git-annex/Command/Unlock.hs
Joey Hess 4392140946
make linkAnnex detect when the file changes as it's being copied/linked in
This fixes a race where the modified file ended up in annex/objects, and
the InodeCache stored in the database was for the modified version, so
git-annex didn't know it had gotten modified.

The race could occur when the smudge filter was running; now it gets the
InodeCache before generating the Key, which avoids the race.
2015-12-22 15:20:03 -04:00

104 lines
2.6 KiB
Haskell

{- git-annex command
-
- Copyright 2010,2015 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.Unlock where
import Common.Annex
import Command
import Annex.Content
import Annex.CatFile
import Annex.Version
import Annex.Link
import Annex.ReplaceFile
import Annex.InodeSentinal
import Utility.InodeCache
import Utility.CopyFile
cmd :: Command
cmd = mkcmd "unlock" "unlock files for modification"
editcmd :: Command
editcmd = mkcmd "edit" "same as unlock"
mkcmd :: String -> String -> Command
mkcmd n d = notDirect $ withGlobalOptions annexedMatchingOptions $
command n SectionCommon d paramPaths (withParams seek)
seek :: CmdParams -> CommandSeek
seek = withFilesInGit $ whenAnnexed start
{- Before v6, the unlock subcommand replaces the symlink with a copy of
- the file's content. In v6 and above, it converts the file from a symlink
- to a pointer. -}
start :: FilePath -> Key -> CommandStart
start file key = ifM (isJust <$> isAnnexLink file)
( do
showStart "unlock" file
ifM (inAnnex key)
( ifM versionSupportsUnlockedPointers
( next $ performNew file key
, startOld file key
)
, do
warning "content not present; cannot unlock"
next $ next $ return False
)
, stop
)
performNew :: FilePath -> Key -> CommandPerform
performNew dest key = do
src <- calcRepo (gitAnnexLocation key)
srcic <- withTSDelta (liftIO . genInodeCache src)
replaceFile dest $ \tmp -> do
r <- linkAnnex' key src srcic tmp
case r of
LinkAnnexOk -> return ()
_ -> error "linkAnnex failed"
next $ cleanupNew dest key
cleanupNew :: FilePath -> Key -> CommandCleanup
cleanupNew dest key = do
stagePointerFile dest =<< hashPointerFile key
return True
startOld :: FilePath -> Key -> CommandStart
startOld file key =
ifM (inAnnex key)
( ifM (isJust <$> catKeyFileHEAD file)
( next $ performOld file key
, do
warning "this has not yet been committed to git; cannot unlock it"
next $ next $ return False
)
, do
warning "content not present; cannot unlock"
next $ next $ return False
)
performOld :: FilePath -> Key -> CommandPerform
performOld dest key = ifM (checkDiskSpace Nothing key 0 True)
( do
src <- calcRepo $ gitAnnexLocation key
tmpdest <- fromRepo $ gitAnnexTmpObjectLocation key
liftIO $ createDirectoryIfMissing True (parentDir tmpdest)
showAction "copying"
ifM (liftIO $ copyFileExternal CopyAllMetaData src tmpdest)
( do
liftIO $ do
removeFile dest
moveFile tmpdest dest
thawContent dest
next $ return True
, do
warning "copy failed!"
next $ return False
)
, do
warning "not enough disk space to copy file"
next $ return False
)