streamclone: extract requirements formatting It will be reused for the formatting of the requirements of the stream v2 part requirement and later for the stream v2 requirements. Differential Revision: https://phab.mercurial-scm.org/D1949

bookmarks: fix pushkey compatibility mode (issue5777) The namespace used for the compatibility mode was missing a trailing 's'.

lazymanifest: avoid reading uninitialized memory I got errors running tests with clang UBSAN [1] enabled. One of them is: ``` --- test-dirstate.t +++ test-dirstate.t.err @@ -85,9 +85,115 @@ $ echo "[extensions]" >> .hg/hgrc $ echo "dirstateex=../dirstateexception.py" >> .hg/hgrc $ hg up 0 - abort: simulated error while recording dirstateupdates - [255] + mercurial/cext/manifest.c:781:13: runtime error: load of value 190, which is not a valid value for type 'bool' + #0 0x7f668a8cf748 in lazymanifest_diff mercurial/cext/manifest.c:781 + #1 0x7f6692fc1dc4 in call_function Python-2.7.11/Python/ceval.c:4350 + ....... + SUMMARY: UndefinedBehaviorSanitizer: invalid-bool-load mercurial/cext/manifest.c:781:13 in + [1] $ hg log -r . -T '{rev}\n' 1 $ hg status - ? a ``` While the code is not technically wrong, but switching the condition would make clang UBSAN happy. So let's do it. The uninitialized memory could come from, for example, `lazymanifest_copy` allocates `self->maxlines` items but only writes the first `self->lines` items. [1]: https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html Test Plan: Run `test-dirstate.t` with UBSAN and it no longer reports the issue. Differential Revision: https://phab.mercurial-scm.org/D1948

unamend: fix command summary line Before this patch, the docstring started with a newline, which led the summary line (shown in e.g. `hg help -c`) to be blank. Differential Revision: https://phab.mercurial-scm.org/D1943

configitems: traverse sections deterministically Otherwise output can be non-deterministic if there are warnings for multiple sections. Differential Revision: https://phab.mercurial-scm.org/D1947

lfs: don't require the .hglfs file to be tracked to control the policy The .hgignore file doesn't need to be tracked, nor does the git equivalent of this file. I'm still a little concerned about the effects of forgetting to commit this file. But the fact that conversions maintain the hashes if only the normal vs external storage changes, should make this less risky.

tests: add a pattern to fix --pure tests Test Plan: ran all tests with and without --pure, everything passed on gcc112. Differential Revision: https://phab.mercurial-scm.org/D1946

streamclone: add a comment about non-publishing being broken with v1 This change was suggested by Gregory Szorc.

streamclone: move requirement update into consumev2 This change was suggested by Gregory Szorc.

streamclone: use readexactly when reading stream v2 Yuya Nishihara pointed out that it is safer.

streamclone: rename '_emit' to '_emit2' for clarity This change was suggested by Gregory Szorc.

help: do not suggest "update --clean ." to cancel uncommitted merge Follows up 41ef02ba329b.

minifileset: note the unsupported file pattern when raising a parse error This was useful in debugging, because I stupidly quoted it out of habit from the command line. This isn't a great example that clearly shows the problem, but I don't know how to improve it. The problem *is* obvious once a complex statement or a clearly bogus string is used.

lfs: don't automatically exclude '.hg*' files from external tracking The only reasons I did this in the first place was because tracking externally seems like it would always be a mistake, and the eol extension does the same thing. Yuya and Jun thought it might be better to not do this[1], so I'll defer to them on this. If a problem with say, .hgtags or .hgeol does arise, it can be added back without breaking existing repos. [1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2018-January/110371.html

lfs: rename {oid} to {lfsoid} Per Yuya, for consistency with {lfspointer}. It might be slightly confusing for there to be {lfsoid} and {lfspointer.oid}. But preventing ambiguity seems more important, and the latter is controlled by the git-lfs spec.

lfs: rename {pointer} to {lfspointer} Per Martin von Zweigbergk's suggestion to keep this unambiguous, for when it is migrated to {files} and friends.

