[lvm-devel] dev-mornfall-lvmcache - lvmcache: Remove VG metadata caches (text, cfg, volume_group) for now.
Petr Rockai
mornfall at fedoraproject.org
Wed Jun 5 12:06:24 UTC 2013
Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=0c9eddbab5ceeee00a4ae393ac33099dd2a31b6b
Commit: 0c9eddbab5ceeee00a4ae393ac33099dd2a31b6b
Parent: a2d9a818cfc469f928239cef7498c87b4afc43ae
Author: Petr Rockai <prockai at redhat.com>
AuthorDate: Mon Feb 4 20:06:41 2013 +0100
Committer: Petr Rockai <prockai at redhat.com>
CommitterDate: Wed Jun 5 12:37:37 2013 +0200
lvmcache: Remove VG metadata caches (text, cfg, volume_group) for now.
---
lib/cache/lvmcache.c | 156 +-------------------------------------------------
1 files changed, 1 insertions(+), 155 deletions(-)
diff --git a/lib/cache/lvmcache.c b/lib/cache/lvmcache.c
index 8d50919..f8c8a9e 100644
--- a/lib/cache/lvmcache.c
+++ b/lib/cache/lvmcache.c
@@ -55,12 +55,7 @@ struct lvmcache_vginfo {
struct lvmcache_vginfo *next; /* Another VG with same name? */
char *creation_host;
size_t vgmetadata_size;
- char *vgmetadata; /* Copy of VG metadata as format_text string */
- struct dm_config_tree *cft; /* Config tree created from vgmetadata */
- /* Lifetime is directly tied to vgmetadata */
- struct volume_group *cached_vg;
unsigned holders;
- unsigned vg_use_count; /* Counter of vg reusage */
unsigned precommitted; /* Is vgmetadata live or precommitted? */
};
@@ -111,27 +106,6 @@ void lvmcache_seed_infos_from_lvmetad(struct cmd_context *cmd)
_has_scanned = 1;
}
-/* Volume Group metadata cache functions */
-static void _free_cached_vgmetadata(struct lvmcache_vginfo *vginfo)
-{
- if (!vginfo || !vginfo->vgmetadata)
- return;
-
- dm_free(vginfo->vgmetadata);
-
- vginfo->vgmetadata = NULL;
-
- /* Release also cached config tree */
- if (vginfo->cft) {
- dm_config_destroy(vginfo->cft);
- vginfo->cft = NULL;
- }
-
- log_debug_cache("Metadata cache: VG %s wiped.", vginfo->vgname);
-
- release_vg(vginfo->cached_vg);
-}
-
/*
* Cache VG metadata against the vginfo with matching vgid.
*/
@@ -139,40 +113,18 @@ static void _store_metadata(struct volume_group *vg, unsigned precommitted)
{
char uuid[64] __attribute__((aligned(8)));
struct lvmcache_vginfo *vginfo;
- char *data;
- size_t size;
if (!(vginfo = lvmcache_vginfo_from_vgid((const char *)&vg->id))) {
stack;
return;
}
- if (!(size = export_vg_to_buffer(vg, &data))) {
- stack;
- _free_cached_vgmetadata(vginfo);
- return;
- }
-
- /* Avoid reparsing of the same data string */
- if (vginfo->vgmetadata && vginfo->vgmetadata_size == size &&
- strcmp(vginfo->vgmetadata, data) == 0)
- dm_free(data);
- else {
- _free_cached_vgmetadata(vginfo);
- vginfo->vgmetadata_size = size;
- vginfo->vgmetadata = data;
- }
-
vginfo->precommitted = precommitted;
if (!id_write_format((const struct id *)vginfo->vgid, uuid, sizeof(uuid))) {
stack;
return;
}
-
- log_debug_cache("Metadata cache: VG %s (%s) stored (%" PRIsize_t " bytes%s).",
- vginfo->vgname, uuid, size,
- precommitted ? ", precommitted" : "");
}
static void _update_cache_info_lock_state(struct lvmcache_info *info,
@@ -205,9 +157,6 @@ static void _update_cache_vginfo_lock_state(struct lvmcache_vginfo *vginfo,
dm_list_iterate_items(info, &vginfo->infos)
_update_cache_info_lock_state(info, locked,
&cached_vgmetadata_valid);
-
- if (!cached_vgmetadata_valid)
- _free_cached_vgmetadata(vginfo);
}
void lvmcache_update_lock_state(const char *vgname, int locked)
@@ -234,16 +183,11 @@ static void _drop_metadata(const char *vgname, int drop_precommitted)
* already invalidated the PV labels (before caching it)
* and we must not do it again.
