* master - lvmetad: use new label_scan for update from lvmlockd
@ 2018-04-23 13:52 David Teigland
0 siblings, 0 replies; 2+ messages in thread
From: David Teigland @ 2018-04-23 13:52 UTC (permalink / raw)
To: lvm-devel
Gitweb: https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=9c71fa02144619a67993920cee2146fed820f49c
Commit: 9c71fa02144619a67993920cee2146fed820f49c
Parent: 098c843c50cdcc2e4f4162037e1ff5975624f3e2
Author: David Teigland <teigland@redhat.com>
AuthorDate: Thu Oct 26 10:58:23 2017 -0500
Committer: David Teigland <teigland@redhat.com>
CommitterDate: Fri Apr 20 11:21:41 2018 -0500
lvmetad: use new label_scan for update from lvmlockd
When lvmlockd indicates that the lvmetad cache is out of
date because of changes by another node, lvmetad_pvscan_vg()
rescans the devices in the VG to update lvmetad. Use the
new label_scan in this function to use the common code and
take advantage of the new aio and reduced reads.
---
lib/cache/lvmetad.c | 435 +++++++++++++++++++++++++++++++++++----------------
1 files changed, 298 insertions(+), 137 deletions(-)
diff --git a/lib/cache/lvmetad.c b/lib/cache/lvmetad.c
index 4b7410c..552dbf0 100644
--- a/lib/cache/lvmetad.c
+++ b/lib/cache/lvmetad.c
@@ -39,7 +39,7 @@ static int64_t _lvmetad_update_timeout;
static int _found_lvm1_metadata = 0;
-static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg);
+static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg, const char *vgid, struct format_type *fmt);
static uint64_t _monotonic_seconds(void)
{
@@ -1093,14 +1093,17 @@ struct volume_group *lvmetad_vg_lookup(struct cmd_context *cmd, const char *vgna
* invalidated the cached vg.
*/
if (rescan) {
- if (!(vg2 = _lvmetad_pvscan_vg(cmd, vg))) {
+ if (!(vg2 = _lvmetad_pvscan_vg(cmd, vg, vgid, fmt))) {
log_debug_lvmetad("VG %s from lvmetad not found during rescan.", vgname);
fid = NULL;
release_vg(vg);
vg = NULL;
goto out;
}
+ fid->ref_count++;
release_vg(vg);
+ fid->ref_count--;
+ fmt->ops->destroy_instance(fid);
vg = vg2;
fid = vg2->fid;
}
@@ -1108,14 +1111,14 @@ struct volume_group *lvmetad_vg_lookup(struct cmd_context *cmd, const char *vgna
dm_list_iterate_items(pvl, &vg->pvs) {
if (!_pv_update_struct_pv(pvl->pv, fid)) {
vg = NULL;
- goto_out; /* FIXME error path */
+ goto_out; /* FIXME: use an error path that disables lvmetad */
}
}
dm_list_iterate_items(pvl, &vg->pvs_outdated) {
if (!_pv_update_struct_pv(pvl->pv, fid)) {
vg = NULL;
- goto_out; /* FIXME error path */
+ goto_out; /* FIXME: use an error path that disables lvmetad */
}
}
@@ -1761,6 +1764,7 @@ int lvmetad_pv_gone_by_dev(struct device *dev)
*/
struct _lvmetad_pvscan_baton {
+ struct cmd_context *cmd;
struct volume_group *vg;
struct format_instance *fid;
};
@@ -1771,7 +1775,7 @@ static int _lvmetad_pvscan_single(struct metadata_area *mda, void *baton)
struct volume_group *vg;
if (mda_is_ignored(mda) ||
- !(vg = mda->ops->vg_read(b->fid, "", mda, NULL, NULL, 1)))
+ !(vg = mda->ops->vg_read(b->fid, "", mda, NULL, NULL)))
return 1;
/* FIXME Also ensure contents match etc. */
@@ -1784,6 +1788,33 @@ static int _lvmetad_pvscan_single(struct metadata_area *mda, void *baton)
}
/*
+ * FIXME: handle errors and do proper comparison of metadata from each area
+ * like vg_read and fall back to real vg_read from disk if there's any problem.
+ */
+
+static int _lvmetad_pvscan_vg_single(struct metadata_area *mda, void *baton)
+{
+ struct _lvmetad_pvscan_baton *b = baton;
+ struct volume_group *vg = NULL;
+
+ if (mda_is_ignored(mda))
+ return 1;
+
+ if (!(vg = mda->ops->vg_read(b->fid, "", mda, NULL, NULL)))
+ return 1;
+
+ if (!b->vg)
+ b->vg = vg;
+ else if (vg->seqno > b->vg->seqno) {
+ release_vg(b->vg);
+ b->vg = vg;
+ } else
+ release_vg(vg);
+
+ return 1;
+}
+
+/*
* The lock manager may detect that the vg cached in lvmetad is out of date,
* due to something like an lvcreate from another host.
* This is limited to changes that only affect the vg (not global state like
@@ -1792,41 +1823,41 @@ static int _lvmetad_pvscan_single(struct metadata_area *mda, void *baton)
* the VG, and that PV may have been reused for another VG.
*/
-static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg)
+static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg,
+ const char *vgid, struct format_type *fmt)
{
char pvid_s[ID_LEN + 1] __attribute__((aligned(8)));
char uuid[64] __attribute__((aligned(8)));
- struct label *label;
- struct volume_group *vg_ret = NULL;
- struct dm_config_tree *vgmeta_ret = NULL;
struct dm_config_tree *vgmeta;
struct pv_list *pvl, *pvl_new;
- struct device_list *devl, *devl_new, *devlsafe;
+ struct device_list *devl, *devlsafe;
struct dm_list pvs_scan;
struct dm_list pvs_drop;
- struct dm_list pvs_new;
+ struct lvmcache_vginfo *vginfo = NULL;
struct lvmcache_info *info = NULL;
struct format_instance *fid;
struct format_instance_ctx fic = { .type = 0 };
struct _lvmetad_pvscan_baton baton;
+ struct volume_group *save_vg;
+ struct dm_config_tree *save_meta;
struct device *save_dev = NULL;
uint32_t save_seqno = 0;
- int missing_devs = 0;
- int check_new_pvs = 0;
+ int found_new_pvs = 0;
+ int retried_reads = 0;
int found;
+ save_vg = NULL;
+ save_meta = NULL;
+ save_dev = NULL;
+ save_seqno = 0;
+
dm_list_init(&pvs_scan);
dm_list_init(&pvs_drop);
- dm_list_init(&pvs_new);
- log_debug_lvmetad("Rescanning VG %s (seqno %u).", vg->name, vg->seqno);
+ log_debug_lvmetad("Rescan VG %s to update lvmetad (seqno %u).", vg->name, vg->seqno);
/*
- * Another host may have added a PV to the VG, and some
- * commands do not always populate their lvmcache with
- * all devs from lvmetad, so they would fail to find
- * the new PV when scanning the VG. So make sure this
- * command knows about all PVs from lvmetad.
