[lvm-devel] master - thin: enable thin snapshot merge
Zdenek Kabelac
zkabelac at fedoraproject.org
Wed Dec 4 13:31:52 UTC 2013
Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=91496e0eda9969f1efcf290803c13d79456067d4
Commit: 91496e0eda9969f1efcf290803c13d79456067d4
Parent: 971ab733b74e0ffecc3f9f60af48628cd3fba1db
Author: Zdenek Kabelac <zkabelac at redhat.com>
AuthorDate: Fri Nov 29 21:28:18 2013 +0100
Committer: Zdenek Kabelac <zkabelac at redhat.com>
CommitterDate: Wed Dec 4 14:30:26 2013 +0100
thin: enable thin snapshot merge
---
WHATS_NEW | 1 +
tools/lvconvert.c | 170 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 168 insertions(+), 3 deletions(-)
diff --git a/WHATS_NEW b/WHATS_NEW
index c81cb7a..5d41700 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
Version 2.02.105 -
=====================================
+ Support lvconvert --merge for thin snapshots.
Add support to read thin device id from table line entry.
Drop extra test for origin when testing merging origin in lv_refresh().
Extend lv_remove_single() to not print info about removed LV.
diff --git a/tools/lvconvert.c b/tools/lvconvert.c
index 84479fe..11ee21a 100644
--- a/tools/lvconvert.c
+++ b/tools/lvconvert.c
@@ -689,6 +689,46 @@ static int _swap_lv_identifiers(struct cmd_context *cmd,
return 1;
}
+static void _move_lv_attributes(struct logical_volume *to, struct logical_volume *from)
+{
+ /* Maybe move this code into _finish_thin_merge() */
+ to->status = from->status; // FIXME maybe some masking ?
+ to->alloc = from->alloc;
+ to->profile = from->profile;
+ to->read_ahead = from->read_ahead;
+ to->major = from->major;
+ to->minor = from->minor;
+ to->timestamp = from->timestamp;
+ to->hostname = from->hostname;
+
+ /* Move tags */
+ dm_list_init(&to->tags);
+ dm_list_splice(&to->tags, &from->tags);
+
+ /* Anything else to preserve? */
+}
+
+/* Finalise merging of lv into merge_lv */
+static int _finish_thin_merge(struct cmd_context *cmd,
+ struct logical_volume *merge_lv,
+ struct logical_volume *lv)
+{
+ if (!_swap_lv_identifiers(cmd, merge_lv, lv)) {
+ log_error("Failed to swap %s with merging %s.",
+ lv->name, merge_lv->name);
+ return 0;
+ }
+
+ /* Preserve origins' attributes */
+ _move_lv_attributes(lv, merge_lv);
+
+ /* Removed LV has to be visible */
+ if (!lv_remove_single(cmd, merge_lv, DONT_PROMPT, 1))
+ return_0;
+
+ return 1;
+}
+
static int _finish_lvconvert_merge(struct cmd_context *cmd,
struct volume_group *vg,
struct logical_volume *lv,
@@ -702,7 +742,14 @@ static int _finish_lvconvert_merge(struct cmd_context *cmd,
}
log_print_unless_silent("Merge of snapshot into logical volume %s has finished.", lv->name);
- if (!lv_remove_single(cmd, snap_seg->cow, DONT_PROMPT, 0)) {
+
+ if (seg_is_thin_volume(snap_seg)) {
+ clear_snapshot_merge(lv);
+
+ if (!_finish_thin_merge(cmd, lv, snap_seg->lv))
+ return_0;
+
+ } else if (!lv_remove_single(cmd, snap_seg->cow, DONT_PROMPT, 0)) {
log_error("Could not remove snapshot %s merged into %s.",
snap_seg->cow->name, lv->name);
return 0;
@@ -742,6 +789,31 @@ static progress_t _poll_merge_progress(struct cmd_context *cmd,
return PROGRESS_UNFINISHED;
}
+static progress_t _poll_thin_merge_progress(struct cmd_context *cmd,
+ struct logical_volume *lv,
+ const char *name __attribute__((unused)),
+ struct daemon_parms *parms)
+{
+ uint32_t device_id;
+
+ if (!lv_thin_device_id(lv, &device_id)) {
+ stack;
+ return PROGRESS_CHECK_FAILED;
+ }
+
+ /*
+ * There is no need to poll more than once,
+ * a thin snapshot merge is immediate.
