mirror of
git://sourceware.org/git/lvm2.git
synced 2024-12-21 13:34:40 +03:00
25b733809a
Lots of changes/very little testing so far => there'll be bugs!
Use 'vgcreate -M text' to create a volume group with its metadata stored
in text files. Text format metadata changes should be reasonably atomic,
with a (basic) automatic recovery mechanism if the system crashes while a
change is in progress.
Add a metadata section to lvm.conf to specify multiple directories if
you want (recommended) to keep multiple copies of the metadata (eg on
different filesystems).
e.g. metadata {
dirs = ["/etc/lvm/metadata1","/usr/local/lvm/metadata2"]
}
Plenty of refinements still in the pipeline.
116 lines
2.8 KiB
C
116 lines
2.8 KiB
C
/*
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* Copyright (C) 2002 Sistina Software (UK) Limited.
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*
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* This file is released under the LGPL.
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*
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*/
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#include "log.h"
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#include "locking.h"
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#include "locking_types.h"
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#include "activate.h"
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#include "config.h"
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#include "defaults.h"
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#include "lvm-file.h"
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#include "lvm-string.h"
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#include "dbg_malloc.h"
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#include <limits.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/file.h>
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#include <fcntl.h>
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#include <dlfcn.h>
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#include <signal.h>
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static void *locking_module = NULL;
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static void (*end_fn) (void) = NULL;
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static int (*lock_fn) (struct cmd_context * cmd, const char *resource,
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int flags) = NULL;
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static int (*init_fn) (int type, struct config_file * cf) = NULL;
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static int lock_resource(struct cmd_context *cmd, const char *resource,
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int flags)
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{
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if (lock_fn)
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return lock_fn(cmd, resource, flags);
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else
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return 0;
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}
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static void fin_external_locking(void)
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{
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if (end_fn)
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end_fn();
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dlclose(locking_module);
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locking_module = NULL;
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end_fn = NULL;
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lock_fn = NULL;
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}
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int init_external_locking(struct locking_type *locking, struct config_file *cf)
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{
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char _lock_lib[PATH_MAX];
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if (locking_module) {
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log_error("External locking already initialised");
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return 1;
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}
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locking->lock_resource = lock_resource;
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locking->fin_locking = fin_external_locking;
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/* Get locking module name from config file */
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strncpy(_lock_lib, find_config_str(cf->root, "global/locking_library",
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'/', "lvm2_locking.so"),
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sizeof(_lock_lib));
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/* If there is a module_dir in the config file then
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look for the locking module in there first and then
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using the normal dlopen(3) mechanism of looking
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down LD_LIBRARY_PATH and /lib, /usr/lib.
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If course, if the library name starts with a slash then
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just use the name... */
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if (_lock_lib[0] != '/') {
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struct stat st;
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char _lock_lib1[PATH_MAX];
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lvm_snprintf(_lock_lib1, sizeof(_lock_lib1),
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"%s/%s",
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find_config_str(cf->root, "global/module_dir",
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'/', "RUBBISH"), _lock_lib);
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/* Does it exist ? */
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if (stat(_lock_lib1, &st) == 0) {
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strcpy(_lock_lib, _lock_lib1);
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}
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}
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log_very_verbose("Opening locking library %s", _lock_lib);
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locking_module = dlopen(_lock_lib, RTLD_LAZY);
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if (!locking_module) {
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log_error("Unable to open external locking module %s",
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_lock_lib);
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return 0;
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}
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/* Get the functions we need */
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init_fn = dlsym(locking_module, "init_locking");
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lock_fn = dlsym(locking_module, "lock_resource");
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end_fn = dlsym(locking_module, "end_locking");
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/* Are they all there ? */
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if (!end_fn || !init_fn || !lock_fn) {
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log_error ("Shared library %s does not contain locking "
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"functions", _lock_lib);
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dlclose(locking_module);
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return 0;
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}
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log_verbose("Opened external locking module %s", _lock_lib);
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return init_fn(2, cf);
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}
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