7ccf642863commit 63d508e885 broke test_readonly.
When a local git remote is readonly, tryCopyCoW run to copy a file
from it failed at withOtherTmp.
Sponsored-by: Dartmouth College's Datalad project
556 lines
20 KiB
Haskell
556 lines
20 KiB
Haskell
{- A "remote" that is just a filesystem directory.
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-
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- Copyright 2011-2021 Joey Hess <id@joeyh.name>
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-
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- Licensed under the GNU AGPL version 3 or higher.
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-}
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{-# LANGUAGE OverloadedStrings #-}
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{-# LANGUAGE RankNTypes #-}
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{-# LANGUAGE CPP #-}
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module Remote.Directory (
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remote,
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finalizeStoreGeneric,
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removeDirGeneric,
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) where
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import qualified Data.ByteString.Lazy as L
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import qualified Data.Map as M
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import qualified System.FilePath.ByteString as P
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import Data.Default
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import Annex.Common
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import Types.Remote
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import Types.Export
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import Types.Creds
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import qualified Git
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import Config.Cost
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import Config
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import Annex.SpecialRemote.Config
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import Remote.Helper.Special
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import Remote.Helper.ExportImport
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import Types.Import
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import qualified Remote.Directory.LegacyChunked as Legacy
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import Annex.CopyFile
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import Annex.Content
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import Annex.Perms
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import Annex.UUID
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import Backend
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import Types.KeySource
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import Types.ProposedAccepted
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import Utility.Metered
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import Utility.Tmp
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import Utility.InodeCache
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import Utility.FileMode
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import Utility.Directory.Create
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import qualified Utility.RawFilePath as R
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remote :: RemoteType
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remote = specialRemoteType $ RemoteType
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{ typename = "directory"
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, enumerate = const (findSpecialRemotes "directory")
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, generate = gen
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, configParser = mkRemoteConfigParser
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[ optionalStringParser directoryField
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(FieldDesc "(required) where the special remote stores data")
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]
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, setup = directorySetup
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, exportSupported = exportIsSupported
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, importSupported = importIsSupported
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, thirdPartyPopulated = False
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}
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directoryField :: RemoteConfigField
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directoryField = Accepted "directory"
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gen :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> RemoteStateHandle -> Annex (Maybe Remote)
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gen r u rc gc rs = do
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c <- parsedRemoteConfig remote rc
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cst <- remoteCost gc cheapRemoteCost
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let chunkconfig = getChunkConfig c
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cow <- liftIO newCopyCoWTried
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return $ Just $ specialRemote c
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(storeKeyM dir chunkconfig cow)
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(retrieveKeyFileM dir chunkconfig cow)
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(removeKeyM dir)
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(checkPresentM dir chunkconfig)
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Remote
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{ uuid = u
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, cost = cst
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, name = Git.repoDescribe r
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, storeKey = storeKeyDummy
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, retrieveKeyFile = retrieveKeyFileDummy
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, retrieveKeyFileCheap = retrieveKeyFileCheapM dir chunkconfig
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, retrievalSecurityPolicy = RetrievalAllKeysSecure
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, removeKey = removeKeyDummy
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, lockContent = Nothing
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, checkPresent = checkPresentDummy
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, checkPresentCheap = True
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, exportActions = ExportActions
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{ storeExport = storeExportM dir cow
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, retrieveExport = retrieveExportM dir cow
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, removeExport = removeExportM dir
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, versionedExport = False
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, checkPresentExport = checkPresentExportM dir
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-- Not needed because removeExportLocation
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-- auto-removes empty directories.
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, removeExportDirectory = Nothing
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, renameExport = renameExportM dir
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}
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, importActions = ImportActions
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{ listImportableContents = listImportableContentsM dir
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, importKey = Just (importKeyM dir)
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, retrieveExportWithContentIdentifier = retrieveExportWithContentIdentifierM dir cow
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, storeExportWithContentIdentifier = storeExportWithContentIdentifierM dir cow
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, removeExportWithContentIdentifier = removeExportWithContentIdentifierM dir
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-- Not needed because removeExportWithContentIdentifier
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-- auto-removes empty directories.
