Make the byteRetriever be passed the callback that consumes the bytestring.
This way, there's no worries about the lazy bytestring not all being read
when the resource that's creating it is closed.
Which in turn lets bup, ddar, and S3 each switch from using an unncessary
fileRetriver to a byteRetriever. So, more efficient on chunks and encrypted
files.
The only remaining fileRetrievers are hook and external, which really do
retrieve to files.
bup already splits files and does rolling deltas, so there is no reason to
use chunking here.
The new API made it easier to add progress support for storeKey, so that's
done. Unfortunately, bup-split still outputs its own progress with -q,
so a little ugly, but not too bad.
Made dropping remove the branch for an object, for two reasons:
1. The new API calls removeKey to roll back a storeKey when the content
changed unexpectedly.
2. So that testremote will be happy.
Also, fixed a bug that caused a crash when removing the branch for an
object in rollback.
Chunking would complicate the assistant's code that checks when a pending
retrieval of a key from glacier is done. It would perhaps be nice to
support it to allow resuming, but not right now.
Converting to the new API still simplifies the code.
The forall a. in Preparer made resourcePrepare not seem to be usable, so
I specialized a to Bool. Which works for both Preparer Storer and
Preparer Retriever, but wouldn't let the Preparer be used for hasKey
as it currently stands.
And fixed a bug found by these tests; retrieveKeyFile would fail
when the dest file was already complete.
This commit was sponsored by Bradley Unterrheiner.
The content of unstable keys can potentially be different in different
repos, so eg, resuming a chunked upload started by another repo would
corrupt data.
This way, when the remote implementation neglects to update progress,
there will still be a somewhat useful progress display, as long as chunks
are used.
No need to read whole FileContent only to write it back out to a file in
this case. Can just rename! Yay.
Also indidentially, fixed an attempt to open a file for write that was
already opened for write, which caused a crash and deadlock.
Putting a callback in the Retriever type allows for the callback to
remove the retrieved file when it's done with it.
I did not really want to make Retriever be fixed to Annex Bool,
but when I tried to use Annex a, I got into some type of type mess.
Needed for eg, Remote.External.
Generally, any Retriever that stores content in a file is responsible for
updating the meter, while ones that procude a lazy bytestring cannot update
the meter, so are not asked to.
Some remotes like External need to run store and retrieve actions in Annex,
not IO. In order to do that lift, I had to dive pretty deep into the
utilities, making Utility.Gpg and Utility.Tmp be partly converted to using
MonadIO, and Control.Monad.Catch for exception handling.
There should be no behavior changes in this commit.
This commit was sponsored by Michael Barabanov.
Leverage the new chunked remotes to automatically resume uploads.
Sort of like rsync, although of course not as efficient since this
needs to start at a chunk boundry.
But, unlike rsync, this method will work for S3, WebDAV, external
special remotes, etc, etc. Only directory special remotes so far,
but many more soon!
This implementation will also allow starting an upload from one repository,
interrupting it, and then resuming the upload to the same remote from
an entirely different repository.
Note that I added a comment that storeKey should atomically move the content
into place once it's all received. This was already an undocumented
requirement -- it's necessary for hasKey to work reliably. This resume code
just uses hasKey to find the first chunk that's missing.
Note that if there are two uploads of the same key to the same chunked remote,
one might resume at the point the other had gotten to, but both will then
redundantly upload. As before.
In the non-resume case, this adds one hasKey call per storeKey, and only
if the remote is configured to use chunks. Future work: Try to eliminate that
hasKey. Notice that eg, `git annex copy --to` checks if the key is present
before sending it, so is already running hasKey.. which could perhaps
be cached and reused.
However, this additional overhead is not very large compared with
transferring an entire large file, and the ability to resume
is certianly worth it. There is an optimisation in place for small files,
that avoids trying to resume if the whole file fits within one chunk.
This commit was sponsored by Georg Bauer.
Leverage the new chunked remotes to automatically resume downloads.
Sort of like rsync, although of course not as efficient since this
needs to start at a chunk boundry.
But, unlike rsync, this method will work for S3, WebDAV, external
special remotes, etc, etc. Only directory special remotes so far,
but many more soon!
This implementation will also properly handle starting a download
from one remote, interrupting, and resuming from another one, and so on.
(Resuming interrupted chunked uploads is similarly doable, although
slightly more expensive.)
