kernel_optimize_test/net/ceph
Ilya Dryomov b049453221 libceph: request a new osdmap if lingering request maps to no osd
This commit does two things.  First, if there are any homeless
lingering requests, we now request a new osdmap even if the osdmap that
is being processed brought no changes, i.e. if a given lingering
request turned homeless in one of the previous epochs and remained
homeless in the current epoch.  Not doing so leaves us with a stale
osdmap and as a result we may miss our window for reestablishing the
watch and lose notifies.

MON=1 OSD=1:

    # cat linger-needmap.sh
    #!/bin/bash
    rbd create --size 1 test
    DEV=$(rbd map test)
    ceph osd out 0
    rbd map dne/dne # obtain a new osdmap as a side effect (!)
    sleep 1
    ceph osd in 0
    rbd resize --size 2 test
    # rbd info test | grep size -> 2M
    # blockdev --getsize $DEV -> 1M

N.B.: Not obtaining a new osdmap in between "osd out" and "osd in"
above is enough to make it miss that resize notify, but that is a
bug^Wlimitation of ceph watch/notify v1.

Second, homeless lingering requests are now kicked just like those
lingering requests whose mapping has changed.  This is mainly to
recognize that a homeless lingering request makes no sense and to
preserve the invariant that a registered lingering request is not
sitting on any of r_req_lru_item lists.  This spares us a WARN_ON,
which commit ba9d114ec5 ("libceph: clear r_req_lru_item in
__unregister_linger_request()") tried to fix the _wrong_ way.

Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
2015-05-20 21:02:14 +03:00
..
crush crush: straw2 bucket type with an efficient 64-bit crush_ln() 2015-04-22 18:33:43 +03:00
armor.c
auth_none.c libceph: Fix NULL pointer dereference in auth client code 2013-07-03 15:32:55 -07:00
auth_none.h net: 8021q/bluetooth/bridge/can/ceph: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
auth_x_protocol.h
auth_x.c libceph: fix sparse endianness warnings 2015-01-08 20:36:57 +03:00
auth_x.h libceph: store session key in cephx authorizer 2014-12-17 20:09:50 +03:00
auth.c
buffer.c libceph: nuke ceph_kvfree() 2014-12-17 20:09:50 +03:00
ceph_common.c libceph, ceph: split ceph_show_options() 2015-04-20 18:55:38 +03:00
ceph_fs.c
ceph_hash.c
ceph_strings.c libceph: nuke pool op infrastructure 2015-02-19 13:31:37 +03:00
crypto.c libceph: do not crash on large auth tickets 2014-11-13 22:21:12 +03:00
crypto.h net: 8021q/bluetooth/bridge/can/ceph: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
debugfs.c libceph: expose client options through debugfs 2015-04-20 18:55:39 +03:00
Kconfig libceph: select CRYPTO_CBC in addition to CRYPTO_AES 2014-10-14 21:03:20 +04:00
Makefile libceph: create source file "net/ceph/snapshot.c" 2013-05-01 21:20:08 -07:00
messenger.c libceph: don't overwrite specific con error msgs 2015-04-20 18:55:37 +03:00
mon_client.c libceph: use mon_client.c/put_generic_request() more 2015-02-19 13:31:37 +03:00
msgpool.c
osd_client.c libceph: request a new osdmap if lingering request maps to no osd 2015-05-20 21:02:14 +03:00
osdmap.c crush: straw2 bucket type with an efficient 64-bit crush_ln() 2015-04-22 18:33:43 +03:00
pagelist.c libceph: reference counting pagelist 2014-10-14 12:56:48 -07:00
pagevec.c mm: gup: use get_user_pages_unlocked 2015-02-11 17:06:05 -08:00
snapshot.c libceph: create source file "net/ceph/snapshot.c" 2013-05-01 21:20:08 -07:00