[lvm-devel] [PATCH 06/15] lvm-merge-lvconvert
Mike Snitzer
snitzer at redhat.com
Fri Nov 20 22:35:46 UTC 2009
From: Mikulas Patocka <mpatocka at redhat.com>
Add --merge support to lvconvert to start merging a snapshot into its
origin, example usage: lvconvert --merge vg/snaplv
Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
---
tools/args.h | 1 +
tools/commands.h | 11 ++++-
tools/lvconvert.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++---
3 files changed, 115 insertions(+), 9 deletions(-)
diff --git a/tools/args.h b/tools/args.h
index 1f2427b..d2476ad 100644
--- a/tools/args.h
+++ b/tools/args.h
@@ -103,6 +103,7 @@ arg(list_ARG, 'l', "list", NULL, 0)
arg(size_ARG, 'L', "size", size_mb_arg, 0)
arg(logicalextent_ARG, 'L', "logicalextent", int_arg_with_sign, 0)
arg(persistent_ARG, 'M', "persistent", yes_no_arg, 0)
+arg(merge_ARG, '\0', "merge", NULL, 0)
arg(major_ARG, 'j', "major", major_arg, 0)
arg(mirrors_ARG, 'm', "mirrors", int_arg_with_sign, 0)
arg(metadatatype_ARG, 'M', "metadatatype", metadatatype_arg, 0)
diff --git a/tools/commands.h b/tools/commands.h
index 85222e4..93e9019 100644
--- a/tools/commands.h
+++ b/tools/commands.h
@@ -119,11 +119,16 @@ xx(lvconvert,
"\t[-v|--verbose]\n"
"\t[-Z|--zero {y|n}]\n"
"\t[--version]" "\n"
- "\tOriginalLogicalVolume[Path] SnapshotLogicalVolume[Path]\n",
+ "\tOriginalLogicalVolume[Path] SnapshotLogicalVolume[Path]\n\n"
+
+ "lvconvert "
+ "--merge\n"
+ "\tSnapshotLogicalVolume[Path]\n",
alloc_ARG, background_ARG, chunksize_ARG, corelog_ARG, interval_ARG,
- mirrorlog_ARG, mirrors_ARG, noudevsync_ARG, regionsize_ARG, repair_ARG,
- snapshot_ARG, test_ARG, use_policies_ARG, yes_ARG, force_ARG, zero_ARG)
+ merge_ARG, mirrorlog_ARG, mirrors_ARG, noudevsync_ARG, regionsize_ARG,
+ repair_ARG, snapshot_ARG, test_ARG, use_policies_ARG, yes_ARG, force_ARG,
+ zero_ARG)
xx(lvcreate,
"Create a logical volume",
diff --git a/tools/lvconvert.c b/tools/lvconvert.c
index d1b86bf..517b4f3 100644
--- a/tools/lvconvert.c
+++ b/tools/lvconvert.c
@@ -18,6 +18,7 @@
struct lvconvert_params {
int snapshot;
+ int merge;
int zero;
const char *origin;
@@ -49,7 +50,7 @@ static int _lvconvert_name_params(struct lvconvert_params *lp,
char *ptr;
const char *vg_name = NULL;
- if (lp->snapshot) {
+ if (lp->snapshot && !lp->merge) {
if (!*pargc) {
log_error("Please specify a logical volume to act as "
"the snapshot origin.");
@@ -99,6 +100,11 @@ static int _lvconvert_name_params(struct lvconvert_params *lp,
if (!apply_lvname_restrictions(lp->lv_name))
return_0;
+ if (*pargc && (lp->snapshot || lp->merge)) {
+ log_error("Extra arguments for snapshots");
+ return 0;
+ }
+
return 1;
}
@@ -110,10 +116,10 @@ static int _read_params(struct lvconvert_params *lp, struct cmd_context *cmd,
memset(lp, 0, sizeof(*lp));
- if (arg_count(cmd, snapshot_ARG) &&
+ if ((arg_count(cmd, snapshot_ARG) || arg_count(cmd, merge_ARG)) &&
(arg_count(cmd, mirrorlog_ARG) || arg_count(cmd, mirrors_ARG) ||
arg_count(cmd, repair_ARG))) {
- log_error("--snapshot argument cannot be mixed "
+ log_error("--snapshot or --merge argument cannot be mixed "
"with --mirrors, --repair or --log");
return 0;
}
@@ -124,6 +130,9 @@ static int _read_params(struct lvconvert_params *lp, struct cmd_context *cmd,
if (arg_count(cmd, snapshot_ARG))
lp->snapshot = 1;
+ if (arg_count(cmd, merge_ARG))
+ lp->merge = 1;
+
if (arg_count(cmd, mirrors_ARG)) {
lp->mirrors = arg_uint_value(cmd, mirrors_ARG, 0);
lp->mirrors_sign = arg_sign_value(cmd, mirrors_ARG, 0);
