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lvm2/lib/device/dev-cache.h
David Teigland 92e1422707 process_each_pv: do full scan earlier to find new devices
Before commit c1f246fedf,
_get_all_devices() did a full device scan before
get_vgnameids() was called.  The full scan in
_get_all_devices() is from calling dev_iter_create(f, 1).
The '1' arg forces a full scan.

By doing a full scan in _get_all_devices(), new devices
were added to dev-cache before get_vgnameids() began
scanning labels.  So, labels would be read from new devices.
(e.g. by the first 'pvs' command after the new device appeared.)

After that commit, _get_all_devices() was called
after get_vgnameids() was finished scanning labels.
So, new devices would be missed while scanning labels.
When _get_all_devices() saw the new devices (after
labels were scanned), those devices were added to
the .cache file.  This meant that the second 'pvs'
command would see the devices because they would be
in .cache.

Now, the full device scan is factored out of
_get_all_devices() and called by itself at the
start of the command so that new devices will
be known before get_vgnameids() scans labels.
2015-12-14 10:02:29 -06:00

71 lines
2.0 KiB
C

/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
*
* 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_DEV_CACHE_H
#define _LVM_DEV_CACHE_H
#include "device.h"
#include "lvm-wrappers.h"
/*
* predicate for devices.
*/
struct dev_filter {
int (*passes_filter) (struct dev_filter * f, struct device * dev);
void (*destroy) (struct dev_filter * f);
void (*wipe) (struct dev_filter * f);
int (*dump) (struct dev_filter * f, int merge_existing);
void *private;
unsigned use_count;
};
/*
* The global device cache.
*/
struct cmd_context;
int dev_cache_init(struct cmd_context *cmd);
int dev_cache_exit(void);
/*
* Returns number of open devices.
*/
int dev_cache_check_for_open_devices(void);
/* Trigger(1) or avoid(0) a scan */
void dev_cache_scan(int do_scan);
int dev_cache_has_scanned(void);
void dev_cache_full_scan(struct dev_filter *f);
int dev_cache_add_dir(const char *path);
int dev_cache_add_loopfile(const char *path);
__attribute__((nonnull(1)))
struct device *dev_cache_get(const char *name, struct dev_filter *f);
// TODO
struct device *dev_cache_get_by_devt(dev_t device, struct dev_filter *f);
void dev_set_preferred_name(struct dm_str_list *sl, struct device *dev);
/*
* Object for iterating through the cache.
*/
struct dev_iter;
struct dev_iter *dev_iter_create(struct dev_filter *f, int dev_scan);
void dev_iter_destroy(struct dev_iter *iter);
struct device *dev_iter_get(struct dev_iter *iter);
void dev_reset_error_count(struct cmd_context *cmd);
#endif