This commit was sponsored by Thomas Djärv.
When chunk=0, always try the unchunked key first. This avoids the overhead
of needing to read the git-annex branch to find the chunkcount.
However, if the unchunked key is not present, go on and try the chunks.
Also, when removing a chunked key, update the chunkcounts even when
chunk=0.
No need to process each L.ByteString chunk, instead ask it to split.
Doesn't seem to have really sped things up much, but it also made the code
simpler.
Note that this does (and already did) buffer in memory. It seems that only
the directory special remote could take advantage of streaming chunks to
files w/o buffering, so probably won't add an interface to allow for that.
This will allow things like WebDAV to opean a single persistent connection
and reuse it for all the chunked data.
The crazy types allow for some nice code reuse.
Push it down from needing to be done in every Storer,
to being checked once inside ChunkedEncryptable.
Also, catch exceptions from PrepareStorer and PrepareRetriever,
just in case..
I'd have liked to keep these two concepts entirely separate,
but that are entagled: Storing a key in an encrypted and chunked remote
need to generate chunk keys, encrypt the keys, chunk the data, encrypt the
chunks, and send them to the remote. Similar for retrieval, etc.
So, here's an implemnetation of all of that.
The total win here is that every remote was implementing encrypted storage
and retrival, and now it can move into this single place. I expect this
to result in several hundred lines of code being removed from git-annex
eventually!
This commit was sponsored by Henrik Ahlgren.
Not yet used by any special remotes, but should not be too hard to add it
to most of them.
storeChunks is the hairy bit! It's loosely based on
Remote.Directory.storeLegacyChunked. The object is read in using a lazy
bytestring, which is streamed though, creating chunks as needed, without
ever buffering more than 1 chunk in memory.
Getting the progress meter update to work right was also fun, since
progress meter values are absolute. Finessed by constructing an offset
meter.
This commit was sponsored by Richard Collins.
Slightly tricky as they are not normal UUIDBased logs, but are instead maps
from (uuid, chunksize) to chunkcount.
This commit was sponsored by Frank Thomas.
Moved old legacy chunking code, and cleaned up the directory and webdav
remotes use of it, so when no chunking is configured, that code is not
used.
The config for new style chunking will be chunk=1M instead of chunksize=1M.
There should be no behavior changes from this commit.
This commit was sponsored by Andreas Laas.
This is a security/usability tradeoff. To avoid exposing the gpg key ids
who can decrypt the repository, users can unset
gcrypt-publish-participants.
The gcrypt-publish-participants option is available in my fork of
git-remote-gcrypt.
This commit was sponsored by Christopher Kernahan.
Catch an exception when ensureInitialized is run in a non-initted
repository. In this case, just read the git config, so that the Git.Repo
object is not LocalUnknown, which is what is used to represent remotes
on eg, drives that are not connected.
The assistant already got this right, and like with the assistant, this
causes an implicit git-annex init of the local remote on the second sync,
once the git-annex branch has been pushed to it.
See this comment for more analysis:
http://git-annex.branchable.com/todo/Recovering_from_a_bad_sync/#comment-64e469a2c1969829ee149cbb41b1c138
This commit was sponsored by jscit.
It is useful to be able to specify an alternative git-annex-shell
program to execute on the remote, e.g., to run a version not on the
PATH. Use remote.<name>.annex-shell if specified, instead of the
default "git-annex-shell" i.e., first so-named executable on the
PATH.
Version 5.20140227 broke creation of glacier repositories, not including
the datacenter and vault in their configuration. This bug is fixed, but
glacier repositories set up with the broken version of git-annex need to
have the datacenter and vault set in order to be usable. This can be done
using git annex enableremote to add the missing settings. For details, see
http://git-annex.branchable.com/bugs/problems_with_glacier/
Motivation: Hook scripts for nautilus or other file managers
need to provide the user with feedback that a file is being downloaded.
This commit was sponsored by THM Schoemaker.
Benchmarking this with 1000 small files being copied, the time reduced from
15.98s to 14.64s -- an 8% improvement in the non-data-transfer overhead of
git-annex copy.
This allows eg, putting .git/annex/tmp on a ram disk, if the disk IO
of temp object files is too annoying (and if you don't want to keep
partially transferred objects across reboots).
