11701 Commits

Author SHA1 Message Date
Mark Vitale
5076dfc14b LINUX: consolidate duplicate code in osi_TryEvictDentries
The two stanzas for HAVE_DCACHE_LOCK are now functionally identical;
remove the preprocessor conditionals and duplicate code.

Minor functional change is incurrred for very old (before 2.6.38) Linux
versions that have dcache_lock; we are now obtaining the d_lock as well.

This is safe because d_lock is also quite old (pre-git, 2.6.12), and it
is a spinlock that's only held for checking d_unhashed.  Therefore, it
should have negligible performance impact.  It cannot cause deadlocks or
violate locking order, because spinlocks can't be held across sleeps.

Change-Id: I08faf204e6bd82c4401cdf6048d12cd551dd18fc
Reviewed-on: https://gerrit.openafs.org/12792
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Andrew Deason <adeason@dson.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2018-01-01 22:05:09 -05:00
Mark Vitale
0678ad26b6 LINUX: consolidate duplicate code in canonical_dentry
The two stanzas for HAVE_DCACHE_LOCK are now identical;
remove the preprocessor conditionals and duplicate code.

No functional change should be incurred by this commit.

Change-Id: I15cd4631d1932dcfb920313acb82fcbe570087e8
Reviewed-on: https://gerrit.openafs.org/12791
Reviewed-by: Andrew Deason <adeason@dson.org>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2018-01-01 21:06:07 -05:00
Mark Vitale
652cd597d9 LINUX: add afs_d_alias_lock & _unlock compat wrappers
Simplify some #ifdefs for HAVE_DCACHE_LOCK by pushing them down into
new helpers in osi_compat.h.

No functional change should be incurred by this commit.

Change-Id: Ia0dc560bc84c8db4b84ddcc77a17bab5fbf93af9
Reviewed-on: https://gerrit.openafs.org/12790
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2018-01-01 18:39:54 -05:00
Mark Vitale
74f4bfc627 LINUX: create afs_linux_dget() compat wrapper
For dentry operations that cover multiple dentry aliases of
a single inode, create a compatibility wrapper to hide differences
between the older dget_locked() and the current dget().

No functional change should be incurred by this commit.

Change-Id: I2bb0d453417f37707018f6ba5859903c3d34c8ff
Reviewed-on: https://gerrit.openafs.org/12789
Reviewed-by: Andrew Deason <adeason@dson.org>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2018-01-01 17:42:57 -05:00
Mark Vitale
367693bd7d Revert "LINUX: do not use d_invalidate to evict dentries"
Linux recently changed the semantics of d_invalidate() to:
- return void
- invalidate even a current working directory

OpenAFS commit c3bbf0b4444db88192eea4580ac9e9ca3de0d286 switched libafs
to use d_prune_aliases() instead.

However, since that commit, several things have happened:
- RHEL 7.4 changed the semantics of d_invalidate() such that it
  invalidates the cwd, but did NOT change the return type to void.
  This broke our autoconf test for detecting the new semantics.
- Further research reveals that d_prune_aliases() was not the best
  choice for replacing d_invalidate().  This is because for directories,
  d_prune_aliases() doesn't invalidate dentries when they are referenced
  by its children, and it doesn't walk the tree trying to invalidate
  child dentries.  So it can leave dentries dangling, if the only
  references to thos dentries are via children.

In preparation for future commits, revert
c3bbf0b4444db88192eea4580ac9e9ca3de0d286 .

Change-Id: Iafbef23a6070180c0e21eb01a2d59385ef52f55c
Reviewed-on: https://gerrit.openafs.org/12788
Reviewed-by: Andrew Deason <adeason@dson.org>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2018-01-01 16:53:32 -05:00
Mark Vitale
f8247078bd Revert "LINUX: eliminate unused variable warning"
This reverts commit 19599b5ef5f7dff2741e13974692fe4a84721b59
to allow also reverting commit
c3bbf0b4444db88192eea4580ac9e9ca3de0d286 .

Change-Id: I2780fe68d352f0f1def198f21127ec944d1d2c1d
Reviewed-on: https://gerrit.openafs.org/12787
Reviewed-by: Andrew Deason <adeason@dson.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2018-01-01 16:02:34 -05:00
Stephan Wiesand
fb1f14d8ee Linux 4.15: check for 2nd argument to pagevec_init
Linux 4.15 removes the distinction between "hot" and "cold" cache
pages, and pagevec_init() no longer takes a "cold" flag as the
second argument. Add a configure test and use it in osi_vnodeops.c .

Change-Id: Ia5287b409b2a811d2250c274579e6f15fd18fdbb
Reviewed-on: https://gerrit.openafs.org/12824
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Tested-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-12-22 23:22:17 -05:00
Stephan Wiesand
be5f5b2aff Linux: use plain page_cache_alloc
Linux 4.15 removes the distinction between "hot" and "cold" cache
pages, and no longer provides page_cache_alloc_cold(). Simply use
page_cache_alloc() instead, rather than adding yet another test.

Change-Id: I34e734223927030f7ff252acb61120366a808ad6
Reviewed-on: https://gerrit.openafs.org/12823
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Tested-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-12-22 23:17:13 -05:00
Pat Riehecky
443dd5367e redhat: separate debuginfo package for kmod rpm
Place the debuginfo for the kmod into its own rpm so that
it doesn't have to track against the userspace packages.

