doc: misc updates for release-process

Signed-off-by: Gary Lowell  <gary.lowell@inktank.com>
Reviewed-by: Ken Dreyer <ken.dreyer@inktank.com>
doc: update release-process for packages

New script to sign rpms in the repo and create the indexes, and
some description of additional packages that might need to be added.

Signed-off-by: Gary Lowell  <gary.lowell@inktank.com>
Reviewed-by: Ken Dreyer <ken.dreyer@inktank.com>
doc: fix reST formatting in release-process

Signed-off-by: Ken Dreyer <ken.dreyer@inktank.com>
doc: rm duplicate info from release-process

The "just push the new tag" bit is already done in the list of commands
above. Remove this piece, since it's duplicated by the "git push"
command above.

The ceph-deploy and backports-sections were empty. Remove them.
doc: update build prerequisites

Based on WIP branch by Gary Lowell <gary.lowell@inktank.com>.

Signed-off-by: Ken Dreyer <ken.dreyer@inktank.com>
rados_connect not thread-safe when using nss (documentation)

I'm not sure whether rados_connect is expected to be threadsafe or not,
so this is just a documentation patch rather than a fix; I'd appreciate
your opinion on whether this is expected behaviour or not.

The race condition is in the call to ceph::crypto::init when called by
common_init_finish, the issue being that it calls NSS_NoDB_Init (not
threadsafe) without locking. It can be reproduced (probabilistically) by
calling rados_connect on different rados_t objects simultaneously, due
to NSS_NoDB_Init's use of PR_CallOnce in nspr (which keeps global state,
and while PR_CallOnce is intended as a locking function, the locking
itself isn't thread-safe, and can pass PR_Lock a null pointer).

The observed behaviour is a segfault on calling rados_connect.
Backtrace, for reference:

    secmodName=secmodName@entry=0x7ffff4f64817 "", updateDir=updateDir@entry=0x7ffff4f64817 "", updCertPrefix=updCertPrefix@entry=0x7ffff4f64817 "",
    updKeyPrefix=updKeyPrefix@entry=0x7ffff4f64817 "", updateID=updateID@entry=0x7ffff4f64817 "", updateName=updateName@entry=0x7ffff4f64817 "",
    initContextPtr=initContextPtr@entry=0x0, initParams=initParams@entry=0x0, readOnly=readOnly@entry=1, noCertDB=noCertDB@entry=1, noModDB=noModDB@entry=1,
    forceOpen=forceOpen@entry=1, noRootInit=noRootInit@entry=1, optimizeSpace=optimizeSpace@entry=1, noSingleThreadedModules=noSingleThreadedModules@entry=0,
    allowAlreadyInitializedModules=allowAlreadyInitializedModules@entry=0, dontFinalizeModules=dontFinalizeModules@entry=0) at nssinit.c:551

Signed-off-by: Sharif Olorin <sio@tesser.org>
Merge pull request #1415 from ceph/wip-build-doc

doc: release-process documentation updates

Reviewed-by: Sage Weil <sage@inktank.com>
Merge pull request #1419 from ceph/wip-doc-prereq

doc: update build prerequisites
Merge pull request #1424 from fractalcat/thread-safety-doc-update

rados_connect not thread-safe when using nss (documentation)

Reviewed-by: Sage Weil <sage@inktank.com>