Added signature for changeset 27b6df1b5adb

Added tag 4.5-rc for changeset 27b6df1b5adb

merge with stable to begin 4.5 freeze # no-check-commit because it's a clean merge

bundle2: increase payload part chunk size to 32kb Bundle2 payload parts are framed chunks. Esentially, we obtain data in equal size chunks of size `preferedchunksize` and emit those to a generator. That generator is fed into a compressor (which can be the no-op compressor, which just re-emits the generator). And the output from the compressor likely goes to a file descriptor or socket. What this means is that small chunk sizes create more Python objects and Python function calls than larger chunk sizes. And as we know, Python object and function call overhead in performance sensitive code matters (at least with CPython). This commit increases the bundle2 part payload chunk size from 4k to 32k. Practically speaking, this means that the chunks we feed into a compressor (implemented in C code) or feed directly into a file handle or socket write() are larger. It's possible the chunks might be larger than what the receiver can handle in one logical operation. But at that point, we're in C code, which is much more efficient at dealing with splitting up the chunk and making multiple function calls than Python is. A downside to larger chunks is that the receiver has to wait for that much data to arrive (either raw or from a decompressor) before it can process the chunk. But 32kb still feels like a small buffer to have to wait for. And in many cases, the client will convert from 8 read(4096) to 1 read(32768). That's happening in Python land. So we cut down on the number of Python objects and function calls, making the client faster as well. I don't think there are any significant concerns to increasing the payload chunk size to 32kb. The impact of this change on performance significant. Using `curl` to obtain a stream clone bundle2 payload from a server on localhost serving the mozilla-unified repository: before: 20.78 user; 7.71 system; 80.5 MB/s after: 13.90 user; 3.51 system; 132 MB/s legacy: 9.72 user; 8.16 system; 132 MB/s bundle2 stream clone generation is still more resource intensive than legacy stream clone (that's likely because of the use of a util.chunkbuffer). But the throughput is the same. We might be in territory we're this is effectively a benchmark of the networking stack or Python's syscall throughput. From the client perspective, `hg clone -U --stream`: before: 33.50 user; 7.95 system; 53.3 MB/s after: 22.82 user; 7.33 system; 72.7 MB/s legacy: 29.96 user; 7.94 system; 58.0 MB/s And for `hg clone --stream` with a working directory update of ~230k files: after: 119.55 user; 26.47 system; 0:57.08 wall legacy: 126.98 user; 26.94 system; 1:05.56 wall So, it appears that bundle2's stream clone is now definitively faster than legacy stream clone! Differential Revision: https://phab.mercurial-scm.org/D1932

bundle2: always advertise client support for stream parts Previously, enabling of stream clone over bundle2 was a server-side only change. And clients would only advertise bundle2 support for stream clones if an experimental config option was set. This situation wasn't forward compatible because in the future (when the feature is enabled on servers by default), an old client would send a request to the server but it wouldn't send its own bundle2 capability support for stream parts. Servers would have to infer that clients not sending this capability were old Mercurial clients that only sent the capability if the feature was explicitly enabled. Implicit and inferred behavior makes implementing servers hard. It's much better to be explicit about client features. We should either make the config option for bundle2 stream clones disable the feature client-side as well (so a server doesn't see a request from a client not advertising stream support). Or we should always advertise stream support if a client is willing to accept stream parts. Since I anticipating stabilizing stream clone support in bundle2 quickly, I think it's safe to always advertise client support in the bundle2 capabilities. So this commit changes things to do that. Because capabilities now vary between client and server, we had to create variations of the variable substitutions for those strings. Differential Revision: https://phab.mercurial-scm.org/D1931

exchange: don't send stream data when server.uncompressed is set Previously, bundle2 stream support would send out data even though the streaming clone feature was disabled. This commit changes the part handler to respect the server config. Differential Revision: https://phab.mercurial-scm.org/D1930

bundle2: don't advertise stream bundle2 capability when feature disabled The server.uncompressed config option can be used to disable streaming clones. While the top-level capability to advertise streaming clone support isn't advertised when this option is set, we were still sending the bundle2-level capabilities advertising support for stream parts. It makes sense to not advertise that support when streaming clones are globally disabled. If the structure of the new code seems a bit odd, it is because we'll have to further tweak the behavior in commit(s) ahead. Differential Revision: https://phab.mercurial-scm.org/D1929