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, removeExportDirectoryWhenEmpty = Nothing
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, checkPresentExportWithContentIdentifier = checkPresentExportWithContentIdentifierM dir
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}
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, whereisKey = Nothing
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, remoteFsck = Nothing
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, repairRepo = Nothing
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, config = c
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, getRepo = return r
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, gitconfig = gc
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, localpath = Just dir'
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, readonly = False
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, appendonly = False
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, untrustworthy = False
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, availability = LocallyAvailable
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, remotetype = remote
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, mkUnavailable = gen r u rc
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(gc { remoteAnnexDirectory = Just "/dev/null" }) rs
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, getInfo = return [("directory", dir')]
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, claimUrl = Nothing
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, checkUrl = Nothing
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, remoteStateHandle = rs
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}
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where
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dir = toRawFilePath dir'
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dir' = fromMaybe (giveup "missing directory") (remoteAnnexDirectory gc)
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directorySetup :: SetupStage -> Maybe UUID -> Maybe CredPair -> RemoteConfig -> RemoteGitConfig -> Annex (RemoteConfig, UUID)
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directorySetup _ mu _ c gc = do
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u <- maybe (liftIO genUUID) return mu
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-- verify configuration is sane
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let dir = maybe (giveup "Specify directory=") fromProposedAccepted $
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M.lookup directoryField c
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absdir <- liftIO $ fromRawFilePath <$> absPath (toRawFilePath dir)
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liftIO $ unlessM (doesDirectoryExist absdir) $
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giveup $ "Directory does not exist: " ++ absdir
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(c', _encsetup) <- encryptionSetup c gc
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-- The directory is stored in git config, not in this remote's
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-- persistant state, so it can vary between hosts.
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gitConfigSpecialRemote u c' [("directory", absdir)]
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return (M.delete directoryField c', u)
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{- Locations to try to access a given Key in the directory.
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- We try more than one since we used to write to different hash
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- directories. -}
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locations :: RawFilePath -> Key -> [RawFilePath]
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locations d k = map (d P.</>) (keyPaths k)
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{- Returns the location off a Key in the directory. If the key is
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- present, returns the location that is actually used, otherwise
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- returns the first, default location. -}
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getLocation :: RawFilePath -> Key -> IO RawFilePath
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getLocation d k = do
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let locs = locations d k
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fromMaybe (Prelude.head locs)
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<$> firstM (doesFileExist . fromRawFilePath) locs
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{- Directory where the file(s) for a key are stored. -}
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storeDir :: RawFilePath -> Key -> RawFilePath
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storeDir d k = P.addTrailingPathSeparator $
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d P.</> hashDirLower def k P.</> keyFile k
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{- Check if there is enough free disk space in the remote's directory to
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- store the key. Note that the unencrypted key size is checked. -}
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storeKeyM :: RawFilePath -> ChunkConfig -> CopyCoWTried -> Storer
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storeKeyM d chunkconfig cow k c m =
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ifM (checkDiskSpaceDirectory d k)
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( do
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void $ liftIO $ tryIO $ createDirectoryUnder d tmpdir
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store
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, giveup "Not enough free disk space."
