bucket_straw2_choose needs to use weights that may be different from
weight_items. For instance to compensate for an uneven distribution
caused by a low number of values. Or to fix the probability biais
introduced by conditional probabilities (see
http://tracker.ceph.com/issues/15653 for more information).

We introduce a weight_set for each straw2 bucket to set the desired
weight for a given item at a given position. The weight of a given item
when picking the first replica (first position) may be different from
the weight the second replica (second position). For instance the weight
matrix for a given bucket containing items 3, 7 and 13 could be as
follows:

          position 0   position 1

item 3     0x10000      0x100000
item 7     0x40000       0x10000
item 13    0x40000       0x10000

When crush_do_rule picks the first of two replicas (position 0), item 7,
3 are four times more likely to be choosen by bucket_straw2_choose than
item 13. When choosing the second replica (position 1), item 3 is ten
times more likely to be choosen than item 7, 13.

By default the weight_set of each bucket exactly matches the content of
item_weights for each position to ensure backward compatibility.

bucket_straw2_choose compares items by using their id. The same ids are
also used to index buckets and they must be unique. For each item in a
bucket an array of ids can be provided for placement purposes and they
are used instead of the ids. If no replacement ids are provided, the
legacy behavior is preserved.

Reflects ceph.git commit 19537a450fd5c5a0bb8b7830947507a76db2ceca.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Previously, pg_to_raw_osds() didn't filter for existent OSDs because
raw_to_up_osds() would filter for "up" ("up" is predicated on "exists")
and raw_to_up_osds() was called directly after pg_to_raw_osds().  Now,
with apply_upmap() call in there, nonexistent OSDs in pg_to_raw_osds()
output can affect apply_upmap().  Introduce remove_nonexistent_osds()
to deal with that.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Move raw_pg_to_pg() call out of get_temp_osds() and into
ceph_pg_to_up_acting_osds(), for upcoming apply_upmap().
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

pg_temp and pg_upmap encodings are the same (PG -> array of osds),
except for the incremental remove: it's an empty mapping in new_pg_temp
for pg_temp and a separate old_pg_upmap set for pg_upmap.  (This isn't
to allow for empty pg_upmap mappings -- apparently, pg_temp just wasn't
looked at as an example for pg_upmap encoding.)

Reuse __decode_pg_temp() for decoding pg_upmap and new_pg_upmap.
__decode_pg_temp() stores into pg_temp union member, but since pg_upmap
union member is identical, reading through pg_upmap later is OK.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Some of these won't be as efficient as they could be (e.g.
ceph_decode_skip_set(... 32 ...) could advance by len * sizeof(u32)
once instead of advancing by sizeof(u32) len times), but that's fine
and not worth a bunch of extra macro code.

Replace skip_name_map() with ceph_decode_skip_map as an example.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Switch to DEFINE_RB_FUNCS2-generated {insert,lookup,erase}_pg_mapping().
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Make __{lookup,remove}_pg_mapping() look like their ceph_spg_mapping
counterparts: take const struct ceph_pg *.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Initially for ceph_pg_mapping, ceph_spg_mapping and ceph_hobject_id,
compared with ceph_pg_compare(), ceph_spg_compare() and hoid_compare()
respectively.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

For luminous and beyond we are encoding the actual spgid, which
requires operating with the correct pg_num, i.e. that of the target
pool.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

need_check_tiering logic doesn't make a whole lot of sense.  Drop it
and apply tiering unconditionally on every calc_target() call instead.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Otherwise we may miss events like PG splits, pool deletions, etc when
we get multiple incremental maps at once.  Because check_pool_dne() can
now be fed an unlinked request, finish_request() needed to be taught to
handle unlinked requests.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

When processing a map update consisting of multiple incrementals, we
may end up running check_linger_pool_dne() on a lingering request that
was previously added to need_resend_linger list.  If it is concluded
that the target pool doesn't exist, the request is killed off while
still on need_resend_linger list, which leads to a crash on a NULL
lreq->osd in kick_requests():

    libceph: linger_id 18446462598732840961 pool does not exist
    BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
    IP: ceph_osdc_handle_map+0x4ae/0x870
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Note that ceph_osd_request_target fields are updated regardless of
RESEND_ON_SPLIT.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Replace it with more fine-grained bools to separate updating
ceph_osd_request_target fields and the decision to resend.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Give upper layers a chance to reencode the message after the connection
is negotiated and ->peer_features is set.  OSD client will use this to
support both luminous and pre-luminous OSDs (in a single cluster): the
former need MOSDOp v8; the latter will continue to be sent MOSDOp v4.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Factor out encode_{pgid,oloc}() and use ceph_encode_string() for oid.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Store both raw pgid and actual spgid in ceph_osd_request_target.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

The old (v15) pi->last_force_request_resend has been repurposed to
make pre-RESEND_ON_SPLIT clients that don't check for PG splits but do
obey pi->last_force_request_resend resend on splits.  See ceph.git
commit 189ca7ec6420 ("mon/OSDMonitor: make pre-luminous clients resend
ops on split").
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Only MON_STATEFUL_SUB, really.  MON_ROUTE_OSDMAP and
OSDSUBOP_NO_SNAPCONTEXT are irrelevant.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

The code has been in place since commit 63244fa1 ("libceph:
introduce ceph_osd_request_target, calc_target()"), and, with the
ceph_{oloc,oid}_copy() issue fixed in the previous commit, is now
in working order.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Reflects ceph.git commit ff1959282826ae6acd7134e1b1ede74ffd1cc04a.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Current code does not update ceph_dentry_info::lease_session once
it is set. If auth mds of corresponding dentry changes, dentry lease
keeps in an invalid state.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Current ceph uses FSID as primary index key of fscache data. This
allows ceph to retain cached data across remount. But this causes
problem (kernel opps, fscache does not support sharing data) when
a filesystem get mounted several times (with fscache enabled, with
different mount options).

The fix is adding a new mount option, which specifies uniquifier
for fscache.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

extra_mon_dispatch() and debugfs' foo_show functions dereference
fsc->mdsc. we should clean up fsc->client->extra_mon_dispatch
and debugfs before destroying fsc->mds.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Previously we were returning values for quota, layout
xattrs without any kind of update -- the user just got
whatever happened to be in our cache.

Clearly this extra round trip has a cost, but reads of
these xattrs are fairly rare, happening on admin
intervention rather than in normal operation.

Link: http://tracker.ceph.com/issues/17939Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Don't re-send interrupted flock request in cases of mds failover
and receiving request forward. Because corresponding 'lock intr'
request may have been finished, it won't get re-sent.

Link: http://tracker.ceph.com/issues/20170Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Ceph needs to flush dirty page in the order in which in which snap
context they belong to. Dirty pages belong to older snap context
should be flushed earlier. if writepage_nounlock() can not flush a
page, it should redirty the page.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Callers of writepage_nounlock() have already ensured non-null
page->mapping.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

The old 'approaching max_size' code expects MDS set max_size to
'2 * reported_size'. This is no longer true. The new code reports
file size when half of previous max_size increment has been used.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

The 'wanted max size' could be sent to inode's old auth mds, re-send
it to inode's new auth mds if necessary. Otherwise write syscall may
hang.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>