tests: add more testing around server.uncompressed We already have testing for server.uncompressed in test-http*.t. However, it doesn't cover the new bundle2 use case. And, we don't have comprehensive testing of advertised capabilities. We add tests to test-clone-uncompressed.t that demonstrate behavior for both legacy and bundle2 configurations. If you look closely, the bundle2 capabilities are advertising stream support when it isn't enabled. That's a bug. In addition, while the client is smart enough to not request a stream clone when the server doesn't have the feature enabled, the getbundle wire protocol command is still sending stream clone data. This doesn't match the behavior of the legacy stream_out wire protocol command. That's also a bug. Tests have been added. While I was here, I also changed how the PID is recorded in $DAEMON_PIDS. If we kill a process, the PID formerly in $DAEMON_PIDS no longer exists. So we should replace that file instead of appending to it. Differential Revision: https://phab.mercurial-scm.org/D1928

bundle2: move version of stream clone into part name I don't like having version numbers as part parameters. It means that parts can theoretically vary wildly in their generation and processing semantics. I think that a named part should have consistent behavior over time. In other words, if you need to introduce new functionality or behavior, that should be expressed by inventing a new bundle2 part, not adding functionality to an existing part. This commit applies this advice to the just-introduced stream clone via bundle2 feature. The "version" part parameter is removed. The name of the bundle2 part is now "stream2" instead of "stream" with "version=v2". Differential Revision: https://phab.mercurial-scm.org/D1927

exchange: send bundle2 stream clones uncompressed Stream clones don't compress well. And compression undermines a point of stream clones which is to trade significant CPU reductions by increasing size. Building upon our introduction of metadata to communicate bundle information back to callers of exchange.getbundlechunks(), we add an attribute to the bundler that communicates whether the bundle is best left uncompressed. We return this attribute as part of the bundle metadata. And the wire protocol honors it when determining whether to compress the wire protocol response. The added test demonstrates that the raw result from the wire protocol is not compressed. It also demonstrates that the server will serve stream responses when the feature isn't enabled. We'll address that in another commit. The effect of this change is that server-side CPU usage for bundle2 stream clones is significantly reduced by removing zstd compression. For the mozilla-unified repository: before: 37.69 user 8.01 system after: 27.38 user 7.34 system Assuming things are CPU bound, that ~10s reduction would translate to faster clones on the client. zstd can decompress at >1 GB/s. So the overhead from decompression on the client is small in the grand scheme of things. But if zlib compression were being used, the overhead would be much greater. Differential Revision: https://phab.mercurial-scm.org/D1926

tests: update test to work with Git 2.16 It looks like Git 2.16 removed the "..." from some strings. Glob over those characters in the test output. Differential Revision: https://phab.mercurial-scm.org/D1935

exchange: return bundle info from getbundlechunks() (API) We generally want a mechanism to pass information about the generated bundle back to callers (in addition to the byte stream). Ideally we would return a bundler from this function and have the caller code to an interface. But the bundling APIs are not great and getbundlechunks() is the best API we have for obtaining bundle contents in a unified manner. We change getbundlechunks() to return a dict that we can use to communicate metadata. We populate that dict with the bundle version number to demonstrate some value. .. api:: exchange.getbundlechunks() now returns a 2-tuple instead of just an iterator. Differential Revision: https://phab.mercurial-scm.org/D1925

exchange: make stream bundle part deterministic repo.requirements is a set. We need to sort it so the part content is deterministic. Differential Revision: https://phab.mercurial-scm.org/D1924

bundle2: specify what capabilities will be used for We currently assume there is a symmetric relationship of bundle2 capabilities between client and server. However, this may not always be the case. We need a bundle2 capability to advertise bundle2 streaming clone support on servers to differentiate it from the existing, legacy streaming clone support. However, servers may wish to disable streaming clone support. If bundle2 capabilities were the same between client and server, a client (which may also be a server) that has disabled streaming clone support would not be able to perform a streaming clone itself! This commit introduces a "role" argument to bundle2.getrepocaps() that explicitly defines the role being performed. This will allow us (and extensions) to alter bundle2 capabilities depending on the operation being performed. Differential Revision: https://phab.mercurial-scm.org/D1923

wireproto: don't compress errors from getbundle() Errors should be small. There's no real need to compress them. Truth be told, there's no good reason to not compress them either. But leaving them uncompressed makes it easier to test failures by looking at the raw HTTP response. This makes it easier for us to write tests. It may make it easier for people writing their own clients. Differential Revision: https://phab.mercurial-scm.org/D1922

