1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-10-28 03:27:58 +03:00
lvm2/lib/cache/lvmetad.h
Peter Rajnoha 8d5cff5b9b lv/vgchange: do not try to connect to lvmetad if socket absent and --sysinit -aay used
If using lv/vgchange --sysinit -aay and lvmetad is enabled, we'd like to
avoid the direct activation and rely on autoactivation instead so
it fits system initialization scripts.

But if we're calling lv/vgchange --sysinit -aay too early when even
lvmetad service is not started yet, we just need to do the direct
activation instead without printing any error messages (while
trying to connect to lvmetad and not finding its socket).

This patch adds two helper functions - "lvmetad_socket_present" and
"lvmetad_used" which can be used to check for this condition properly
and avoid these lvmetad connections when the socket is not present
(and hence lvmetad is not yet running).
2013-11-26 14:51:23 +01:00

187 lines
6.2 KiB
C

/*
* Copyright (C) 2012 Red Hat, Inc.
*
* This file is part of LVM2.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _LVM_METAD_H
#define _LVM_METAD_H
#include "config-util.h"
struct volume_group;
struct cmd_context;
struct dm_config_tree;
enum activation_change;
typedef int (*activation_handler) (struct cmd_context *cmd,
const char *vgid, int partial,
enum activation_change activate);
#ifdef LVMETAD_SUPPORT
/*
* Initialise the communication with lvmetad. Normally called by
* lvmcache_init. Sets up a global handle for our process.
*/
void lvmetad_init(struct cmd_context *);
/*
* Override the use of lvmetad for retrieving scan results and metadata.
*/
void lvmetad_set_active(int);
/*
* Configure the socket that lvmetad_init will use to connect to the daemon.
*/
void lvmetad_set_socket(const char *);
/*
* Check whether lvmetad is used.
*/
int lvmetad_used(void);
/*
* Check if lvmetad socket is present (either the one set by lvmetad_set_socket
* or the default one if not set). For example, this may be used before calling
* lvmetad_active() check that does connect to the socket - this would produce
* various connection errors if the socket is not present.
*/
int lvmetad_socket_present(void);
/*
* Check whether lvmetad is active (where active means both that it is running
* and that we have a working connection with it).
*/
int lvmetad_active(void);
/*
* Connect to lvmetad unless the connection is already open or lvmetad is
* not configured to be used. If we fail to connect, print a warning.
*/
void lvmetad_connect_or_warn(void);
/*
* Drop connection to lvmetad. A subsequent lvmetad_init() will re-establish
* the connection (possibly at a different socket path).
*/
void lvmetad_disconnect(void);
/*
* Set the "lvmetad validity token" (currently only consists of the lvmetad
* filter. See lvm.conf.
*/
void lvmetad_set_token(const struct dm_config_value *filter);
/*
* Release allocated token.
*/
void lvmetad_release_token(void);
// FIXME What's described here doesn't appear to be implemented yet.
/*
* Send a new version of VG metadata to lvmetad. This is normally called after
* vg_write but before vg_commit. After vg_commit, lvmetad_vg_commit is called
* to seal the transaction. The result of lvmetad_vg_update is that the new
* metadata is stored tentatively in lvmetad, but it is not used until
* lvmetad_vg_commit. The request is validated immediately and lvmetad_vg_commit
* only constitutes a pointer update.
*/
int lvmetad_vg_update(struct volume_group *vg);
/*
* Inform lvmetad that a VG has been removed. This is not entirely safe, but is
* only needed during vgremove, which does not wipe PV labels and therefore
* cannot mark the PVs as gone.
*/
int lvmetad_vg_remove(struct volume_group *vg);
/*
* Notify lvmetad that a PV has been found. It is not an error if the PV is
* already marked as present in lvmetad. If a non-NULL vg pointer is supplied,
* it is taken to represent the metadata read from the MDA(s) present on that
* PV. It *is* an error if: the VG is already known to lvmetad, the sequence
* number on the cached and on the discovered PV match but the metadata content
* does not.
*/
int lvmetad_pv_found(const struct id *pvid, struct device *dev,
const struct format_type *fmt, uint64_t label_sector,
struct volume_group *vg, activation_handler handler);
/*
* Inform the daemon that the device no longer exists.
*/
int lvmetad_pv_gone(dev_t devno, const char *pv_name, activation_handler handler);
int lvmetad_pv_gone_by_dev(struct device *dev, activation_handler handler);
/*
* Request a list of all PVs available to lvmetad. If requested, this will also
* read labels off all the PVs to populate lvmcache.
*/
int lvmetad_pv_list_to_lvmcache(struct cmd_context *cmd);
/*
* Lookup an individual PV.
* If found is not NULL, it is set according to whether or not the PV is found,
* otherwise if the PV is not found an error is returned.
*/
int lvmetad_pv_lookup(struct cmd_context *cmd, struct id pvid, int *found);
int lvmetad_pv_lookup_by_dev(struct cmd_context *cmd, struct device *dev, int *found);
/*
* Request a list of all VGs available to lvmetad and use it to fill in
* lvmcache..
*/
int lvmetad_vg_list_to_lvmcache(struct cmd_context *cmd);
/*
* Find a VG by its ID or its name in the lvmetad cache. Gives NULL if the VG is
* not found.
*/
struct volume_group *lvmetad_vg_lookup(struct cmd_context *cmd,
const char *vgname, const char *vgid);
/*
* Scan a single device and update lvmetad with the result(s).
*/
int lvmetad_pvscan_single(struct cmd_context *cmd, struct device *dev,
activation_handler handler);
int lvmetad_pvscan_all_devs(struct cmd_context *cmd, activation_handler handler);
# else /* LVMETAD_SUPPORT */
# define lvmetad_init(cmd) do { } while (0)
# define lvmetad_disconnect() do { } while (0)
# define lvmetad_set_active(a) do { } while (0)
# define lvmetad_set_socket(a) do { } while (0)
# define lvmetad_used() (0)
# define lvmetad_socket_present() (0)
# define lvmetad_active() (0)
# define lvmetad_connect_or_warn() do { } while (0)
# define lvmetad_set_token(a) do { } while (0)
# define lvmetad_release_token() do { } while (0)
# define lvmetad_vg_update(vg) (1)
# define lvmetad_vg_remove(vg) (1)
# define lvmetad_pv_found(pvid, dev, fmt, label_sector, vg, handler) (1)
# define lvmetad_pv_gone(devno, pv_name, handler) (1)
# define lvmetad_pv_gone_by_dev(dev, handler) (1)
# define lvmetad_pv_list_to_lvmcache(cmd) (1)
# define lvmetad_pv_lookup(cmd, pvid, found) (0)
# define lvmetad_pv_lookup_by_dev(cmd, dev, found) (0)
# define lvmetad_vg_list_to_lvmcache(cmd) (1)
# define lvmetad_vg_lookup(cmd, vgname, vgid) (NULL)
# define lvmetad_pvscan_single(cmd, dev, handler) (0)
# define lvmetad_pvscan_all_devs(cmd, handler) (0)
# endif /* LVMETAD_SUPPORT */
#endif