git-annex/Command/ReKey.hs
Joey Hess 78a3d44ea0
get rid of racy addLink
The remaining callers all did not rely on it checking gitignore, so were
easy to convert.

They were susceptable to the same overwrite race as add and fix,
although less likely to have it and a narrower window than add's race.

Command.Rekey in passing got an unncessary call to removeFile deleted.
addSymlink handles deleting any existing worktree file.
2022-06-14 14:47:15 -04:00

135 lines
4.2 KiB
Haskell

{- git-annex command
-
- Copyright 2012-2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Command.ReKey where
import Command
import qualified Annex
import Annex.Content
import Annex.Ingest
import Annex.Link
import Annex.Perms
import Annex.ReplaceFile
import Logs.Location
import Annex.InodeSentinal
import Utility.InodeCache
import qualified Utility.RawFilePath as R
cmd :: Command
cmd = command "rekey" SectionPlumbing
"change keys used for files"
(paramRepeating $ paramPair paramPath paramKey)
(seek <$$> optParser)
data ReKeyOptions = ReKeyOptions
{ reKeyThese :: CmdParams
, batchOption :: BatchMode
}
optParser :: CmdParamsDesc -> Parser ReKeyOptions
optParser desc = ReKeyOptions
<$> cmdParams desc
<*> parseBatchOption False
-- Split on the last space, since a FilePath can contain whitespace,
-- but a Key very rarely does.
batchParser :: String -> Annex (Either String (RawFilePath, Key))
batchParser s = case separate (== ' ') (reverse s) of
(rk, rf)
| null rk || null rf -> return $ Left "Expected: \"file key\""
| otherwise -> case deserializeKey (reverse rk) of
Nothing -> return $ Left "bad key"
Just k -> do
let f = reverse rf
f' <- liftIO $ relPathCwdToFile (toRawFilePath f)
return $ Right (f', k)
seek :: ReKeyOptions -> CommandSeek
seek o = case batchOption o of
Batch fmt -> batchOnly Nothing (reKeyThese o) $
batchInput fmt batchParser
(batchCommandAction . uncurry start)
NoBatch -> withPairs
(\(si, p) -> commandAction (start si (parsekey p)))
(reKeyThese o)
where
parsekey (file, skey) =
(toRawFilePath file, fromMaybe (giveup "bad key") (deserializeKey skey))
start :: SeekInput -> (RawFilePath, Key) -> CommandStart
start si (file, newkey) = ifAnnexed file go stop
where
go oldkey
| oldkey == newkey = stop
| otherwise = starting "rekey" ai si $
perform file oldkey newkey
ai = ActionItemTreeFile file
perform :: RawFilePath -> Key -> Key -> CommandPerform
perform file oldkey newkey = do
ifM (inAnnex oldkey)
( unlessM (linkKey file oldkey newkey) $
giveup "failed creating link from old to new key"
, unlessM (Annex.getState Annex.force) $
giveup $ fromRawFilePath file ++ " is not available (use --force to override)"
)
next $ cleanup file newkey
{- Make a hard link to the old key content (when supported),
- to avoid wasting disk space. -}
linkKey :: RawFilePath -> Key -> Key -> Annex Bool
linkKey file oldkey newkey = ifM (isJust <$> isAnnexLink file)
{- If the object file is already hardlinked to elsewhere, a hard
- link won't be made by getViaTmpFromDisk, but a copy instead.
- This avoids hard linking to content linked to an
- unlocked file, which would leave the new key unlocked
- and vulnerable to corruption. -}
( getViaTmpFromDisk RetrievalAllKeysSecure DefaultVerify newkey (AssociatedFile Nothing) $ \tmp -> unVerified $ do
oldobj <- calcRepo (gitAnnexLocation oldkey)
isJust <$> linkOrCopy' (return True) newkey oldobj tmp Nothing
, do
{- The file being rekeyed is itself an unlocked file; if
- it's hard linked to the old key, that link must be broken. -}
oldobj <- calcRepo (gitAnnexLocation oldkey)
v <- tryNonAsync $ do
st <- liftIO $ R.getFileStatus file
when (linkCount st > 1) $ do
freezeContent oldobj
replaceWorkTreeFile (fromRawFilePath file) $ \tmp -> do
let tmp' = toRawFilePath tmp
unlessM (checkedCopyFile oldkey oldobj tmp' Nothing) $
error "can't lock old key"
thawContent tmp'
ic <- withTSDelta (liftIO . genInodeCache file)
case v of
Left e -> do
warning (show e)
return False
Right () -> do
r <- linkToAnnex newkey file ic
return $ case r of
LinkAnnexFailed -> False
LinkAnnexOk -> True
LinkAnnexNoop -> True
)
cleanup :: RawFilePath -> Key -> CommandCleanup
cleanup file newkey = do
ifM (isJust <$> isAnnexLink file)
( do
-- Update symlink to use the new key.
addSymlink file newkey Nothing
, do
mode <- liftIO $ catchMaybeIO $ fileMode <$> R.getFileStatus file
liftIO $ whenM (isJust <$> isPointerFile file) $
writePointerFile file newkey mode
stagePointerFile file mode =<< hashPointerFile newkey
)
whenM (inAnnex newkey) $
logStatus newkey InfoPresent
return True