This makes the direct mode to v6 upgrade able to be performed in one clone
of a repository without affecting other clones, which can continue using v5
and direct mode.
This does mean that it has to write out temp files containing updated
objects for the merge. So may use more disk space, and disk IO, but that
should generally win out over needing to launch N separate
git hash-object processes.
An unlocked present file does not have a pointer file in the worktree, so
info skipped counting it.
It may be that unused was also affected by the problem, but it seemed not
to be in my tests. I think because of the use of the associatedFilesFilter.
This fix slows down both info and unused a little bit, since they have to
query the contents of files from git, but only when handling unlocked files.
Only reverse adjust the changes in the commit, which means that adjustments
do not need to be generally cleanly reversable.
For example, an adjustment can unlock all locked files, but does not need
to worry about files that were originally unlocked when reversing, because
it will only ever be run on files that have been changed. So, it's ok
if it locks all files when reversed, or even leaves all files as-is when
reversed.
Using adjusted/unlocked/master made lots of git stuff dealing with "master"
complain that it was ambiguous. This new appoach is more like view branch
names, and shows the adjustment right there in the branch display even if
only the basename of the branch is shown.
There's a race here, but entering an adjusted branch for the first time is
not something to do when a commit is being made at the same time. Although,
may want to prevent the assistant from committing while entering the
adjusted branch.
So, it will pull and push the original branch, not the adjusted one.
And, for merging, it will use updateAdjustedBranch (not implemented yet).
Note that remaining uses of Git.Branch.current need to be checked too;
for things that should act on the original branch, and not the adjusted
branch.
"git annex adjust" may be a temporary interface, but works for a proof of
concept.
It is pretty fast at creating the adjusted branch. The main overhead is
injecting pointer files. It might be worth optimising that by reusing the
symlink target as the pointer file content. When I tried to do that,
the problem was that the clean filter doesn't use that same format, and so
git thought files had changed. Could be dealt with, perhaps make the clean
filter use symlink format for pointer files when on an adjusted branch?
But the real overhead is in checking out the branch, when git runs the
smudge filter once per file. That is perhaps too slow to be usable,
although it may only affect initial checkout of the branch, and not
updates. TBD.
* add, addurl, import, importfeed: When in a v6 repository on a crippled
filesystem, add files unlocked.
* annex.addunlocked: New configuration setting, makes files always be
added unlocked. (v6 only)
The problem with having the slashes unescaped is, it broke parsing, since
the parser takes the filename to get the part containing the key.
That particularly affected URL keys.
This makes the format be the same as symlinks point to, which keeps things
simple.
Existing pointer files will continue to work ok.
Before, the call to mkProgressUpdater created the directory as a
side-effect, but since that ignored failure to create it, this led to
a "does not exist" exception when the transfer lock file was created,
rather than a permissions error.
So, make sure the directory exists before trying to lock the file in it.
When a PermissionDenied exception is caught, skip making the transfer lock.
This lets downloads from readonly remotes happen.
If an upload is being tried, and the lock file can't be written due to
permissions, then probably the actual transfer will fail for the same
reason, so I think it's ok that it continues w/o taking the lock in that
case.
The type checker should have noticed this, but the changes to mapM
that make it accept any Traversable hid the fact that it was not being
passed a list at all. Thus, what should have returned an empty list most
of the time instead returned [""] which was treated as the name of the
associated file, with disasterout consequences.
When I have time, I should add a test case checking what sync --content
drops. I should also consider replacing mapM with one re-specialized to
lists.
Previously, it only flushed when the queue got larger than 1.
Also, make the queue auto-flush when items are added, rather than needing
to be flushed as a separate step. This simplifies the code and make it more
efficient too, as it avoids needing to read the queue out of the state to
check if it should be flushed.
The homomorphs are back, just encoded such that it doesn't crash in LANG=C
However, I noticed a bug in the old escaping; [pseudoSlash] was escaped the
same as ['/','/']. Fixed by using '%' to escape pseudoSlash. Which requires
doubling '%' to escape it, but that's already done in the escaping of
worktree filenames in a view, so is probably ok.
Linking the file to the tmp dir was not necessary in the clean
filter, and it caused the ctime to change, which caused git to think
the file was changed. This caused git status to get slow as it kept
re-cleaning unchanged files.
Fixes several bugs with updates of pointer files. When eg, running
git annex drop --from localremote
it was updating the pointer file in the local repository, not the remote.
Also, fixes drop ../foo when run in a subdir, and probably lots of other
problems. Test suite drops from ~30 to 11 failures now.
TopFilePath is used to force thinking about what the filepath is relative
to.