.git/annex/misctmp must be on the same filesystem as the git work tree,
since files are moved to there in a way that will not work cross-device,
as well as symlinked into there.
I first wanted to put the tmp objects in .git/annex/objects/tmp, but
that would pose transition problems on upgrade when partially transferred
objects existed.
git annex info does not currently show the size of .git/annex/misctemp,
since it should stay small. It would also be ok to make something clean it
out, periodically.
This breakage seems to have been caused way back in a1eded86,
but I am pretty sure rsync.net support has not been entirely
broken since last April. AFAICS, the generated .ssh/config
has not changed since then -- it has never included a Username setting
line. So, I am puzzled at when this reversion was introduced.
Note that the breakage only affected checkpresent and remove. Upload and
download use the ssh connection caching, which includes a -l username.
Removed instance, got it all to build using fromRef. (With a few things
that really need to show something using a ref for debugging stubbed out.)
Then added back Read instance, and made Logs.View use it for serialization.
This changes the view log format.
Potentially fixes some FD leak if an action on an opened file handle fails
for some reason. There have been some hard to reproduce reports of
git-annex leaking FDs, and this may solve them.
Similar to the assistant, this honors any configured preferred content
expressions.
I am not entirely happpy with the implementation. It would be nicer if
the seek function returned a list of actions which included the individual
file gets and copies and drops, rather than the current list of calls to
syncContent. This would allow getting rid of the somewhat reundant display
of "sync file [ok|failed]" after the get/put display.
But, do that, withFilesInGit would need to somehow be able to construct
such a mixed action list. And it would be less efficient than the current
implementation, which is able to reuse several values between eg get and
drop.
Note that currently this does not try to satisfy numcopies when
getting/putting files (numcopies are of course checked when dropping
files!) This makes it like the assistant, and unlike get --auto
and copy --auto, which do duplicate files when numcopies is not yet
satisfied. I don't know if this is the right decision; it only seemed to
make sense to have this parallel the assistant as far as possible to start
with, since I know the assistant works.
This commit was sponsored by Øyvind Andersen Holm.
Known problems:
1. Tries to tahoe start when daemon is already running.
2. If multiple tahoe remotes are set up on the same computer,
they will have the same node.url configured by default,
and this confuses tahoe commands.
This commit was sponsored by LeastAuthority.com
This allows a remote to store a piece of arbitrary state associated with a
key. This is needed to support Tahoe, where the file-cap is calculated from
the data stored in it, and used to retrieve a key later. Glacier also would
be much improved by using this.
GETSTATE and SETSTATE are added to the external special remote protocol.
Note that the state is left as-is even when a key is removed from a remote.
It's up to the remote to decide when it wants to clear the state.
The remote state log, $KEY.log.rmt, is a UUID-based log. However,
rather than using the old UUID-based log format, I created a new variant
of that format. The new varient is more space efficient (since it lacks the
"timestamp=" hack, and easier to parse (and the parser doesn't mess with
whitespace in the value), and avoids compatability cruft in the old one.
This seemed worth cleaning up for these new files, since there could be a
lot of them, while before UUID-based logs were only used for a few log
files at the top of the git-annex branch. The transition code has also
been updated to handle these new UUID-based logs.
This commit was sponsored by Daniel Hofer.
This was unexpectedly difficult because of a depdenency cycle. To parse a
preferred content expression involves several things that need to operate
on the list of remotes. Which needs Remote.External. The only way to avoid
this cycle (I tried breaking it at several points) was to skip parsing the
expression in SETWANTED.
That's sorta ok, because git-annex already has to deal with unparsable
preferred content expressions being stored, in order to handle eg,
upgrades. But I'm still not very happy that I cannot check it.
I feel this is a strong indication that I need to beware of further
bloating the special remote protocol interface.
Changed protocol spec to make SETCONFIG only store it persistently when run
during INITREMOTE. I see no reason to support storing it persistently at
other times, and doing so would unnecessarily complicate the code.
Also, letting that be done would probably result in use for storing data that
doesn't really belong there, and special remote authors who don't
understand how the union merging works would probably be surprised the
results.
That complicated special remote programs, because they had to avoid making
PREPARE fail if some configuration is missing, because the remote might not
be initialized yet. Instead, complicate git-annex slightly by only sending
PREPARE immediately before some other request other than INITREMOTE (or
PREPARE of course).
This has not been tested at all. It compiles!
