Seem there are several races that happen when 2 threads run PidLock.tryLock
at the same time. One involves checkSaneLock of the side lock file, which may
be deleted by another process that is dropping the lock, causing checkSaneLock
to fail. And even with the deletion disabled, it can still fail, Probably due
to linkToLock failing when a second thread overwrites the lock file.
The same can happen when 2 processes do, but then one process just fails
to take the lock, which is fine. But with 2 threads, some actions where failing
even though the process as a whole had the pid lock held.
Utility.LockPool.PidLock already maintains a STM lock, and since it uses
LockShared, 2 threads can hold the pidlock at the same time, and when
the first thread drops the lock, it will remain held by the second
thread, and so the pid lock file should not get deleted until the last
thread to hold it drops the lock. Which is the right behavior, and why a
LockShared STM lock is used in the first place.
The problem is that each time it takes the STM lock, it then also calls
PidLock.tryLock. So that was getting called repeatedly and concurrently.
Fixed by noticing when the shared lock is already held, and stop calling
PidLock.tryLock again, just use the pid lock that already exists then.
Also, LockFile.PidLock.tryLock was deleting the pid lock when it failed
to take the lock, which was entirely wrong. It should only drop the side
lock.
Sponsored-by: Dartmouth College's Datalad project
It ought to exist, since linkToLock has just created it. However,
Lustre seems to have a rather probabilisitic view of the contents of a
directory, so catching the error if it somehow does not exist and
running the same code path that would be ran if linkToLock failed
might avoid this fun Lustre failure.
Sponsored-by: Dartmouth College's Datalad project
Commit b6e4ed9aa7 made non-annexed files
be re-uploaded every time, since they're not tracked in the location log,
and it made it check the location log. Don't do that for non-annexed files.
Sponsored-by: Brock Spratlen on Patreon
This version of git -- or its new default "ort" resolver -- handles such
a conflict by staging two files, one with the original name and the other
named file~ref. Use unmergedSiblingFile when the latter is detected.
(It doesn't do that when the conflict is between a directory and a file
or symlink though, so see previous commit for how that case is handled.)
The sibling file has to be deleted separately, because cleanConflictCruft
may not delete it -- that only handles files that are annex links,
but the sibling file may be the non-annexed file side of the conflict.
The graftin code had assumed that, when the other side of a conclict
is a symlink, the file in the work tree will contain the non-annexed
content that we want it to contain. But that is not the case with the new
git; the file may be the annex link and needs to be replaced with the
content, while the annex link will be written as a -variant file.
(The weird doesDirectoryExist check in graftin turns out to still be
needed, test suite failed when I tried to remove it.)
Test suite passes with new git with ort resolver default. Have not tried it
with old git or other defaults.
Sponsored-by: Noam Kremen on Patreon
The new "ort" resolver uses different filenames than what the test suite
accepted when resolving a conflict between a directory an an annexed
file. Make the test looser in what it accepts, so it will work with old
and new git.
Other tests still look for "conflictor.variant" as a prefix,
because when eg resolving a conflicted merge of 2 annexed files,
the filename is not changed by the ort resolver, and I didn't want to
unncessarily loosen the test.
Also I'm not entirely happy with the filenames used by the ort resolver,
see comment.
There's still another test failure caused by that resolver that is not
fixed yet.
See comment for analysis.
At first I thought I'd need to convert all T.unpack in git-annex, but
luckily not -- so long as the Text is read from a file, the filesystem
encoding is applied and T.unpack is fine. It's only when using Feed
that the filesystem encoding is not applied.
While this fixes the crash, it does result in some mojibake, eg:
itemid=http://www.manager-tools.com/2014/01/choosing-a-company-work-chapter-7-���-questions/
Have not tracked that down, but it must be unrelated, because
I've verified that it roundtrips when using encodeUf8:
joey@darkstar:~/src/git-annex>LANG=C ghci Utility/FileSystemEncoding.hs
ghci> useFileSystemEncoding
ghci> Just f <- Text.Feed.Import.parseFeedFromFile "/home/joey/tmp/career_tools_podcasts.xml"
ghci> Just (_, x) = Text.Feed.Query.getItemId (Text.Feed.Query.feedItems f !! 0)
ghci> decodeBS (Data.Text.Encoding.encodeUtf8 x)
"http://www.manager-tools.com/2014/01/choosing-a-company-work-chapter-7-\56546\56448\56467-questions/"
ghci> writeFile "foo" $ decodeBS (Data.Text.Encoding.encodeUtf8 x)
Writes a file containing the ENDASH character.
Sponsored-by: Jochen Bartl on Patreon
git-lfs: Fix interoperability with gitlab's implementation of the git-lfs
protocol, which requests Content-Encoding chunked.
Sponsored-by: Dartmouth College's Datalad project