The data stored in the sqlite db is still just a plain string, and
TopFilePath is a newtype, so there's no overhead involved in using it in
DataBase.Keys.
WorkTree.lookupFile was finding a key for a file that's deleted from the
work tree, which is different than the v5 behavior (though perhaps the same
as the direct mode behavior). Fix by checking that the work tree file exists
before catting its key.
Hopefully this won't slow down much, probably the catKey is much more expensive.
I can't see any way to optimise this, except perhaps to make Command.Unused
check if work tree files exist before/after calling lookupFile. But,
it seems better to make lookupFile really only find keys for worktree files;
that's what it's intended to do.
Else, queued file stages won't have reached the index, and it won't find
everthing.
This evidently fixes a reversion in my work today, although I don't see how
I broke it. It didn't use to flush the queue first, before, and worked
somehow.
Test suite for v5 is back to 100% green now.
The smudge filter does need to be run, because if the key is in the local
annex already (due to renaming, or a copy of a file added, or a new file
added and its content has already arrived), git merge smudges the file and
this should provide its content.
This does probably mean that in merge conflict resolution, git smudges the
existing file, re-copying all its content to it, and then the file is
deleted. So, not efficient.
This is a behavior change for merge conflicts between locked files
that both pointed to the same key, in different ways.
Before, the conflict was resolved, but the file was renamed to .variant.
This was unnecessary, because there was only one variant.
Of course, this also handles conflicts between unlocked and locked, or even
two unlocked files with different pointer contents.
Since the file was present and locked, its annex object was not in the
inode cache. So, despite not needing to update the annex object when the
clean filter is run on the content by git merge, it does need to record the
inode cache of the annex object. Otherwise, the annex object will be
assumed to be bad, since its inode is not cached.
Several tricky parts:
* When the conflict is just between the same key being locked and unlocked,
the unlocked version wins, and the file is not renamed in this case.
* Need to update associated file map when conflict resolution renames
an unlocked file.
* git merge runs the smudge filter on the conflicting file, and actually
overwrites the file with the same content it had before, and so
invalidates its inode cache. This makes it difficult to know when it's
safe to remove such files as conflict cruft, without going so far as to
compare their entire contents.
Dealt with this by preventing the smudge filter from populating the file
when a merge is run. However, that also prevents the smudge filter being
run for non-conflicting files, so eg moving a file won't put its new
content into place.
* Ideally, if a merge or a merge conflict resolution renames an unlocked
file, the file in the work tree can just be moved, rather than copying
the content to a new worktree file.
This is attempted to be done in merge conflict resolution, but
due to git merge's behavior of running smudge filters, what actually
seems to happen is the old worktree file with the content is deleted and
rewritten as a pointer file, so doesn't get reused.
So, this is probably not as efficient as it optimally could be.
If that becomes a problem, could look into running the merge in a separate
worktree and updating the real worktree more efficiently, similarly to the
direct mode merge. However, the direct mode merge had a lot of bugs, and
I'd rather not use that more error-prone method unless really needed.
Decided it's too scary to make v6 unlocked files have 1 copy by default,
but that should be available to those who need it. This is consistent with
git-annex not dropping unused content without --force, etc.
* Added annex.thin setting, which makes unlocked files in v6 repositories
be hard linked to their content, instead of a copy. This saves disk
space but means any modification of an unlocked file will lose the local
(and possibly only) copy of the old version.
* Enable annex.thin by default on upgrade from direct mode to v6, since
direct mode made the same tradeoff.
* fix: Adjusts unlocked files as configured by annex.thin.
This optimisation was not necessary, and didn't work for v6 unlocked files.
Typically only a small number of files will be changed by a commit, so just
catKey them all.
This can happen when ingesting a new file in either locked or unlocked
mode, when some unlocked files in the repo use the same key, and the
content was not locally available before.
This fixes a race where the modified file ended up in annex/objects, and
the InodeCache stored in the database was for the modified version, so
git-annex didn't know it had gotten modified.
The race could occur when the smudge filter was running; now it gets the
InodeCache before generating the Key, which avoids the race.
In v5, lookupFile is supposed to only look at symlinks on disk (except when
in direct mode).
Note that v6 also has a bug when a locked file's symlink is deleted and is
replaced with a new file. It sees that a link is staged and gets that
key.
The problem is that shutdown is not always called, particularly in the test
suite. So, a database connection would be opened, possibly some changes
queued, and then not shut down.
One way this can happen is when using Annex.eval or Annex.run with a new
state. A better fix might be to make both of them call Keys.shutdown
(and be sure to do it even if the annex action threw an error).
