Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=103c188681fce748e... Commit: 103c188681fce748ef193115c126bfbbc65fbab9 Parent: aed8bc8ae7b2f1c20a84470b033daababfb7c166 Author: David Teigland teigland@redhat.com AuthorDate: Thu Jun 30 12:02:43 2016 -0500 Committer: David Teigland teigland@redhat.com CommitterDate: Thu Jun 30 17:08:50 2016 -0500
lvconvert: add comments describing conversions
--- tools/lvconvert.c | 387 ++++++++++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 352 insertions(+), 35 deletions(-)
diff --git a/tools/lvconvert.c b/tools/lvconvert.c index 3b98116..795deef 100644 --- a/tools/lvconvert.c +++ b/tools/lvconvert.c @@ -18,6 +18,25 @@ #include "lv_alloc.h" #include "lvconvert_poll.h"
+/* + * Guidelines for mapping options to operations. + * + * There should be a clear and unique correspondence between an option + * name and the operation to be performed. + * + * An option with a given name should always perform the same operation. + * If the same operation applies to two types of LV, then the same option + * name can be used with both LV types. But, a given option name should + * not be used to perform different operations depending on the LV type it + * is used with. + * + * --merge and --split are examples where a single option name has been + * overloaded with different operations. The case of --split has been + * corrected with the clear and unique variations --splitcache, + * --splitsnapshot, --splitmirror, which should allow --split to be + * deprecated. (The same is still needed for --merge.) + */ + struct lvconvert_params { /* Exactly one of these options is chosen */ int merge; /* Either merge_snapshot or merge_mirror is also set */ @@ -3295,24 +3314,44 @@ static int _lvconvert_cache(struct cmd_context *cmd, * moved into the _convert_lvtype_operation() functions below. */
+/* + * Separate a COW snapshot LV from its origin. + * lvconvert --splitsnapshot LV + */ + static int _convert_cow_snapshot_splitsnapshot(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_splitsnapshot(cmd, lv, lp); }
+/* + * Merge a COW snapshot LV into its origin. + * lvconvert --merge LV + */ + static int _convert_cow_snapshot_merge(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_merge_old_snapshot(cmd, lv, lp); }
+/* + * Merge a snapshot thin LV into its origin. + * lvconvert --merge LV + */ + static int _convert_thin_volume_merge(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_merge_thin_snapshot(cmd, lv, lp); }
+/* + * Split and preserve a cache pool from the data portion of a thin pool LV. + * lvconvert --splitcache LV + */ + static int _convert_thin_pool_splitcache(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3328,6 +3367,11 @@ static int _convert_thin_pool_splitcache(struct cmd_context *cmd, struct logical return _lvconvert_split_cached(cmd, sublv1); }
+/* + * Split and remove a cache pool from the data portion of a thin pool LV. + * lvconvert --uncache LV + */ + static int _convert_thin_pool_uncache(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3343,16 +3387,35 @@ static int _convert_thin_pool_uncache(struct cmd_context *cmd, struct logical_vo return _lvconvert_uncache(cmd, sublv1, lp); }
+/* + * Repair a thin pool LV. + * lvconvert --repair LV + */ + static int _convert_thin_pool_repair(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_thin_pool_repair(cmd, lv, lp); }
+/* + * Convert the data portion of a thin pool LV to a cache LV. + * lvconvert --type cache LV + * + * Required options: + * --cachepool LV + * + * Auxiliary operation: + * Converts the --cachepool arg to a cache pool if it is not already. + * + * Alternate syntax: + * lvconvert --cache LV + */ + static int _convert_thin_pool_cache(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { - /* lvconvert --cache includes an implicit conversion of the cachepool arg to type cache-pool. */ + /* lvconvert --type cache includes an implicit conversion of the cachepool arg to type cache-pool. */ if (!_lvconvert_pool(cmd, lv, lp)) { log_error("Implicit conversion of --cachepool arg to type cache-pool failed."); return 0; @@ -3363,24 +3426,49 @@ static int _convert_thin_pool_cache(struct cmd_context *cmd, struct logical_volu return _lvconvert_cache(cmd, lv, lp); }