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)
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where
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store = case chunkconfig of
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LegacyChunks chunksize ->
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let go _k b p = liftIO $ Legacy.store
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(fromRawFilePath d)
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chunksize
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(finalizeStoreGeneric d)
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k b p
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(fromRawFilePath tmpdir)
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(fromRawFilePath destdir)
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in byteStorer go k c m
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NoChunks ->
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let go _k src p = do
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void $ fileCopier cow src tmpf p Nothing
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liftIO $ finalizeStoreGeneric d tmpdir destdir
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in fileStorer go k c m
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_ ->
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let go _k b p = liftIO $ do
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meteredWriteFile p tmpf b
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finalizeStoreGeneric d tmpdir destdir
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in byteStorer go k c m
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tmpdir = P.addTrailingPathSeparator $ d P.</> "tmp" P.</> kf
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tmpf = fromRawFilePath tmpdir </> fromRawFilePath kf
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kf = keyFile k
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destdir = storeDir d k
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checkDiskSpaceDirectory :: RawFilePath -> Key -> Annex Bool
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checkDiskSpaceDirectory d k = do
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annexdir <- fromRepo gitAnnexObjectDir
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samefilesystem <- liftIO $ catchDefaultIO False $
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(\a b -> deviceID a == deviceID b)
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<$> R.getFileStatus d
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<*> R.getFileStatus annexdir
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checkDiskSpace (Just d) k 0 samefilesystem
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{- Passed a temp directory that contains the files that should be placed
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- in the dest directory, moves it into place. Anything already existing
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- in the dest directory will be deleted. File permissions will be locked
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- down. -}
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finalizeStoreGeneric :: RawFilePath -> RawFilePath -> RawFilePath -> IO ()
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finalizeStoreGeneric d tmp dest = do
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removeDirGeneric (fromRawFilePath d) dest'
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createDirectoryUnder d (parentDir dest)
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renameDirectory (fromRawFilePath tmp) dest'
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-- may fail on some filesystems
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void $ tryIO $ do
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mapM_ (preventWrite . toRawFilePath) =<< dirContents dest'
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preventWrite dest
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where
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dest' = fromRawFilePath dest
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retrieveKeyFileM :: RawFilePath -> ChunkConfig -> CopyCoWTried -> Retriever
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retrieveKeyFileM d (LegacyChunks _) _ = Legacy.retrieve locations d
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retrieveKeyFileM d NoChunks cow = fileRetriever' $ \dest k p iv -> do
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src <- liftIO $ fromRawFilePath <$> getLocation d k
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void $ fileCopier cow src (fromRawFilePath dest) p iv
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retrieveKeyFileM d _ _ = byteRetriever $ \k sink ->
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sink =<< liftIO (L.readFile . fromRawFilePath =<< getLocation d k)
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retrieveKeyFileCheapM :: RawFilePath -> ChunkConfig -> Maybe (Key -> AssociatedFile -> FilePath -> Annex ())
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-- no cheap retrieval possible for chunks
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retrieveKeyFileCheapM _ (UnpaddedChunks _) = Nothing
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retrieveKeyFileCheapM _ (LegacyChunks _) = Nothing
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#ifndef mingw32_HOST_OS
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retrieveKeyFileCheapM d NoChunks = Just $ \k _af f -> liftIO $ do
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file <- fromRawFilePath <$> (absPath =<< getLocation d k)
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ifM (doesFileExist file)
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( createSymbolicLink file f
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, giveup "content file not present in remote"
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)
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#else
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retrieveKeyFileCheapM _ _ = Nothing
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#endif
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removeKeyM :: RawFilePath -> Remover
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removeKeyM d k = liftIO $ removeDirGeneric
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(fromRawFilePath d)
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(fromRawFilePath (storeDir d k))
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{- Removes the directory, which must be located under the topdir.
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-
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- Succeeds even on directories and contents that do not have write
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- permission, if it's possible to turn the write bit on.
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-
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- If the directory does not exist, succeeds as long as the topdir does
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- exist. If the topdir does not exist, fails, because in this case the
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- remote is not currently accessible and probably still has the content
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- we were supposed to remove from it.
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-}
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removeDirGeneric :: FilePath -> FilePath -> IO ()
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removeDirGeneric topdir dir = do
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void $ tryIO $ allowWrite (toRawFilePath dir)
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#ifdef mingw32_HOST_OS
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{- Windows needs the files inside the directory to be writable
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- before it can delete them. -}
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void $ tryIO $ mapM_ (allowWrite . toRawFilePath) =<< dirContents dir
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#endif
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tryNonAsync (removeDirectoryRecursive dir) >>= \case
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Right () -> return ()
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Left e ->
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unlessM (doesDirectoryExist topdir <&&> (not <$> doesDirectoryExist dir)) $
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throwM e
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checkPresentM :: RawFilePath -> ChunkConfig -> CheckPresent
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checkPresentM d (LegacyChunks _) k = Legacy.checkKey d locations k
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checkPresentM d _ k = checkPresentGeneric d (locations d k)
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checkPresentGeneric :: RawFilePath -> [RawFilePath] -> Annex Bool
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checkPresentGeneric d ps = checkPresentGeneric' d $
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liftIO $ anyM (doesFileExist . fromRawFilePath) ps
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checkPresentGeneric' :: RawFilePath -> Annex Bool -> Annex Bool
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checkPresentGeneric' d check = ifM check
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( return True
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, ifM (liftIO $ doesDirectoryExist (fromRawFilePath d))
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( return False
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, giveup $ "directory " ++ fromRawFilePath d ++ " is not accessible"
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)
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)
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storeExportM :: RawFilePath -> CopyCoWTried -> FilePath -> Key -> ExportLocation -> MeterUpdate -> Annex ()
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storeExportM d cow src _k loc p = do
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liftIO $ createDirectoryUnder d (P.takeDirectory dest)
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-- Write via temp file so that checkPresentGeneric will not
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-- see it until it's fully stored.
