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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
libceph: safely decode max_osd value in osdmap_decode()

max_osd value is not covered by any ceph_decode_need().  Use a safe
version of ceph_decode_* macro to decode it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
libceph: check length of osdmap osd arrays

Check length of osd_state, osd_weight and osd_addr arrays.  They
should all have exactly max_osd elements after the call to
osdmap_set_max_osd().

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
libceph: fix crush_decode() call site in osdmap_decode()

The size of the memory area feeded to crush_decode() should be limited
not only by osdmap end, but also by the crush map length.  Also, drop
unnecessary dout() (dout() in crush_decode() conveys the same info) and
step past crush map only if it is decoded successfully.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
libceph: fixup error handling in osdmap_apply_incremental()

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.  Follow osdmap_decode() and 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>
libceph: nuke bogus encoding version check in osdmap_apply_incremental()

Only version 6 of osdmap encoding is supported, anything other than
version 6 results in an error and halts the decoding process.  Checking
if version is >= 5 is therefore bogus.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
libceph: fix and clarify ceph_decode_need() sizes

Sum up sizeof(...) results instead of (incorrectly) hard-coding the
number of bytes, expressed in ints and longs.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
libceph: rename __decode_pool{,_names}() to decode_pool{,_names}()

To be in line with all the other osdmap decode helpers.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
libceph: introduce decode{,_new}_pools() and switch to them

Consolidate pools (full map, map<u64, pg_pool_t>) and new_pools (inc
map, same) decoding logic into a common helper and switch to it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
libceph: switch osdmap_set_max_osd() to krealloc()

Use krealloc() instead of rolling our own.  (krealloc() with a NULL
first argument acts as a kmalloc()).  Properly initalize the new array
elements.  This is needed to make future additions to osdmap easier.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>