FIXES 132034

Change-Id: I60a753275d896a89c1f6896c653d78a4e1fe7e2c
Reviewed-on: https://gerrit.openafs.org/11867
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2017-12-20 11:28:31 -05:00
Christof Hanke
fd4eaebb60 Avoid gcc warning
When using the configure option --enable-checking with gcc 7.2.1,
the compilation fails with

vutil.c:860:20: error: ‘%s’ directive writing up to 255 bytes into \
a region of size 63 [-Werror=format-overflow=]

This can be seen in the logs of the openSUSE Tumbleweed builder
for e.g. build 2368.
Avoid this warning by using snprintf which is provided by libroken
for all platforms.

Change-Id: I6acd3a1c06760abc8144c0892812c3bb50477227
Reviewed-on: https://gerrit.openafs.org/12813
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2017-12-18 23:37:22 -05:00
Marcio Barbosa
6e57b22642 macos: make the OpenAFS client aware of APFS
Apple has introduced a new file system called APFS. Starting from High
Sierra, APFS replaces Mac OS Extended (HFS+) as the default file system
for solid-state drives and other flash storage devices.

The current OpenAFS client is not aware of APFS. As a result, the
installation of the current client into an APFS volume will panic the
machine.

To fix this problem, make the OpenAFS client aware of APFS.

Change-Id: Ib5ac88b87f348744864f4e33f1f222efbc852d41
Reviewed-on: https://gerrit.openafs.org/12743
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-12-18 16:57:20 -05:00
Marcio Barbosa
e533d07370 macos: packaging support for MacOS X 10.13
This commit introduces the new set of changes / files required to
successfully create the dmg installer on OS X 10.13 "High Sierra".

Change-Id: Id9da3cf959627a13d8cfd1d1d7412820e46ad63e
Reviewed-on: https://gerrit.openafs.org/12742
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-12-18 16:57:06 -05:00
Marcio Barbosa
804c9cbf50 macos: add support for MacOS 10.13
This commit introduces the new set of changes / files required to
successfully build the OpenAFS source code on OS X 10.13 "High Sierra".

Change-Id: I51928279d97c9d86c67db7de5eb7fc9d317fd381
Reviewed-on: https://gerrit.openafs.org/12741
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2017-12-17 15:31:31 -05:00
Benjamin Kaduk
edc5463f3d Fix macro used to check kernel_read() argument order
The m4 macro implementing the configure check is called
LINUX_KERNEL_READ_OFFSET_IS_LAST, but it defines a preprocessor symbol
that is just KERNEL_READ_OFFSET_IS_LAST.  Our code needs to check
for the latter being defined, not the former.

Reported by Aaron Ucko.

Change-Id: Id7cd3245b6a8eb05f83c03faee9c15bab8d0f6e8
Reviewed-on: https://gerrit.openafs.org/12808
Reviewed-by: Anders Kaseorg <andersk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-12-14 21:55:01 -05:00
Benjamin Kaduk
894555f93a OPENAFS-SA-2017-001: rx: Sanity-check received MTU and twind values
Rather than blindly trusting the values received in the
(unauthenticated) ack packet trailer, apply some minmial sanity checks
to received values.  natMTU and regular MTU values are subject to
Rx minmium/maximum packet sizes, and the transmit window cannot drop
below one without risk of deadlock.

The maxDgramPackets value that can also be present in the trailer
already has sufficient sanity checking.

Extremely low MTU values (less than 28 == RX_HEADER_SIZE) can cause us
to set a negative "maximum usable data" size that gets used as an
(unsigned) packet length for subsequent allocation and computation,
triggering an assertion when the connection is used to transmit data.

FIXES 134450

Change-Id: I37698ff166da47a57aa0d1962ae8effc74e30851
2017-12-05 08:25:44 -06:00
Benjamin Kaduk
4fa0ee620c afs: Fix bounds check in PNewCell
Reported by the opensuse buildbot:

  CC [M]  /home/buildbot/opensuse-tumbleweed-i386-builder/build/src/libafs/MODLOAD-4.13.12-1-default-MP/rx_packet.o
/home/buildbot/opensuse-tumbleweed-i386-builder/build/src/afs/afs_pioctl.c: In function ‘PNewCell’:
/home/buildbot/opensuse-tumbleweed-i386-builder/build/src/afs/afs_pioctl.c:3075:55: error: ‘*’ in boolean context, suggest ‘&&’ instead [-Werror=int-in-bool-context]
     if ((afs_pd_remaining(ain) < AFS_MAXCELLHOSTS +3) * sizeof(afs_int32))
         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~

The bug was introduced in commit 718f85a8b6.

Change-Id: Iae55a99e35266aa763fb431f2acc4eba09fa5357
Reviewed-on: https://gerrit.openafs.org/12782
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-11-28 10:15:37 -05:00
Benjamin Kaduk
66b74e78ba rx: fix call refcount leak in error case
The recent event handling normalization in commit
304d758983b499dc568d6ca57b6e92df24b69de8 had event handlers switch
to dropping their reference on the associated connection/call just
before return.  An early return case was missed in the conversion,
leading to a refcount leak in an error case.

