git-annex/Annex/Tmp.hs
Joey Hess a64fca92f6
Fix race in cleanup of othertmp directory that could result in a failure attempting to access it.
Need to create the directory after the lock is held, not before.

The other racing process would need to shut down at just the wrong time,
running cleanupOtherTmp.

This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
2019-02-02 13:56:31 -04:00

57 lines
1.8 KiB
Haskell

{- git-annex tmp files
-
- Copyright 2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.Tmp where
import Common
import Annex
import Annex.Locations
import Annex.LockFile
import Annex.Perms
import Types.CleanupActions
import Data.Time.Clock.POSIX
-- | For creation of tmp files, other than for key's contents.
--
-- The action should normally clean up whatever files it writes to the temp
-- directory that is passed to it. However, once the action is done,
-- any files left in that directory may be cleaned up by another process at
-- any time.
withOtherTmp :: (FilePath -> Annex a) -> Annex a
withOtherTmp a = do
addCleanup OtherTmpCleanup cleanupOtherTmp
tmpdir <- fromRepo gitAnnexTmpOtherDir
tmplck <- fromRepo gitAnnexTmpOtherLock
withSharedLock (const tmplck) $ do
void $ createAnnexDirectory tmpdir
a tmpdir
-- | Cleans up any tmp files that were left by a previous
-- git-annex process that got interrupted or failed to clean up after
-- itself for some other reason.
--
-- Does not do anything if withOtherTmp is running.
cleanupOtherTmp :: Annex ()
cleanupOtherTmp = do
tmplck <- fromRepo gitAnnexTmpOtherLock
void $ tryIO $ tryExclusiveLock (const tmplck) $ do
tmpdir <- fromRepo gitAnnexTmpOtherDir
void $ liftIO $ tryIO $ removeDirectoryRecursive tmpdir
-- This is only to clean up cruft left by old versions of
-- git-annex; it can be removed eventually.
oldtmp <- fromRepo gitAnnexTmpOtherDirOld
liftIO $ mapM_ cleanold =<< dirContentsRecursive oldtmp
liftIO $ void $ tryIO $ removeDirectory oldtmp -- when empty
where
cleanold f = do
now <- liftIO getPOSIXTime
let oldenough = now - (60 * 60 * 24 * 7)
catchMaybeIO (modificationTime <$> getSymbolicLinkStatus f) >>= \case
Just mtime | realToFrac mtime <= oldenough ->
void $ tryIO $ nukeFile f
_ -> return ()