+ * Make sure this command knows about all PVs from lvmetad.
*/
lvmcache_seed_infos_from_lvmetad(cmd);
@@ -1841,54 +1872,111 @@ static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct v
dm_list_add(&pvs_scan, &devl->list);
}
-scan_more:
+ /*
+ * Rescan labels/metadata only from devs that we previously
+ * saw in the VG. If we find below that there are new PVs
+ * in the VG, we'll have to rescan all devices to find which
+ * device(s) are now being used.
+ */
+ log_debug_lvmetad("Rescan VG %s scanning data from devs in previous metadata.", vg->name);
+
+ label_scan_devs(cmd, &pvs_scan);
/*
- * Run the equivalent of lvmetad_pvscan_single on each dev in the VG.
+ * Check if any pvs_scan entries are no longer PVs.
+ * In that case, label_read/_find_label_header will have
+ * found no label_header, and would have dropped the
+ * info struct for the device from lvmcache. So, if
+ * we look up the info struct here and don't find it,
+ * we can infer it's no longer a PV.
+ *
+ * FIXME: we should record specific results from the
+ * label_read and then check specifically for whatever
+ * result means "no label was found", rather than going
+ * about this indirectly via the lvmcache side effects.
*/
dm_list_iterate_items_safe(devl, devlsafe, &pvs_scan) {
- if (!devl->dev)
- continue;
+ if (!(info = lvmcache_info_from_pvid(devl->dev->pvid, devl->dev, 0))) {
+ /* Another host removed this PV from the VG. */
+ log_debug_lvmetad("Rescan VG %s from %s dropping dev (no label).",
+ vg->name, dev_name(devl->dev));
+ dm_list_move(&pvs_drop, &devl->list);
+ }
+ }
- log_debug_lvmetad("Rescan VG %s scanning %s.", vg->name, dev_name(devl->dev));
+ fic.type = FMT_INSTANCE_MDAS | FMT_INSTANCE_AUX_MDAS;
+ fic.context.vg_ref.vg_name = vg->name;
+ fic.context.vg_ref.vg_id = vgid;
- if (!label_read(devl->dev, &label, 0)) {
- /* Another host removed this PV from the VG. */
- log_debug_lvmetad("Rescan VG %s found %s was removed.", vg->name, dev_name(devl->dev));
+ retry_reads:
- if ((info = lvmcache_info_from_pvid(devl->dev->pvid, NULL, 0)))
- lvmcache_del(info);
+ if (!(fid = fmt->ops->create_instance(fmt, &fic))) {
+ /* FIXME: are there only internal reasons for failures here? */
+ log_error("Reading VG %s failed to create format instance.", vg->name);
+ return NULL;
+ }
- dm_list_move(&pvs_drop, &devl->list);
- continue;
- }
+ /* FIXME: not sure if this is necessary */
+ fid->ref_count++;
- info = (struct lvmcache_info *) label->info;
+ baton.fid = fid;
+ baton.cmd = cmd;
- baton.vg = NULL;
- baton.fid = lvmcache_fmt(info)->ops->create_instance(lvmcache_fmt(info), &fic);
- if (!baton.fid)
- return_NULL;
+ /*
+ * FIXME: this vg_read path does not have the ability to repair
+ * any problems with the VG, e.g. VG on one dev has an older
+ * seqno. When vg_read() is reworked, we need to fall back
+ * to using that from here (and vg_read's from lvmetad) when
+ * there is a problem. Perhaps by disabling lvmetad when a
+ * VG problem is detected, causing commands to fully fall
+ * back to disk, which will repair the VG. Then lvmetad can
+ * be repopulated and re-enabled (possibly automatically.)
+ */
- if (baton.fid->fmt->features & FMT_OBSOLETE) {
- log_debug_lvmetad("Ignoring obsolete format on PV %s in VG %s.", dev_name(devl->dev), vg->name);
- lvmcache_fmt(info)->ops->destroy_instance(baton.fid);
+ /*
+ * Do a low level vg_read on each dev, verify the vg returned
+ * from metadata on each device is for the VG being read
+ * (the PV may have been removed from the VG being read and
+ * added to a different one), and return this vg to the caller
+ * as the current vg to use.
+ *
+ * The label scan above will have saved in lvmcache which
+ * vg each device is used in, so we could figure that part
+ * out without doing the vg_read.
+ */
+ dm_list_iterate_items_safe(devl, devlsafe, &pvs_scan) {
+ if (!devl->dev)
+ continue;
+
+ log_debug_lvmetad("Rescan VG %s getting metadata from %s.",
+ vg->name, dev_name(devl->dev));
+
+ /*
+ * The info struct for this dev knows what and where
+ * the mdas are for this dev (the label scan saved
+ * the mda locations for this dev on the lvmcache info struct).
+ */
+ if (!(info = lvmcache_info_from_pvid(devl->dev->pvid, devl->dev, 0))) {
+ log_debug_lvmetad("Rescan VG %s from %s dropping dev (no info).",
+ vg->name, dev_name(devl->dev));
dm_list_move(&pvs_drop, &devl->list);
continue;
}
+ baton.vg = NULL;
+
/*
* Read VG metadata from this dev's mdas.
*/
- lvmcache_foreach_mda(info, _lvmetad_pvscan_single, &baton);
+ lvmcache_foreach_mda(info, _lvmetad_pvscan_vg_single, &baton);
/*
* The PV may have been removed from the VG by another host
* since we last read the VG.
*/
if (!baton.vg) {
- log_debug_lvmetad("Rescan VG %s did not find %s.", vg->name, dev_name(devl->dev));
- lvmcache_fmt(info)->ops->destroy_instance(baton.fid);
+ log_debug_lvmetad("Rescan VG %s from %s dropping dev (no metadata).",
+ vg->name, dev_name(devl->dev));
dm_list_move(&pvs_drop, &devl->list);
continue;
}
@@ -1898,10 +1986,15 @@ scan_more:
* different VG since we last read the VG.
