assistant: when an add fails, requeue it for later

See analysis in bug report for one way this could happen.
This commit is contained in:
Joey Hess 2013-04-23 18:23:04 -04:00
parent 53674cc3fd
commit ca72b1ac7b
2 changed files with 26 additions and 3 deletions

View file

@ -256,14 +256,14 @@ handleAdds delayadd cs = returnWhen (null incomplete) $ do
| otherwise = a
add :: Change -> Assistant (Maybe Change)
add change@(InProcessAddChange { keySource = ks }) = do
add change@(InProcessAddChange { keySource = ks }) =
alertWhile' (addFileAlert $ keyFilename ks) $
liftM ret $ catchMaybeIO <~> do
sanitycheck ks $ do
key <- liftAnnex $ do
showStart "add" $ keyFilename ks
Command.Add.ingest $ Just ks
maybe failedingest (done change $ keyFilename ks) key
maybe (failedingest change) (done change $ keyFilename ks) key
where
{- Add errors tend to be transient and will be automatically
- dealt with, so don't pass to the alert code. -}
@ -306,7 +306,8 @@ handleAdds delayadd cs = returnWhen (null incomplete) $ do
mkpairs k = map (\c -> (inodeCacheToKey ct c, k)) <$>
recordedInodeCache k
failedingest = do
failedingest change = do
refill [change]
liftAnnex showEndFail
return Nothing

View file

@ -22,3 +22,25 @@ OS: Arch Linux
Please provide any additional information below.
The assistant in this case is being used as nothing more than a way for me to see which files have been added (--verbose, --foreground and --debug with 'watch' outputs nothing..). No remotes or anything like that.
> I have made the assistant re-queue any file that it fails to add,
> so it will retry it later. Typically within a few seconds. [[done]]
>
> I have only been able to think of one scenario in which this could
> happen. It's pretty unusual:
>
> * Something writes to a file, and closes it.
> * Assistant sees file has no writers, and locks it down in preparation
> to add it.
> * Something then re-opens the file to write to it some more.
> Note that it would seem to need to bypass permissions that prevent
> the file from being written to in order to do this. It makes a change
> to the file.
> * Assistant is checksumming file, reaches end, and detects it has been
> tampered with and gives up.
>
> I would still like more information about circumstances that
> cause this to happen, because while a possible scenario, the
> above is too weird to believe anyone could run into it.
>
> --[[Joey]]