Commit Graph

427990 Commits

Author SHA1 Message Date
Ilya Dryomov
597b52f6ca libceph: fixup error handling in osdmap_decode()
The existing error handling scheme requires resetting err to -EINVAL
prior to calling any ceph_decode_* macro.  This is ugly and fragile,
and there already are a few places where we would return 0 on error,
due to a missing reset.  Fix this by adding a special e_inval label to
be used by all ceph_decode_* macros.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-04 21:07:38 -07:00
Ilya Dryomov
a2505d63ee libceph: split osdmap allocation and decode steps
Split osdmap allocation and initialization into a separate function,
ceph_osdmap_decode().

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-04 21:07:37 -07:00
Ilya Dryomov
38a8d56023 libceph: dump osdmap and enhance output on decode errors
Dump osdmap in hex on both full and incremental decode errors, to make
it easier to match the contents with error offset.  dout() map epoch
and max_osd value on success.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-04 21:07:35 -07:00
Ilya Dryomov
1c00240e00 libceph: dump pg_temp mappings to debugfs
Dump pg_temp mappings to /sys/kernel/debug/ceph/<client>/osdmap,
one 'pg_temp <pgid> [<osd>, ..., <osd>]' per line, e.g:

    pg_temp 2.6 [2,3,4]

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-04 21:07:34 -07:00
Ilya Dryomov
0a2800d728 libceph: do not prefix osd lines with \t in debugfs output
To save screen space in anticipation of more fields (e.g. primary
affinity).

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-04 21:07:32 -07:00
Ilya Dryomov
35fea3a18a libceph: refer to osdmap directly in osdmap_show()
To make it more readable and save screen space.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-04 21:07:31 -07:00
Ilya Dryomov
07bd7de47a crush: support chooseleaf_vary_r tunable (tunables3) by default
Add TUNABLES3 feature (chooseleaf_vary_r tunable) to a set of features
supported by default.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2014-04-04 21:07:29 -07:00
Ilya Dryomov
d83ed858f1 crush: add SET_CHOOSELEAF_VARY_R step
This lets you adjust the vary_r tunable on a per-rule basis.

Reflects ceph.git commit f944ccc20aee60a7d8da7e405ec75ad1cd449fac.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2014-04-04 21:07:28 -07:00
Ilya Dryomov
e2b149cc4b crush: add chooseleaf_vary_r tunable
The current crush_choose_firstn code will re-use the same 'r' value for
the recursive call.  That means that if we are hitting a collision or
rejection for some reason (say, an OSD that is marked out) and need to
retry, we will keep making the same (bad) choice in that recursive
selection.

Introduce a tunable that fixes that behavior by incorporating the parent
'r' value into the recursive starting point, so that a different path
will be taken in subsequent placement attempts.

Note that this was done from the get-go for the new crush_choose_indep
algorithm.

This was exposed by a user who was seeing PGs stuck in active+remapped
after reweight-by-utilization because the up set mapped to a single OSD.

Reflects ceph.git commit a8e6c9fbf88bad056dd05d3eb790e98a5e43451a.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2014-04-04 21:07:26 -07:00
Ilya Dryomov
6ed1002f36 crush: allow crush rules to set (re)tries counts to 0
These two fields are misnomers; they are *retry* counts.

Reflects ceph.git commit f17caba8ae0cad7b6f8f35e53e5f73b444696835.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2014-04-04 21:07:25 -07:00
Ilya Dryomov
48a163dbb5 crush: fix off-by-one errors in total_tries refactor
Back in 27f4d1f6bc32c2ed7b2c5080cbd58b14df622607 we refactored the CRUSH
code to allow adjustment of the retry counts on a per-pool basis.  That
commit had an off-by-one bug: the previous "tries" counter was a *retry*
count, not a *try* count, but the new code was passing in 1 meaning
there should be no retries.

Fix the ftotal vs tries comparison to use < instead of <= to fix the
problem.  Note that the original code used <= here, which means the
global "choose_total_tries" tunable is actually counting retries.
Compensate for that by adding 1 in crush_do_rule when we pull the tunable
into the local variable.