The only known missing things are support for encryption, and for get/set
of special remote configuration, and of key state. (The latter needs
separate work to add a new per-key log file to store that state.)
Only thing I don't much like is that initremote needs to be passed both
type=external and externaltype=foo. It would be better to have just
type=foo
Most of this is quite straightforward code, that largely wrote itself given
the types. The only tricky parts were:
* Need to lock the remote when using it to eg make a request, because
in theory git-annex could have multiple threads that each try to use
a remote at the same time. I don't think that git-annex ever does
that currently, but better safe than sorry.
* Rather than starting up every external special remote program when
git-annex starts, they are started only on demand, when first used.
This will avoid slowdown, especially when running fast git-annex query
commands. Once started, they keep running until git-annex stops, currently,
which may not be ideal, but it's hard to know a better time to stop them.
* Bit of a chicken and egg problem with caching the cost of the remote,
because setting annex-cost in the git config needs the remote to already
be set up. Managed to finesse that.
This commit was sponsored by Lukas Anzinger.
This is mostly straightforward, but did turn out quite nicely stronly
typed, and with a quite nice automatic tokenization and parsing of received
messages.
Made a few minor changes to the protocol to clear up ambiguities and make
it easier to parse. Note particularly that setting remote configuration
is moved to a separate command, which allows a remote to set arbitrary data.
Fixed up a number of things that had worked around there not being a way to
get that.
Most notably, transfer info files on windows now include the process id,
since no locking is currently done. This means the file format varies
between windows and unix.
I think both of these are all that's affected, but I went ahead and fixed
all the remotes that set their config to M.empty to instead store the
actual config. Who knows what will expect it to be actually present in
future, the Remote instance of getGpgEncParams came to..
Currently only implemented for local git remotes. May try to add support
to git-annex-shell for ssh remotes later. Could concevably also be
supported by some special remote, although that seems unlikely.
Cronner user this when available, and when not falls back to
fsck --fast --from remote
git annex fsck --from does not itself use this interface.
To do so, I would need to pass --fast and all other options that influence
fsck on to the git annex fsck that it runs inside the remote. And that
seems like a lot of work for a result that would be no better than
cd remote; git annex fsck
This may need to be revisited if git-annex-shell gets support, since it
may be the case that the user cannot ssh to the server to run git-annex
fsck there, but can run git-annex-shell there.
This commit was sponsored by Damien Diederen.
addurl: Improve message when adding url with wrong size to existing file.
Before the message suggested the url didn't exist.
Fixed handling of URL keys that have no recorded size. Before, if the key
has no size, the url also had to not declare any size, which was unlikely
and wrong, or it was taken to not exist. This probably would mostly affect
keys that were added to the annex with addurl --relaxed.
gcrypt needs to be able to fast-forward the master branch. If a git
repository is set up with git init --shared --bare, it gets that set, and
pushing to it will then fail, even when it's up-to-date.
recvkey was told it was receiving a HMAC key from a direct mode repo,
and that confused it into rejecting the transfer, since it has no way to
verify a key using that backend, since there is no HMAC backend.
I considered making recvkey skip verification in the case of an unknown
backend. However, that could lead to bad results; a key can legitimately be
in the annex with a backend that the remote git-annex-shell doesn't know
about. Better to keep it rejecting if it cannot verify.
Instead, made the gcrypt special remote not set the direct mode flag when
sending (and receiving) files.
Also, added some recvkey messages when its checks fail, since otherwise
all that is shown is a confusing error message from rsync when the remote
git-annex-shell exits nonzero.
Overridable with --user-agent option.
Not yet done for S3 or WebDAV due to limitations of libraries used --
nether allows a user-agent header to be specified.
This commit sponsored by Michael Zehrer.
This pulls off quite a nice trick: When given a path on rsync.net, it
determines if it is an encrypted git repository that the user has
the key to decrypt, and merges with it. This is works even when
the local repository had no idea that the gcrypt remote exists!
(As previously done with local drives.)
This commit sponsored by Pedro Côrte-Real
When generating the path for rsync, /~/ is not valid, so change to
just host:dir
Note that git remotes specified in host:dir form are internally converted
to the ssh:// url form, so this was especially needed..
This is a massive win on OSX, which doesn't have a sha256sum normally.
Only use external hash commands when the file is > 1 mb,
since cryptohash is quite close to them in speed.