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viaTmp go (fromRawFilePath dest) ()
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where
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dest = exportPath d loc
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go tmp () = void $ fileCopier cow src tmp p Nothing
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retrieveExportM :: RawFilePath -> CopyCoWTried -> Key -> ExportLocation -> FilePath -> MeterUpdate -> Annex ()
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retrieveExportM d cow _k loc dest p = void $ fileCopier cow src dest p Nothing
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where
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src = fromRawFilePath $ exportPath d loc
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removeExportM :: RawFilePath -> Key -> ExportLocation -> Annex ()
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removeExportM d _k loc = liftIO $ do
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removeWhenExistsWith R.removeLink src
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removeExportLocation d loc
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where
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src = exportPath d loc
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checkPresentExportM :: RawFilePath -> Key -> ExportLocation -> Annex Bool
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checkPresentExportM d _k loc =
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checkPresentGeneric d [exportPath d loc]
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renameExportM :: RawFilePath -> Key -> ExportLocation -> ExportLocation -> Annex (Maybe ())
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renameExportM d _k oldloc newloc = liftIO $ do
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createDirectoryUnder d (P.takeDirectory dest)
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renameFile (fromRawFilePath src) (fromRawFilePath dest)
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removeExportLocation d oldloc
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return (Just ())
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where
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src = exportPath d oldloc
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dest = exportPath d newloc
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exportPath :: RawFilePath -> ExportLocation -> RawFilePath
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exportPath d loc = d P.</> fromExportLocation loc
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{- Removes the ExportLocation's parent directory and its parents, so long as
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- they're empty, up to but not including the topdir. -}
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removeExportLocation :: RawFilePath -> ExportLocation -> IO ()
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removeExportLocation topdir loc =
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go (Just $ P.takeDirectory $ fromExportLocation loc) (Right ())
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where
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go _ (Left _e) = return ()
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go Nothing _ = return ()
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go (Just loc') _ =
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let p = fromRawFilePath $ exportPath topdir $
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mkExportLocation loc'
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in go (upFrom loc') =<< tryIO (removeDirectory p)
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listImportableContentsM :: RawFilePath -> Annex (Maybe (ImportableContents (ContentIdentifier, ByteSize)))
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listImportableContentsM dir = liftIO $ do
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l <- dirContentsRecursive (fromRawFilePath dir)
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l' <- mapM (go . toRawFilePath) l
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return $ Just $ ImportableContents (catMaybes l') []
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where
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go f = do
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st <- R.getFileStatus f
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mkContentIdentifier f st >>= \case
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Nothing -> return Nothing
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Just cid -> do
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relf <- relPathDirToFile dir f
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sz <- getFileSize' f st
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return $ Just (mkImportLocation relf, (cid, sz))
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-- Make a ContentIdentifier that contains the size and mtime of the file.
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-- If the file is not a regular file, this will return Nothing.
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--
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-- The inode is zeroed because often this is used for import from a
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-- FAT filesystem, whose inodes change each time it's mounted, and
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-- including inodes would cause repeated re-hashing of files, and
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-- bloat the git-annex branch with changes to content identifier logs.