This was noticed looking at output from a user provided osdmap.
Unfortunately the map doesn't illustrate the change in mapping behavior
and I haven't managed to construct one yet that does.  Inspection of the
crush debug output now aligns with prior versions, though.

Reflects ceph.git commit 795704fd615f0b008dcc81aa088a859b2d075138.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2014-04-04 21:07:23 -07:00
Yan, Zheng
cc48c3e85f ceph: don't include ceph.{file,dir}.layout vxattr in listxattr()
This avoids 'cp -a' modifying layout of new files/directories.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-04 21:07:21 -07:00
Yan, Zheng
1e5c6649ff ceph: check buffer size in ceph_vxattrcb_layout()
If buffer size is zero, return the size of layout vxattr. If buffer
size is not zero, check if it is large enough for layout vxattr.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-04 21:07:19 -07:00
Yan, Zheng
00bd8edb86 ceph: fix null pointer dereference in discard_cap_releases()
send_mds_reconnect() may call discard_cap_releases() after all
release messages have been dropped by cleanup_cap_releases()

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-04-04 21:07:17 -07:00
Yan, Zheng
d90deda69c libceph: fix oops in ceph_msg_data_{pages,pagelist}_advance()
When there is no more data, ceph_msg_data_{pages,pagelist}_advance()
should not move on to the next page.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-04 21:07:15 -07:00
Fabian Frederick
5f75ce5781 ceph: Remove get/set acl on symlinks
Remove unsupported symlink operations.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-04-04 21:07:14 -07:00
Yan, Zheng
d9ffc4f770 ceph: set mds_wanted when MDS reply changes a cap to auth cap
When adjusting caps client wants, MDS does not record caps that are
not allowed. For non-auth MDS, it does not record WR caps. So when
a MDS reply changes a non-auth cap to auth cap, client needs to set
cap's mds_wanted according to the reply.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-04 21:07:12 -07:00
Yan, Zheng
eb13e832f8 ceph: use fl->fl_file as owner identifier of flock and posix lock
flock and posix lock should use fl->fl_file instead of process ID
as owner identifier. (posix lock uses fl->fl_owner. fl->fl_owner
is usually equal to fl->fl_file, but it also can be a customized
value). The process ID of who holds the lock is just for F_GETLK
fcntl(2).

The fix is rename the 'pid' fields of struct ceph_mds_request_args
and struct ceph_filelock to 'owner', rename 'pid_namespace' fields
to 'pid'. Assign fl->fl_file to the 'owner' field of lock messages.
We also set the most significant bit of the 'owner' field. MDS can
use that bit to distinguish between old and new clients.

The MDS counterpart of this patch modifies the flock code to not
take the 'pid_namespace' into consideration when checking conflict
locks.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-04-04 21:07:11 -07:00
Yan, Zheng
eb70c0ce4e ceph: forbid mandatory file lock
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-04 21:07:09 -07:00
Yan, Zheng
0e8e95d6d7 ceph: use fl->fl_type to decide flock operation
VFS does not directly pass flock's operation code to filesystem's
flock callback. It translates the operation code to the form how
posix lock's parameters are presented.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-04 21:07:08 -07:00
Yan, Zheng
8c93cd610c ceph: update i_max_size even if inode version does not change
handle following sequence of events:
 - client releases a inode with i_max_size > 0. The release message
   is queued. (is not sent to the auth MDS)
 - a 'lookup' request reply from non-auth MDS returns the same inode.
 - client opens the inode in write mode. The version of inode trace
   in 'open' request reply is equal to the cached inode's version.
 - client requests new max size. The MDS ignores the request because
   it does not affect client's write range

