[lvm-devel] master - thin: snapshot merge support
Zdenek Kabelac
zkabelac at fedoraproject.org
Wed Dec 4 13:31:39 UTC 2013
Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=e286904da6a253394c050abde780269571289268
Commit: e286904da6a253394c050abde780269571289268
Parent: 572983d7931eac9347dad79b7d9b13f640bfaeaf
Author: Zdenek Kabelac <zkabelac at redhat.com>
AuthorDate: Fri Nov 29 15:51:28 2013 +0100
Committer: Zdenek Kabelac <zkabelac at redhat.com>
CommitterDate: Wed Dec 4 14:30:25 2013 +0100
thin: snapshot merge support
---
lib/metadata/lv_manip.c | 4 ++--
lib/metadata/merge.c | 13 +++++++++++++
lib/metadata/metadata-exported.h | 3 ++-
lib/metadata/metadata.h | 3 ++-
lib/metadata/snapshot_manip.c | 15 ++++++++++++++-
lib/metadata/thin_manip.c | 21 +++++++++++++++++++--
lib/thin/thin.c | 30 +++++++++++++++++++++++++++---
7 files changed, 79 insertions(+), 10 deletions(-)
diff --git a/lib/metadata/lv_manip.c b/lib/metadata/lv_manip.c
index 6846f4a..2458447 100644
--- a/lib/metadata/lv_manip.c
+++ b/lib/metadata/lv_manip.c
@@ -491,14 +491,14 @@ struct lv_segment *alloc_lv_segment(const struct segment_type *segtype,
/* If this is thin volume, thin snapshot is being created */
if (lv_is_thin_volume(thin_pool_lv)) {
seg->transaction_id = first_seg(first_seg(thin_pool_lv)->pool_lv)->transaction_id;
- if (!attach_pool_lv(seg, first_seg(thin_pool_lv)->pool_lv, thin_pool_lv))
+ if (!attach_pool_lv(seg, first_seg(thin_pool_lv)->pool_lv, thin_pool_lv, NULL))
return_NULL;
/* Use the same external origin */
if (!attach_thin_external_origin(seg, first_seg(thin_pool_lv)->external_lv))
return_NULL;
} else if (lv_is_thin_pool(thin_pool_lv)) {
seg->transaction_id = first_seg(thin_pool_lv)->transaction_id;
- if (!attach_pool_lv(seg, thin_pool_lv, NULL))
+ if (!attach_pool_lv(seg, thin_pool_lv, NULL, NULL))
return_NULL;
} else {
log_error(INTERNAL_ERROR "Volume %s is not thin volume or thin pool",
diff --git a/lib/metadata/merge.c b/lib/metadata/merge.c
index c22e922..93e4bfa 100644
--- a/lib/metadata/merge.c
+++ b/lib/metadata/merge.c
@@ -258,6 +258,19 @@ int check_lv_segments(struct logical_volume *lv, int complete_vg)
lv->name, seg->external_lv->name);
inc_error_count;
}
+
+ if (seg->merge_lv) {
+ if (!lv_is_thin_volume(seg->merge_lv)) {
+ log_error("LV %s: thin volume segment %u merging LV %s is not flagged as a thin LV",
+ lv->name, seg_count, seg->merge_lv->name);
+ inc_error_count;
+ }
+ if (!lv_is_merging_origin(seg->merge_lv)) {
+ log_error("LV %s: merging LV %s is not flagged as merging.",
+ lv->name, seg->merge_lv->name);
+ inc_error_count;
+ }
+ }
} else {
if (seg->pool_lv) {
log_error("LV %s: segment %u must not have thin pool LV set",
diff --git a/lib/metadata/metadata-exported.h b/lib/metadata/metadata-exported.h
index 0186c61..9798197 100644
--- a/lib/metadata/metadata-exported.h
+++ b/lib/metadata/metadata-exported.h
@@ -360,6 +360,7 @@ struct lv_segment {
uint32_t chunk_size; /* For snapshots/thin_pool. In sectors. */
/* For thin_pool, 128..2097152. */
struct logical_volume *origin; /* snap and thin */
+ struct logical_volume *merge_lv; /* thin, merge descendent lv into this ancestor */
struct logical_volume *cow;
struct dm_list origin_list;
uint32_t region_size; /* For mirrors, replicators - in sectors */
@@ -881,7 +882,7 @@ int lv_is_visible(const struct logical_volume *lv);
int pv_is_in_vg(struct volume_group *vg, struct physical_volume *pv);
-/* Given a cow LV, return return the snapshot lv_segment that uses it */
+/* Given a cow or thin LV, return the snapshot lv_segment that uses it */
struct lv_segment *find_snapshot(const struct logical_volume *lv);