Change-Id: Ie3d0bc9474fdbc09be9c753f4d0192c8cca68351
Reviewed-on: https://gerrit.openafs.org/12781
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-11-28 10:14:50 -05:00
Marcio Barbosa
3ce55426ee afs: fix kernel_write / kernel_read arguments
The order / content of the arguments passed to kernel_write and
kernel_read are not right. As a result, the kernel will panic if one of
the functions in question is called.

[kaduk@mit.edu: include configure check for multiple kernel_read()
variants, per linux commits bdd1d2d3d251c65b74ac4493e08db18971c09240
and e13ec939e96b13e664bb6cee361cc976a0ee621a]

FIXES 134440

Change-Id: I4753dee61f1b986bbe6a12b5568d1a8db30c65f8
Reviewed-on: https://gerrit.openafs.org/12769
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Tested-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-11-27 22:14:21 -05:00
Benjamin Kaduk
2ae84bf053 Sprinkle rx_GetConnection() for concision
Instead of inlining the body (taking the lock, incrementing the
refcount, and dropping the lock), use the convenience function
designed for this purpose.

Change-Id: I674d389e61e42710ef340e202992748e66c5e763
Reviewed-on: https://gerrit.openafs.org/12772
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-11-22 20:26:38 -05:00
Benjamin Kaduk
01bcfd3e14 rx: fix mutex leak in error case
Reported by Mark Vitale

Change-Id: I3269fbb0f87285bcb9af64f4ad81791177582e6d
Reviewed-on: https://gerrit.openafs.org/12771
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-11-22 20:22:30 -05:00
Benjamin Kaduk
a7a3108e60 Add event-related mutex assertions
In utility functions that access fields of type struct rxevent *,
assert that the appropriate lock is held for the access in question.

These assertions are only compiled in when built with -DOPR_DEBUG_LOCKS,
which can be enbled by --debug-locks at configure time.

Change-Id: I16885a4d37a0f094f0d365c54e8157ed92070c69
Reviewed-on: https://gerrit.openafs.org/12757
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-11-22 20:21:44 -05:00
Benjamin Kaduk
304d758983 Standardize rx_event usage
Go over all consumers of the rx event framework and normalize its usage
according to the following principles:

rxevent_Post() is used to create an event, and it returns an event
handle (with a reference on the event structure) that can be used
to cancel the event before its timeout fires.  (There is also an
additional reference on the event held by the global event tree.)
In all(*) usage within the tree, that event handle is stored within
either an rx_connection or an rx_call.  Reads/writes to the member variable
that holds the event handle require either the conn_data_lock or call
lock, respectively -- that means that in most cases, callers of
rxevent_Post() and rxevent_Cancel() will be holding one of those
aforementioned locks.  The event handlers themselves will need to
modify the call/connection object according to the nature of the
event, which requires holding those same locks, and also a guarantee
that the call/connection is still a live object and has not been
deallocated!  Whether or not rxevent_Cancel() succeeds in cancelling
the event before it fires, whenever passed a non-NULL event structure
it will NULL out the supplied pointer and drop a reference on the
event structure.  This is the correct behavior, since the caller
has asked to cancel the event and has no further use for the event
handle or its reference on the event structure.  The caller of
rxevent_Cancel() must check its return value to know whether or
not the event was cancelled before its handler was able to run.

The interaction window between the call/connection lock and the lock
protecting the red/black tree of pending events opens up a somewhat
problematic race window.  Because the application thread is expected
to hold the call/connection lock around rxevent_Cancel() (to protect
the write to the field in the call/connection structure that holds
an event handle), and rxevent_Cancel() must take the lock protecting
the red/black tree of events, this establishes a lock order with the
call/connection lock taken before the eventTree lock.  This is in
conflict with the event handler thread, which must take the eventTree
lock first, in order to select an event to run (and thus know what
additional lock would need to be taken, by virtue of what handler
function is to be run).  The conflict is easy to resolve in the
standard way, by having a local pointer to the event that is obtained
while the event is removed from the red/black tree under the eventTree
lock, and then the eventTree lock can be dropped and the event run
based on the local variable referring to it.  The race window occurs
when the caller of rxevent_Cancel() holds the call/connection lock,
and rxevent_Cancel() obtains the eventTree lock just after the event
handler thread drops it in order to run the event.  The event handler
function begins to execute, and immediately blocks trying to obtain
the call/connection lock.  Now that rxevent_Cancel() has the eventTree
lock it can proceed to search the tree, fail to find the indicated event
in the tree, clear out the event pointer from the call/connection
data structure, drop its caller's reference to the event structure,
and return failure (the event was not cancelled).  Only then does the
caller of rxevent_Cancel() drop the call/connection lock and allow
the event handler to make progress.

This race is not necessarily problematic if appropriate care is taken,
but in the previous code such was not the case.  In particular, it
is a common idiom for the firing event to call rxevent_Put() on itself,
to release the handle stored in the call/connection that could have
been used to cancel the event before it fired.  Failing to do so would
result in a memory leak of event structures; however, rxevent_Put() does
not check for a NULL argument, so a segfault (NULL dereference) was
observed in the test suite when the race occurred and the event handler
tried to rxevent_Put() the reference that had already been released by
the unsuccessful rxevent_Cancel() call.  Upon inspection, many (but not
all) of the uses in rx.c were susceptible to a similar race condition
and crash.

