[lvm-devel] master - lvconvert: detaching cachevol with missing PVs
David Teigland
teigland at sourceware.org
Fri Sep 20 15:00:51 UTC 2019
Gitweb: https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=5d3bced5eab1244939958422446e0dfb5b6b79d4
Commit: 5d3bced5eab1244939958422446e0dfb5b6b79d4
Parent: b46dce0badb221b1417231e7bbf2d7d898a5a8c1
Author: David Teigland <teigland at redhat.com>
AuthorDate: Tue Sep 17 16:32:34 2019 -0500
Committer: David Teigland <teigland at redhat.com>
CommitterDate: Fri Sep 20 09:59:37 2019 -0500
lvconvert: detaching cachevol with missing PVs
. For dm-cache in writethrough, always allow splitcache,
whether the cache is missing PVs or not.
. For dm-cache in writeback, if the cache is missing PVs,
allow splitcache with force and yes.
. For dm-writecache, if the cache is missing PVs,
allow splitcache with force and yes.
---
lib/metadata/cache_manip.c | 8 ++--
lib/metadata/lv_manip.c | 2 +-
lib/metadata/metadata-exported.h | 2 +-
tools/lvconvert.c | 84 ++++++++++++++++++++++++++++++-------
4 files changed, 74 insertions(+), 22 deletions(-)
diff --git a/lib/metadata/cache_manip.c b/lib/metadata/cache_manip.c
index 7ea2c0e..65589f7 100644
--- a/lib/metadata/cache_manip.c
+++ b/lib/metadata/cache_manip.c
@@ -655,7 +655,7 @@ static int _lv_detach_cache_vol_while_active(struct cmd_context *cmd, struct log
return 1;
}
-static int _lv_detach_cache_vol_while_inactive(struct cmd_context *cmd, struct logical_volume *cache_lv)
+static int _lv_detach_cache_vol_while_inactive(struct cmd_context *cmd, struct logical_volume *cache_lv, int noflush)
{
struct lv_segment *cache_seg = first_seg(cache_lv);
struct logical_volume *corigin_lv;
@@ -673,7 +673,7 @@ static int _lv_detach_cache_vol_while_inactive(struct cmd_context *cmd, struct l
* With these modes there is no flush needed so we can immediately
* detach without temporarily activating the LV to flush it.
*/
- if ((cache_mode == CACHE_MODE_WRITETHROUGH) || (cache_mode == CACHE_MODE_PASSTHROUGH))
+ if ((cache_mode == CACHE_MODE_WRITETHROUGH) || (cache_mode == CACHE_MODE_PASSTHROUGH) || noflush)
goto detach;
/*
@@ -727,7 +727,7 @@ static int _lv_detach_cache_vol_while_inactive(struct cmd_context *cmd, struct l
return 1;
}
-int lv_detach_cache_vol(struct logical_volume *cache_lv)
+int lv_detach_cache_vol(struct logical_volume *cache_lv, int noflush)
{
struct cmd_context *cmd = cache_lv->vg->cmd;
@@ -739,7 +739,7 @@ int lv_detach_cache_vol(struct logical_volume *cache_lv)
if (lv_is_active(cache_lv))
return _lv_detach_cache_vol_while_active(cmd, cache_lv);
else
- return _lv_detach_cache_vol_while_inactive(cmd, cache_lv);
+ return _lv_detach_cache_vol_while_inactive(cmd, cache_lv, noflush);
}
/*
diff --git a/lib/metadata/lv_manip.c b/lib/metadata/lv_manip.c
index 6451368..107074a 100644
--- a/lib/metadata/lv_manip.c
+++ b/lib/metadata/lv_manip.c
@@ -6256,7 +6256,7 @@ int lv_remove_single(struct cmd_context *cmd, struct logical_volume *lv,
return_0;
if (lv_is_cache(lv) && lv_is_cache_vol(first_seg(lv)->pool_lv)) {
- if (!lv_detach_cache_vol(lv)) {
+ if (!lv_detach_cache_vol(lv, 0)) {
log_error("Failed to detach cache from %s", display_lvname(lv));
