shaba/lvm2
1
0
Fork 0
mirror of git://sourceware.org/git/lvm2.git synced 2025-08-06 21:49:28 +03:00
Code Releases Activity

lvmlockd: rescan lockd VG in two new cases

Browse Source 
Previously, a command would only rescan a lockd VG
when lvmetad returned the "vg_invalid" flag indicating
that the cached copy was invalid (which is done by
lvmlockd.)  This is still the only usual reason for
rescanning a lockd VG, but two new special cases are
added where we also do the rescan:

. When the --shared option is used to display lockd VGs
  from hosts not using lvmlockd.  This is the same case
  as using --foreign to display foreign VGs, but --shared
  was missing the corresponding bits to rescan the VGs.

. When a lockd VG is allowed to be read for displaying
  after failing to acquire the lock from lvmlockd.  In
  this case, the usual mechanism for validating the
  cache is missed, so assume the cache would have been
  invalidated.  (This had been a previous todo item
  that was lost during other cleanup.)

These were long-standing todos that were lost track of.
This commit is contained in:
David Teigland
2015-08-26 14:06:39 -05:00
parent 231b7df6cc
commit 32e22a0037
3 changed files with 77 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
lib/cache/lvmetad.c vendored
View File

@ -434,6 +434,7 @@ struct volume_group *lvmetad_vg_lookup(struct cmd_context *cmd, const char *vgna
struct format_type *fmt;
struct dm_config_node *pvcn;
struct pv_list *pvl;
int rescan = 0;
if (!lvmetad_active())
return NULL;
@ -492,16 +493,56 @@ struct volume_group *lvmetad_vg_lookup(struct cmd_context *cmd, const char *vgna
if (!(vg = import_vg_from_lvmetad_config_tree(reply.cft, fid)))
goto_out;
/*
* Read the VG from disk, ignoring the lvmetad copy in these
* cases:
*
* 1. The host is not using lvmlockd, but is reading lockd VGs
* using the --shared option. The shared option is meant to
* let hosts not running lvmlockd look at lockd VGs, like the
* foreign option allows hosts to look at foreign VGs. When
* --foreign is used, the code forces a rescan since the local
* lvmetad cache of foreign VGs is likely stale. Similarly,
* for --shared, have the code reading the shared VGs below
* not use the cached copy from lvmetad but to rescan the VG.
*
* 2. The host failed to acquire the VG lock from lvmlockd for
* the lockd VG. In this case, the usual mechanisms for
* updating the lvmetad copy of the VG have been missed. Since
* we don't know if the cached copy is valid, assume it's not.
*
* 3. lvmetad has returned the "vg_invalid" flag, which is the
* usual mechanism used by lvmlockd/lvmetad to cause a host to
* reread a VG from disk that has been modified from another
* host.
*/
if (is_lockd_type(vg->lock_type) && cmd->include_shared_vgs) {
log_debug_lvmetad("Rescan VG %s because including shared", vgname);
rescan = 1;
} else if (is_lockd_type(vg->lock_type) && cmd->lockd_vg_rescan) {
log_debug_lvmetad("Rescan VG %s because no lvmlockd lock is held", vgname);
rescan = 1;
} else if (dm_config_find_node(reply.cft->root, "vg_invalid")) {
log_debug_lvmetad("Rescan VG %s because lvmetad returned invalid", vgname);
rescan = 1;
}
/*
* locking may have detected a newer vg version and
* invalidated the cached vg.
*/
if (dm_config_find_node(reply.cft->root, "vg_invalid")) {
if (rescan) {
log_debug_lvmetad("Update invalid lvmetad cache for VG %s", vgname);
vg2 = lvmetad_pvscan_vg(cmd, vg);
release_vg(vg);
vg = vg2;
fid = vg->fid;
if (!vg) {
log_debug_lvmetad("VG %s from lvmetad not found during rescan.", vgname);
fid = NULL;
goto out;
} else
fid = vg->fid;
}
dm_list_iterate_items(pvl, &vg->pvs) {