The test suite also papers over a related issue in that the event handler
in the test suite always knows that the data structure containing the
event handle will remain live, since it is a global array that is allocated
for the entire scope of the test.  In rx.c, events are associated with
calls and connections that have a finite lifetime, so we need to take care
to ensure that the call/connection pointer stored in the event remains
valid for the duration of the event's lifecycle.  In particular, even an
attempt to take the call/connection lock to check whether the corresponding
event field is NULL is fraught with risk, as it could crash if the lock
(and containing call/connection) has already been destroyed!  There are
several potential ways to ensure the liveness of the associated
call/connection while the event handler runs, most notably to take care
in the call/connection destruction path to ensure that all associated
events are either successfully cancelled or run to completion before
tearing down the call/connection structure, and to give the pending event
its own reference on the associated call/connection.  Here, we opt for
the latter, acknowledging that this may result in the event handler thread
doing the full call/connection teardown and delay the firing of subsequent
events.  This is deemed acceptable, as pending events are for intentionally
delayed tasks, and some extra delay is probably acceptable.  (The various
keepalive events and the challenge event could delay the user experience
and/or security properties if significantly delayed, but I do not believe
that this change admits completely unbounded delay in the event handler
thread, so the practical risk seems minimal.)

Accordingly, this commit attempts to ensure that:

* Each event holds a formal reference on its associated call/connection.
* The appropriate lock is held for all accesses to event pointers in
  call/connection structures.
* Each event handler (after taking the appropriate lock) checks whether
  it raced with rxevent_Cancel() and only drops the call/connection's
  reference to the event if the race did not occur.
* Each event handler drops its reference to the associated call/connection
  *after* doing any actions that might access/modify the call/connection.
* The per-event reference on the associated call/connection is dropped by
  the thread that removes the event from the red/black tree.  That is,
  the event handler function if the event runs, or by the caller of
  rxevent_Cancel() when the cancellation succeed.
* No non-NULL event handles remain in a call/connection being destroyed,
  which would indicate a refcounting error.

(*) There is an additional event used in practice, to reap old connections,
    but it is effectively a background task that reschedules itself
    periodically, with no handle to the event retained so as to be able
    to cancel it.  As such, it is unaffected by the concerns raised here.

While here, standardize on the rx_GetConnection() function for incrementing
the reference count on a connection object, instead of inlining the
corresponding mutex lock/unlock and variable access.

Also enable refcount checking unconditionally on unix, as this is a
rather invasive change late in the 1.8.0 release process and we want
to get as much sanity checking coverage as possible.

Change-Id: I27bcb932ec200ff20364fb1b83ea811221f9871c
Reviewed-on: https://gerrit.openafs.org/12756
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-11-22 20:17:40 -05:00
Michael Laß
311f1d28a2 gtx: link against libtinfo if termlib is seperated
If ncurses is built with "./configure --with-termlib=tinfo", gtx fails
to link because of an undefined reference to the LINES symbol which is
then provided by libtinfo.so and not libncurses.so.

If ncurses is present, additionally check whether LINES is provided by
ncurses or tinfo and set $LIB_curses accordingly.

This change is based on a patch provided by Bastian Beischer.

FIXES 134420

Change-Id: I3e29c61405d90d0b850bafe4c51125bef433452b
Reviewed-on: https://gerrit.openafs.org/12760
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-11-06 20:17:41 -05:00
Benjamin Kaduk
e0c5ada214 Correct m4 conditionals in curses.m4
AS_IF does not invoke the test(1) shell builtin for us, so we must
take care to consistently use it ourself.

While here, sprinkle some missing double-quotes around variable
expansions in AS_IF statements in this file.

Submitted by Bastian Beischer.

FIXES 134414

Change-Id: Iccfe311011f17de6317cf64abdc58b0812b81b8c
Reviewed-on: https://gerrit.openafs.org/12738
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Benjamin Kaduk <kaduk@mit.edu>
2017-10-16 19:26:36 -04:00
Damien Diederen
5ee516b378 Linux: Use kernel_read/kernel_write when __vfs variants are unavailable
We hide the uses of set_fs/get_fs behind a macro, as those functions
are likely to soon become unavailable:

> Christoph Hellwig suggested removing all calls outside of the core
> filesystem and architecture code; Andy Lutomirski went one step
> further and said they should all go.

    https://lwn.net/Articles/722267/

Change-Id: Ib668f8fdb62ca01fe14321c07bd14d218744d909
Reviewed-on: https://gerrit.openafs.org/12729
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-10-04 11:27:49 -04:00
Michael Meffie
a71288a387 redhat: avoid rpmbuild exclude directives
Older versions of rpmbuild do not support the files exclude directive,
so fall back to the old way in which we remove the files to be excluded
and list the files to be included.

Change-Id: If64df382ef372aa1078f1703a34942a1930bdc88
Reviewed-on: https://gerrit.openafs.org/12733
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-10-03 22:13:50 -04:00
Michael Meffie
4d247e1ae4 redhat: move .krb variants to the kauth-client subpackage
Move the deprecated klog.krb, pagsh.krb, and tokens.krb programs and man
pages to the optional openafs-kauth-client subpackage.