return 0;
}
diff --git a/lib/metadata/metadata-exported.h b/lib/metadata/metadata-exported.h
index a910aa3..1c10390 100644
--- a/lib/metadata/metadata-exported.h
+++ b/lib/metadata/metadata-exported.h
@@ -1276,7 +1276,7 @@ struct logical_volume *lv_cache_create(struct logical_volume *pool_lv,
struct logical_volume *origin_lv);
int lv_cache_wait_for_clean(struct logical_volume *cache_lv, int *is_clean);
int lv_cache_remove(struct logical_volume *cache_lv);
-int lv_detach_cache_vol(struct logical_volume *cache_lv);
+int lv_detach_cache_vol(struct logical_volume *cache_lv, int noflush);
int wipe_cache_pool(struct logical_volume *cache_pool_lv);
/* -- metadata/cache_manip.c */
diff --git a/tools/lvconvert.c b/tools/lvconvert.c
index d64ab22..77aad9d 100644
--- a/tools/lvconvert.c
+++ b/tools/lvconvert.c
@@ -1841,16 +1841,53 @@ static int _lvconvert_split_and_keep_cache(struct cmd_context *cmd,
struct logical_volume *lv_fast)
{
struct lv_segment *cache_seg = first_seg(lv);
-
- log_debug("Detaching cache %s from LV %s.", display_lvname(lv_fast), display_lvname(lv));
+ int cache_mode = cache_seg->cache_mode;
+ int noflush = 0;
if (!archive(lv->vg))
return_0;
if (lv_is_cache_vol(cache_seg->pool_lv)) {
- if (!lv_detach_cache_vol(lv))
+ log_debug("Detaching cachevol %s from LV %s.", display_lvname(lv_fast), display_lvname(lv));
+
+ /*
+ * Detaching a writeback cache generally requires flushing;
+ * doing otherwise can mean data loss/corruption.
+ * If the cache devices are missing, the cache can't be
+ * flushed, so require the user to use a force option to
+ * detach the cache in this case.
+ */
+ if ((cache_mode != CACHE_MODE_WRITETHROUGH) && lv_is_partial(lv_fast)) {
+ if (!arg_count(cmd, force_ARG)) {
+ log_warn("WARNING: writeback cache on %s is not complete and cannot be flushed.", display_lvname(lv_fast));
+ log_warn("WARNING: cannot detach writeback cache from %s without --force.", display_lvname(lv));
+ log_error("Conversion aborted.");
+ return 0;
+ }
+
+ log_warn("WARNING: Data may be lost by detaching writeback cache without flushing.");
+
+ if (!arg_count(cmd, yes_ARG) &&
+ yes_no_prompt("Detach writeback cache %s from %s without flushing data?",
+ display_lvname(lv_fast),
+ display_lvname(lv)) == 'n') {
+ log_error("Conversion aborted.");
+ return 0;
+ }
+
+ noflush = 1;
+ }
+
+ if (!lv_detach_cache_vol(lv, noflush))
return_0;
} else {
+ log_debug("Detaching cachepool %s from LV %s.", display_lvname(lv_fast), display_lvname(lv));
+
+ if (vg_missing_pv_count(lv->vg)) {
+ log_error("Cannot split cache pool while PVs are missing, see --uncache to delete cache pool.");
+ return 0;
+ }
+
if (!lv_cache_remove(lv))
return_0;
}
@@ -1860,7 +1897,7 @@ static int _lvconvert_split_and_keep_cache(struct cmd_context *cmd,
backup(lv->vg);
- log_print_unless_silent("Logical volume %s is not cached and cache pool %s is unused.",
+ log_print_unless_silent("Logical volume %s is not cached and %s is unused.",
display_lvname(lv), display_lvname(lv_fast));
return 1;
@@ -1895,7 +1932,7 @@ static int _lvconvert_split_and_remove_cache(struct cmd_context *cmd,
