[lvm-devel] [PATCH 14/15] lvm-merge-onactivate
Mike Snitzer
snitzer at redhat.com
Fri Nov 20 22:35:54 UTC 2009
Merge on activate support.
If either the origin or snapshot that is to be merged is open the merge
will not start; only the merge metadata will be written. The merge will
start on the next activation of the origin (or via lvchange --refresh)
IFF both the origin and snapshot are closed.
Merge on activate is particularly important if we want to merge over a
mounted filesystem that cannot be unmounted (until next boot) --- for
example root.
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
Cc: Mikulas Patocka <mpatocka at redhat.com>
---
lib/activate/dev_manager.c | 18 ++++++++++++++++++
lib/report/report.c | 12 ++++++++++--
tools/lvconvert.c | 23 +++++++++++++++++++----
3 files changed, 47 insertions(+), 6 deletions(-)
diff --git a/lib/activate/dev_manager.c b/lib/activate/dev_manager.c
index 7208ecd..52103e3 100644
--- a/lib/activate/dev_manager.c
+++ b/lib/activate/dev_manager.c
@@ -1047,12 +1047,30 @@ static int _add_new_lv_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
struct lv_segment *seg;
struct lv_layer *lvlayer;
struct dm_tree_node *dnode;
+ struct dm_info dinfo;
char *name, *dlid, *lv_name;
uint32_t max_stripe_size = UINT32_C(0);
uint32_t read_ahead = lv->read_ahead;
uint32_t read_ahead_flags = UINT32_C(0);
uint16_t udev_flags = 0;
+ if (lv_is_origin(lv) && lv->merging_snapshot && !layer) {
+ /*
+ * Clear merge attributes if merge isn't currently possible:
+ * either origin or merging snapshot are open
+ * (must refresh info's open_count, so using the tree's
+ * existing nodes' info isn't an option)
+ */
+ if ((dev_manager_info(dm->mem, NULL, lv,
+ 0, 1, 0, &dinfo, NULL) && dinfo.open_count) ||
+ (dev_manager_info(dm->mem, NULL, lv->merging_snapshot->cow,
+ 0, 1, 0, &dinfo, NULL) && dinfo.open_count)) {
+ /* clear merge attributes */
+ lv->merging_snapshot->status &= ~SNAPSHOT_MERGE;
+ lv->merging_snapshot = NULL;
+ }
+ }
+
lv_name = lv->name;
if (lv_is_cow(lv) && find_cow(lv)->status & SNAPSHOT_MERGE) {
if (layer) {
diff --git a/lib/report/report.c b/lib/report/report.c
index b65b492..878c7e0 100644
--- a/lib/report/report.c
+++ b/lib/report/report.c
@@ -1041,8 +1041,16 @@ static int _snpercent_disp(struct dm_report *rh __attribute((unused)), struct dm
if (!lv_snapshot_percent(lv, &snap_percent, &percent_range) ||
(percent_range == PERCENT_INVALID)) {
- *sortval = UINT64_C(100);
- dm_report_field_set_value(field, "100.00", sortval);
+ if (!lv->merging_snapshot) {
+ *sortval = UINT64_C(100);
+ dm_report_field_set_value(field, "100.00", sortval);
+ } else {
+ /* onactivate merge that hasn't started yet would
+ * otherwise display incorrect snap% in origin
+ */
+ *sortval = UINT64_C(0);
+ dm_report_field_set_value(field, "", sortval);
+ }
return 1;
}
diff --git a/tools/lvconvert.c b/tools/lvconvert.c
index 7447007..b398775 100644
--- a/tools/lvconvert.c
+++ b/tools/lvconvert.c
@@ -979,6 +979,7 @@ static int lvconvert_merge(struct cmd_context *cmd,
struct lvconvert_params *lp)
{
int r = 0;
+ int merge_on_activate = 0;
struct logical_volume *origin = origin_from_cow(lv);
struct lv_segment *cow_seg = find_cow(lv);
struct lvinfo info;
@@ -994,16 +995,20 @@ static int lvconvert_merge(struct cmd_context *cmd,
return 0;
}
+ /*
+ * merge on origin's next activation if either the
+ * origin or snapshot LV are currently open
+ */
if (lv_info(cmd, origin, &info, 1, 0)) {
if (info.open_count) {
- log_error("Can't merge over open origin volume");
- return 0;
+ log_print("Can't merge over open origin volume");
+ merge_on_activate = 1;
}
}
if (lv_info(cmd, lv, &info, 1, 0)) {
if (info.open_count) {
- log_error("Can't merge when snapshot is open");
- return 0;
+ log_print("Can't merge when snapshot is open");
+ merge_on_activate = 1;
}
}
@@ -1025,6 +1030,16 @@ static int lvconvert_merge(struct cmd_context *cmd,
if (!vg_write(lv->vg))
return_0;
+ if (merge_on_activate) {
+ /* commit vg but skip starting the merge */
+ if (!vg_commit(lv->vg))
+ return_0;
+ r = 1;
+ log_print("Merging of snapshot %s will start "
+ "next activation.", lv->name);
+ goto out;
+ }
+
/* Perform merge */
if (!suspend_lv(cmd, origin)) {
log_error("Failed to suspend origin %s", origin->name);
--
1.6.5.2
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