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--
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-- This does mean that swaps of two files with the same size and
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-- mtime won't be noticed, nor will modifications to files that
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-- preserve the size and mtime. Both very unlikely so acceptable.
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mkContentIdentifier :: RawFilePath -> FileStatus -> IO (Maybe ContentIdentifier)
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mkContentIdentifier f st =
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fmap (ContentIdentifier . encodeBS . showInodeCache)
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<$> toInodeCache' noTSDelta f st 0
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guardSameContentIdentifiers :: a -> ContentIdentifier -> Maybe ContentIdentifier -> a
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guardSameContentIdentifiers cont old new
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| new == Just old = cont
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| otherwise = giveup "file content has changed"
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importKeyM :: RawFilePath -> ExportLocation -> ContentIdentifier -> ByteSize -> MeterUpdate -> Annex (Maybe Key)
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importKeyM dir loc cid sz p = do
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backend <- chooseBackend f
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unsizedk <- fst <$> genKey ks p backend
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let k = alterKey unsizedk $ \kd -> kd
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{ keySize = keySize kd <|> Just sz }
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currcid <- liftIO $ mkContentIdentifier absf
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=<< R.getFileStatus absf
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guardSameContentIdentifiers (return (Just k)) cid currcid
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where
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f = fromExportLocation loc
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absf = dir P.</> f
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ks = KeySource
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{ keyFilename = f
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, contentLocation = absf
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, inodeCache = Nothing
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}
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retrieveExportWithContentIdentifierM :: RawFilePath -> CopyCoWTried -> ExportLocation -> ContentIdentifier -> FilePath -> Annex Key -> MeterUpdate -> Annex Key
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retrieveExportWithContentIdentifierM dir cow loc cid dest mkkey p =
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precheck docopy
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where
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f = exportPath dir loc
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f' = fromRawFilePath f
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docopy = ifM (liftIO $ tryCopyCoW cow f' dest p)
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( do
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k <- mkkey
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postcheckcow (return k)
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, docopynoncow
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)
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docopynoncow = do
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#ifndef mingw32_HOST_OS
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let open = do
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-- Need a duplicate fd for the post check, since
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-- hGetContentsMetered closes its handle.
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fd <- openFd f' ReadOnly Nothing defaultFileFlags
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dupfd <- dup fd
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h <- fdToHandle fd
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return (h, dupfd)
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let close (h, dupfd) = do
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hClose h
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closeFd dupfd
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bracketIO open close $ \(h, dupfd) -> do
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#else
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let open = openBinaryFile f' ReadMode
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let close = hClose
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bracketIO open close $ \h -> do
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#endif
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liftIO $ hGetContentsMetered h p >>= L.writeFile dest
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k <- mkkey
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#ifndef mingw32_HOST_OS
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postchecknoncow dupfd (return k)
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#else
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postchecknoncow (return k)
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#endif
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-- Check before copy, to avoid expensive copy of wrong file
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-- content.
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precheck cont = guardSameContentIdentifiers cont cid
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=<< liftIO . mkContentIdentifier f
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=<< liftIO (R.getFileStatus f)
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-- Check after copy, in case the file was changed while it was
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-- being copied.
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--
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-- When possible (not on Windows), check the same handle
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-- that the file was copied from. Avoids some race cases where
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-- the file is modified while it's copied but then gets restored
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-- to the original content afterwards.
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--
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-- This does not guard against every possible race, but neither
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-- can InodeCaches detect every possible modification to a file.
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-- It's probably as good or better than git's handling of similar
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-- situations with files being modified while it's updating the
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-- working tree for a merge.
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#ifndef mingw32_HOST_OS
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postchecknoncow fd cont = do
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#else
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postchecknoncow cont = do
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#endif
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currcid <- liftIO $ mkContentIdentifier f
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#ifndef mingw32_HOST_OS
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=<< getFdStatus fd
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#else
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=<< R.getFileStatus f
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#endif
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guardSameContentIdentifiers cont cid currcid
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-- When copy-on-write was done, cannot check the handle that was
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-- copied from, but such a copy should run very fast, so
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-- it's very unlikely that the file changed after precheck,
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-- the modified version was copied CoW, and then the file was
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-- restored to the original content before this check.