if (first_seg(seg->pool_lv)->cache_mode != CACHE_MODE_WRITETHROUGH) {
if (!arg_count(cmd, force_ARG)) {
log_error("Conversion aborted.");
- log_error("Cannot uncache writethrough cache volume %s without --force.",
+ log_error("Cannot uncache writeback cache volume %s without --force.",
display_lvname(lv));
return 0;
}
@@ -4607,7 +4644,7 @@ static int _lvconvert_detach_writecache(struct cmd_context *cmd,
struct logical_volume *lv,
struct logical_volume *lv_fast);
-static int _lvconvert_split_cache_vol(struct cmd_context *cmd,
+static int _lvconvert_split_cache_single(struct cmd_context *cmd,
struct logical_volume *lv,
struct processing_handle *handle)
{
@@ -4635,6 +4672,7 @@ static int _lvconvert_split_cache_vol(struct cmd_context *cmd,
} else if (lv_is_thin_pool(lv)) {
lv_main = seg_lv(first_seg(lv), 0); /* cached _tdata */
lv_fast = first_seg(lv_main)->pool_lv;
+
} else if (lv_is_vdo_pool(lv)) {
lv_main = seg_lv(first_seg(lv), 0); /* cached _vdata */
lv_fast = first_seg(lv_main)->pool_lv;
@@ -4694,13 +4732,11 @@ static int _lvconvert_split_cache_vol(struct cmd_context *cmd,
int lvconvert_split_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
{
- if (cmd->command->command_enum == lvconvert_split_and_remove_cache_CMD) {
- cmd->handles_missing_pvs = 1;
- cmd->partial_activation = 1;
- }
+ cmd->handles_missing_pvs = 1;
+ cmd->partial_activation = 1;
return process_each_lv(cmd, 1, cmd->position_argv, NULL, NULL, READ_FOR_UPDATE,
- NULL, NULL, &_lvconvert_split_cache_vol);
+ NULL, NULL, &_lvconvert_split_cache_single);
}
static int _lvconvert_raid_types_single(struct cmd_context *cmd, struct logical_volume *lv,
@@ -5246,11 +5282,6 @@ fail:
return 0;
}
-/*
- * TODO: add a new option that will skip activating and flushing the
- * writecache and move directly to detaching.
- */
-
static int _lvconvert_detach_writecache(struct cmd_context *cmd,
struct logical_volume *lv,
struct logical_volume *lv_fast)
@@ -5269,6 +5300,26 @@ static int _lvconvert_detach_writecache(struct cmd_context *cmd,
if (!archive(lv->vg))
return_0;
+ if (lv_is_partial(lv_fast)) {
+ if (!arg_count(cmd, force_ARG)) {
+ log_warn("WARNING: writecache on %s is not complete and cannot be flushed.", display_lvname(lv_fast));
+ log_warn("WARNING: cannot detach writecache from %s without --force.", display_lvname(lv));
+ log_error("Conversion aborted.");
+ return 0;
+ }
+
+ log_warn("WARNING: Data may be lost by detaching writecache without flushing.");
+
+ if (!arg_count(cmd, yes_ARG) &&
+ yes_no_prompt("Detach writecache %s from %s without flushing data?",
+ display_lvname(lv_fast), display_lvname(lv)) == 'n') {
+ log_error("Conversion aborted.");
+ return 0;
+ }
+
+ goto detach;
+ }
+
/*
* Activate LV internally since the LV needs to be active to flush.
* LV_TEMPORARY should keep the LV from being exposed to the user
@@ -5315,6 +5366,7 @@ static int _lvconvert_detach_writecache(struct cmd_context *cmd,
lv->status &= ~LV_TEMPORARY;
+ detach:
if (!_lv_writecache_detach(cmd, lv, lv_fast)) {
log_error("Failed to detach writecache from %s", display_lvname(lv));
return 0;
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