Change-Id: I09a2e36b60f9d47726a6a314a26db88e44575567
Reviewed-on: https://gerrit.openafs.org/12732
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-10-03 22:13:04 -04:00
Michael Meffie
671db4ca5a redhat: specify man pages without wildcards
Currently, some of the man pages are specified with the full name and
some are specified with a wildcard for the filename extension. Instead,
specify all the man pages without a wildcards to be more consistent and
to avoid putting incorrect man pages in packages.

This change removes a stray copy the klog.krb5.1 man page from
openafs-kauth-client subpackage and moves the AuthLog/AuthLog.dir man
pages to the optional openafs-kauth-server subpackage.

Change-Id: Id30a6174c532a9a00f850d6ca2722158293d5118
Reviewed-on: https://gerrit.openafs.org/12731
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-10-03 22:11:57 -04:00
Michael Meffie
a9810b829b redhat: remove afsd.fuse man page
The afsd.fuse binary is not currently packaged; do not package the man
page.

Change-Id: Ia0dd4fa72dc8a87e2c835798b6fbe1213d71da5f
Reviewed-on: https://gerrit.openafs.org/12730
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-10-03 22:09:40 -04:00
Marcio Barbosa
68ec78950a ubik: avoid DISK_Begin on sites that didn't vote for sync
As already described on 7c708506, SDISK_Begin fails on remotes if
lastYesState is not set. To fix this problem, 7c708506 does not allow
write transactions until we know that lastYesState is set on at least
quorum (ubik_syncSiteAdvertised == 1). In other words, if enough sites
received a beacon packet informing that a sync-site was elected, write
transactions will be allowed. This means that ubik_syncSiteAdvertised
can be true while lastYesState is not set in a few sites.

Consider the following scenario in a cell with frequent write
transactions:

Site A => Sync-site (up)
Site B => Remote 1 (up)
Site C => Remote 2 (down - unreachable)

Since A and B are up, we have quorum. After the second wave of beacons,
ubik_syncSiteAdvertised will be true and write transactions will be
allowed. At some point, C is not unreachable anymore. Site A sends a
copy of its database to C, but C did not vote for A yet (lastYesState ==
0). A new write transaction is initialized and, since lastYesState is
not set on C, DISK_Begin fails on this remote site and C is marked as
down. Since C is reachable, A will mark this remote site as up. The
sync-site will send its database to C, but C did not vote for A yet. A
new write transaction is initialized and, since lastYesState is not set
on C, DISK_Begin fails on this remote site and C is marked as down. In a
cell with frequent write transactions, this cycle will repeat forever.
As a result, the sync-site will be constantly sending its database to C
and quorum will be operating with less sites, increasing the chances
of re-elections.

To fix this problem, do not call DISK_Begin on remotes that did not
vote for the sync-site yet.

Change-Id: I27f5122a089064e7b83beba3533261d8a4e31c64
Reviewed-on: https://gerrit.openafs.org/12715
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-10-03 22:08:22 -04:00
Damien Diederen
929e77a886 Linux: Test for __vfs_write rather than __vfs_read
The following commit:

    commit eb031849d52e61d24ba54e9d27553189ff328174
    Author: Christoph Hellwig <hch@lst.de>
    Date:   Fri Sep 1 17:39:23 2017 +0200

        fs: unexport __vfs_read/__vfs_write

unexports both __vfs_read and __vfs_write, but keeps the former in
fs.h--as it is is still being used by another part of the tree.

This situation results in a false positive in our Autoconf check,
which does not see the export statements, and ends up marking the
corresponding API as available.

That, in turn, causes some code which assumes symmetry with
__vfs_write to fail to compile.

Switch to testing for __vfs_write, which correctly marks the API as
unavailable.

Change-Id: I392f2b17b4de7bd81d549c84e6f7b5ef05e1b999
Reviewed-on: https://gerrit.openafs.org/12728
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-10-02 20:10:47 -04:00
Anders Kaseorg
0a9a6b57ce vol: Fix two buffers being one char too short
Fixes these warnings:

namei_ops.c: In function 'namei_copy_on_write':
namei_ops.c:1328:31: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
  snprintf(path, sizeof(path), "%s-tmp", name.n_path);
                               ^~~~~~~~
namei_ops.c:1328:2: note: 'snprintf' output between 5 and 260 bytes into a destination of size 259
  snprintf(path, sizeof(path), "%s-tmp", name.n_path);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

vol_split.c: In function 'split_volume':
vol_split.c:576:22: warning: 'sprintf' may write a terminating nul past the end of the destination [-Wformat-overflow=]
     sprintf(symlink, "#%s", V_name(newvol));
                      ^~~~~
vol_split.c:576:5: note: 'sprintf' output between 2 and 33 bytes into a destination of size 32
     sprintf(symlink, "#%s", V_name(newvol));
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Change-Id: If212ebc29fa3fe10fe1e2f70dfb5f7509c269ae9
Reviewed-on: https://gerrit.openafs.org/12722
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2017-09-02 15:41:19 -04:00
Seth Forshee
962f4838dc Linux: Include linux/uaccess.h rather than asm/uaccess.h if present
Starting with Linux 4.12 there is a module build error on s390
due to asm/uaccess.h using a macro defined in the common header.
The common header has been around since 2.6.18 and has always
included asm/uaccess.h, so switch to using the common header
whenever it is present.