/* Given a cow LV, return its origin */
diff --git a/lib/metadata/metadata.h b/lib/metadata/metadata.h
index 21ac204..0ab63f2 100644
--- a/lib/metadata/metadata.h
+++ b/lib/metadata/metadata.h
@@ -462,11 +462,12 @@ int fixup_imported_mirrors(struct volume_group *vg);
* From thin_manip.c
*/
int attach_pool_lv(struct lv_segment *seg, struct logical_volume *pool_lv,
- struct logical_volume *origin_lv);
+ struct logical_volume *origin_lv, struct logical_volume *merge_lv);
int detach_pool_lv(struct lv_segment *seg);
int attach_pool_message(struct lv_segment *pool_seg, dm_thin_message_t type,
struct logical_volume *lv, uint32_t delete_id,
int auto_increment);
+int lv_is_merging_thin_snapshot(const struct logical_volume *lv);
int pool_has_message(const struct lv_segment *seg,
const struct logical_volume *lv, uint32_t device_id);
int pool_below_threshold(const struct lv_segment *pool_seg);
diff --git a/lib/metadata/snapshot_manip.c b/lib/metadata/snapshot_manip.c
index e9a6d87..e563a78 100644
--- a/lib/metadata/snapshot_manip.c
+++ b/lib/metadata/snapshot_manip.c
@@ -27,7 +27,8 @@ int lv_is_origin(const struct logical_volume *lv)
int lv_is_cow(const struct logical_volume *lv)
{
- return (!lv_is_origin(lv) && lv->snapshot) ? 1 : 0;
+ /* Make sure a merging thin origin isn't confused as a cow LV */
+ return (!lv_is_thin_volume(lv) && !lv_is_origin(lv) && lv->snapshot) ? 1 : 0;
}
static uint64_t _cow_max_size(uint64_t origin_size, uint32_t chunk_size)
@@ -150,6 +151,13 @@ void init_snapshot_merge(struct lv_segment *snap_seg,
origin->snapshot = snap_seg;
origin->status |= MERGING;
+ if (lv_is_thin_volume(origin)) {
+ snap_seg->merge_lv = origin;
+ /* Making thin LV inivisible with regular log */
+ lv_set_hidden(snap_seg->lv);
+ return;
+ }
+
/*
* Even though lv_is_visible(snap_seg->lv) returns 0,
* the snap_seg->lv (name: snapshotX) is _not_ hidden;
@@ -166,6 +174,11 @@ void init_snapshot_merge(struct lv_segment *snap_seg,
void clear_snapshot_merge(struct logical_volume *origin)
{
/* clear merge attributes */
+ if (origin->snapshot->merge_lv)
+ /* Removed thin volume has to be visible */
+ lv_set_visible(origin->snapshot->lv);
+
+ origin->snapshot->merge_lv = NULL;
origin->snapshot->status &= ~MERGING;
origin->snapshot = NULL;
origin->status &= ~MERGING;
diff --git a/lib/metadata/thin_manip.c b/lib/metadata/thin_manip.c
index b3fedcf..0223752 100644
--- a/lib/metadata/thin_manip.c
+++ b/lib/metadata/thin_manip.c
@@ -60,7 +60,7 @@ int attach_pool_data_lv(struct lv_segment *pool_seg, struct logical_volume *pool
}
int attach_pool_lv(struct lv_segment *seg, struct logical_volume *pool_lv,
- struct logical_volume *origin)
+ struct logical_volume *origin, struct logical_volume *merge_lv)
{
seg->pool_lv = pool_lv;
seg->lv->status |= THIN_VOLUME;
@@ -69,7 +69,19 @@ int attach_pool_lv(struct lv_segment *seg, struct logical_volume *pool_lv,
if (origin && !add_seg_to_segs_using_this_lv(origin, seg))
return_0;
- return add_seg_to_segs_using_this_lv(pool_lv, seg);
+ if (!add_seg_to_segs_using_this_lv(pool_lv, seg))
+ return_0;
+
+ if (merge_lv) {
+ if (origin != merge_lv) {
+ if (!add_seg_to_segs_using_this_lv(merge_lv, seg))
+ return_0;
+ }
+
+ init_snapshot_merge(seg, merge_lv);
+ }
+
+ return 1;
}
int detach_pool_lv(struct lv_segment *seg)
@@ -247,6 +259,11 @@ int detach_thin_external_origin(struct lv_segment *seg)
return 1;
}
+int lv_is_merging_thin_snapshot(const struct logical_volume *lv)
+{
+ return (first_seg(lv)->status & MERGING) ? 1 : 0;
+}
+
/*
* Check whether pool has some message queued for LV or for device_id
* When LV is NULL and device_id is 0 it just checks for any message.