*/
if (strcmp(baton.vg->name, vg->name)) {
- log_debug_lvmetad("Rescan VG %s found different VG %s on PV %s.",
- vg->name, baton.vg->name, dev_name(devl->dev));
+ log_debug_lvmetad("Rescan VG %s from %s dropping dev (other VG %s).",
+ vg->name, dev_name(devl->dev), baton.vg->name);
+ release_vg(baton.vg);
+ continue;
+ }
+
+ if (!(vgmeta = export_vg_to_config_tree(baton.vg))) {
+ log_error("VG export to config tree failed");
release_vg(baton.vg);
- dm_list_move(&pvs_drop, &devl->list);
continue;
}
@@ -1911,20 +2004,35 @@ scan_more:
* read from each other dev.
*/
- if (!save_seqno)
- save_seqno = baton.vg->seqno;
-
- if (!(vgmeta = export_vg_to_config_tree(baton.vg))) {
- log_error("VG export to config tree failed");
- release_vg(baton.vg);
- return NULL;
+ if (save_vg && (save_seqno != baton.vg->seqno)) {
+ /* FIXME: fall back to vg_read to correct this. */
+ log_warn("WARNING: inconsistent metadata for VG %s on devices %s seqno %u and %s seqno %u.",
+ vg->name, dev_name(save_dev), save_seqno,
+ dev_name(devl->dev), baton.vg->seqno);
+ log_warn("WARNING: temporarily disable lvmetad to repair metadata.");
+
+ /* Use the most recent */
+ if (save_seqno < baton.vg->seqno) {
+ release_vg(save_vg);
+ dm_config_destroy(save_meta);
+ save_vg = baton.vg;
+ save_meta = vgmeta;
+ save_seqno = baton.vg->seqno;
+ save_dev = devl->dev;
+ } else {
+ release_vg(baton.vg);
+ dm_config_destroy(vgmeta);
+ }
+ continue;
}
- if (!vgmeta_ret) {
- vgmeta_ret = vgmeta;
+ if (!save_vg) {
+ save_vg = baton.vg;
+ save_meta = vgmeta;
+ save_seqno = baton.vg->seqno;
save_dev = devl->dev;
} else {
- struct dm_config_node *meta1 = vgmeta_ret->root;
+ struct dm_config_node *meta1 = save_meta->root;
struct dm_config_node *meta2 = vgmeta->root;
struct dm_config_node *sib1 = meta1->sib;
struct dm_config_node *sib2 = meta2->sib;
@@ -1949,73 +2057,128 @@ scan_more:
meta2->sib = NULL;
if (compare_config(meta1, meta2)) {
+ /* FIXME: fall back to vg_read to correct this. */
+ log_warn("WARNING: inconsistent metadata for VG %s on devices %s seqno %u and %s seqno %u.",
+ vg->name, dev_name(save_dev), save_seqno,
+ dev_name(devl->dev), baton.vg->seqno);
+ log_warn("WARNING: temporarily disable lvmetad to repair metadata.");
log_error("VG %s metadata comparison failed for device %s vs %s",
vg->name, dev_name(devl->dev), save_dev ? dev_name(save_dev) : "none");
- _log_debug_inequality(vg->name, vgmeta_ret->root, vgmeta->root);
+ _log_debug_inequality(vg->name, save_meta->root, vgmeta->root);
meta1->sib = sib1;
meta2->sib = sib2;
- dm_config_destroy(vgmeta);
- dm_config_destroy(vgmeta_ret);
+
+ /* no right choice, just use the previous copy */
release_vg(baton.vg);
- return NULL;
+ dm_config_destroy(vgmeta);
}
meta1->sib = sib1;
meta2->sib = sib2;
+ release_vg(baton.vg);
dm_config_destroy(vgmeta);
}
+ }
- /*
- * Look for any new PVs in the VG metadata that were not in our
- * previous version of the VG. Add them to pvs_new to be
- * scanned in this loop just like the old PVs.
- */
- if (!check_new_pvs) {
- check_new_pvs = 1;
- dm_list_iterate_items(pvl_new, &baton.vg->pvs) {
- found = 0;
- dm_list_iterate_items(pvl, &vg->pvs) {
- if (pvl_new->pv->dev != pvl->pv->dev)
- continue;
- found = 1;
- break;
- }
- if (found)
- continue;
- if (!pvl_new->pv->dev) {
- strncpy(pvid_s, (char *) &pvl_new->pv->id, sizeof(pvid_s) - 1);
- if (!id_write_format((const struct id *)&pvid_s, uuid, sizeof(uuid)))
- stack;
- log_error("Device not found for PV %s in VG %s", uuid, vg->name);
- missing_devs++;
+ /* FIXME: see above */
+ fid->ref_count--;
+
+ /*
+ * Look for any new PVs in the VG metadata that were not in our
+ * previous version of the VG.
+ *
+ * (Don't look for new PVs after a rescan and retry.)
+ */
+ found_new_pvs = 0;
+
+ if (save_vg && !retried_reads) {
+ dm_list_iterate_items(pvl_new, &save_vg->pvs) {
+ found = 0;
+ dm_list_iterate_items(pvl, &vg->pvs) {
+ if (pvl_new->pv->dev != pvl->pv->dev)
continue;
- }
- if (!(devl_new = dm_pool_zalloc(cmd->mem, sizeof(*devl_new))))
- return_NULL;
- devl_new->dev = pvl_new->pv->dev;
- dm_list_add(&pvs_new, &devl_new->list);
- log_debug_lvmetad("Rescan VG %s found %s was added.", vg->name, dev_name(devl_new->dev));
+ found = 1;
+ break;
+ }
+
+ /*
+ * PV in new VG metadata not found in old VG metadata.
+ * There's a good chance we don't know about this new
+ * PV or what device it's on; a label scan is needed
+ * of all devices so we know which device the VG is
+ * now using.
+ */
+ if (!found) {
+ found_new_pvs++;
+ strncpy(pvid_s, (char *) &pvl_new->pv->id, sizeof(pvid_s) - 1);
+ if (!id_write_format((const struct id *)&pvid_s, uuid, sizeof(uuid)))
+ stack;
+ log_debug_lvmetad("Rescan VG %s found new PV %s.", vg->name, uuid);
}
}
+ }
- release_vg(baton.vg);
+ if (!save_vg && retried_reads) {
+ log_error("VG %s not found after rescanning devices.", vg->name);
+ goto out;
}
/*
- * Do the same scanning above for any new PVs.
+ * Do a full rescan of devices, then look up which devices the
+ * scan found for this VG name, and select those devices to
+ * read metadata from in the loop above (rather than the list
+ * of devices we created from our last copy of the vg metadata.)