SHA is still used to calculate HMACs. I don't quite understand
cryptohash's API for those.
Used the following benchmark to arrive at the 1 mb number.
1 mb file:
benchmarking sha256/internal
mean: 13.86696 ms, lb 13.83010 ms, ub 13.93453 ms, ci 0.950
std dev: 249.3235 us, lb 162.0448 us, ub 458.1744 us, ci 0.950
found 5 outliers among 100 samples (5.0%)
4 (4.0%) high mild
1 (1.0%) high severe
variance introduced by outliers: 10.415%
variance is moderately inflated by outliers
benchmarking sha256/external
mean: 14.20670 ms, lb 14.17237 ms, ub 14.27004 ms, ci 0.950
std dev: 230.5448 us, lb 150.7310 us, ub 427.6068 us, ci 0.950
found 3 outliers among 100 samples (3.0%)
2 (2.0%) high mild
1 (1.0%) high severe
2 mb file:
benchmarking sha256/internal
mean: 26.44270 ms, lb 26.23701 ms, ub 26.63414 ms, ci 0.950
std dev: 1.012303 ms, lb 925.8921 us, ub 1.122267 ms, ci 0.950
variance introduced by outliers: 35.540%
variance is moderately inflated by outliers
benchmarking sha256/external
mean: 26.84521 ms, lb 26.77644 ms, ub 26.91433 ms, ci 0.950
std dev: 347.7867 us, lb 210.6283 us, ub 571.3351 us, ci 0.950
found 6 outliers among 100 samples (6.0%)
import Crypto.Hash
import Data.ByteString.Lazy as L
import Criterion.Main
import Common
testfile :: FilePath
testfile = "/run/shm/data" -- on ram disk
main = defaultMain
[ bgroup "sha256"
[ bench "internal" $ whnfIO internal
, bench "external" $ whnfIO external
]
]
sha256 :: L.ByteString -> Digest SHA256
sha256 = hashlazy
internal :: IO String
internal = show . sha256 <$> L.readFile testfile
external :: IO String
external = do
s <- readProcess "sha256sum" [testfile]
return $ fst $ separate (== ' ') s
Now can tell if a repo uses gcrypt or not, and whether it's decryptable
with the current gpg keys.
This closes the hole that undecryptable gcrypt repos could have before been
combined into the repo in encrypted mode.
When adding a removable drive, it's now detected if the drive contains
a gcrypt special remote, and that's all handled nicely. This includes
fetching the git-annex branch from the gcrypt repo in order to find
out how to set up the special remote.
Note that gcrypt repos that are not git-annex special remotes are not
supported. It will attempt to detect such a gcrypt repo and refuse
to use it. (But this is hard to do any may fail; see
https://github.com/blake2-ppc/git-remote-gcrypt/issues/6)
The problem with supporting regular gcrypt repos is that we don't know
what the gcrypt.participants setting is intended to be for the repo.
So even if we can decrypt it, if we push changes to it they might not be
visible to other participants.
Anyway, encrypted sneakernet (or mailnet) is now fully possible with the
git-annex assistant! Assuming that the gpg key distribution is handled
somehow, which the assistant doesn't yet help with.
This commit was sponsored by Navishkar Rao.
To support this, a core.gcrypt-id is stored by git-annex inside the git
config of a local gcrypt repository, when setting it up.
That is compared with the remote's cached gcrypt-id. When different, a
drive has been changed. git-annex then looks up the remote config for
the uuid mapped from the core.gcrypt-id, and tweaks the configuration
appropriately. When there is no known config for the uuid, it will refuse to
use the remote.
Use rsync for gcrypt remotes that are not local to the disk.
(Note that I have punted on supporting http transport for now, it doesn't
seem likely to be very useful.)
This was mostly quite easy, it just uses the rsync special remote to handle
the transfers. The git repository url is converted to a RsyncOptions
structure, which required parsing it separately, since the rsync special
remote only supports rsync urls, which use a different format.
Note that annexed objects are now stored at the top of the gcrypt repo,
rather than inside annex/objects. This simplified the rsync suport,
since it doesn't have to arrange to create that directory. And git-annex
is not going to be run directly within gcrypt repos -- or if in some
strance scenario it was, it would make sense for it to not see the
encrypted objects.
