This is an improved straw bucket that correctly avoids any data movement
between items A and B when neither A nor B's weights are changed. Said
differently, if we adjust the weight of item C (including adding it anew
or removing it completely), we will only see inputs move to or from C,
never between other items in the bucket.
Notably, there is not intermediate scaling factor that needs to be
calculated. The mapping function is a simple function of the item weights.
The below commits were squashed together into this one (mostly to avoid
adding and then yanking a ~6000 lines worth of crush_ln_table):
- crush: add a straw2 bucket type
- crush: add crush_ln to calculate nature log efficently
- crush: improve straw2 adjustment slightly
- crush: change crush_ln to provide 32 more digits
- crush: fix crush_get_bucket_item_weight and bucket destroy for straw2
- crush/mapper: fix divide-by-0 in straw2
(with div64_s64() for draw = ln / w and INT64_MIN -> S64_MIN - need
to create a proper compat.h in ceph.git)
Reflects ceph.git commits 242293c908e923d474910f2b8203fa3b41eb5a53,
32a1ead92efcd351822d22a5fc37d159c65c1338,
6289912418c4a3597a11778bcf29ed5415117ad9,
35fcb04e2945717cf5cfe150b9fa89cb3d2303a1,
6445d9ee7290938de1e4ee9563912a6ab6d8ee5f,
b5921d55d16796e12d66ad2c4add7305f9ce2353.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Crush temporary buffers are allocated as per replica size configured
by the user. When there are more final osds (to be selected as per
rule) than the replicas, buffer overlaps and it causes crash. Now, it
ensures that at most num-rep osds are selected even if more number of
osds are allowed by the rule.
Reflects ceph.git commits 6b4d1aa99718e3b367496326c1e64551330fabc0,
234b066ba04976783d15ff2abc3e81b6cc06fb10.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Add a client_options attribute for showing libceph options. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Split ceph_show_options() into two pieces and move the piece responsible for printing client (libceph) options into net/ceph. This way people adding a libceph option wouldn't have to remember to update code in fs/ceph. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
- specific con->error_msg messages (e.g. "protocol version mismatch")
end up getting overwritten by a catch-all "socket error on read
/ write", introduced in commit 3a140a0d5c4b ("libceph: report socket
read/write error message")
- "bad message sequence # for incoming message" loses to "bad crc" due
to the fact that -EBADMSG is used for both
Fix it, and tidy up con->error_msg assignments and pr_errs while at it.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This reverts commit 89baaa570ab0b476db09408d209578cfed700e9f.
Dirty page throttling should be sufficient for us in the general case
so there is no need to use __GFP_MEMALLOC - it would be needed only in
the swap-over-rbd case, which we currently don't support. (It would
probably take approximately the commit that is being reverted to add
that support, but we would also need the "swap" option to distinguish
from the general case and make sure swap ceph_client-s aren't shared
with anything else.) See ceph-devel threads [1] and [2] for the
details of why enabling pfmemalloc reserves for all cases is a bad
thing.
On top of potential system lockups related to drained emergency
reserves, this turned out to cause ceph lockups in case peers are on
the same host and communicating via loopback due to sk_filter()
dropping pfmemalloc skbs on the receiving side because the receiving
loopback socket is not tagged with SOCK_MEMALLOC.
[1] "SOCK_MEMALLOC vs loopback"
http://www.spinics.net/lists/ceph-devel/msg22998.html
[2] "[PATCH] libceph: don't set memalloc flags in loopback case"
http://www.spinics.net/lists/ceph-devel/msg23392.html
Conflicts:
net/ceph/messenger.c [ context: tcp_nodelay option ]
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Sage Weil <sage@redhat.com>
Cc: stable@vger.kernel.org # 3.18+, needs backporting
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Mel Gorman <mgorman@suse.de>
Pull Ceph changes from Sage Weil:
"On the RBD side, there is a conversion to blk-mq from Christoph,
several long-standing bug fixes from Ilya, and some cleanup from
Rickard Strandqvist.
On the CephFS side there is a long list of fixes from Zheng, including
improved session handling, a few IO path fixes, some dcache management
correctness fixes, and several blocking while !TASK_RUNNING fixes.
The core code gets a few cleanups and Chaitanya has added support for
TCP_NODELAY (which has been used on the server side for ages but we
somehow missed on the kernel client).
There is also an update to MAINTAINERS to fix up some email addresses
and reflect that Ilya and Zheng are doing most of the maintenance for
RBD and CephFS these days. Do not be surprised to see a pull request
come from one of them in the future if I am unavailable for some
reason"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (27 commits)
MAINTAINERS: update Ceph and RBD maintainers
libceph: kfree() in put_osd() shouldn't depend on authorizer
libceph: fix double __remove_osd() problem
rbd: convert to blk-mq
ceph: return error for traceless reply race
ceph: fix dentry leaks
ceph: re-send requests when MDS enters reconnecting stage
ceph: show nocephx_require_signatures and notcp_nodelay options
libceph: tcp_nodelay support
rbd: do not treat standalone as flatten
ceph: fix atomic_open snapdir
ceph: properly mark empty directory as complete
client: include kernel version in client metadata
ceph: provide seperate {inode,file}_operations for snapdir
ceph: fix request time stamp encoding
ceph: fix reading inline data when i_size > PAGE_SIZE
ceph: avoid block operation when !TASK_RUNNING (ceph_mdsc_close_sessions)
ceph: avoid block operation when !TASK_RUNNING (ceph_get_caps)
ceph: avoid block operation when !TASK_RUNNING (ceph_mdsc_sync)
rbd: fix error paths in rbd_dev_refresh()
...
a255651d4cad ("ceph: ensure auth ops are defined before use") made
kfree() in put_osd() conditional on the authorizer. A mechanical
mistake most likely - fix it.
Cc: Alex Elder <elder@linaro.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>
It turns out it's possible to get __remove_osd() called twice on the
same OSD. That doesn't sit well with rb_erase() - depending on the
shape of the tree we can get a NULL dereference, a soft lockup or
a random crash at some point in the future as we end up touching freed
memory. One scenario that I was able to reproduce is as follows:
<osd3 is idle, on the osd lru list>
<con reset - osd3>
con_fault_finish()
osd_reset()
<osdmap - osd3 down>
ceph_osdc_handle_map()
<takes map_sem>
kick_requests()
<takes request_mutex>
reset_changed_osds()
__reset_osd()
__remove_osd()
<releases request_mutex>
<releases map_sem>
<takes map_sem>
<takes request_mutex>
__kick_osd_requests()
__reset_osd()
__remove_osd() <-- !!!
A case can be made that osd refcounting is imperfect and reworking it
would be a proper resolution, but for now Sage and I decided to fix
this by adding a safe guard around __remove_osd().
Fixes: http://tracker.ceph.com/issues/8087
Cc: Sage Weil <sage@redhat.com>
Cc: stable@vger.kernel.org # 3.9+: 7c6e6fc53e73: libceph: assert both regular and lingering lists in __remove_osd()
Cc: stable@vger.kernel.org # 3.9+: cc9f1f518cec: libceph: change from BUG to WARN for __remove_osd() asserts
Cc: stable@vger.kernel.org # 3.9+
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>