@@ -131,7 +140,17 @@ static int _read_params(struct lvconvert_params *lp, struct cmd_context *cmd,
lp->alloc = arg_uint_value(cmd, alloc_ARG, ALLOC_INHERIT);
- if (lp->snapshot) {
+ if (lp->merge) {
+ if (arg_count(cmd, regionsize_ARG) || arg_count(cmd, chunksize_ARG) ||
+ arg_count(cmd, zero_ARG) || arg_count(cmd, regionsize_ARG)) {
+ log_error("invalid arguments for snapshot merge");
+ return 0;
+ }
+
+ if (!(lp->segtype = get_segtype_from_string(cmd, "snapshot")))
+ return_0;
+
+ } else if (lp->snapshot) {
if (arg_count(cmd, regionsize_ARG)) {
log_error("--regionsize is only available with mirrors");
return 0;
@@ -894,6 +913,73 @@ out:
return r;
}
+static int lvconvert_merge(struct cmd_context *cmd,
+ struct logical_volume *lv,
+ struct lvconvert_params *lp)
+{
+ int r = 0;
+ struct logical_volume *origin = origin_from_cow(lv);
+ struct lv_segment *cow_seg = find_cow(lv);
+
+ /* Check if merge is possible */
+ if (cow_seg->status & SNAPSHOT_MERGE) {
+ log_error("Snapshot %s is already merging", lv->name);
+ return 0;
+ }
+ if (origin->merging_snapshot) {
+ log_error("Snapshot %s is already merging into the origin",
+ origin->merging_snapshot->cow->name);
+ return 0;
+ }
+
+ /*
+ * Even though lv_is_visible(cow_seg->lv) returns 0,
+ * the cow_seg->lv (name: snapshotX) is _not_ hidden;
+ * this is part of the lvm2 snapshot fiction. Must
+ * clear VISIBLE_LV directly (lv_set_visible can't)
+ * - cow_seg->lv->status is used to control whether 'lv'
+ * (with user provided snapshot LV name) is visible
+ * - this also enables vg_validate() to succeed with
+ * merge metadata (cow_seg->lv is now "internal")
+ */
+ cow_seg->lv->status &= ~VISIBLE_LV;
+ cow_seg->status |= SNAPSHOT_MERGE;
+ origin->merging_snapshot = cow_seg;
+
+ /* store vg on disk(s) */
+ if (!vg_write(lv->vg))
+ return_0;
+
+ /* Perform merge */
+ if (!suspend_lv(cmd, origin)) {
+ log_error("Failed to suspend origin %s", origin->name);
+ vg_revert(lv->vg);
+ goto out;
+ }
+
+ if (!vg_commit(lv->vg)) {
+ if (!resume_lv(cmd, origin))
+ stack;
+ goto_out;
+ }
+
+ if (!resume_lv(cmd, origin)) {
+ log_error("Failed to reactivate origin %s", origin->name);
+ goto out;
+ }
+
+ if (!deactivate_lv(cmd, lv)) {
+ log_warn("WARNING: Unable to deactivate merging snapshot %s", lv->name);
+ /* merge is running regardless of this deactivation failure */
+ }
+
+ r = 1;
+ log_print("Merging of volume %s started.", lv->name);
+out:
+ backup(lv->vg);
+ return r;
+}
+
static int lvconvert_single(struct cmd_context *cmd, struct logical_volume *lv,
void *handle)
{
@@ -904,7 +990,7 @@ static int lvconvert_single(struct cmd_context *cmd, struct logical_volume *lv,
return ECMD_FAILED;
}
- if (lv_is_cow(lv)) {
+ if (lv_is_cow(lv) && !lp->merge) {
log_error("Can't convert snapshot logical volume \"%s\"",
lv->name);
return ECMD_FAILED;
@@ -920,7 +1006,21 @@ static int lvconvert_single(struct cmd_context *cmd, struct logical_volume *lv,
return ECMD_FAILED;
}
- if (lp->snapshot) {
+ if (lp->merge) {
+ if (!lv_is_cow(lv)) {
+ log_error("Logical volume \"%s\" is not a snapshot",
+ lv->name);
+ return ECMD_FAILED;
+ }
+ if (!archive(lv->vg)) {
+ stack;
+ return ECMD_FAILED;
+ }
+ if (!lvconvert_merge(cmd, lv, lp)) {
+ stack;
+ return ECMD_FAILED;
+ }
+ } else if (lp->snapshot) {
if (lv->status & MIRRORED) {
log_error("Unable to convert mirrored LV \"%s\" into a snapshot.", lv->name);
return ECMD_FAILED;
--
1.6.5.2
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