+ */
+
+ if (device_id != find_snapshot(lv)->device_id) {
+ log_error("LV %s is not merged.", lv->name);
+ return PROGRESS_CHECK_FAILED;
+ }
+
+ return PROGRESS_FINISHED_ALL; /* Merging happend */
+}
+
static struct poll_functions _lvconvert_mirror_fns = {
.get_copy_vg = _get_lvconvert_vg,
.get_copy_lv = _get_lvconvert_lv,
@@ -756,6 +828,13 @@ static struct poll_functions _lvconvert_merge_fns = {
.finish_copy = _finish_lvconvert_merge,
};
+static struct poll_functions _lvconvert_thin_merge_fns = {
+ .get_copy_vg = _get_lvconvert_vg,
+ .get_copy_lv = _get_lvconvert_lv,
+ .poll_progress = _poll_thin_merge_progress,
+ .finish_copy = _finish_lvconvert_merge,
+};
+
int lvconvert_poll(struct cmd_context *cmd, struct logical_volume *lv,
unsigned background)
{
@@ -782,7 +861,9 @@ int lvconvert_poll(struct cmd_context *cmd, struct logical_volume *lv,
if (lv_is_merging_origin(lv))
return poll_daemon(cmd, lv_full_name, uuid, background, 0,
- &_lvconvert_merge_fns, "Merged");
+ lv_is_thin_volume(lv) ?
+ &_lvconvert_thin_merge_fns : &_lvconvert_merge_fns,
+ "Merged");
return poll_daemon(cmd, lv_full_name, uuid, background, 0,
&_lvconvert_mirror_fns, "Converted");
@@ -2097,6 +2178,88 @@ out:
return r;
}
+static int _lvconvert_merge_thin_snapshot(struct cmd_context *cmd,
+ struct logical_volume *lv,
+ struct lvconvert_params *lp)
+{
+ int origin_is_active = 0, r = 0;
+ struct lv_segment *snap_seg = first_seg(lv);
+ struct logical_volume *origin = snap_seg->origin;
+
+ if (!origin) {
+ log_error("\"%s\" is not a mergeable logical volume.",
+ lv->name);
+ return 0;
+ }
+
+ /* Check if merge is possible */
+ if (lv_is_merging_origin(origin)) {
+ log_error("Snapshot %s is already merging into the origin.",
+ find_snapshot(origin)->lv->name);
+ return 0;
+ }
+
+ if (lv_is_external_origin(origin)) {
+ log_error("\"%s\" is read-only external origin \"%s\".",
+ lv->name, origin_from_cow(lv)->name);
+ return 0;
+ }
+
+ if (lv_is_origin(origin)) {
+ log_error("Merging into the old snapshot origin %s is not supported.",
+ origin->name);
+ return 0;
+ }
+
+ if (!archive(lv->vg))
+ return_0;
+
+ // FIXME: allow origin to be specified
+ // FIXME: verify snapshot is descendant of specified origin
+
+ /*
+ * Prevent merge with open device(s) as it would likely lead
+ * to application/filesystem failure. Merge on origin's next
+ * activation if either the origin or snapshot LV can't be
+ * deactivated.
+ */
+ if (!deactivate_lv(cmd, lv))
+ log_print_unless_silent("Delaying merge since snapshot is open.");
+ else if ((origin_is_active = lv_is_active(origin)) &&
+ !deactivate_lv(cmd, origin))
+ log_print_unless_silent("Delaying merge since origin volume is open.");
+ else {
+ /*
+ * Both thin snapshot and origin are inactive,
+ * replace the origin LV with its snapshot LV.
+ */
+ if (!_finish_thin_merge(cmd, origin, lv))
+ goto_out;
+
+ if (origin_is_active && !activate_lv(cmd, lv)) {
+ log_error("Failed to reactivate origin %s.", lv->name);
+ goto out;
+ }
+
+ r = 1;
+ goto out;
+ }
+
+ init_snapshot_merge(snap_seg, origin);
+
+ /* Commit vg, merge will start with next activation */
+ if (!vg_write(lv->vg) || !vg_commit(lv->vg))
+ return_0;
+
+ log_print_unless_silent("Merging of thin snapshot %s will occur on "
+ "next activation.", lv->name);
+ r = 1;
+out:
+ backup(lv->vg);
+
+ return r;
+}
+
static int _lvconvert_thinpool_repair(struct cmd_context *cmd,
struct logical_volume *pool_lv,
struct lvconvert_params *lp)
@@ -2742,7 +2905,8 @@ static int _lvconvert_single(struct cmd_context *cmd, struct logical_volume *lv,
}
}
if (lp->merge) {
- if (!_lvconvert_merge_old_snapshot(cmd, lv, lp)) {
+ if ((lv_is_thin_volume(lv) && !_lvconvert_merge_thin_snapshot(cmd, lv, lp)) ||
+ (!lv_is_thin_volume(lv) && !_lvconvert_merge_old_snapshot(cmd, lv, lp))) {
log_print_unless_silent("Unable to merge LV \"%s\" into its origin.", lv->name);
return ECMD_FAILED;
}
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