tests: teach get-with-headers.py some new tricks We add the ability to specify arbitrary HTTP request headers and to save the HTTP response body to a file. These will be used in upcoming commits. Differential Revision: https://phab.mercurial-scm.org/D1921

tests: use argparse in get-with-headers.py I'm about to add another flag and I don't want to deal with this organic, artisanal argument parser. Differential Revision: https://phab.mercurial-scm.org/D1920

convert: use a collections.deque This function was doing a list.pop(0) on a list whose length was the number of revisions to convert. Popping an early element from long lists is not an efficient operation. collections.deque supports efficient inserts and pops at both ends. So we switch to that data structure. When converting the mozilla-unified repository, which has 445,748 revisions, this change makes the "sorting..." step of `hg convert --sourcesort` significantly faster: before: ~59.2s after: ~1.3s Differential Revision: https://phab.mercurial-scm.org/D1934

repair: invalidate volatile sets after stripping Matt Harbison reported that some tests were broken on Windows after 1a09dad8b85a (evolution: report new unstable changesets, 2018-01-14). The failures were exactly as seen in this patch. The failures actually seemed correct, which made me wonder why they didn't fail the same way on Linux. It turned out to be a cache invalidation problem. The new orphan mentioned in the test case actually does get created when we're re-applying the temporary bundle that's created while stripping. However, without the invalidation, it appears that there was already an orphan before applying the temporary bundle. The warnings about unknown working parent appear because the aformentioned changeset means that we're now accessing the dirstate while it's invalid. We may want to suppress these messages that happen in the intermediate strip state, but they're technically correct (although confusing to the user), so I think just fixing the cache invalidation is fine for now. I haven't figured out why the caches seemed to get correctly invalidated on Windows. Differential Revision: https://phab.mercurial-scm.org/D1933

subrepo: handle 'C:' style paths on the command line (issue5770) If you think 'C:' and 'C:\' are equivalent paths, see the inline comment before proceeding. The problem here was that several commands that take a URL argument (incoming, outgoing, pull, and push) will use that value to set 'repo._subtoppath' on the repository object after command specific manipulation of it, but before converting it to an absolute path. When an operation is performed on a relative subrepo, subrepo._abssource() will posixpath.join() this value with the relative subrepo path. That adds a '/' after the drive letter, changing how it is evaluated by abspath()/realpath() in vfsmod.vfs(..., realpath=True) as the subrepo is instantiated. I initially tried sanitizing the path in url.localpath(), because url.isabs() only checks that it starts with a drive letter. By the sample behavior, this is clearly not an absolute path. (Though the comment in isabs() is weasely- this style path can't be joined either.) But not everything funnels through there, and it required explicitly calling localpath() in hg.parseurl() and assigning to url.path to fix. But then tests failed with urls like 'a#0'. Next up was sanitizing the path in the url constructor. That caused doctest failures, because there are drive letter tests, so those got expanded in system specific ways. Yuya correctly pointed out that util.url is a parser, and shouldn't be substituting the path too. Rather than fixing every command call site, just convert it in the common subrepo location. I don't see any sanitizing on the path config options, so I fixed those too. Note that while the behavior is fixed here, there are still places where 'comparing with C:' gets printed out, and that's not great for debugging purposes. (Specifically I saw it in `hg incoming -B C:`, without subrepos.) While clone will write out an absolute default path, I wonder what would happen if a user edited that path to be 'C:'. (I don't think supporting relative paths in .hgrc is a sane thing to do, but while we're poking holes in things...) Since this is such an oddball case, it still leaks through in places, and there seems to be a lot of duplicate url parsing, maybe the url parsing should be moved to dispatch, and provide the command with a url object? Then we could convert this to an absolute path once, and not have to worry about it in the rest of the code. I also checked '--cwd C:' on the command line, and it was previously working because os.chdir() will DTRT. Finally, one other note from the url.localpath() experimenting. I don't see any cases where 'self._hostport' can hold a drive letter. So I'm wondering if that is wrong/old code.

