From 6d8b95d6bf0d7b5666efc02379fe55e8d02e1ebe Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Sun, 17 Feb 2013 15:05:55 -0400 Subject: fully support core.symlinks=false in all relevant symlink handling code Refactored annex link code into nice clean new library. Audited and dealt with calls to createSymbolicLink. Remaining calls are all safe, because: Annex/Link.hs: ( liftIO $ createSymbolicLink linktarget file only when core.symlinks=true Assistant/WebApp/Configurators/Local.hs: createSymbolicLink link link test if symlinks can be made Command/Fix.hs: liftIO $ createSymbolicLink link file command only works in indirect mode Command/FromKey.hs: liftIO $ createSymbolicLink link file command only works in indirect mode Command/Indirect.hs: liftIO $ createSymbolicLink l f refuses to run if core.symlinks=false Init.hs: createSymbolicLink f f2 test if symlinks can be made Remote/Directory.hs: go [file] = catchBoolIO $ createSymbolicLink file f >> return True fast key linking; catches failure to make symlink and falls back to copy Remote/Git.hs: liftIO $ catchBoolIO $ createSymbolicLink loc file >> return True ditto Upgrade/V1.hs: liftIO $ createSymbolicLink link f v1 repos could not be on a filesystem w/o symlinks Audited and dealt with calls to readSymbolicLink. Remaining calls are all safe, because: Annex/Link.hs: ( liftIO $ catchMaybeIO $ readSymbolicLink file only when core.symlinks=true Assistant/Threads/Watcher.hs: ifM ((==) (Just link) <$> liftIO (catchMaybeIO $ readSymbolicLink file)) code that fixes real symlinks when inotify sees them It's ok to not fix psdueo-symlinks. Assistant/Threads/Watcher.hs: mlink <- liftIO (catchMaybeIO $ readSymbolicLink file) ditto Command/Fix.hs: stopUnless ((/=) (Just link) <$> liftIO (catchMaybeIO $ readSymbolicLink file)) $ do command only works in indirect mode Upgrade/V1.hs: getsymlink = takeFileName <$> readSymbolicLink file v1 repos could not be on a filesystem w/o symlinks Audited and dealt with calls to isSymbolicLink. (Typically used with getSymbolicLinkStatus, but that is just used because getFileStatus is not as robust; it also works on pseudolinks.) Remaining calls are all safe, because: Assistant/Threads/SanityChecker.hs: | isSymbolicLink s -> addsymlink file ms only handles staging of symlinks that were somehow not staged (might need to be updated to support pseudolinks, but this is only a belt-and-suspenders check anyway, and I've never seen the code run) Command/Add.hs: if isSymbolicLink s || not (isRegularFile s) avoids adding symlinks to the annex, so not relevant Command/Indirect.hs: | isSymbolicLink s -> void $ flip whenAnnexed f $ only allowed on systems that support symlinks Command/Indirect.hs: whenM (liftIO $ not . isSymbolicLink <$> getSymbolicLinkStatus f) $ do ditto Seek.hs:notSymlink f = liftIO $ not . isSymbolicLink <$> getSymbolicLinkStatus f used to find unlocked files, only relevant in indirect mode Utility/FSEvents.hs: | Files.isSymbolicLink s = runhook addSymlinkHook $ Just s Utility/FSEvents.hs: | Files.isSymbolicLink s -> Utility/INotify.hs: | Files.isSymbolicLink s -> Utility/INotify.hs: checkfiletype Files.isSymbolicLink addSymlinkHook f Utility/Kqueue.hs: | Files.isSymbolicLink s = callhook addSymlinkHook (Just s) change all above are lower-level, not relevant Audited and dealt with calls to isSymLink. Remaining calls are all safe, because: Annex/Direct.hs: | isSymLink (getmode item) = This is looking at git diff-tree objects, not files on disk Command/Unused.hs: | isSymLink (LsTree.mode l) = do This is looking at git ls-tree, not file on disk Utility/FileMode.hs:isSymLink :: FileMode -> Bool Utility/FileMode.hs:isSymLink = checkMode symbolicLinkMode low-level Done!! --- Backend.hs | 41 ++++------------------------------------- 1 file changed, 4 insertions(+), 37 deletions(-) (limited to 'Backend.hs') diff --git a/Backend.hs b/Backend.hs index 076f7c2ce..6bbf3f75e 100644 --- a/Backend.hs +++ b/Backend.hs @@ -17,12 +17,11 @@ module Backend ( maybeLookupBackendName ) where -import System.Posix.Files - import Common.Annex import qualified Annex import Annex.CheckAttr import Annex.CatFile +import Annex.Link import Types.Key import Types.KeySource import qualified Types.Backend as B @@ -77,15 +76,12 @@ genKey' (b:bs) source = do | otherwise = c {- Looks up the key and backend corresponding to an annexed file, - - by examining what the file symlinks to. + - by examining what the file links to. - - - In direct mode, there is often no symlink on disk, in which case - - the symlink is looked up in git instead. However, a real symlink + - In direct mode, there is often no link on disk, in which case + - the symlink is looked up in git instead. However, a real link - on disk still takes precedence over what was committed to git in direct - mode. - - - - On a filesystem that does not support symlinks, git will instead store - - the symlink target in a regular file. -} lookupFile :: FilePath -> Annex (Maybe (Key, Backend)) lookupFile file = do @@ -107,35 +103,6 @@ lookupFile file = do " (unknown backend " ++ bname ++ ")" return Nothing -{- Checks if a file is a symlink to a key. - - - - On a filesystem that does not support symlinks, git will instead store - - the symlink target in a regular file. (Only look at first 8k of file, - - more than enough for any symlink target.) - -} -isAnnexLink :: FilePath -> Annex (Maybe Key) -isAnnexLink file = maybe Nothing makekey <$> gettarget - where - gettarget = ifM (coreSymlinks <$> Annex.getGitConfig) - ( liftIO $ catchMaybeIO $ readSymbolicLink file - , liftIO $ catchMaybeIO $ take 8192 <$> readFile file - ) - makekey l - | isLinkToAnnex l = fileKey $ takeFileName l - | otherwise = Nothing - -{- Creates a symlink on disk. - - - - On a filesystem that does not support symlinks, writes the link target - - to a file. Note that git will only treat the file as a symlink if - - it's staged as such. - -} -makeAnnexLink :: String -> FilePath -> Annex () -makeAnnexLink linktarget file = ifM (coreSymlinks <$> Annex.getGitConfig) - ( liftIO $ createSymbolicLink linktarget file - , liftIO $ writeFile file linktarget - ) - {- Looks up the backend that should be used for a file. - That can be configured on a per-file basis in the gitattributes file. -} chooseBackend :: FilePath -> Annex (Maybe Backend) -- cgit v1.2.3