git-annex/Annex/WorkTree.hs
Joey Hess e2d4c133f5
init: fix data loss bug
Fix bug that lost modifications to unlocked files when init is re-ran in an
already initialized repo.

In retrospect needing scanUnlockedFiles False in the direct mode upgrade
path was a good hint that it was unsafe when used with True.

However, this bug did not affect upgrade from v5. In such an upgrade, an
unlocked file that is modified is left as-is. The only place
scanUnlockedFiles True did overwrite modified unlocked files is during an
git-annex init of a repo that was already initialized by git-annex.

(I also tried a scenario where the repo had not been initialized by
git-annex yet, but was cloned from a v7 repo with an unlocked file, and the
pointer file replaced with some other content, and the data loss did not
occur in that situation.)

Since the fixed scanUnlockedFiles avoids overwriting non-pointer files,
it should be safe to run in any situation, so there's no need any longer
for the parameter.
2019-11-05 12:41:15 -04:00

110 lines
3.5 KiB
Haskell

{- git-annex worktree files
-
- Copyright 2013-2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Annex.WorkTree where
import Annex.Common
import Annex.Link
import Annex.CatFile
import Annex.Content
import Annex.ReplaceFile
import Annex.CurrentBranch
import Annex.InodeSentinal
import Utility.InodeCache
import Git.FilePath
import qualified Git.Ref
import qualified Git.LsTree
import qualified Git.Types
import Database.Types
import qualified Database.Keys
import qualified Database.Keys.SQL
{- Looks up the key corresponding to an annexed file in the work tree,
- by examining what the file links to.
-
- An unlocked file will not have a link on disk, so fall back to
- looking for a pointer to a key in git.
-
- When in an adjusted branch that may have hidden the file, looks for a
- pointer to a key in the original branch.
-}
lookupFile :: FilePath -> Annex (Maybe Key)
lookupFile = lookupFile' catkeyfile
where
catkeyfile file =
ifM (liftIO $ doesFileExist file)
( catKeyFile file
, catKeyFileHidden file =<< getCurrentBranch
)
lookupFileNotHidden :: FilePath -> Annex (Maybe Key)
lookupFileNotHidden = lookupFile' catkeyfile
where
catkeyfile file =
ifM (liftIO $ doesFileExist file)
( catKeyFile file
, return Nothing
)
lookupFile' :: (FilePath -> Annex (Maybe Key)) -> FilePath -> Annex (Maybe Key)
lookupFile' catkeyfile file = isAnnexLink file >>= \case
Just key -> return (Just key)
Nothing -> catkeyfile file
{- Modifies an action to only act on files that are already annexed,
- and passes the key on to it. -}
whenAnnexed :: (FilePath -> Key -> Annex (Maybe a)) -> FilePath -> Annex (Maybe a)
whenAnnexed a file = ifAnnexed file (a file) (return Nothing)
ifAnnexed :: FilePath -> (Key -> Annex a) -> Annex a -> Annex a
ifAnnexed file yes no = maybe no yes =<< lookupFile file
{- Find all unlocked files and update the keys database for them.
-
- This is expensive, and so normally the associated files are updated
- incrementally when changes are noticed. So, this only needs to be done
- when initializing/upgrading a v6+ mode repository.
-
- Also, the content for the unlocked file may already be present as
- an annex object. If so, populate the pointer file with it.
- But if worktree file does not have a pointer file's content, it is left
- as-is.
-}
scanUnlockedFiles :: Annex ()
scanUnlockedFiles = whenM (inRepo Git.Ref.headExists) $ do
Database.Keys.runWriter $
liftIO . Database.Keys.SQL.dropAllAssociatedFiles
(l, cleanup) <- inRepo $ Git.LsTree.lsTree Git.LsTree.LsTreeRecursive Git.Ref.headRef
forM_ l $ \i ->
when (isregfile i) $
maybe noop (add i)
=<< catKey (Git.LsTree.sha i)
liftIO $ void cleanup
where
isregfile i = case Git.Types.toTreeItemType (Git.LsTree.mode i) of
Just Git.Types.TreeFile -> True
Just Git.Types.TreeExecutable -> True
_ -> False
add i k = do
let tf = Git.LsTree.file i
Database.Keys.runWriter $
liftIO . Database.Keys.SQL.addAssociatedFileFast (toIKey k) tf
whenM (inAnnex k) $ do
f <- fromRepo $ fromTopFilePath tf
liftIO (isPointerFile f) >>= \case
Just k' | k' == k -> do
destmode <- liftIO $ catchMaybeIO $ fileMode <$> getFileStatus f
ic <- replaceFile f $ \tmp ->
linkFromAnnex k tmp destmode >>= \case
LinkAnnexOk ->
withTSDelta (liftIO . genInodeCache tmp)
LinkAnnexNoop -> return Nothing
LinkAnnexFailed -> liftIO $ do
writePointerFile tmp k destmode
return Nothing
maybe noop (restagePointerFile (Restage True) f) ic
_ -> noop