dummysmtpd: don't die on client connection errors The connection refused error in test-patchbomb-tls.t[1] is sporadic, but one of the more often seen errors on Windows. I added enough logging to a file and dumped it out at the end to make the following observations: - The listening socket is successfully created and bound to the port, and the "listening at..." message is always logged. - Generally, the following is the entire log output, with the "accepted ..." message having been added after `sslutil.wrapserversocket`: listening at localhost:$HGPORT $LOCALIP ssl error accepted connect accepted connect $LOCALIP from=quux to=foo, bar $LOCALIP ssl error - In the cases that fail, asyncore.loop() in the run() method is exiting, but not with an exception. - In the cases that fail, the following is logged right after "listening ...": Traceback (most recent call last): File "c:\\Python27\\lib\\asyncore.py", line 83, in read obj.handle_read_event() File "c:\\Python27\\lib\\asyncore.py", line 443, in handle_read_event self.handle_accept() File "../tests/dummysmtpd.py", line 80, in handle_accept conn = sslutil.wrapserversocket(conn, ui, certfile=self._certfile) File "..\\mercurial\\sslutil.py", line 570, in wrapserversocket return sslcontext.wrap_socket(sock, server_side=True) File "c:\\Python27\\lib\\ssl.py", line 363, in wrap_socket _context=self) File "c:\\Python27\\lib\\ssl.py", line 611, in __init__ self.do_handshake() File "c:\\Python27\\lib\\ssl.py", line 840, in do_handshake self._sslobj.do_handshake() error: [Errno 10054] $ECONNRESET$ - If the base class handler is overridden completely, the the first "ssl error" line is replaced by the stacktrace, but the other lines are unchanged. The client behaves no differently, whether or not the server stacktraced. In general, `./run-tests.py --local -j9 -t9000 test-patchbomb-tls.t --runs-per-test 20` would show the issue after a run or two. With this change, `./run-tests.py --local -j9 -t9000 test-patchbomb-tls.t --loop` ran 800 times without a hiccup. This makes me wonder if the other connection refused messages that bubble up on occasion are caused by a similar issue. It seems a bit drastic to kill the whole server on account of a single communication failure with a client. # no-check-commit because of handle_error() [1] https://buildbot.mercurial-scm.org/builders/Win7%20x86_64%20hg%20tests/builds/421/steps/run-tests.py%20%28python%202.7.13%29/logs/stdio

cext: define MIN macro only if it is not yet defined MIN macro is defined in <sys/param.h> on macOS Sierra. Therefore as HAVE_BSD_STATFS is defined in osutil.c, 'MIN' macro redefined warning is emitted.

copyright: update to 2018 January seems to be a good month to do this.

tests: glob copyright years in test-extension.t Other tests already do this.

test-sshserver: stabilize for Windows

test-branch-change: stabilize for Windows

test-sparse: make the '.hg' exclusion filter Windows compatible

lfs: rename {lfsattrs} to {pointer} This seems more descriptive.

lfs: expand the user facing documentation

streamclone: also stream caches to the client When stream clone is used over bundle2, relevant cache files are also streamed. This is expected to be a massive performance win for clone since no important cache will have to be recomputed. Some performance numbers: (All times are wall-clock times in seconds, 2 attempts per case.) # Mozilla-Central ## Clone over ssh over lan V1 streaming: 234.3 239.6 V2 streaming: 248.4 243.7 ## Clone over ssh over Internet V1 streaming: 175.5 110.9 V2 streaming: 109.1 111.0 ## Clone over HTTP over lan V1 streaming: 105.3 105.6 V2 streaming: 112.7 111.4 ## Clone over HTTP over internet V1 streaming: 105.6 114.6 V2 streaming: 226.7 225.9 ## Hg tags V1 streaming (no cache): 1.084 1.071 V2 streaming (cache): 0.312 0.325 ## Hg branches V1 streaming (no cache): 14.047 14.148 V2 streaming (with cache): 0.312 0.333 # Pypy ## Clone over ssh over internet V1 streaming: 29.4 30.1 V2 streaming: 31.2 30.1 ## Clone over http over internet V1 streaming: 29.7 29.7 V2 streaming: 75.2 72.9 (since ssh and lan are not affected, there seems to be an issue with how we read/write the http stream on connection with latency, unrelated to the format) ## Hg tags V1 streaming (no cache): 1.752 1.664 V2 streaming (with cache): 0.274 0.260 ## Hg branches V1 streaming (no cache): 4.469 4.728 V2 streaming (with cache): 0.318 0.321 # Private repository: * 500K revision revisions * 11K topological heads * 28K branch heads ## hg tags no cache: 1543.332 with cache: 4.900 ## hg branches no cache: 91.828 with cache: 2.955

caches: make 'cachetocopy' available in scmutil For more code to use this information, we need it to be more publicly available.

