Note that while before checkTransfer this called getLock with WriteLock,
getLockStatus's use of ReadLock will also notice any exclusive locks.
Since transfer info files are only locked exclusively, never shared,
there is no behavior change.
Also, fixes checkLocked to actually return Just False when the file
exists, but is not locked.
Also fixes a test suite failures introduced in recent commits, where
inAnnexSafe failed in indirect mode, since it tried to open the lock file
ReadWrite. This is why the new checkLocked opens it ReadOnly.
This commit was sponsored by Chad Horohoe.
The nice refactoring in ec7dd0446a
highlighted a bug in lockContent -- when the content is not present,
this incorrectly created an empty lock file, using the same filename
as the content file.
This seems like it could result in empty objects, which fsck would detect
and complain about. Both drop and move --to call lockContent, as does
Remote.Git.dropKey -- I think we got lucky and this bug didn't show up
because both all of those only operate on files that are present. So
this bug could only manifest if there was a race, and a file's content
was dropped at just the wrong time, just as another process was about to
drop it. (And then only if the other process's dropping failed, otherwise
it'd delete the empty object file.)
Hmm, move --from also called lockContent. Unnecessarily, since the content
is not being removed from the local annex. In this case, the combination of
the 2 bugs could result in an empty lock file being written, and then if
the download of the content failed, left in the object directory as the
content.
This commit also optimises lockContent, avoiding an unncessary
doesFileExist test and instead just catching the exception that's thrown
when the file doesn't exist.
This commit was sponsored by Justine Lam.
Added a convenience Utility.LockFile that is not a windows/posix
portability shim, but still manages to cut down on the boilerplate around
locking.
This commit was sponsored by Johan Herland.
This was a bug, but it was only used for ssh locks and by the hook special
remote locking. At least in the case of ssh locks, the lock files happened
to already exist before this tried to use them, so the bug didn't cause
anything to break.
This does mean that eg, copying multiple files to a local remote will
become slightly slower, since it now restarts git-cat-file after each copy.
Should not be significant slowdown.
The reason git-cat-file is run on the remote at all is to update its
location log. In order to add an item to it, it needs to get the current
content of the log. Finding a way to avoid needing to do that would be a
good path to avoiding this slowdown if it does become a problem somehow.
This commit was sponsored by Evan Deaubl.
(With the exception of daemon pid locking.)
This fixes at part of #758630. I reproduced the assistant locking eg, a
removable drive's annex journal lock file and forking a long-running
git-cat-file process that inherited that lock.
This did not affect Windows.
Considered doing a portable Utility.LockFile layer, but git-annex uses
posix locks in several special ways that have no direct Windows equivilant,
and it seems like it would mostly be a complication.
This commit was sponsored by Protonet.
Note that this means getopt parsing is done even when not in a git
repository, even though currently cmdnorepo is not passed the results of
it. I'd like to move to cmdnorepo not doing its own ad-hoc option parsing,
so this is really a good thing. (But as long as eg, getOptionFlag needs an
Annex monad, it cannot be used in cmdnorepo handling.)
There is a potential for problems if any cmdnorepo branch of a command
handles options that are not in its regular getopt, but that would be a bug
anyway.
This is needed only because of the new MonadMask needed for bracket
in the new version. Ifdefing it everywhere is not practical, since the
Setup.hs uses it.
