buttondialogtitle")
+    self.file_dialog = ButtonDialogTitle:new{
+        title = orig_title,
+        title_align = orig_title_align,
+        buttons = orig_buttons,
+    }
+    UIManager:show(self.file_dialog)
+    return true
+end
+
 return CoverMenu
diff --git a/plugins/coverbrowser.koplugin/listmenu.lua b/plugins/coverbrowser.koplugin/listmenu.lua
index 998ff6f5f..186f7a44b 100644
--- a/plugins/coverbrowser.koplugin/listmenu.lua
+++ b/plugins/coverbrowser.koplugin/listmenu.lua
@@ -188,6 +188,25 @@ function ListMenuItem:update()
         h = self.height - 2 * self.underline_h
     }
 
+    -- We'll draw a border around cover images, it may not be
+    -- needed with some covers, but it's nicer when cover is
+    -- a pure white background (like rendered text page)
+    local border_size = 1
+    local max_img_w = dimen.h - 2*border_size -- width = height, squared
+    local max_img_h = dimen.h - 2*border_size
+    local cover_specs = {
+        sizetag = "s",
+        max_cover_w = max_img_w,
+        max_cover_h = max_img_h,
+    }
+    -- Make it available to our menu, for batch extraction
+    -- to know what size is needed for current view
+    if self.do_cover_image then
+        self.menu.cover_specs = cover_specs
+    else
+        self.menu.cover_specs = false
+    end
+
     local file_mode = lfs.attributes(self.filepath, "mode")
     if file_mode == "directory" then
         self.is_directory = true
@@ -226,9 +245,6 @@ function ListMenuItem:update()
             self.file_deleted = true
         end
         -- File
-        local border_size = 1
-        local max_img_w = dimen.h - 2*border_size -- width = height, squared
-        local max_img_h = dimen.h - 2*border_size
 
         local bookinfo = BookInfoManager:getBookInfo(self.filepath, self.do_cover_image)
         if bookinfo and self.do_cover_image and not bookinfo.ignore_cover then
@@ -550,11 +566,7 @@ function ListMenuItem:update()
             -- a new extraction will have to be made when one switch to image mode
             if self.do_cover_image then
                 -- Not in db, we're going to fetch some cover
-                self.cover_specs = {
-                    sizetag = "s",
-                    max_cover_w = max_img_w,
-                    max_cover_h = max_img_h,
-                }
+                self.cover_specs = cover_specs
             end
             --
             if self.do_hint_opened and DocSettings:hasSidecarFile(self.filepath) then
diff --git a/plugins/coverbrowser.koplugin/main.lua b/plugins/coverbrowser.koplugin/main.lua
index c936c5fb7..bf81b04ad 100644
--- a/plugins/coverbrowser.koplugin/main.lua
+++ b/plugins/coverbrowser.koplugin/main.lua
@@ -23,6 +23,9 @@ local _FileChooser_onSwipe_orig = FileChooser.onSwipe
 local FileManagerHistory = require("apps/filemanager/filemanagerhistory")
 local _FileManagerHistory_updateItemTable_orig = FileManagerHistory.updateItemTable
 
+local FileManager = require("apps/filemanager/filemanager")
+local _FileManager_tapPlus_orig = FileManager.tapPlus
+
 -- Available display modes
 local DISPLAY_MODES = {
     -- nil or ""                -- classic : filename only
@@ -120,11 +123,9 @@ function CoverBrowser:addToMainMenu(menu_items)
             callback = function()
                 if G_reader_settings:readSetting("home_dir_display_name") then
                     G_reader_settings:delSetting("home_dir_display_name")
-                    local FileManager = require("apps/filemanager/filemanager")
                     if FileManager.instance then FileManager.instance:reinit() end
                 else
                     G_reader_settings:saveSetting("home_dir_display_name", "~")
-                    local FileManager = require("apps/filemanager/filemanager")
                     if FileManager.instance then FileManager.instance:reinit() end
                 end
             end,
@@ -381,7 +382,6 @@ function CoverBrowser:addToMainMenu(menu_items)
 end
 
