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lvm2/lib/cache/lvmetad.h
Peter Rajnoha a5f01dad22 filters: refresh filters when lvmetad use is toggled
We need to use proper filter chain when we disable lvmetad use
explicitly in the code by calling lvmetad_set_active(0) while
overriding existing configuration. We need to reinitialize filters
in this case so proper filter chain is used. The same applies
for the other way round - when we enable lvmetad use explicitly in
the code (though this is not yet used).
2014-09-30 16:08:05 +02:00

188 lines
6.3 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 *vgname, const char *vgid,
int partial, int changed,
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(struct cmd_context *, 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(cmd, 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