diff --git a/lib/thin/thin.c b/lib/thin/thin.c
index 8477aac..5f0c271 100644
--- a/lib/thin/thin.c
+++ b/lib/thin/thin.c
@@ -456,7 +456,7 @@ static int _thin_text_import(struct lv_segment *seg,
struct dm_hash_table *pv_hash __attribute__((unused)))
{
const char *lv_name;
- struct logical_volume *pool_lv, *origin = NULL, *external_lv = NULL;
+ struct logical_volume *pool_lv, *origin = NULL, *external_lv = NULL, *merge_lv = NULL;
if (!dm_config_get_str(sn, "thin_pool", &lv_name))
return SEG_LOG_ERROR("Thin pool must be a string in");
@@ -475,6 +475,13 @@ static int _thin_text_import(struct lv_segment *seg,
return SEG_LOG_ERROR("Unknown origin %s in", lv_name);
}
+ if (dm_config_has_node(sn, "merge")) {
+ if (!dm_config_get_str(sn, "merge", &lv_name))
+ return SEG_LOG_ERROR("Merge lv must be a string in");
+ if (!(merge_lv = find_lv(seg->lv->vg, lv_name)))
+ return SEG_LOG_ERROR("Unknown merge lv %s in", lv_name);
+ }
+
if (!dm_config_get_uint32(sn, "device_id", &seg->device_id))
return SEG_LOG_ERROR("Could not read device_id for");
@@ -490,7 +497,7 @@ static int _thin_text_import(struct lv_segment *seg,
return SEG_LOG_ERROR("Unknown external origin %s in", lv_name);
}
- if (!attach_pool_lv(seg, pool_lv, origin))
+ if (!attach_pool_lv(seg, pool_lv, origin, merge_lv))
return_0;
if (!attach_thin_external_origin(seg, external_lv))
@@ -509,6 +516,8 @@ static int _thin_text_export(const struct lv_segment *seg, struct formatter *f)
outf(f, "external_origin = \"%s\"", seg->external_lv->name);
if (seg->origin)
outf(f, "origin = \"%s\"", seg->origin->name);
+ if (seg->merge_lv)
+ outf(f, "merge = \"%s\"", seg->merge_lv->name);
return 1;
}
@@ -519,7 +528,7 @@ static int _thin_add_target_line(struct dev_manager *dm,
struct cmd_context *cmd __attribute__((unused)),
void **target_state __attribute__((unused)),
struct lv_segment *seg,
- const struct lv_activate_opts *laopts __attribute__((unused)),
+ const struct lv_activate_opts *laopts,
struct dm_tree_node *node, uint64_t len,
uint32_t *pvmove_mirror_count __attribute__((unused)))
{
@@ -537,6 +546,21 @@ static int _thin_add_target_line(struct dev_manager *dm,
return 0;
}
+ if (!laopts->no_merging) {
+ /*
+ * merge support for thinp snapshots is implemented by
+ * simply swapping the thinp device_id of the snapshot
+ * and origin.
+ */
+ if (seg->merge_lv) {
+ /* snapshot, use merging lv's device_id */
+ device_id = first_seg(seg->merge_lv)->device_id;
+ } else if (lv_is_merging_origin(seg->lv)) {
+ /* origin, use merging snapshot's device_id */
+ device_id = find_snapshot(seg->lv)->device_id;
+ }
+ }
+
if (!dm_tree_node_add_thin_target(node, len, pool_dlid, device_id))
return_0;
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