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postcheckcow cont = do
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currcid <- liftIO $ mkContentIdentifier f
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=<< R.getFileStatus f
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guardSameContentIdentifiers cont cid currcid
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storeExportWithContentIdentifierM :: RawFilePath -> CopyCoWTried -> FilePath -> Key -> ExportLocation -> [ContentIdentifier] -> MeterUpdate -> Annex ContentIdentifier
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storeExportWithContentIdentifierM dir cow src _k loc overwritablecids p = do
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|
liftIO $ createDirectoryUnder dir (toRawFilePath destdir)
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withTmpFileIn destdir template $ \tmpf tmph -> do
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|
liftIO $ hClose tmph
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|
void $ fileCopier cow src tmpf p Nothing
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let tmpf' = toRawFilePath tmpf
|
|
resetAnnexFilePerm tmpf'
|
|
liftIO (getFileStatus tmpf) >>= liftIO . mkContentIdentifier tmpf' >>= \case
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|
Nothing -> giveup "unable to generate content identifier"
|
|
Just newcid -> do
|
|
checkExportContent dir loc
|
|
overwritablecids
|
|
(giveup "unsafe to overwrite file")
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|
(const $ liftIO $ rename tmpf dest)
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|
return newcid
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|
where
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|
dest = fromRawFilePath $ exportPath dir loc
|
|
(destdir, base) = splitFileName dest
|
|
template = relatedTemplate (base ++ ".tmp")
|
|
|
|
removeExportWithContentIdentifierM :: RawFilePath -> Key -> ExportLocation -> [ContentIdentifier] -> Annex ()
|
|
removeExportWithContentIdentifierM dir k loc removeablecids =
|
|
checkExportContent dir loc removeablecids (giveup "unsafe to remove modified file") $ \case
|
|
DoesNotExist -> return ()
|
|
KnownContentIdentifier -> removeExportM dir k loc
|
|
|
|
checkPresentExportWithContentIdentifierM :: RawFilePath -> Key -> ExportLocation -> [ContentIdentifier] -> Annex Bool
|
|
checkPresentExportWithContentIdentifierM dir _k loc knowncids =
|
|
checkPresentGeneric' dir $
|
|
checkExportContent dir loc knowncids (return False) $ \case
|
|
DoesNotExist -> return False
|
|
KnownContentIdentifier -> return True
|
|
|
|
data CheckResult = DoesNotExist | KnownContentIdentifier
|
|
|
|
-- Checks if the content at an ExportLocation is in the knowncids,
|
|
-- and only runs the callback that modifies it if it's safe to do so.
|
|
--
|
|
-- This should avoid races to the extent possible. However,
|
|
-- if something has the file open for write, it could write to the handle
|
|
-- after the callback has overwritten or deleted it, and its write would
|
|
-- be lost, and we don't need to detect that.
|
|
-- (In similar situations, git doesn't either!)
|
|
--
|
|
-- It follows that if something is written to the destination file
|
|
-- shortly before, it's acceptable to run the callback anyway, as that's
|
|
-- nearly indistinguishable from the above case.
|
|
--
|
|
-- So, it suffices to check if the destination file's current
|
|
-- content is known, and immediately run the callback.
|
|
checkExportContent :: RawFilePath -> ExportLocation -> [ContentIdentifier] -> Annex a -> (CheckResult -> Annex a) -> Annex a
|
|
checkExportContent dir loc knowncids unsafe callback =
|
|
tryWhenExists (liftIO $ R.getFileStatus dest) >>= \case
|
|
Just destst
|
|
| not (isRegularFile destst) -> unsafe
|
|
| otherwise -> catchDefaultIO Nothing (liftIO $ mkContentIdentifier dest destst) >>= \case
|
|
Just destcid
|
|
| destcid `elem` knowncids -> callback KnownContentIdentifier
|
|
-- dest exists with other content
|
|
| otherwise -> unsafe
|
|
-- should never happen
|
|
Nothing -> unsafe
|
|
-- dest does not exist
|
|
Nothing -> callback DoesNotExist
|
|
where
|
|
dest = exportPath dir loc
|