+ *
+ * Case 1: VG we knew is no longer on any of the devices we knew it
+ * to be on (save_vg is NULL, which means the metadata wasn't found
+ * when reading mdas on each of the initial pvs_scan devices).
+ * Rescan all devs and then retry reading metadata from the devs that
+ * the scan finds associated with this VG.
+ *
+ * Case 2: VG has new PVs but we don't know what devices they are
+ * so rescan all devs and then retry reading metadata from the devs
+ * that the scan finds associated with this VG.
+ *
+ * (N.B. after a retry, we don't check for found_new_pvs.)
*/
- if (!dm_list_empty(&pvs_new)) {
+ if (!save_vg || found_new_pvs) {
+ if (!save_vg)
+ log_debug_lvmetad("Rescan VG %s did not find VG on previous devs.", vg->name);
+ if (found_new_pvs)
+ log_debug_lvmetad("Rescan VG %s scanning all devs to find new PVs.", vg->name);
+
+ label_scan(cmd);
+
+ if (!(vginfo = lvmcache_vginfo_from_vgname(vg->name, NULL))) {
+ log_error("VG %s vg info not found after rescanning devices.", vg->name);
+ goto out;
+ }
+
+ /*
+ * Set pvs_scan to devs that the label scan found
+ * in the VG and retry the metadata reading loop.
+ */
dm_list_init(&pvs_scan);
- dm_list_splice(&pvs_scan, &pvs_new);
- dm_list_init(&pvs_new);
- log_debug_lvmetad("Rescan VG %s found new PVs to scan.", vg->name);
- goto scan_more;
- }
- if (missing_devs) {
- if (vgmeta_ret)
- dm_config_destroy(vgmeta_ret);
- return_NULL;
+ if (!lvmcache_get_vg_devs(cmd, vginfo, &pvs_scan)) {
+ log_error("VG %s info devs not found after rescanning devices.", vg->name);
+ goto out;
+ }
+
+ log_debug_lvmetad("Rescan VG %s has %d PVs after label scan.",
+ vg->name, dm_list_size(&pvs_scan));
+
+ if (save_vg)
+ release_vg(save_vg);
+ if (save_meta)
+ dm_config_destroy(save_meta);
+ save_vg = NULL;
+ save_meta = NULL;
+ save_dev = NULL;
+ save_seqno = 0;
+ found_new_pvs = 0;
+ retried_reads = 1;
+ goto retry_reads;
}
/*
@@ -2024,52 +2187,50 @@ scan_more:
dm_list_iterate_items(devl, &pvs_drop) {
if (!devl->dev)
continue;
- log_debug_lvmetad("Rescan VG %s dropping %s.", vg->name, dev_name(devl->dev));
- if (!lvmetad_pv_gone_by_dev(devl->dev))
- return_NULL;
+ log_debug_lvmetad("Rescan VG %s removing %s from lvmetad.", vg->name, dev_name(devl->dev));
+ if (!lvmetad_pv_gone_by_dev(devl->dev)) {
+ /* FIXME: use an error path that disables lvmetad */
+ log_error("Failed to remove %s from lvmetad.", dev_name(devl->dev));
+ }
}
/*
- * Update the VG in lvmetad.
+ * Update lvmetad with the newly read version of the VG.
+ * When the seqno is unchanged the cached VG can be left.
*/
- if (vgmeta_ret) {
- fid = lvmcache_fmt(info)->ops->create_instance(lvmcache_fmt(info), &fic);
- if (!(vg_ret = import_vg_from_config_tree(vgmeta_ret, fid))) {
- log_error("VG import from config tree failed");
- lvmcache_fmt(info)->ops->destroy_instance(fid);
- goto out;
+ if (save_vg && (save_seqno != vg->seqno)) {
+ dm_list_iterate_items(devl, &pvs_scan) {
+ if (!devl->dev)
+ continue;
+ log_debug_lvmetad("Rescan VG %s removing %s from lvmetad to replace.",
+ vg->name, dev_name(devl->dev));
+ if (!lvmetad_pv_gone_by_dev(devl->dev)) {
+ /* FIXME: use an error path that disables lvmetad */
+ log_error("Failed to remove %s from lvmetad.", dev_name(devl->dev));
+ }
}
+ log_debug_lvmetad("Rescan VG %s updating lvmetad from seqno %u to seqno %u.",
+ vg->name, vg->seqno, save_seqno);
+
/*
- * Update lvmetad with the newly read version of the VG.
- * When the seqno is unchanged the cached VG can be left.
+ * If this vg_update fails the cached metadata in
+ * lvmetad will remain invalid.
*/
- if (save_seqno != vg->seqno) {
- dm_list_iterate_items(devl, &pvs_scan) {
- if (!devl->dev)
- continue;
- log_debug_lvmetad("Rescan VG %s dropping to replace %s.", vg->name, dev_name(devl->dev));
- if (!lvmetad_pv_gone_by_dev(devl->dev))
- return_NULL;
- }
-
- log_debug_lvmetad("Rescan VG %s updating lvmetad from seqno %u to seqno %u.",
- vg->name, vg->seqno, save_seqno);
-
- /*
- * If this vg_update fails the cached metadata in
- * lvmetad will remain invalid.
- */
- vg_ret->lvmetad_update_pending = 1;
- if (!lvmetad_vg_update_finish(vg_ret))
- log_error("Failed to update lvmetad with new VG meta");
+ save_vg->lvmetad_update_pending = 1;
+ if (!lvmetad_vg_update_finish(save_vg)) {
+ /* FIXME: use an error path that disables lvmetad */
+ log_error("Failed to update lvmetad with new VG meta");
}
- dm_config_destroy(vgmeta_ret);
}
out:
- if (vg_ret)
- log_debug_lvmetad("Rescan VG %s done (seqno %u).", vg_ret->name, vg_ret->seqno);
- return vg_ret;
+ if (!save_vg && fid)
+ fmt->ops->destroy_instance(fid);
+ if (save_meta)
+ dm_config_destroy(save_meta);
+ if (save_vg)
+ log_debug_lvmetad("Rescan VG %s done (new seqno %u).", save_vg->name, save_vg->seqno);
+ return save_vg;
}
int lvmetad_pvscan_single(struct cmd_context *cmd, struct device *dev,
^ permalink raw reply related [flat|nested] 2+ messages in thread
* master - lvmetad: use new label_scan for update from lvmlockd
@ 2018-04-23 13:49 David Teigland
0 siblings, 0 replies; 2+ messages in thread
From: David Teigland @ 2018-04-23 13:49 UTC (permalink / raw)
To: lvm-devel
Gitweb: https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=9c71fa02144619a67993920cee2146fed820f49c
Commit: 9c71fa02144619a67993920cee2146fed820f49c
Parent: 098c843c50cdcc2e4f4162037e1ff5975624f3e2
Author: David Teigland <teigland@redhat.com>
AuthorDate: Thu Oct 26 10:58:23 2017 -0500
Committer: David Teigland <teigland@redhat.com>
CommitterDate: Fri Apr 20 11:21:41 2018 -0500
lvmetad: use new label_scan for update from lvmlockd
When lvmlockd indicates that the lvmetad cache is out of
date because of changes by another node, lvmetad_pvscan_vg()
rescans the devices in the VG to update lvmetad. Use the
new label_scan in this function to use the common code and
take advantage of the new aio and reduced reads.