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-04-04 21:07:06 -07:00
Yan, Zheng
a255060451 ceph: make sure write caps are registered with auth MDS
Only auth MDS can issue write caps to clients, so don't consider
write caps registered with non-auth MDS as valid.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-04 21:07:05 -07:00
Yan, Zheng
c137a32a40 ceph: print inode number for LOOKUPINO request
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-04-03 10:33:54 +08:00
Yan, Zheng
19913b4eac ceph: add get_name() NFS export callback
Use the newly introduced LOOKUPNAME MDS request to connect child
inode to its parent directory.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-04-03 10:33:53 +08:00
Yan, Zheng
8996f4f23d ceph: fix ceph_fh_to_parent()
ceph_fh_to_parent() returns dentry that corresponds to the 'ino' field
of struct ceph_nfs_confh. This is wrong, it should return dentry that
corresponds to the 'parent_ino' field.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-04-03 10:33:53 +08:00
Yan, Zheng
9017c2ec78 ceph: add get_parent() NFS export callback
The callback uses LOOKUPPARENT MDS request to find parent.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-04-03 10:33:53 +08:00
Yan, Zheng
4f32b42dca ceph: simplify ceph_fh_to_dentry()
MDS handles LOOKUPHASH and LOOKUPINO MDS requests in the same way.
So __cfh_to_dentry() is redundant.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-04-03 10:33:53 +08:00
Yunchuan Wen
f1fc4fee3b ceph: fscache: Wait for completion of object initialization
The object store limit needs to be updated after writing,
and this can be done provided the corresponding object has already
been initialized. Current object initialization is done asynchrously,
which introduce a race if a file is opened, then immediately followed
by a writing, the initialization may have not completed, the code will
reach the ASSERT in fscache_submit_exclusive_op() to cause kernel
bug.

Tested-by: Milosz Tanski <milosz@adfin.com>
Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
Signed-off-by: Min Chen <minchen@ubuntukylin.com>
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
2014-04-03 10:33:53 +08:00
Yunchuan Wen
32d3e148dd ceph: fscache: Update object store limit after file writing
Synchronize object->store_limit[_l] with new inode->i_size after file writing.

Tested-by: Milosz Tanski <milosz@adfin.com>
Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
Signed-off-by: Min Chen <minchen@ubuntukylin.com>
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
2014-04-03 10:33:53 +08:00
Yunchuan Wen
020c4bddc0 ceph: fscache: add an interface to synchronize object store limit
Add an interface to explicitly synchronize object->store_limit[_l]
with inode->i_size

Tested-by: Milosz Tanski <milosz@adfin.com>
Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
Signed-off-by: Min Chen <minchen@ubuntukylin.com>
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
2014-04-03 10:33:53 +08:00
Sage Weil
4b58c9b19b ceph: do not set r_old_dentry_dir on link()
This is racy--we do not know whather d_parent has changed out from
underneath us because i_mutex is not held on the source inode's directory.

Also, taking this reference is useless.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-03 10:33:53 +08:00
Sage Weil
844d87c332 ceph: do not assume r_old_dentry[_dir] always set together
Do not assume that r_old_dentry implies that r_old_dentry_dir is also
true.  Separate out the ref cleanup and make the debugs dump behave when
it is NULL.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-03 10:33:53 +08:00
Sage Weil
752c8bdcfe ceph: do not chain inode updates to parent fsync
The fsync(dirfd) only covers namespace operations, not inode updates.
We do not need to cover setattr variants or O_TRUNC.

Reported-by: Al Viro <viro@xeniv.linux.org.uk>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-03 10:33:52 +08:00
Sage Weil
180061a58c ceph: avoid useless ceph_get_dentry_parent_inode() in ceph_rename()
This is just old_dir; no reason to abuse the dcache pointers.

Reported-by: Al Viro <viro.zeniv.linux.org.uk>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-03 10:33:52 +08:00
Yan, Zheng
15289dc85b ceph: let MDS adjust readdir 'frag'
If readdir 'frag' is adjusted, readdir 'offset' should be reset.
Otherwise some dentries may be lost when readdir and fragmenting
directory happen at the some.

