1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-22 17:35:59 +03:00
lvm2/lib/metadata/cache_manip.c
Zdenek Kabelac c2876ee1c9 cache: enforce local exlusive activation
For cache flushing local exlusive activation is needed.
2014-04-01 21:29:28 +02:00

305 lines
8.3 KiB
C

/*
* Copyright (C) 2014 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
*/
#include "lib.h"
#include "metadata.h"
#include "locking.h"
#include "pv_map.h"
#include "lvm-string.h"
#include "toolcontext.h"
#include "lv_alloc.h"
#include "pv_alloc.h"
#include "display.h"
#include "segtype.h"
#include "archiver.h"
#include "activate.h"
#include "str_list.h"
#include "defaults.h"
#include "lvm-exec.h"
int update_cache_pool_params(struct volume_group *vg, unsigned attr,
int passed_args,
uint32_t data_extents, uint32_t extent_size,
int *chunk_size_calc_method, uint32_t *chunk_size,
thin_discards_t *discards,
uint64_t *pool_metadata_size, int *zero)
{
uint64_t min_meta_size;
if ((*chunk_size < DM_CACHE_MIN_DATA_BLOCK_SIZE) ||
(*chunk_size > DM_CACHE_MAX_DATA_BLOCK_SIZE)) {
log_error("Chunk size must be in the range %s to %s.",
display_size(vg->cmd, DM_CACHE_MIN_DATA_BLOCK_SIZE),
display_size(vg->cmd, DM_CACHE_MAX_DATA_BLOCK_SIZE));
return 0;
}
if (*chunk_size & (DM_CACHE_MIN_DATA_BLOCK_SIZE - 1)) {
log_error("Chunk size must be a multiple of %u sectors.",
DM_CACHE_MIN_DATA_BLOCK_SIZE);
return 0;
}
/*
* Default meta size is:
* (4MiB + (16 Bytes for each chunk-sized block))
* ... plus a good amount of padding (2x) to cover any
* policy hint data that may be added in the future.
*/
min_meta_size = 16 * (data_extents * vg->extent_size);
min_meta_size /= *chunk_size; /* # of Bytes we need */
min_meta_size *= 2; /* plus some padding */
min_meta_size /= 512; /* in sectors */
min_meta_size += 4*1024*2; /* plus 4MiB */
if (!*pool_metadata_size)
*pool_metadata_size = min_meta_size;
if (*pool_metadata_size < min_meta_size) {
*pool_metadata_size = min_meta_size;
log_print("Increasing metadata device size to %"
PRIu64 " sectors", *pool_metadata_size);
}
if (*pool_metadata_size > (2 * DEFAULT_CACHE_POOL_MAX_METADATA_SIZE)) {
*pool_metadata_size = 2 * DEFAULT_CACHE_POOL_MAX_METADATA_SIZE;
log_print("Reducing metadata device size to %" PRIu64 " sectors",
*pool_metadata_size);
}
return 1;
}
/*
* lv_cache_create
* @pool
* @origin
*
* Given a cache_pool and an origin, link the two and create a
* cached LV.
*
* Returns: cache LV on success, NULL on failure
*/
struct logical_volume *lv_cache_create(struct logical_volume *pool,
struct logical_volume *origin)
{
const struct segment_type *segtype;
struct cmd_context *cmd = pool->vg->cmd;
struct logical_volume *cache_lv;
struct lv_segment *seg;
if (!lv_is_cache_pool(pool)) {
log_error(INTERNAL_ERROR
"%s is not a cache_pool LV", pool->name);
return NULL;
}
if (!dm_list_empty(&pool->segs_using_this_lv)) {
seg = get_only_segment_using_this_lv(pool);
log_error("%s is already in use by %s",
pool->name, seg ? seg->lv->name : "another LV");
return NULL;
}
if (lv_is_cache_type(origin)) {
/*
* FIXME: We can layer caches, insert_layer_for_lv() would
* have to do a better job renaming the LVs in the stack
* first so that there isn't a name collision with <name>_corig.
* The origin under the origin would become *_corig_corig
* before renaming the origin above to *_corig.
*/
log_error(INTERNAL_ERROR
"The origin, %s, cannot be of cache type",
origin->name);
return NULL;
}
if (!(segtype = get_segtype_from_string(cmd, "cache")))
return_NULL;
cache_lv = origin;
if (!(origin = insert_layer_for_lv(cmd, cache_lv, CACHE, "_corig")))
return_NULL;
seg = first_seg(cache_lv);
seg->segtype = segtype;
if (!attach_pool_lv(seg, pool, NULL, NULL))
return_NULL;
return cache_lv;
}
/*
* Cleanup orphan device in the table with temporary activation
* since in the suspend() we can't deactivate unused nodes
* and the resume() phase mishandles orphan nodes.