---
lib/cache/lvmetad.c | 435 +++++++++++++++++++++++++++++++++++----------------
1 files changed, 298 insertions(+), 137 deletions(-)
diff --git a/lib/cache/lvmetad.c b/lib/cache/lvmetad.c
index 4b7410c..552dbf0 100644
--- a/lib/cache/lvmetad.c
+++ b/lib/cache/lvmetad.c
@@ -39,7 +39,7 @@ static int64_t _lvmetad_update_timeout;
static int _found_lvm1_metadata = 0;
-static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg);
+static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg, const char *vgid, struct format_type *fmt);
static uint64_t _monotonic_seconds(void)
{
@@ -1093,14 +1093,17 @@ struct volume_group *lvmetad_vg_lookup(struct cmd_context *cmd, const char *vgna
* invalidated the cached vg.
*/
if (rescan) {
- if (!(vg2 = _lvmetad_pvscan_vg(cmd, vg))) {
+ if (!(vg2 = _lvmetad_pvscan_vg(cmd, vg, vgid, fmt))) {
log_debug_lvmetad("VG %s from lvmetad not found during rescan.", vgname);
fid = NULL;
release_vg(vg);
vg = NULL;
goto out;
}
+ fid->ref_count++;
release_vg(vg);
+ fid->ref_count--;
+ fmt->ops->destroy_instance(fid);
vg = vg2;
fid = vg2->fid;
}
@@ -1108,14 +1111,14 @@ struct volume_group *lvmetad_vg_lookup(struct cmd_context *cmd, const char *vgna
dm_list_iterate_items(pvl, &vg->pvs) {
if (!_pv_update_struct_pv(pvl->pv, fid)) {
vg = NULL;
- goto_out; /* FIXME error path */
+ goto_out; /* FIXME: use an error path that disables lvmetad */
}
}
dm_list_iterate_items(pvl, &vg->pvs_outdated) {
if (!_pv_update_struct_pv(pvl->pv, fid)) {
vg = NULL;
- goto_out; /* FIXME error path */
+ goto_out; /* FIXME: use an error path that disables lvmetad */
}
}
@@ -1761,6 +1764,7 @@ int lvmetad_pv_gone_by_dev(struct device *dev)
*/
struct _lvmetad_pvscan_baton {
+ struct cmd_context *cmd;
struct volume_group *vg;
struct format_instance *fid;
};
@@ -1771,7 +1775,7 @@ static int _lvmetad_pvscan_single(struct metadata_area *mda, void *baton)
struct volume_group *vg;
if (mda_is_ignored(mda) ||
- !(vg = mda->ops->vg_read(b->fid, "", mda, NULL, NULL, 1)))
+ !(vg = mda->ops->vg_read(b->fid, "", mda, NULL, NULL)))
return 1;
/* FIXME Also ensure contents match etc. */
@@ -1784,6 +1788,33 @@ static int _lvmetad_pvscan_single(struct metadata_area *mda, void *baton)
}
/*
+ * FIXME: handle errors and do proper comparison of metadata from each area
+ * like vg_read and fall back to real vg_read from disk if there's any problem.
+ */
+
+static int _lvmetad_pvscan_vg_single(struct metadata_area *mda, void *baton)
+{
+ struct _lvmetad_pvscan_baton *b = baton;
+ struct volume_group *vg = NULL;
+
+ if (mda_is_ignored(mda))
+ return 1;
+
+ if (!(vg = mda->ops->vg_read(b->fid, "", mda, NULL, NULL)))
+ return 1;
+
+ if (!b->vg)
+ b->vg = vg;
+ else if (vg->seqno > b->vg->seqno) {
+ release_vg(b->vg);
+ b->vg = vg;
+ } else
+ release_vg(vg);
+
+ return 1;
+}
+
+/*
* The lock manager may detect that the vg cached in lvmetad is out of date,
* due to something like an lvcreate from another host.
* This is limited to changes that only affect the vg (not global state like
@@ -1792,41 +1823,41 @@ static int _lvmetad_pvscan_single(struct metadata_area *mda, void *baton)
* the VG, and that PV may have been reused for another VG.
*/
-static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg)
+static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg,
+ const char *vgid, struct format_type *fmt)
{
char pvid_s[ID_LEN + 1] __attribute__((aligned(8)));
char uuid[64] __attribute__((aligned(8)));
- struct label *label;
- struct volume_group *vg_ret = NULL;
- struct dm_config_tree *vgmeta_ret = NULL;
struct dm_config_tree *vgmeta;
struct pv_list *pvl, *pvl_new;
- struct device_list *devl, *devl_new, *devlsafe;
+ struct device_list *devl, *devlsafe;
struct dm_list pvs_scan;
struct dm_list pvs_drop;
- struct dm_list pvs_new;
+ struct lvmcache_vginfo *vginfo = NULL;
struct lvmcache_info *info = NULL;
struct format_instance *fid;
struct format_instance_ctx fic = { .type = 0 };
struct _lvmetad_pvscan_baton baton;
+ struct volume_group *save_vg;
+ struct dm_config_tree *save_meta;
struct device *save_dev = NULL;
uint32_t save_seqno = 0;
- int missing_devs = 0;
- int check_new_pvs = 0;
+ int found_new_pvs = 0;
+ int retried_reads = 0;
int found;
+ save_vg = NULL;
+ save_meta = NULL;
+ save_dev = NULL;
+ save_seqno = 0;
+
dm_list_init(&pvs_scan);
dm_list_init(&pvs_drop);
- dm_list_init(&pvs_new);
- log_debug_lvmetad("Rescanning VG %s (seqno %u).", vg->name, vg->seqno);
+ log_debug_lvmetad("Rescan VG %s to update lvmetad (seqno %u).", vg->name, vg->seqno);
/*
- * Another host may have added a PV to the VG, and some
- * commands do not always populate their lvmcache with
- * all devs from lvmetad, so they would fail to find
- * the new PV when scanning the VG. So make sure this
- * command knows about all PVs from lvmetad.