Another way to fix this issue is let MDS adjust readdir 'frag'.
The code that handles MDS reply reset the readdir 'offset' if
the readdir reply is different than the requested one.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
2014-04-03 10:33:52 +08:00
Yan, Zheng
dcd3cc05e5 ceph: fix reset_readdir()
When changing readdir postion, fi->next_offset should be set to 0
if the new postion is not in the first dirfrag.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Yan, Zheng
f049420607 ceph: fix ceph_dir_llseek()
Comparing offset with inode->i_sb->s_maxbytes doesn't make sense for
directory. For a fragmented directory, offset (frag_t, off) can be
larger than inode->i_sb->s_maxbytes.

At the very beginning of ceph_dir_llseek(), local variable old_offset
is initialized to parameter offset. This doesn't make sense neither.
Old_offset should be ceph_make_fpos(fi->frag, fi->next_offset).

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov
0ccd592669 rbd: prefix rbd writes with CEPH_OSD_OP_SETALLOCHINT osd op
In an effort to reduce fragmentation, prefix every rbd write with
a CEPH_OSD_OP_SETALLOCHINT osd op with an expected_write_size value set
to the object size (1 << order).  Backwards compatibility is taken care
of on the libceph/osd side.

"The CEPH_OSD_OP_SETALLOCHINT hint is durable, in that it's enough to
do it once.  The reason every rbd write is prefixed is that rbd doesn't
explicitly create objects and relies on writes creating them
implicitly, so there is no place to stick a single hint op into.  To
get around that we decided to prefix every rbd write with a hint (just
like write and setattr ops, hint op will create an object implicitly if
it doesn't exist)."

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov
deb236b300 rbd: num_ops parameter for rbd_osd_req_create()
In preparation for prefixing rbd writes with an allocation hint
introduce a num_ops parameter for rbd_osd_req_create().  The rationale
is that not every write request is a write op that needs to be prefixed
(e.g. watch op), so the num_ops logic needs to be in the callers.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov
7cc69d42e6 libceph: bump CEPH_OSD_MAX_OP to 3
Our longest osd request now contains 3 ops: copyup+hint+write.

Also, CEPH_OSD_MAX_OP value in a BUG_ON in rbd_osd_req_callback() was
hard-coded to 2.  Fix it, and switch to rbd_assert while at it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:52 +08:00
Ilya Dryomov
c647b8a8c6 libceph: add support for CEPH_OSD_OP_SETALLOCHINT osd op
This is primarily for rbd's benefit and is supposed to combat
fragmentation:

"... knowing that rbd images have a 4m size, librbd can pass a hint
that will let the osd do the xfs allocation size ioctl on new files so
that they are allocated in 1m or 4m chunks.  We've seen cases where
users with rbd workloads have very high levels of fragmentation in xfs
and this would mitigate that and probably have a pretty nice
performance benefit."

SETALLOCHINT is considered advisory, so our backwards compatibility
mechanism here is to set FAILOK flag for all SETALLOCHINT ops.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:51 +08:00
Ilya Dryomov
7b25bf5f02 libceph: encode CEPH_OSD_OP_FLAG_* op flags
Encode ceph_osd_op::flags field so that it gets sent over the wire.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:51 +08:00
Ilya Dryomov
42dd037c08 rbd: fix error paths in rbd_img_request_fill()
Doing rbd_obj_request_put() in rbd_img_request_fill() error paths is
not only insufficient, but also triggers an rbd_assert() in
rbd_obj_request_destroy():

    Assertion failure in rbd_obj_request_destroy() at line 1867:

    rbd_assert(obj_request->img_request == NULL);

rbd_img_obj_request_add() adds obj_requests to the img_request, the
opposite is rbd_img_obj_request_del().  Use it.