*
* TODO: improve libdm to handle this case automatically
*/
static int _cleanup_orphan_lv(struct logical_volume *lv)
{
lv->status |= LV_TEMPORARY;
if (!activate_lv(lv->vg->cmd, lv)) {
log_error("Failed to activate temporary %s", lv->name);
return 0;
}
if (!deactivate_lv(lv->vg->cmd, lv)) {
log_error("Failed to deactivate temporary %s", lv->name);
return 0;
}
lv->status &= ~LV_TEMPORARY;
return 1;
}
/*
* lv_cache_remove
* @cache_lv
*
* Given a cache LV, remove the cache layer. This will unlink
* the origin and cache_pool, remove the cache LV layer, and promote
* the origin to a usable non-cached LV of the same name as the
* given cache_lv.
*
* Returns: 1 on success, 0 on failure
*/
int lv_cache_remove(struct logical_volume *cache_lv)
{
struct cmd_context *cmd = cache_lv->vg->cmd;
const char *policy_name;
uint64_t dirty_blocks;
struct lv_segment *cache_seg = first_seg(cache_lv);
struct logical_volume *corigin_lv;
struct logical_volume *cache_pool_lv;
if (!lv_is_cache(cache_lv)) {
log_error(INTERNAL_ERROR "LV %s is not cached.", cache_lv->name);
return 0;
}
/* Active volume is needed (writeback only?) */
if (!lv_is_active_locally(cache_lv) &&
!activate_lv_excl_local(cache_lv->vg->cmd, cache_lv)) {
log_error("Failed to active cache locally %s.", cache_lv->name);
return 0;
}
/*
* FIXME:
* Before the link can be broken, we must ensure that the
* cache has been flushed. This may already be the case
* if the cache mode is writethrough (or the cleaner
* policy is in place from a previous half-finished attempt
* to remove the cache_pool). It could take a long time to
* flush the cache - it should probably be done in the background.
*
* Also, if we do perform the flush in the background and we
* happen to also be removing the cache/origin LV, then we
* could check if the cleaner policy is in place and simply
* remove the cache_pool then without waiting for the flush to
* complete.
*/
if (!lv_cache_policy_info(cache_lv, &policy_name, NULL, NULL))
return_0;
if (strcmp(policy_name, "cleaner")) {
/* We must swap in the cleaner to flush the cache */
log_print_unless_silent("Flushing cache for %s.", cache_lv->name);
/*
* Is there are clean way to free the memory for the name
* and argv when changing the policy?
*/
cache_seg->policy_name = "cleaner";
cache_seg->policy_argc = 0;
cache_seg->policy_argv = NULL;
/* update the kernel to put the cleaner policy in place */
if (!vg_write(cache_lv->vg))
return_0;
if (!suspend_lv(cmd, cache_lv))
return_0;
if (!vg_commit(cache_lv->vg))
return_0;
if (!resume_lv(cmd, cache_lv))
return_0;
}
//FIXME: use polling to do this...
do {
if (!lv_cache_block_info(cache_lv, NULL,
&dirty_blocks, NULL, NULL))
return_0;
log_print_unless_silent("%" PRIu64 " blocks must still be flushed.",
dirty_blocks);
if (dirty_blocks)
sleep(1);
} while (dirty_blocks);
cache_pool_lv = cache_seg->pool_lv;
if (!detach_pool_lv(cache_seg))
return_0;
/* Regular LV which user may remove if there are problems */
corigin_lv = seg_lv(cache_seg, 0);
lv_set_visible(corigin_lv);
if (!remove_layer_from_lv(cache_lv, corigin_lv))
return_0;
if (!vg_write(cache_lv->vg))
return_0;
/*
* suspend_lv on this cache LV suspends all components:
* - the top-level cache LV
* - the origin
* - the cache_pool _cdata and _cmeta
*/
if (!suspend_lv(cmd, cache_lv))
return_0;
if (!vg_commit(cache_lv->vg))
return_0;
/* resume_lv on this (former) cache LV will resume all */
/*
* FIXME: currently we can't easily avoid execution of
* blkid on resumed error device
*/
if (!resume_lv(cmd, cache_lv))
return_0;
/*
* cleanup orphan devices
*
* FIXME:
* fix _add_dev() to support this case better
* since the should be handled interanlly by resume_lv()
* which should autoremove any orhpans
*/
if (!_cleanup_orphan_lv(corigin_lv)) /* _corig */
return_0;
if (!_cleanup_orphan_lv(seg_lv(first_seg(cache_pool_lv), 0))) /* _cdata */
return_0;
if (!_cleanup_orphan_lv(first_seg(cache_pool_lv)->metadata_lv)) /* _cmeta */
return_0;
if (!lv_remove(corigin_lv))
return_0;
return 1;
}