Change-Id: Iaab0d7652483a2a2b1f144f3e90b6d3b902c146d
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Reviewed-on: https://gerrit.openafs.org/12714
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2017-08-28 23:04:18 -04:00
Michael Meffie
e739eaa650 redhat: move bosserver and fssync-debug man pages
Move the bosserver and fssync-debug/dafssync-debug man pages to the
openafs-server package, which distributes those programs.

Change-Id: I9c84ad485834177fd43b28acd444d3d54c648cc8
Reviewed-on: https://gerrit.openafs.org/12601
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Benjamin Kaduk <kaduk@mit.edu>
2017-08-05 19:00:05 -04:00
Michael Meffie
5b79f95f74 redhat: kauth client and server sub-packages
Move the kaserver and kauth client programs to conditionally built
packages called openafs-kauth-server and openafs-kauth-client.
Packagers can build these by specifying '--with kauth'. They are not
built by default to discourage use.

This commit subsumes the openafs-kpasswd package into the
openafs-kauth-client package.

Change-Id: I1322f05d7fe11d466c9ed71a5059c21b759d95ab
Reviewed-on: https://gerrit.openafs.org/12600
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Benjamin Kaduk <kaduk@mit.edu>
2017-08-05 18:58:36 -04:00
Michael Meffie
54e478328f redhat: do not package kauth by default
Do not package kaserver and related programs by default to discourage
use. Add the '--with kauth' rpmbuild option to allow packagers to
continue include the kauth programs for compatibility.

Change-Id: I8bf9f6dc221afc22ed6c9a33cf101d705e6c4920
Reviewed-on: https://gerrit.openafs.org/12597
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Benjamin Kaduk <kaduk@mit.edu>
2017-08-05 18:56:38 -04:00
Benjamin Kaduk
6d59b7c4b4 Default to crypt mode for unix clients
Though the protection offered by rxkad, even with rxkad-k5 and rxkad-kdf, is
insufficient to protect traffic from a determined attacker, it remains the
case that the internet is not a safe place for user data to travel in the
clear, and has not been for a long time.  The Windows client encrypts by
default, and all or nearly all the Unix client packaging scripts set crypt
mode by default.  Catch up to reality and default to crypt mode in the
Unix cache manager.

Change-Id: If0061ddca3bedf0df1ade8cb61ccb710ec1181d4
Reviewed-on: https://gerrit.openafs.org/12668
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2017-08-05 18:47:04 -04:00
Marcio Barbosa
f7ccf0aa00 ubik: remove useless signal call
The current version does not have a corresponding LWP_WaitProcess call
for the beacon_globals.ubik_amSyncSite global. As a result, the
LWP_NoYieldSignal(&beacon_globals.ubik_amSyncSite) signal call can be
safely removed.

Change-Id: I72c4ccfe8e68551673dc728dd699ba8c561d76d1
Reviewed-on: https://gerrit.openafs.org/12673
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2017-08-03 21:10:21 -04:00
Marcio Barbosa
da704137f4 ubik: update epoch as soon as sync-site is elected
The ubik_epochTime represents the time at which the coordinator first
received its coordinator mandate. However, this global is currently not
updated at the moment when a new sync-site is elected. Instead,
ubik_epochTime is only updated at the very end of the first write
transaction, when a new database label is written (in udisk_commit).
This causes at least 2 different issues:

For one, this means that we change ubik_epochTime while a remote
transaction is in progress. If VOTE_Beacon is called after
ubik_epochTime is updated, but before the remote transaction ends, the
remote sites will detect that the transaction id in ubik_currentTrans is
wrong (via urecovery_CheckTid(), since the epoch doesn't match), and
they will abort the transaction. This means the transaction will fail,
and it may cause a loss of quorum until another election is completed.

Another issue is that ubik_epochTime can be 0 at the beginning of a
write transaction, if this is the first election that this site has won.
Since ubik_epochTime is used to construct transaction ids, this means
that we can have different transactions that originate from different
sites at different times, but they have the same epoch in their tid.
For example, say a write transaction starts with epoch 0, but the
originating site is killed/interrupted before finishing. That write
transaction will linger on remote sites in ubik_currentTrans with an
epoch of 0 (since the originating site will never call
DISK_ReleaseLocks, or DISK_Abort, etc). Normally the sync site will kill
such a lingering transaction via urecovery_CheckTid, but since the epoch
is 0, and the election winner's epoch is also 0, the transaction looks
valid and may never be killed. If that transaction is holding a lock on
the database, this means that the database will forever remain locked,
effectively preventing any access to the db on that site.

To fix both of these issues, update ubik_epochTime with the current
time as soon as we win the election. This ensures that the epoch is not
updated in the middle of a transaction, and it ensures that all
transactions are created with a unique epoch: the epoch of the election
that we won.

Note that with this commit, we do not ever set ubik_epochTime to the
magic value of '2' during database init. The special '2' epoch only
needs to be set in the database itself, and it is never an actual epoch
that represents a real quorum that went through the election process.
The database will be labelled with a 'real' epoch after the first write,
like normal.