Fixes: http://tracker.ceph.com/issues/7327

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:51 +08:00
Ilya Dryomov
62054da65c rbd: remove out_partial label in rbd_img_request_fill()
Commit 03507db631 ("rbd: fix buffer size for writes to images with
snapshots") moved the call to rbd_img_obj_request_add() up, making the
out_partial label bogus.  Remove it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
2014-04-03 10:33:50 +08:00
Ilya Dryomov
9d521470a4 libceph: a per-osdc crush scratch buffer
With the addition of erasure coding support in the future, scratch
variable-length array in crush_do_rule_ary() is going to grow to at
least 200 bytes on average, on top of another 128 bytes consumed by
rawosd/osd arrays in the call chain.  Replace it with a buffer inside
struct osdmap and a mutex.  This shouldn't result in any contention,
because all osd requests were already serialized by request_mutex at
that point; the only unlocked caller was ceph_ioctl_get_dataloc().

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2014-04-03 10:33:50 +08:00
Linus Torvalds
455c6fdbd2 Linux 3.14 2014-03-30 20:40:15 -07:00
Linus Torvalds
fedc1ed0f1 Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Switch mnt_hash to hlist, turning the races between __lookup_mnt() and
  hash modifications into false negatives from __lookup_mnt() (instead
  of hangs)"

On the false negatives from __lookup_mnt():
 "The *only* thing we care about is not getting stuck in __lookup_mnt().
  If it misses an entry because something in front of it just got moved
  around, etc, we are fine.  We'll notice that mount_lock mismatch and
  that'll be it"

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch mnt_hash to hlist
  don't bother with propagate_mnt() unless the target is shared
  keep shadowed vfsmounts together
  resizable namespace.c hashes
2014-03-30 17:26:08 -07:00
Randy Dunlap
01358e562a MAINTAINERS: resume as Documentation maintainer
I am the new kernel tree Documentation maintainer (except for parts that
are handled by other people, of course).

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-30 17:22:28 -07:00
Linus Torvalds
915ac4e26e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input updates from Dmitry Torokhov:
 "Some more updates for the input subsystem.

  You will get a fix for race in mousedev that has been causing quite a
  few oopses lately and a small fixup for force feedback support in
  evdev"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: mousedev - fix race when creating mixed device
  Input: don't modify the id of ioctl-provided ff effect on upload failure
2014-03-30 17:20:40 -07:00
Eric Paris
aa4af831bb AUDIT: Allow login in non-init namespaces
It its possible to configure your PAM stack to refuse login if audit
messages (about the login) were unable to be sent.  This is common in
many distros and thus normal configuration of many containers.  The PAM
modules determine if audit is enabled/disabled in the kernel based on
the return value from sending an audit message on the netlink socket.
If userspace gets back ECONNREFUSED it believes audit is disabled in the
kernel.  If it gets any other error else it refuses to let the login
proceed.

Just about ever since the introduction of namespaces the kernel audit
subsystem has returned EPERM if the task sending a message was not in
the init user or pid namespace.  So many forms of containers have never
worked if audit was enabled in the kernel.

BUT if the container was not in net_init then the kernel network code
would send ECONNREFUSED (instead of the audit code sending EPERM).  Thus
by pure accident/dumb luck/bug if an admin configured the PAM stack to
reject all logins that didn't talk to audit, but then ran the login
untility in the non-init_net namespace, it would work!! Clearly this was
a bug, but it is a bug some people expected.

With the introduction of network namespace support in 3.14-rc1 the two
bugs stopped cancelling each other out.  Now, containers in the
non-init_net namespace refused to let users log in (just like PAM was
configfured!) Obviously some people were not happy that what used to let
users log in, now didn't!

This fix is kinda hacky.  We return ECONNREFUSED for all non-init
relevant namespaces.  That means that not only will the old broken
non-init_net setups continue to work, now the broken non-init_pid or
non-init_user setups will 'work'.  They don't really work, since audit
isn't logging things.  But it's what most users want.

In 3.15 we should have patches to support not only the non-init_net
(3.14) namespace but also the non-init_pid and non-init_user namespace.
So all will be right in the world.  This just opens the doors wide open
on 3.14 and hopefully makes users happy, if not the audit system...

Reported-by: Andre Tomt <andre@tomt.net>
Reported-by: Adam Richter <adam_richter2004@yahoo.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-30 17:02:53 -07:00