+ * Make sure this command knows about all PVs from lvmetad.
*/
lvmcache_seed_infos_from_lvmetad(cmd);
@@ -1841,54 +1872,111 @@ static struct volume_group *_lvmetad_pvscan_vg(struct cmd_context *cmd, struct v
dm_list_add(&pvs_scan, &devl->list);
}
-scan_more:
+ /*
+ * Rescan labels/metadata only from devs that we previously
+ * saw in the VG. If we find below that there are new PVs
+ * in the VG, we'll have to rescan all devices to find which
+ * device(s) are now being used.
+ */
+ log_debug_lvmetad("Rescan VG %s scanning data from devs in previous metadata.", vg->name);
+
+ label_scan_devs(cmd, &pvs_scan);
/*
- * Run the equivalent of lvmetad_pvscan_single on each dev in the VG.
+ * Check if any pvs_scan entries are no longer PVs.
+ * In that case, label_read/_find_label_header will have
+ * found no label_header, and would have dropped the
+ * info struct for the device from lvmcache. So, if
+ * we look up the info struct here and don't find it,
+ * we can infer it's no longer a PV.
+ *
+ * FIXME: we should record specific results from the
+ * label_read and then check specifically for whatever
+ * result means "no label was found", rather than going
+ * about this indirectly via the lvmcache side effects.
*/
dm_list_iterate_items_safe(devl, devlsafe, &pvs_scan) {
- if (!devl->dev)
- continue;
+ if (!(info = lvmcache_info_from_pvid(devl->dev->pvid, devl->dev, 0))) {
+ /* Another host removed this PV from the VG. */
+ log_debug_lvmetad("Rescan VG %s from %s dropping dev (no label).",
+ vg->name, dev_name(devl->dev));
+ dm_list_move(&pvs_drop, &devl->list);
+ }
+ }
- log_debug_lvmetad("Rescan VG %s scanning %s.", vg->name, dev_name(devl->dev));
+ fic.type = FMT_INSTANCE_MDAS | FMT_INSTANCE_AUX_MDAS;
+ fic.context.vg_ref.vg_name = vg->name;
+ fic.context.vg_ref.vg_id = vgid;
- if (!label_read(devl->dev, &label, 0)) {
- /* Another host removed this PV from the VG. */
- log_debug_lvmetad("Rescan VG %s found %s was removed.", vg->name, dev_name(devl->dev));
+ retry_reads:
- if ((info = lvmcache_info_from_pvid(devl->dev->pvid, NULL, 0)))
- lvmcache_del(info);
+ if (!(fid = fmt->ops->create_instance(fmt, &fic))) {
+ /* FIXME: are there only internal reasons for failures here? */
+ log_error("Reading VG %s failed to create format instance.", vg->name);
+ return NULL;
+ }
- dm_list_move(&pvs_drop, &devl->list);
- continue;
- }
+ /* FIXME: not sure if this is necessary */
+ fid->ref_count++;
- info = (struct lvmcache_info *) label->info;
+ baton.fid = fid;
+ baton.cmd = cmd;
- baton.vg = NULL;
- baton.fid = lvmcache_fmt(info)->ops->create_instance(lvmcache_fmt(info), &fic);
- if (!baton.fid)
- return_NULL;
+ /*
+ * FIXME: this vg_read path does not have the ability to repair
+ * any problems with the VG, e.g. VG on one dev has an older
+ * seqno. When vg_read() is reworked, we need to fall back
+ * to using that from here (and vg_read's from lvmetad) when
+ * there is a problem. Perhaps by disabling lvmetad when a
+ * VG problem is detected, causing commands to fully fall
+ * back to disk, which will repair the VG. Then lvmetad can
+ * be repopulated and re-enabled (possibly automatically.)
+ */
- if (baton.fid->fmt->features & FMT_OBSOLETE) {
- log_debug_lvmetad("Ignoring obsolete format on PV %s in VG %s.", dev_name(devl->dev), vg->name);
- lvmcache_fmt(info)->ops->destroy_instance(baton.fid);
+ /*
+ * Do a low level vg_read on each dev, verify the vg returned
+ * from metadata on each device is for the VG being read
+ * (the PV may have been removed from the VG being read and
+ * added to a different one), and return this vg to the caller
+ * as the current vg to use.
+ *
+ * The label scan above will have saved in lvmcache which
+ * vg each device is used in, so we could figure that part
+ * out without doing the vg_read.
+ */
+ dm_list_iterate_items_safe(devl, devlsafe, &pvs_scan) {
+ if (!devl->dev)
+ continue;
+
+ log_debug_lvmetad("Rescan VG %s getting metadata from %s.",
+ vg->name, dev_name(devl->dev));
+
+ /*
+ * The info struct for this dev knows what and where
+ * the mdas are for this dev (the label scan saved
+ * the mda locations for this dev on the lvmcache info struct).
+ */
+ if (!(info = lvmcache_info_from_pvid(devl->dev->pvid, devl->dev, 0))) {
+ log_debug_lvmetad("Rescan VG %s from %s dropping dev (no info).",
+ vg->name, dev_name(devl->dev));
dm_list_move(&pvs_drop, &devl->list);
continue;
}
+ baton.vg = NULL;
+
/*
* Read VG metadata from this dev's mdas.
*/
- lvmcache_foreach_mda(info, _lvmetad_pvscan_single, &baton);
+ lvmcache_foreach_mda(info, _lvmetad_pvscan_vg_single, &baton);
/*
* The PV may have been removed from the VG by another host
* since we last read the VG.
*/
if (!baton.vg) {
- log_debug_lvmetad("Rescan VG %s did not find %s.", vg->name, dev_name(devl->dev));
- lvmcache_fmt(info)->ops->destroy_instance(baton.fid);
+ log_debug_lvmetad("Rescan VG %s from %s dropping dev (no metadata).",
+ vg->name, dev_name(devl->dev));
dm_list_move(&pvs_drop, &devl->list);
continue;
}
@@ -1898,10 +1986,15 @@ scan_more:
* different VG since we last read the VG.