Complication: Sometimes they're run reusing an existing state, so shutting
down a database connection could cause problems for other users of that
same state. I think this would need a MVar holding the database handle,
so it could be emptied once shut down, and another user of the database
connection could then start up a new one if it got shut down. But, what if
2 threads were concurrently using the same database handle and one shut it
down while the other was writing to it? Urgh.
Might have to go that route eventually to get the database access to run
fast enough. For now, a quick fix to get the test suite happier, at the
expense of speed.
This covers the case where multiple files have the same content and are
added with git add. Previously only the one that was linked to the annex
got its inode cached; now both are.
When a v6 unlocked files is removed from the work tree,
unused doesn't show it. When it gets removed from the index,
unused does show it. This is the same as a locked file.
If multiple files point to the same annex object, the user may want to
modify them independently, so don't use a hard link.
Also, check diskreserve when copying.
Before the smudge filter added a trailing newline, but other things that
wrote formatPointer to a file did not.
also some new pointer staging code to use later
This avoids querying the database when the content file doen't exist
(or otherwise fails the provided check). However, it does add overhead of
querying the database, and will certianly impact performance.
The Keys database can hold multiple inode caches for a given key. One for
the annex object, and one for each pointer file, which may not be hard
linked to it.
Inode caches for a key are recorded when its content is added to the annex,
but only if it has known pointer files. This is to avoid the overhead of
maintaining the database when not needed.
When the smudge filter outputs a file's content, the inode cache is not
updated, because git's smudge interface doesn't let us write the file. So,
dropping will fall back to doing an expensive verification then. Ideally,
git's interface would be improved, and then the inode cache could be
updated then too.
Renamed the db to keys, since it is various info about a Keys.
Dropping a key will update its pointer files, as long as their content can
be verified to be unmodified. This falls back to checksum verification, but
I want it to use an InodeCache of the key, for speed. But, I have not made
anything populate that cache yet.
This removes ambiguity, because while someone might have "WORM--foo" in a
file that's not intended to be a git-annex pointer file,
"annex/objects/WORM--foo" is less likely.
Also, 664cc987e8 had a caveat about symlink
targets being parsed as pointer files, and now the same parser is used for
both.
I did not include any hash directories before the key in the pointer file,
as they're not needed. However, if they were included, the parser would
still work ok.
Backend.lookupFile is changed to always fall back to catKey when
operating on a file that's not a symlink.
catKey is changed to understand pointer files, as well as annex symlinks.
Before, catKey needed a file mode witness, to be sure it was looking at a
symlink. That was complicated stuff. Now, it doesn't actually care if a
file in git is a symlink or not; in either case asking git for the content
of the file will get the pointer to the key.
This does mean that git-annex will treat a link
foo -> WORM--bar as a git-annex file, and also treats
a regular file containing annex/objects/WORM--bar as a git-annex file.
Calling catKey could make git-annex commands need to do more work than
before. This would especially be the case if a repo contained many regular
files, and only a few annexed files, as now git-annex will need to ask
git about the contents of the regular files.
Was not putting it inside the temp dir, but next to it!
This was just wrong, and it led to a longer filename that desired being
used, leading to some bug reports.
Since all places where a repo is used in direct mode need to have git-annex
upgraded before the repo can safely be converted to v6, the upgrade needs
to be manual for now.
I suppose that at some point I'll want to drop all the direct mode support
code. At that point, will stop supporting v5, and will need to auto-upgrade
any remaining v5 repos. If possible, I'd like to carry the direct mode
support for say, a year or so, to give people plenty of time to upgrade and
avoid disruption.
When core.sharedRepository is set, annex object files are not made mode
444, since that prevents a user other than the file owner from locking
them. Instead, a mode such as 664 is used in this case.
replaceFile created a temp file, which was guaranteed to not overlap with
another temp file. However, makeAnnexLink then deleted that file, in
preparation for making the symlink in its place. This caused a race, since
some other replaceFile could create a temp file, using the same name!
I was able to reproduce the race easily running git-annex add -J10 in a
directory with 100 files (all with different contents). Some files would
get ingested into the annex, but their annex links would fail to be added.
There could be other situations where this same problem could occur.
Perhaps when the assistant is adding a file, if the user manually also ran
git-annex add. Perhaps in cases not involving adding a file.
The new replaceFile makes a temprary directory, which is guaranteed to be
unique, and doesn't make a temp file in there. makeAnnexLink can thus
create the symlink without problem and the race is avoided.
Audited all calls to replaceFile to make sure that the old behavior of
providing an empty temp file was not relied on.
The general problem of asking for a temp file and deleting it as part of
the process of using it could reach beyond replaceFile. Did some quick
audits and didn't find other cases of it. Probably only symlink creation
stuff would tend to make that mistake, mostly.