[kaduk@mit.edu: comment the locking strategy in ubeacon_Interact()]

Change-Id: I6cdcf5a73c1ea564622bfc8ab7024d9901af4bc8
Reviewed-on: https://gerrit.openafs.org/12609
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-08-03 20:24:29 -04:00
Joe Gorse
32ddf88547 LINUX: afs_create infinite fetchStatus loop
For a file in a directory with the CStatd bit cleared, we can get
an infinite fetchStatus loop.

In afs_create(), afs_getDCache() may return NULL due to an error.
If unchecked it will loop which may produce multiple fetchStatus()
calls to the fileserver.

Credit: Yadav Yadavendra for identifying and analysing this issue.

Change-Id: Iecd77d49a5f3e8bb629396c57246736b39aa935f
Reviewed-on: https://gerrit.openafs.org/12651
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-08-03 20:21:04 -04:00
Michael Meffie
8e1ca72b1c volser: preserve volume stats by default
Commit dfceff1d3a66e76246537738720f411330808d64 added the
-preserve-vol-stats flag to the volume server. This enabled a change in
the volume server to preserve volume usage statistics during reclone and
restore operations. Otherwise, volume usage counters of read-only
volumes are cleared when volumes are released, making it difficult to
track usage with the volume stats.

Make this feature the default behavior of the volume server and provide
the option -clear-vol-stats to use the old behavior if so desired.  This
change makes the -preserve-vol-stats the default, and keeps it as a
hidden flag for sites which may already have that flag set in the
BosConfig.

Since this changes a default behavior of the volume server, this change
is only appropriate on a major or minor release boundary, not in the
middle of a stable series.

Change-Id: I3706ede64b7b18a80b39ebd55f2e1824bb7dbc57
Reviewed-on: https://gerrit.openafs.org/12674
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-08-02 20:28:23 -04:00
Marcio Barbosa
7c70850615 ubik: avoid early DISK_Begin calls we know will fail
Currently, we can start a write transaction on a site immediately after
it is elected as the sync site. However, after commit d47beca1,
SDISK_Begin on remote sites will fail right after an election occurs
(since lastYesState is not set, and so urecovery_AllBetter will fail).
And after commit fac0b742, this error is always noticed and propagated
back to the application.

As a result, when we try to write immediately after a sync site is
elected, the transaction will fail with UNOQUORUM, the remote sites will
be marked as down, and we may lose quorum and require another election
to be performed. This can easily happen repeatedly for a site that
frequently tries to make changes to a ubik database.

To avoid marking other sites down and going through another election
process, do not allow write transactions until we know that lastYesState
is set on the remote sites. We do this by waiting until the next wave of
beacons are sent, which tell the remote sites that we are the sync site.
In other words, only allow write transactions after the sync site knows
that the remote sites also know that the sync site has been elected.

With this commit, a write transaction immediately after an election
will still fail with UNOQUORUM, but we avoid triggering an error on the
remote sites, and avoid losing quorum in this situation.

Change-Id: I9e1a76b4022e6d734af1165d94c12e90af04974d
Reviewed-on: https://gerrit.openafs.org/12592
Reviewed-by: Andrew Deason <adeason@dson.org>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Benjamin Kaduk <kaduk@mit.edu>
2017-08-02 20:10:50 -04:00
Marcio Barbosa
8f46ca0826 ubik: allow remote dbase relabel if up to date
When a site is elected the sync-site, its database is not immediately
relabeled. The database in question will be relabeled at the end of the
first write transaction (in udisk_commit). To do so, the dbase->version
is updated on the sync-site first (1) and then the versions of the
remote sites are updated through SDISK_SetVersion() (2).

In order to make sure that the remote site holds the same database as
the sync-site, the SDISK_SetVersion() function checks if the current
version held by the remote site (ubik_dbVersion) is equal to the
original version stored by the sync-site (oldversionp). If
ubik_dbVersion is not equal to oldversionp, SDISK_SetVersion() will
fail with USYNC.

However, ubik_dbVersion can be updated by the vote thread at any time.
That is, if the sync site calls VOTE_Beacon() on the remote site between
events (1) and (2), the remote site will set ubik_dbVersion to the new
version, while ubik_dbase->version is still set to the old version. As
a result, ubik_dbVersion will not be equal to oldversionp and
SDISK_SetVersion() will fail with USYNC. This failure may cause a loss
of quorum until another election is completed.

To fix this problem, let SDISK_SetVersion() relabel the database when
ubik_dbase->version is equal to oldversionp. In order to try to only
affect the scenario described above, also check if ubik_dbVersion is
equal to newversionp.

Change-Id: I97e6f8cacd1c9bca0b4c72374c058c5fe5b638b3
Reviewed-on: https://gerrit.openafs.org/12613
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-08-02 20:09:07 -04:00
Joe Gorse
3c12ff9fbb afs: fix repeated BulkStatus calls for directories.
There is a filetype comparison check in afs_DoBulkStat just after
BulkFetch RPC. This check will fail for directories even though
bulkStatus was done for directories.

This code is apparently necessary for Darwin, but it causes this problem
otherwise. Thus it is removed from the rest of the builds using the
AFS_DARWIN_ENV preprocessor variable.

Credit: Yadav Yadavendra for identifying and analysing this issue.

