test: Use correct path to /dev in lvchange-raid.sh.
udev: run pvscan --cache via systemd-run in udev if the PV label is detected lost

If the PV label is lost (e.g. by doing a dd on the device), call
"systemd-run pvscan --cache <major>:<minor>" in 69-dm-lvm-metad.rules
to inform lvmetad about this state.

The reason for this is that ENV{SYSTEMD_WANTS}="lvm2-pvscan@<major>:<minor>"
logic will not cause the pvscan to be fired in this case since this works
only on proper device addition/removal cycle - the lvm2-pvscan service's
ExecStop is called only on proper REMOVE event - the service is bound to
device existence. Hence we need pvscan call via systemd-run (that
instantiates a quick transient service just to call the command).

See also https://bugzilla.redhat.com/show_bug.cgi?id=1063813.
cmirrord:  Clean-up stray warning message

cmirrord polls for messages on the kernel and cluster interfaces.
Sometimes it is possible for messages to be received on the cluster
interface and be waiting for processing while the node is in the
process of leaving the cluster group.  When this happens, the
messages received on the cluster interface are attempted to be
dispatched, but an error is returned because the connection is no
longer valid.  It is a harmless situation.  So, if we get the
specific error (CS_ERR_BAD_HANDLE) and we know that we have left
the group, then simply don't print the message.
config: fixup default values for selected config settings

These settings don't have any default value predefined:
  log/file
  log/activate_file
  global/library_dir

This settings has default value but not yet declared in config_settings.h:
  global/locking_library (default is DEFAULT_LOCKING_LIB)
config: use mempool for config paths used in find_config_tree_* functions

Using mempool is much safer than using the global static variable.
The global variable would be rewritten on each find_config_tree_* call
and we need to be very careful not to get into this problem (we don't
do now, but we can with the patches for "runtime defaults" that will follow).
config: add CFG_DEFAULT_RUN_TIME for config options with runtime defaults

Previously, we declared a default value as undefined ("NULL") for
settings which require runtime context to be set first (e.g. settings
for paths that rely on SYSTEM_DIR environment variable or they depend
on any other setting in some way).

If we want to output default values as they are really used in runtime,
we should make it possible to define a default value as function which
is evaluated, not just providing a firm constant value as it was before.

This patch defines simple prototypes for such functions. Also, there's
new helper macros "cfg_runtime" and "cfg_array_runtime" - they provide
exactly the same functionality as the original "cfg" and "cfg_array"
macros when defining the configuration settings in config_settings.h,
but they don't set the constant default value. Instead, they automatically
link the configuration setting definition with one of these functions:

  typedef int (*t_fn_CFG_TYPE_BOOL) (struct cmd_context *cmd, struct profile *profile);
  typedef int (*t_fn_CFG_TYPE_INT) (struct cmd_context *cmd, struct profile *profile);
  typedef float (*t_fn_CFG_TYPE_FLOAT) (struct cmd_context *cmd, struct profile *profile);
  typedef const char* (*t_fn_CFG_TYPE_STRING) (struct cmd_context *cmd, struct profile *profile);
  typedef const char* (*t_fn_CFG_TYPE_ARRAY) (struct cmd_context *cmd, struct profile *profile);

(The new macros actually set the CFG_DEFAULT_RUNTIME flag properly and
set the default value link to the function accordingly).

Then such configuration setting requires a function of selected type to
be defined. This function has a predefined name:

  get_default_<id>

...where the <id> is the id of the setting as defined in
config_settings.h. For example "backup_archive_dir_CFG" if defined
as a setting with default value evaluated in runtime with "cfg_runtime"
will automatically have "get_default_backup_archive_dir_CFG" function
linked to this setting to get the default value.
config: runtime default for devices/cache, devices/cache_dir

The devices/cache and devices/cache_dir are evaluated in runtime this way:

  - if devices/cache is set, use it

  - if devices_cache/dir or devices/cache_file_prefix is set, make up a
    path out of that for devices/cache in runtime, taking into account
    the LVM_SYSTEM_DIR environment variable if set

  - otherwise make up the path out of default which is:
    <LVM_SYSTEM_DIR>/<cache_dir>/<cache_file_prefix>.cache

With the runtime defaults, we can encode this easily now. Also, the lvm
dumpconfig can show proper and exact information about this setting then
(the variant that shows default values).
config: runtime default for backup/backup_dir, backup/archive_dir

The backup/backup_dir and backup/archive_dir default value is evaluated
in runtime and takes LVM_SYSTEM_DIR into consideration...
config: runtime default for config/profile_dir

The config/profile_dir default value takes LVM_SYSTEM_DIR into consideraton.
config: runtime default for activation/mirror_image_fault_policy

The activation/mirror_image_fault_policy default value copies the
value (or default one) used for activation/mirror_device_fault_policy.
config: separate cfg_def_default_value_hint out of cfg_def_get_default_value

If the config setting is defined as having no default value, but it's
still not NULL, it means such a value acts as a *hint* only
(e.g. a starting value from which the default value is calculated).

The new "cfg_def_get_default_value_hint" will always return the value
as defined in config_settings.h.

The original "cfg_def_get_default_value" will always return 0/NULL if
the config setting is defined with CFG_DEFAULT_UNDEFINED flag (hence
ignoring the hint).

This is needed for proper distiction between a correct default value
and the value which is just a hint or a starting point in calculation,
but it's not the final value (yes, we do have such settings!).
config: runtime default for allocation/thin_pool_chunk_size

The allocation/thin_pool_chunk_size is a bit more complex. It's default
value is evaluated in runtime based on selected thin_pool_chunk_size_policy.
But the value is just a starting point. The calculation then continues
with dependency on the properties of the devices used. Which means for
such a default value, we know only the starting value.
config: add default for allocation/cache_pool_chunk_size

The same as for allocation/thin_pool_chunk_size - the default value
used is just a starting point. The calculation continues using the
properties of the devices actually used.
cleanup: remove superfluous forward declaration
WHATS_NEW: config handling changes
tests: fix name-mangling test and remove udev transaction in dmsetup wrapper
configure: drop duplicated SUBST

These subst are already there from pkg_config
readline: switch to new-style readline typedef

Based on patch:
https://www.redhat.com/archives/lvm-devel/2014-March/msg00015.html

The CPPFunction typedef (among others) have been deprecated in favour of
specific prototyped typedefs since readline 4.2 (circa 2001).
It's been working since because compatibility typedefs have been in
place until they where removed in the recent readline 6.3 release.
Switch to the new style to avoid build breakage.

But also add full backward compatibility with define.

Signed-off-by: Gustavo Zacarias <gustavo zacarias com ar>
makefiles: use BLKID/UDEV_CFLAGS properly

blkid.h needs BLKID_CFLAGS
Do not add UDEV_CFLAGS everywhere and use it only when needed.
makefiles: link blkid library only to lvm

Don't add blkid to every linkage.
Link udev library just with lvm tools.
Drop extra linkage of udev library, since deps from libdevmapper
are already resolved in linked -ldevmapper.