*/
if (strcmp(baton.vg->name, vg->name)) {
- log_debug_lvmetad("Rescan VG %s found different VG %s on PV %s.",
- vg->name, baton.vg->name, dev_name(devl->dev));
+ log_debug_lvmetad("Rescan VG %s from %s dropping dev (other VG %s).",
+ vg->name, dev_name(devl->dev), baton.vg->name);
+ release_vg(baton.vg);
+ continue;
+ }
+
+ if (!(vgmeta = export_vg_to_config_tree(baton.vg))) {
+ log_error("VG export to config tree failed");
release_vg(baton.vg);
- dm_list_move(&pvs_drop, &devl->list);
continue;
}
@@ -1911,20 +2004,35 @@ scan_more:
* read from each other dev.
*/
- if (!save_seqno)
- save_seqno = baton.vg->seqno;
-
- if (!(vgmeta = export_vg_to_config_tree(baton.vg))) {
- log_error("VG export to config tree failed");
- release_vg(baton.vg);
- return NULL;
+ if (save_vg && (save_seqno != baton.vg->seqno)) {
+ /* FIXME: fall back to vg_read to correct this. */
+ log_warn("WARNING: inconsistent metadata for VG %s on devices %s seqno %u and %s seqno %u.",
+ vg->name, dev_name(save_dev), save_seqno,
+ dev_name(devl->dev), baton.vg->seqno);
+ log_warn("WARNING: temporarily disable lvmetad to repair metadata.");
+
+ /* Use the most recent */
+ if (save_seqno < baton.vg->seqno) {
+ release_vg(save_vg);
+ dm_config_destroy(save_meta);
+ save_vg = baton.vg;
+ save_meta = vgmeta;
+ save_seqno = baton.vg->seqno;
+ save_dev = devl->dev;
+ } else {
+ release_vg(baton.vg);
+ dm_config_destroy(vgmeta);
+ }
+ continue;
}
- if (!vgmeta_ret) {
- vgmeta_ret = vgmeta;
+ if (!save_vg) {
+ save_vg = baton.vg;
+ save_meta = vgmeta;
+ save_seqno = baton.vg->seqno;
save_dev = devl->dev;
} else {
- struct dm_config_node *meta1 = vgmeta_ret->root;
+ struct dm_config_node *meta1 = save_meta->root;
struct dm_config_node *meta2 = vgmeta->root;
struct dm_config_node *sib1 = meta1->sib;
struct dm_config_node *sib2 = meta2->sib;
@@ -1949,73 +2057,128 @@ scan_more:
meta2->sib = NULL;
if (compare_config(meta1, meta2)) {
+ /* FIXME: fall back to vg_read to correct this. */
+ log_warn("WARNING: inconsistent metadata for VG %s on devices %s seqno %u and %s seqno %u.",
+ vg->name, dev_name(save_dev), save_seqno,
+ dev_name(devl->dev), baton.vg->seqno);
+ log_warn("WARNING: temporarily disable lvmetad to repair metadata.");
log_error("VG %s metadata comparison failed for device %s vs %s",
vg->name, dev_name(devl->dev), save_dev ? dev_name(save_dev) : "none");
- _log_debug_inequality(vg->name, vgmeta_ret->root, vgmeta->root);
+ _log_debug_inequality(vg->name, save_meta->root, vgmeta->root);
meta1->sib = sib1;
meta2->sib = sib2;
- dm_config_destroy(vgmeta);
- dm_config_destroy(vgmeta_ret);
+
+ /* no right choice, just use the previous copy */
release_vg(baton.vg);
- return NULL;
+ dm_config_destroy(vgmeta);
}
meta1->sib = sib1;
meta2->sib = sib2;
+ release_vg(baton.vg);
dm_config_destroy(vgmeta);
}
+ }
- /*
- * Look for any new PVs in the VG metadata that were not in our
- * previous version of the VG. Add them to pvs_new to be
- * scanned in this loop just like the old PVs.
- */
- if (!check_new_pvs) {
- check_new_pvs = 1;
- dm_list_iterate_items(pvl_new, &baton.vg->pvs) {
- found = 0;
- dm_list_iterate_items(pvl, &vg->pvs) {
- if (pvl_new->pv->dev != pvl->pv->dev)
- continue;
- found = 1;
- break;
- }
- if (found)
- continue;
- if (!pvl_new->pv->dev) {
- strncpy(pvid_s, (char *) &pvl_new->pv->id, sizeof(pvid_s) - 1);
- if (!id_write_format((const struct id *)&pvid_s, uuid, sizeof(uuid)))
- stack;
- log_error("Device not found for PV %s in VG %s", uuid, vg->name);
- missing_devs++;
+ /* FIXME: see above */
+ fid->ref_count--;
+
+ /*
+ * Look for any new PVs in the VG metadata that were not in our
+ * previous version of the VG.
+ *
+ * (Don't look for new PVs after a rescan and retry.)
+ */
+ found_new_pvs = 0;
+
+ if (save_vg && !retried_reads) {
+ dm_list_iterate_items(pvl_new, &save_vg->pvs) {
+ found = 0;
+ dm_list_iterate_items(pvl, &vg->pvs) {
+ if (pvl_new->pv->dev != pvl->pv->dev)
continue;
- }
- if (!(devl_new = dm_pool_zalloc(cmd->mem, sizeof(*devl_new))))
- return_NULL;
- devl_new->dev = pvl_new->pv->dev;
- dm_list_add(&pvs_new, &devl_new->list);
- log_debug_lvmetad("Rescan VG %s found %s was added.", vg->name, dev_name(devl_new->dev));
+ found = 1;
+ break;
+ }
+
+ /*
+ * PV in new VG metadata not found in old VG metadata.
+ * There's a good chance we don't know about this new
+ * PV or what device it's on; a label scan is needed
+ * of all devices so we know which device the VG is
+ * now using.
+ */
+ if (!found) {
+ found_new_pvs++;
+ strncpy(pvid_s, (char *) &pvl_new->pv->id, sizeof(pvid_s) - 1);
+ if (!id_write_format((const struct id *)&pvid_s, uuid, sizeof(uuid)))
+ stack;
+ log_debug_lvmetad("Rescan VG %s found new PV %s.", vg->name, uuid);
}
}
+ }
- release_vg(baton.vg);
+ if (!save_vg && retried_reads) {
+ log_error("VG %s not found after rescanning devices.", vg->name);
+ goto out;
}
/*
- * Do the same scanning above for any new PVs.
+ * Do a full rescan of devices, then look up which devices the
+ * scan found for this VG name, and select those devices to
+ * read metadata from in the loop above (rather than the list
+ * of devices we created from our last copy of the vg metadata.)