Change-Id: I9645f0e7a3327cb5f20cdf3ba2bf1cc5b1509bb5
Reviewed-on: https://gerrit.openafs.org/12610
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2017-07-30 20:44:52 -04:00
Michael Meffie
90acda692a relocate old afs docs to doc/txt
Move the afs/DOC files to the top-leve doc/txt directory, since this has
become the home for developer oriented documentation.

Change-Id: I128d338c69534b4ee6043105a7cfd390b280afe3
Reviewed-on: https://gerrit.openafs.org/12662
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-07-26 19:39:43 -04:00
Stephan Wiesand
77c5e4f3fb Linux: fix whitespace in osi_sysctl.c
Remove dozens of trailing spaces and make consistent use of tabs
for indentation throughout the file.

Change-Id: Ibbd17d2b9828590ffd84b76aac70646e9fe9cb2c
Reviewed-on: https://gerrit.openafs.org/12665
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
2017-07-26 11:40:02 -04:00
Andrew Deason
b0461f2def LINUX: Workaround d_splice_alias/d_lookup race
Before Linux kernel commit 4919c5e45a91b5db5a41695fe0357fbdff0d5767,
d_splice_alias in some cases can d_rehash the given dentry without
attaching it to the given inode, right before the dentry is unhashed
again. This means that for a few moments, that negative dentry is
visible to __d_lookup, and thus is visible to path lookup and can be
given to afs_linux_dentry_revalidate.

Currently, afs_linux_dentry_revalidate will say that the dentry is
valid, because d_time and other fields are set; it's just not attached
to an inode. This causes an ENOENT error on lookup, even though the
file is there (and no OpenAFS code said otherwise).

Normally this race is rare, but it can be frequently exercised if
we access the same directory via different names at the same time.
This can happen with multiple mountpoints to the same volume, or by
accessing an @sys directory via its abbreviated and expanded forms.

To get around this, make afs_linux_dentry_revalidate check negative
'dentry's to see if they are unhashed. We also lock the parent inode,
in order to guarantee that a problematic d_splice_alias call isn't
running at the same time (and thus, we know the dentry will not be
unhashed immediately afterwards). This slows down
afs_linux_dentry_revalidate for valid negative 'dentry's a little, but
it allows us to use negative dentry's at all.

Linux kernel commit 4919c5e45a91b5db5a41695fe0357fbdff0d5767 fixes
this issue, which was included in 2.6.34, so don't do this workaround
for 2.6.34 and on.

Change-Id: I8e58ebed4441151832054b1ef3f1aa5af1c4a9b5
Reviewed-on: https://gerrit.openafs.org/12638
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-07-26 08:37:12 -04:00
Stephan Wiesand
d55b41072c Linux 4.13: use designated initializers where required
struct path is declared with the "designated_init" attribute,
and module builds now use -Werror=designated-init. Cope.

And as pointed out by Michael Meffie, struct ctl_table has
the same requirement now, so use a designated initializer
for the final element of the sysctl table too.

Change-Id: I0ec45aac961dcefa0856a15ee218085626a357c7
Reviewed-on: https://gerrit.openafs.org/12663
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Benjamin Kaduk <kaduk@mit.edu>
2017-07-26 08:27:00 -04:00
Michael Meffie
030a9849e2 afs: fix afs_xserver deadlock in afsdb refresh
When setting up a new volume, the cache manager calls afs_GetServer() to
setup the server object for each fileserver associated with the volume.
The afs_GetServer() function locks afs_xserver and then, among other
things, calls afs_GetCell() to lookup the cell info by cell number.

When the cache manager is running in afsdb mode, afs_GetCell() will
attempt to refresh the cell info if the time-to-live has been exceeded
since the last call to afs_GetCell(). During this refresh the AFSDB
calls afs_GetServer() to update the vlserver information. The afsdb
handler thread and the thread processing the volume setup become
deadlocked since the afs_xserver lock is already held at this point.

This bug will manifest when the DNS SRV record TTL is smaller than the
time the fileservers respond to the GetCapabilities RPC within
afs_GetServer() and there are multiple read-only servers for a volume.

Avoid the deadlock by using the afs_GetCellStale() variant within
afs_GetServer(). This variant returns the memory resident cell info
without the afsdb upcall and the subsequent afs_GetServer() call.

Change-Id: Iad57870f84c5e542a5ee20f00ea03b3fc87683a1
Reviewed-on: https://gerrit.openafs.org/12652
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-07-26 08:17:00 -04:00
Michael Meffie
a6ad67485b afs: restore force_if_down check when getting connections
Commit cb9e029255420608308127b0609179a46d9983ad removed the
force_if_down check in afs_ConnBySA, which effictively turned on
force_if_down flag for every call to afs_ConnBySA. This caused
afs_ConnBySA to always return connections, even for server addresses
marked down and force_if_down set to 0.

One serious consequence of this bug is the cache manager will retry the
preferred vlserver indefinitely when it is unreachable. This is because
the loop in afs_ConnMHosts always tries hosts in preferred order and
expects afs_ConnBySA to return a NULL if the server address has no
connections because it is marked down.

Restore the check for server addresses marked down to honor the
force_if_down flag again so we do not get connections for down servers
unless requested.

Change-Id: Ia117354929a62b0cedc218040649e9e0b8d8ed23
Reviewed-on: https://gerrit.openafs.org/12653
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
2017-07-25 21:57:33 -04:00