streamclone: add support for cloning non append-only file The phaseroots are stored in a non append-only file in the repository. We include them in the stream too. Since they are not append-only, we have to keep a copy around while we hold the lock to be able to stream them later. Since phase get exchanged within the stream we can skip requesting them independently. As a side effect, this will fixes issue5648 once the feature is enabled by default.

streamclone: tests phase exchange during stream clone We add a test dedicated to phases. As reported in issue 5648 stream from a non publishing server is currently broken (does not preserve the phase). We'll fix it with 'v2' support in the next changesets.

streamclone: add support for bundle2 based stream clone The feature put to use the various bits introduced previously. If the server supports it, the client will request its stream clone through bundle2 instead of the legacy 'stream_out' commands. The bundle2 version use the better 'v2' version of stream bundles. The 'v2' format is not finalized yet. Now that there are some code running it, we can start working on it again. Performance numbers are available at the end of this series.

pull: preindent some code Next changesets will add support for using stream cloning with bundle2. We introduce indentation change first for clarity.

pull: reorganize bundle2 argument bundling We are about to add the ability to use stream bundle with bundle2. Before doing so, we need to gather some code that will not be used in the bundle2 case. There is no behavior change within this changeset.

clone: allow bundle2's stream clone with 'server.disablefullbundle' The previous check was a bit too strict and would not recognize a get bundle not requesting changegroup.

bundle2: add support for a 'stream' parameter to 'getbundle' This parameter can be used to request a stream bundle.

bundle2: add a 'stream' part handler for stream cloning The part contains the necessary arguments and payload to handle a stream bundle v2. It will be put to use in later changesets.

streamclone: rework canperformstreamclone There is code about bundle2 laying around in `canperformstreamclone` but not put to any uses. As we discovered with the previous patch, streambundle 'v1' won't work on bundle2 because they are readline based. So we jump to 'v2' as the first expected supported version.

streamclone: define first iteration of version 2 of stream format (This patch is based on a first draft from Gregory Szorc, with deeper rework) Version 1 of the stream clone format was invented many years ago and suffers from a few deficiencies: 1) Filenames are stored in store-encoded (on filesystem) form rather than in their internal form. This makes future compatibility with new store filename encodings more difficult. 2) File entry "headers" consist of a newline of the file name followed by the string file size. Converting strings to integers is avoidable overhead. We can't store filenames with newlines (manifests have this limitation as well, so it isn't a major concern). But the big concern here is the necessity for readline(). Scanning for newlines means reading ahead and that means extra buffer allocations and slicing (in Python) and this makes performance suffer. 3) Filenames aren't compressed optimally. Filenames should be compressed well since there is a lot of repeated data. However, since they are scattered all over the stream (with revlog data in between), they typically fall outside the window size of the compressor and don't compress. 4) It can only exchange stored based content, being able to exchange caches too would be nice. 5) It is limited to a stream-based protocol and isn't suitable for an on-disk format for general repository reading because the offset of individual file entries requires scanning the entire file to find file records. As part of enabling streaming clones to work in bundle2, #2 proved to have a significant negative impact on performance. Since bundle2 provides the opportunity to start fresh, Gregory Szorc figured he would take the opportunity to invent a new streaming clone data format. The new format devised in this series addresses #1, #2, and #4. It punts on #3 because it was complex without yielding a significant gain and on #5 because devising a new store format that "packs" multiple revlogs into a single "packed revlog" is massive scope bloat. However, this v2 format might be suitable for streaming into a "packed revlog" with minimal processing. If it works, great. If not, we can always invent stream format when it is needed. This patch only introduces the bases of the format. We'll get it usable through bundle2 first, then we'll extend the format in future patches to bring it to its full potential (especially #4).

util: implement varint functions This will be useful in an incoming version-2 of the stream format.

util: move 'readexactly' in the util module This function is used in multiple place, having it in util would be better. (existing caller will be migrated in another series)

lfs: separate a debug message from the subsequent abort message