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lvm2/lib/cache/lvmetad.h
Petr Rockai f14f2d4378 lvmetad: Fix autoactivation for MDA-less PVs.
Calling pvscan --cache with -aay on a PV without an MDA would spuriously fail
with an internal error, because of an incorrect assumption that a parsed VG
structure was always available. This is not true and the autoactivation handler
needs to call vg_read to obtain metadata in cases where the PV had no MDAs to
parse. Therefore, we pass vgid into the handler instead of the (possibly NULL)
VG coming from the PV's MDA.
2012-12-12 13:19:04 +01:00

168 lines
5.6 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 active (where active means both that it is running
* and that we have a working connection with it).
*/
int lvmetad_active(void);
/* Print a warning if lvmetad is enabled but we failed to connect. */
void lvmetad_warning(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);
/*
* 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 *device,
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_active() (0)
# define lvmetad_warning() 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, device, 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