This commit was sponsored by Sheila Miguez
This is a git-remote-gcrypt encrypted special remote. Only sending files
in to the remote works, and only for local repositories.
Most of the work so far has involved making initremote work. A particular
problem is that remote setup in this case needs to generate its own uuid,
derivied from the gcrypt-id. That required some larger changes in the code
to support.
For ssh remotes, this will probably just reuse Remote.Rsync's code, so
should be easy enough. And for downloading from a web remote, I will need
to factor out the part of Remote.Git that does that.
One particular thing that will need work is supporting hot-swapping a local
gcrypt remote. I think it needs to store the gcrypt-id in the git config of the
local remote, so that it can check it every time, and compare with the
cached annex-uuid for the remote. If there is a mismatch, it can change
both the cached annex-uuid and the gcrypt-id. That should work, and I laid
some groundwork for it by already reading the remote's config when it's
local. (Also needed for other reasons.)
This commit was sponsored by Daniel Callahan.
Cipher is now a datatype
data Cipher = Cipher String | MacOnlyCipher String
which makes more precise its interpretation MAC-only vs. MAC + used to
derive a key for symmetric crypto.
With the initremote parameters "encryption=pubkey keyid=788A3F4C".
/!\ Adding or removing a key has NO effect on files that have already
been copied to the remote. Hence using keyid+= and keyid-= with such
remotes should be used with care, and make little sense unless the point
is to replace a (sub-)key by another. /!\
Also, a test case has been added to ensure that the cipher and file
contents are encrypted as specified by the chosen encryption scheme.
/!\ It is to be noted that revoking a key does NOT necessarily prevent
the owner of its private part from accessing data on the remote /!\
The only sound use of `keyid-=` is probably to replace a (sub-)key by
another, where the private part of both is owned by the same
person/entity:
git annex enableremote myremote keyid-=2512E3C7 keyid+=788A3F4C
Reference: http://git-annex.branchable.com/bugs/Using_a_revoked_GPG_key/
* Other change introduced by this patch:
New keys now need to be added with option `keyid+=`, and the scheme
specified (upon initremote only) with `encryption=`. The motivation for
this change is to open for new schemes, e.g., strict asymmetric
encryption.
git annex initremote myremote encryption=hybrid keyid=2512E3C7
git annex enableremote myremote keyid+=788A3F4C
When quvi is installed, git-annex addurl automatically uses it to detect
when an page is a video, and downloads the video file.
web special remote: Also support using quvi, for getting files,
or checking if files exist in the web.
This commit was sponsored by Mark Hepburn. Thanks!
I thought at first this was a Windows specific problem, but it's not;
this affects checking any non-bare repository exported via http. Which is
a potentially important use case!
The actual bug was the case where Right False was returned by the first url
short-curcuited later checks. But the whole method used felt like code
I'd no longer write, and the use of undefined was particularly disgusting.
So I rewrote it.
Also added an action display.
This commit was sponsored by Eric Hanchrow. Thanks!
annexLocations uses OS-native directory separators, but for an url,
it needs to use / even on Windows.
This is an ugly workaround. Could parameterize a lot of stuff in
annexLocations to fix it better. I suspect this is probably the only place
it's needed though.
The checkpresent hook can return either True or, False, or fail with a message
if it cannot successfully check the remote. Currently for glacier, when
--trust-glacier is not set, it always returns False. Crucially, in the case
when a file is in glacier, this is telling git-annex it's not there, so copy
re-uploads it. This is not desirable; it breaks using glacier-cli to retreive
that file later, and it wastes money/bandwidth.
What if it instead, when the glacier inventory is missing a
file, it returns False. And when the glacier inventory has a file, unless
--trust-glacier is set, it *fails*.
The result would be:
* `git annex copy --to glacier` would only send things not listed in inventory. If a file is listed in the inventory, `copy`
would complain that --trust-glacier` is not set, and not re-upload the file.
* `git annex drop` would only trust that glacier has a file when --trust-glacier is set. Behavior unchanged.
* `git annex move --to glacier`, when the file is not listed in inventory, would send the file, and delete it locally. Behavior unchanged.
* `git annex move --to glacier`, when the file is listed in inventory, would only trust that glacier has the file when --trust-glacier is set
* `git annex copy --from glacier` / `git annex get`, when the file is located in glacier, would trust the location log, and attempt to get the file from glacier.