+ *
+ * Case 1: VG we knew is no longer on any of the devices we knew it
+ * to be on (save_vg is NULL, which means the metadata wasn't found
+ * when reading mdas on each of the initial pvs_scan devices).
+ * Rescan all devs and then retry reading metadata from the devs that
+ * the scan finds associated with this VG.
+ *
+ * Case 2: VG has new PVs but we don't know what devices they are
+ * so rescan all devs and then retry reading metadata from the devs
+ * that the scan finds associated with this VG.
+ *
+ * (N.B. after a retry, we don't check for found_new_pvs.)
*/
- if (!dm_list_empty(&pvs_new)) {
+ if (!save_vg || found_new_pvs) {
+ if (!save_vg)
+ log_debug_lvmetad("Rescan VG %s did not find VG on previous devs.", vg->name);
+ if (found_new_pvs)
+ log_debug_lvmetad("Rescan VG %s scanning all devs to find new PVs.", vg->name);
+
+ label_scan(cmd);
+
+ if (!(vginfo = lvmcache_vginfo_from_vgname(vg->name, NULL))) {
+ log_error("VG %s vg info not found after rescanning devices.", vg->name);
+ goto out;
+ }
+
+ /*
+ * Set pvs_scan to devs that the label scan found
+ * in the VG and retry the metadata reading loop.
+ */
dm_list_init(&pvs_scan);
- dm_list_splice(&pvs_scan, &pvs_new);
- dm_list_init(&pvs_new);
- log_debug_lvmetad("Rescan VG %s found new PVs to scan.", vg->name);
- goto scan_more;
- }
- if (missing_devs) {
- if (vgmeta_ret)
- dm_config_destroy(vgmeta_ret);
- return_NULL;
+ if (!lvmcache_get_vg_devs(cmd, vginfo, &pvs_scan)) {
+ log_error("VG %s info devs not found after rescanning devices.", vg->name);
+ goto out;
+ }
+
+ log_debug_lvmetad("Rescan VG %s has %d PVs after label scan.",
+ vg->name, dm_list_size(&pvs_scan));
+
+ if (save_vg)
+ release_vg(save_vg);
+ if (save_meta)
+ dm_config_destroy(save_meta);
+ save_vg = NULL;
+ save_meta = NULL;
+ save_dev = NULL;
+ save_seqno = 0;
+ found_new_pvs = 0;
+ retried_reads = 1;
+ goto retry_reads;
}
/*
@@ -2024,52 +2187,50 @@ scan_more:
dm_list_iterate_items(devl, &pvs_drop) {
if (!devl->dev)
continue;
- log_debug_lvmetad("Rescan VG %s dropping %s.", vg->name, dev_name(devl->dev));
- if (!lvmetad_pv_gone_by_dev(devl->dev))
- return_NULL;
+ log_debug_lvmetad("Rescan VG %s removing %s from lvmetad.", vg->name, dev_name(devl->dev));
+ if (!lvmetad_pv_gone_by_dev(devl->dev)) {
+ /* FIXME: use an error path that disables lvmetad */
+ log_error("Failed to remove %s from lvmetad.", dev_name(devl->dev));
+ }
}
/*
- * Update the VG in lvmetad.
+ * Update lvmetad with the newly read version of the VG.
+ * When the seqno is unchanged the cached VG can be left.
*/
- if (vgmeta_ret) {
- fid = lvmcache_fmt(info)->ops->create_instance(lvmcache_fmt(info), &fic);
- if (!(vg_ret = import_vg_from_config_tree(vgmeta_ret, fid))) {
- log_error("VG import from config tree failed");
- lvmcache_fmt(info)->ops->destroy_instance(fid);
- goto out;
+ if (save_vg && (save_seqno != vg->seqno)) {
+ dm_list_iterate_items(devl, &pvs_scan) {
+ if (!devl->dev)
+ continue;
+ log_debug_lvmetad("Rescan VG %s removing %s from lvmetad to replace.",
+ vg->name, dev_name(devl->dev));
+ if (!lvmetad_pv_gone_by_dev(devl->dev)) {
+ /* FIXME: use an error path that disables lvmetad */
+ log_error("Failed to remove %s from lvmetad.", dev_name(devl->dev));
+ }
}
+ log_debug_lvmetad("Rescan VG %s updating lvmetad from seqno %u to seqno %u.",
+ vg->name, vg->seqno, save_seqno);
+
/*
- * Update lvmetad with the newly read version of the VG.
- * When the seqno is unchanged the cached VG can be left.
+ * If this vg_update fails the cached metadata in
+ * lvmetad will remain invalid.
*/
- if (save_seqno != vg->seqno) {
- dm_list_iterate_items(devl, &pvs_scan) {
- if (!devl->dev)
- continue;
- log_debug_lvmetad("Rescan VG %s dropping to replace %s.", vg->name, dev_name(devl->dev));
- if (!lvmetad_pv_gone_by_dev(devl->dev))
- return_NULL;
- }
-
- log_debug_lvmetad("Rescan VG %s updating lvmetad from seqno %u to seqno %u.",
- vg->name, vg->seqno, save_seqno);
-
- /*
- * If this vg_update fails the cached metadata in
- * lvmetad will remain invalid.
- */
- vg_ret->lvmetad_update_pending = 1;
- if (!lvmetad_vg_update_finish(vg_ret))
- log_error("Failed to update lvmetad with new VG meta");
+ save_vg->lvmetad_update_pending = 1;
+ if (!lvmetad_vg_update_finish(save_vg)) {
+ /* FIXME: use an error path that disables lvmetad */
+ log_error("Failed to update lvmetad with new VG meta");
}
- dm_config_destroy(vgmeta_ret);
}
out:
- if (vg_ret)
- log_debug_lvmetad("Rescan VG %s done (seqno %u).", vg_ret->name, vg_ret->seqno);
- return vg_ret;
+ if (!save_vg && fid)
+ fmt->ops->destroy_instance(fid);
+ if (save_meta)
+ dm_config_destroy(save_meta);
+ if (save_vg)
+ log_debug_lvmetad("Rescan VG %s done (new seqno %u).", save_vg->name, save_vg->seqno);
+ return save_vg;
}
int lvmetad_pvscan_single(struct cmd_context *cmd, struct device *dev,
^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2018-04-23 13:52 UTC | newest]
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2018-04-23 13:52 master - lvmetad: use new label_scan for update from lvmlockd David Teigland
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2018-04-23 13:49 David Teigland
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