Instead, only display transport error if the configlist output doesn't
include an annex.uuid line, even an empty one.
A recent change made git-annex init try to get all the remote uuids, and so
the transport error would be displayed by it. It was also displayed when
eg, copying files to a remote that had no uuid yet.
sync, merge, assistant: When git merge failed for a reason other than a
conflicted merge, such as a crippled filesystem not allowing particular
characters in filenames, git-annex would make a merge commit that could
omit such files or otherwise be bad. Fixed by aborting the whole merge
process when git merge fails for any reason other than a merge conflict.
Implemented with no additional overhead of compares etc.
This is safe to do for presence logs because of their locality of change;
a given repo's presence logs are only ever changed in that repo, or in a
repo that has just been actively changing the content of that repo.
So, we don't need to worry about a split-brain situation where there'd
be disagreement about the location of a key in a repo. And so, it's ok to
not update the timestamp when that's the only change that would be made
due to logging presence info.
sideAction is for things not generally related to the current action being
performed. And, it adds a newline after the side action. This was not the
right thing to use for stuff like "checksum", where doing a checksum is
part of the git annex get process, and indeed we want it to display
"(checksum...) ok"
By definition, a trusted repository is trusted to always have its location
tracking log accurate. Thus, it should never be in a position where content
is being dropped from it concurrently, as that would result in the location
tracking log not being accurate.
This avoids a failure where eg, we start with RecentlyVerifiedCopies
for all remotes, and so didn't do any active verification, which is
required.
Also, dedup the list of VerifiedCopies when checking if we have enough,
in case 2 copies of a UUID slip in.
See doc/bugs/concurrent_drop--from_presence_checking_failures.mdwn for
discussion about why 1 locked copy is all we can require, and how this
fixes concurrent dropping bugs.
Note that, since nothing yet generates a VerifiedCopyLock yet, this commit
breaks dropping temporarily.
There should be no behavior changes in this commit, it just adds a more
expressive data type and adjusts code that had been passing around a [UUID]
or sometimes a Maybe Remote to instead use [VerifiedCopy].
Although, since some functions were taking two different [UUID] lists,
there's some potential for me to have gotten it horribly wrong.
Also, rename lockContent to lockContentExclusive
inAnnexSafe should perhaps be eliminated, and instead use
`lockContentShared inAnnex`. However, I'm waiting on that, as there are
only 2 call sites for inAnnexSafe and it's fiddly.
In c6632ee5c8, it actually only handled
uploading objects to a shared repository. To avoid verification when
downloading objects from a shared repository, was a lot harder.
On the plus side, if the process of downloading a file from a remote
is able to verify its content on the side, the remote can indicate this
now, and avoid the extra post-download verification.
As of yet, I don't have any remotes (except Git) using this ability.
Some more work would be needed to support it in special remotes.
It would make sense for tahoe to implicitly verify things downloaded from it;
as long as you trust your tahoe server (which typically runs locally),
there's cryptographic integrity. OTOH, despite bup being based on shas,
a bup repo under an attacker's control could have the git ref used for an
object changed, and so a bup repo shouldn't implicitly verify. Indeed,
tahoe seems unique in being trustworthy enough to implicitly verify.
* When annex objects are received into git repositories, their checksums are
verified then too.
* To get the old, faster, behavior of not verifying checksums, set
annex.verify=false, or remote.<name>.annex-verify=false.
* setkey, rekey: These commands also now verify that the provided file
matches the key, unless annex.verify=false.
* reinject: Already verified content; this can now be disabled by
setting annex.verify=false.
recvkey and reinject already did verification, so removed now duplicate
code from them. fsck still does its own verification, which is ok since it
does not use getViaTmp, so verification doesn't happen twice when using fsck
--from.
I couldn't find a good way to make an *empty* index file (zero byte file
won't do), so I punted and just don't make index.lock when there's no index
yet. This means some other git process could race and write an index file
at the same time as the merge is ongoing, in theory. Only happens in new
repos though.
Oh boy, not again. So, another place that the filesystem encoding needs to
be applied. Yay.
In passing, I changed decodeBS so if a NUL is embedded in the input, the
resulting FilePath doesn't get truncated at that NUL. This was needed to
make prop_b64_roundtrips pass, and on reviewing the callers of decodeBS, I
didn't see any where this wouldn't make sense. When a FilePath is used to
operate on the filesystem, it'll get truncated at a NUL anyway, whereas if
a String is being used for something else, it might conceivably have a NUL
in it, and we wouldn't want it to get truncated when going through
decodeBS.
(NB: There may be a speed impact from this change.)