*/
- if (!drop_precommitted && vginfo->precommitted && !vginfo->vgmetadata)
- log_error(INTERNAL_ERROR "metadata commit (or revert) missing before "
- "dropping metadata from cache.");
if (drop_precommitted || !vginfo->precommitted)
dm_list_iterate_items(info, &vginfo->infos)
info->status |= CACHE_INVALID;
- _free_cached_vgmetadata(vginfo);
-
/* VG revert */
if (drop_precommitted)
vginfo->precommitted = 0;
@@ -603,114 +547,18 @@ int lvmcache_label_scan(struct cmd_context *cmd, int full_scan)
struct volume_group *lvmcache_get_vg(struct cmd_context *cmd, const char *vgname,
const char *vgid, unsigned precommitted)
{
- struct lvmcache_vginfo *vginfo;
- struct volume_group *vg = NULL;
- struct format_instance *fid;
- struct format_instance_ctx fic;
-
- /*
- * We currently do not store precommitted metadata in lvmetad at
- * all. This means that any request for precommitted metadata is served
- * using the classic scanning mechanics, and read from disk or from
- * lvmcache.
- */
- if (lvmetad_active() && !precommitted) {
- /* Still serve the locally cached VG if available */
- if (vgid && (vginfo = lvmcache_vginfo_from_vgid(vgid)) &&
- vginfo->vgmetadata && (vg = vginfo->cached_vg))
- goto out;
+ if (lvmetad_active() && !precommitted)
return lvmetad_vg_lookup(cmd, vgname, vgid);
- }
-
- if (!vgid || !(vginfo = lvmcache_vginfo_from_vgid(vgid)) || !vginfo->vgmetadata)
- return NULL;
-
- if (!_vginfo_is_valid(vginfo))
- return NULL;
-
- /*
- * Don't return cached data if either:
- * (i) precommitted metadata is requested but we don't have it cached
- * - caller should read it off disk;
- * (ii) live metadata is requested but we have precommitted metadata cached
- * and no devices are suspended so caller may read it off disk.
- *
- * If live metadata is requested but we have precommitted metadata cached
- * and devices are suspended, we assume this precommitted metadata has
- * already been preloaded and committed so it's OK to return it as live.
- * Note that we do not clear the PRECOMMITTED flag.
- */
- if ((precommitted && !vginfo->precommitted) ||
- (!precommitted && vginfo->precommitted && !critical_section()))
- return NULL;
-
- /* Use already-cached VG struct when available */
- if ((vg = vginfo->cached_vg))
- goto out;
-
- fic.type = FMT_INSTANCE_MDAS | FMT_INSTANCE_AUX_MDAS;
- fic.context.vg_ref.vg_name = vginfo->vgname;
- fic.context.vg_ref.vg_id = vgid;
- if (!(fid = vginfo->fmt->ops->create_instance(vginfo->fmt, &fic)))
- return_NULL;
-
- /* Build config tree from vgmetadata, if not yet cached */
- if (!vginfo->cft &&
- !(vginfo->cft =
- dm_config_from_string(vginfo->vgmetadata)))
- goto_bad;
-
- if (!(vg = import_vg_from_config_tree(vginfo->cft, fid)))
- goto_bad;
-
- /* Cache VG struct for reuse */
- vginfo->cached_vg = vg;
- vginfo->holders = 1;
- vginfo->vg_use_count = 0;
- vg->vginfo = vginfo;
-
- if (!dm_pool_lock(vg->vgmem, detect_internal_vg_cache_corruption()))
- goto_bad;
-
-out:
- vginfo->holders++;
- vginfo->vg_use_count++;
- log_debug_cache("Using cached %smetadata for VG %s with %u holder(s).",
- vginfo->precommitted ? "pre-committed " : "",
- vginfo->vgname, vginfo->holders);
-
- return vg;
-
-bad:
- _free_cached_vgmetadata(vginfo);
return NULL;
}
-// #if 0
int lvmcache_vginfo_holders_dec_and_test_for_zero(struct lvmcache_vginfo *vginfo)
{
- log_debug_cache("VG %s decrementing %d holder(s) at %p.",
- vginfo->cached_vg->name, vginfo->holders, vginfo->cached_vg);
-
if (--vginfo->holders)
return 0;
- if (vginfo->vg_use_count > 1)
- log_debug_cache("VG %s reused %d times.",
- vginfo->cached_vg->name, vginfo->vg_use_count);
-
- /* Debug perform crc check only when it's been used more then once */
- if (!dm_pool_unlock(vginfo->cached_vg->vgmem,
- detect_internal_vg_cache_corruption() &&
- (vginfo->vg_use_count > 1)))
- stack;
-
- vginfo->cached_vg->vginfo = NULL;
- vginfo->cached_vg = NULL;
-
return 1;
}
-// #endif
struct dm_list *lvmcache_get_vgids(struct cmd_context *cmd,
int include_internal)
@@ -873,8 +721,6 @@ static int _free_vginfo(struct lvmcache_vginfo *vginfo)
struct lvmcache_vginfo *primary_vginfo, *vginfo2;
int r = 1;
- _free_cached_vgmetadata(vginfo);
-
vginfo2 = primary_vginfo = lvmcache_vginfo_from_vgname(vginfo->vgname, NULL);
if (vginfo == primary_vginfo) {
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