 function CoverBrowser:refreshFileManagerInstance(cleanup, post_init)
-    local FileManager = require("apps/filemanager/filemanager")
     local fm = FileManager.instance
     if fm then
         local fc = fm.file_chooser
@@ -433,6 +433,7 @@ function CoverBrowser:setupFileManagerDisplayMode(display_mode)
         FileChooser.onCloseWidget = _FileChooser_onCloseWidget_orig
         FileChooser.onSwipe = _FileChooser_onSwipe_orig
         FileChooser._recalculateDimen = _FileChooser__recalculateDimen_orig
+        FileManager.tapPlus = _FileManager_tapPlus_orig
         -- Also clean-up what we added, even if it does not bother original code
         FileChooser._updateItemsBuildUI = nil
         FileChooser._do_cover_images = nil
@@ -475,6 +476,12 @@ function CoverBrowser:setupFileManagerDisplayMode(display_mode)
         FileChooser._do_hint_opened = true -- dogear at bottom
     end
 
+    -- Replace this FileManager method with the one from CoverMenu
+    -- (but first, make the original method saved here as local available
+    -- to CoverMenu)
+    CoverMenu._FileManager_tapPlus_orig = _FileManager_tapPlus_orig
+    FileManager.tapPlus = CoverMenu.tapPlus
+
     if init_done then
         self:refreshFileManagerInstance()
     else
diff --git a/plugins/coverbrowser.koplugin/mosaicmenu.lua b/plugins/coverbrowser.koplugin/mosaicmenu.lua
index 60633c27e..e24302c75 100644
--- a/plugins/coverbrowser.koplugin/mosaicmenu.lua
+++ b/plugins/coverbrowser.koplugin/mosaicmenu.lua
@@ -374,13 +374,32 @@ function MosaicMenuItem:update()
         h = self.height - self.underline_h
     }
 
+    -- We'll draw a border around cover images, it may not be
+    -- needed with some covers, but it's nicer when cover is
+    -- a pure white background (like rendered text page)
+    local border_size = 1
+    local max_img_w = dimen.w - 2*border_size
+    local max_img_h = dimen.h - 2*border_size
+    local cover_specs = {
+        sizetag = "M",
+        max_cover_w = max_img_w,
+        max_cover_h = max_img_h,
+    }
+    -- Make it available to our menu, for batch extraction
+    -- to know what size is needed for current view
+    if self.do_cover_image then
+        self.menu.cover_specs = cover_specs
+    else
+        self.menu.cover_specs = false
+    end
+
     local file_mode = lfs.attributes(self.filepath, "mode")
     if file_mode == "directory" then
         self.is_directory = true
         -- Directory : rounded corners
         local margin = Screen:scaleBySize(5) -- make directories less wide
         local padding = Screen:scaleBySize(5)
-        local border_size = Screen:scaleBySize(2) -- make directories bolder
+        border_size = Screen:scaleBySize(2) -- make directories bolder
         local dimen_in = Geom:new{
             w = dimen.w - (margin + padding + border_size)*2,
             h = dimen.h - (margin + padding + border_size)*2
@@ -420,12 +439,6 @@ function MosaicMenuItem:update()
             self.file_deleted = true
         end
         -- File : various appearances
-        -- We'll draw a border around cover images, it may not be
-        -- needed with some covers, but it's nicer when cover is
-        -- a pure white background (like rendered text page)
-        local border_size = 1
-        local max_img_w = dimen.w - 2*border_size
-        local max_img_h = dimen.h - 2*border_size
 
         if self.do_hint_opened and DocSettings:hasSidecarFile(self.filepath) then
             self.been_opened = true
@@ -544,11 +557,7 @@ function MosaicMenuItem:update()
             -- a new extraction will have to be made when one switch to image mode
             if self.do_cover_image then
                 -- Not in db, we're going to fetch some cover
-                self.cover_specs = {
-                    sizetag = "M",
-                    max_cover_w = max_img_w,
-                    max_cover_h = max_img_h,
-                }
+                self.cover_specs = cover_specs
             end
             -- Same as real FakeCover, but let it be squared (like a file)
             local hint = "…" -- display hint it's being loaded