shaba/lvm2
1
0
Fork 0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-21 13:34:40 +03:00
Code Releases Activity

metadata: Eliminate redundant nested VG metadata

Browse Source 
Only lv_committed() now uses vg->vg_committed and it appears redundant
if its contents match the enclosing VG so don't waste cycles creating it
when that's known to be true when no write lock is held so the struct
won't get modified.
This commit is contained in:
Alasdair G Kergon 2017-11-14 15:38:55 +00:00
parent 7a5728fb4c
commit b5f62a143d
2 changed files with 31 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
WHATS_NEW
View File

@ -1,5 +1,6 @@
Version 2.02.177 -
====================================
Eliminate redundant nested VG metadata in VG struct.
Avoid importing persistent filter in vgscan/pvscan/vgrename.
Fix memleak of string buffer when vgcfgbackup runs in secure mode.
Do not print error when clvmd cannot find running clvmd.

64
lib/metadata/metadata.c
View File

@ -897,46 +897,41 @@ int vgcreate_params_validate(struct cmd_context *cmd,
return 1;
}
static void _vg_wipe_cached_precommitted(struct volume_group *vg)
{
release_vg(vg->vg_precommitted);
vg->vg_precommitted = NULL;
}
static void _vg_move_cached_precommitted_to_committed(struct volume_group *vg)
{
release_vg(vg->vg_committed);
vg->vg_committed = vg->vg_precommitted;
vg->vg_precommitted = NULL;
}
/*
* Update content of precommitted VG
*
* TODO: Optimize in the future, since lvmetad needs similar
* config tree processing in lvmetad_vg_update().
*/
static int _vg_update_vg_precommitted(struct volume_group *vg)
static int _vg_update_embedded_copy(struct volume_group *vg, struct volume_group **vg_embedded)
{
struct dm_config_tree *cft_precommitted;
struct dm_config_tree *cft;
release_vg(vg->vg_precommitted);
vg->vg_precommitted = NULL;
_vg_wipe_cached_precommitted(vg);
/* Copy the VG using an export followed by import */
if (!(cft_precommitted = export_vg_to_config_tree(vg)))
if (!(cft = export_vg_to_config_tree(vg)))
return_0;
if (!(vg->vg_precommitted = import_vg_from_config_tree(cft_precommitted, vg->fid))) {
dm_config_destroy(cft_precommitted);
if (!(*vg_embedded = import_vg_from_config_tree(cft, vg->fid))) {
dm_config_destroy(cft);
return_0;
}
dm_config_destroy(cft_precommitted);
return 1;
}
static int _vg_update_vg_committed(struct volume_group *vg)
{
if (dm_pool_locked(vg->vgmem))
return 1;
if (vg->vg_committed || is_orphan_vg(vg->name)) /* we already have it */
return 1;
if (!_vg_update_vg_precommitted(vg))
return_0;
vg->vg_committed = vg->vg_precommitted;
vg->vg_precommitted = NULL;
dm_config_destroy(cft);
return 1;
}
@ -949,7 +944,6 @@ static struct volume_group *_vg_make_handle(struct cmd_context *cmd,
struct volume_group *vg,
uint32_t failure)
{
/* Never return a cached VG structure for a failure */
if (vg && vg->vginfo && failure != SUCCESS) {
release_vg(vg);
@ -961,8 +955,13 @@ static struct volume_group *_vg_make_handle(struct cmd_context *cmd,
vg->read_status = failure;
if (vg->fid && !_vg_update_vg_committed(vg))
vg->read_status |= FAILED_ALLOCATION;
/*
* If we hold a write lock and might be changing the VG contents, embed a pristine
* copy of the VG metadata for the activation code to use later
*/
if (vg->fid && !dm_pool_locked(vg->vgmem) && !vg->vg_committed && !is_orphan_vg(vg->name))
if (vg_write_lock_held() && !_vg_update_embedded_copy(vg, &vg->vg_committed))
vg->read_status |= FAILED_ALLOCATION;
return vg;
}
@ -3092,7 +3091,7 @@ int vg_write(struct volume_group *vg)
}
}
if (!_vg_update_vg_precommitted(vg)) /* prepare precommited */
if (!_vg_update_embedded_copy(vg, &vg->vg_precommitted)) /* prepare precommited */
return_0;
lockd_vg_update(vg);
@ -3177,9 +3176,7 @@ int vg_commit(struct volume_group *vg)
pvl->pv->status &= ~PV_MOVED_VG;
/* This *is* the original now that it's commited. */
release_vg(vg->vg_committed);
vg->vg_committed = vg->vg_precommitted;
vg->vg_precommitted = NULL;
_vg_move_cached_precommitted_to_committed(vg);
}
/* If update failed, remove any cached precommitted metadata. */
@ -3212,8 +3209,7 @@ void vg_revert(struct volume_group *vg)
}
}
release_vg(vg->vg_precommitted); /* VG is no longer needed */
vg->vg_precommitted = NULL;
_vg_wipe_cached_precommitted(vg); /* VG is no longer needed */
dm_list_iterate_items(mda, &vg->fid->metadata_areas_in_use) {
if (mda->ops->vg_revert &&