+/* + * Replace the metadata LV in a thin pool LV. + * lvconvert --poolmetadata NewLV --thinpool LV + * FIXME: this will change so --swap-poolmetadata defines the operation. + * FIXME: should be lvconvert --swap-poolmetadata NewLV LV + */ + static int _convert_thin_pool_swapmetadata(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_pool(cmd, lv, lp); }
+/* + * Split and preserve a cache pool from a cache LV. + * lvconvert --splitcache LV + */ + static int _convert_cache_volume_splitcache(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_split_cached(cmd, lv); }
+/* + * Split and remove a cache pool from a cache LV. + * lvconvert --uncache LV + */ + static int _convert_cache_volume_uncache(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_uncache(cmd, lv, lp); }
+/* + * Split images from the raid1|mirror origin of a cache LV and use them to create a new LV. + * lvconvert --splitmirrors Number LV + * + * Required options: + * --trackchanges | --name Name + */ + static int _convert_cache_volume_splitmirrors(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3398,12 +3486,26 @@ static int _convert_cache_volume_splitmirrors(struct cmd_context *cmd, struct lo return 0; }
+/* + * Convert a cache LV to a thin pool (using the cache LV for thin pool data). + * lvconvert --type thin-pool LV + * + * Alternate syntax: + * This is equivalent to above, but not preferred because it's ambiguous and inconsistent. + * lvconvert --thinpool LV + */ + static int _convert_cache_volume_thin_pool(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_pool(cmd, lv, lp); }
+/* + * Split a cache volume from a cache pool LV. + * lvconvert --splitcache LV + */ + static int _convert_cache_pool_splitcache(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3429,30 +3531,63 @@ static int _convert_cache_pool_splitcache(struct cmd_context *cmd, struct logica return _lvconvert_split_cached(cmd, sublv1); }
+/* + * Replace the metadata LV in a cache pool LV. + * lvconvert --poolmetadata NewLV --cachepool LV + * FIXME: this will change so --swap-poolmetadata defines the operation. + * FIXME: should be lvconvert --swap-poolmetadata NewLV LV + */ + static int _convert_cache_pool_swapmetadata(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_pool(cmd, lv, lp); }
+/* + * Change the number of images in a mirror LV. + * lvconvert --mirrors Number LV + */ + static int _convert_mirror_number(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_mirrors(cmd, lv, lp); }
+/* + * Split images from a mirror LV and use them to create a new LV. + * lvconvert --splitmirrors Number LV + * + * Required options: + * --name Name + */ + static int _convert_mirror_splitmirrors(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_mirrors(cmd, lv, lp); }
+/* + * Change the type of log used by a mirror LV. + * lvconvert --mirrorlog Type LV + */ + static int _convert_mirror_log(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_mirrors(cmd, lv, lp); }
+/* + * Replace failed PVs in a mirror LV. + * lvconvert --repair LV + * + * Auxiliary operation: + * Removes missing, empty PVs from the VG, like vgreduce. + */ + static int _convert_mirror_repair(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3469,18 +3604,38 @@ static int _convert_mirror_repair(struct cmd_context *cmd, struct logical_volume return ret; }
+/* + * Convert mirror LV to raid1 LV. + * lvconvert --type raid1 LV + * + * FIXME: this is not yet implemented in the raid code. + */ + static int _convert_mirror_raid(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_raid(lv, lp); }
+/* + * Change the number of images in a raid1 LV. + * lvconvert --mirrors Number LV + */ + static int _convert_raid_number(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_raid(lv, lp); }
+/* + * Split images from a raid1 LV and use them to create a new LV. + * lvconvert --splitmirrors Number LV + * + * Required options: + * --trackchanges | --name Name + */ + static int _convert_raid_splitmirrors(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3488,6 +3643,12 @@ static int _convert_raid_splitmirrors(struct cmd_context *cmd, struct logical_vo return _lvconvert_raid(lv, lp); }
+/* + * Merge a raid1 LV into originalLV if the raid1 LV was + * previously split from the originalLV using --trackchanges. + * lvconvert --merge LV + */ + static int _convert_raid_merge(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3495,6 +3656,14 @@ static int _convert_raid_merge(struct cmd_context *cmd, struct logical_volume *l return _lvconvert_raid(lv, lp); }
+/* + * Replace failed PVs in a raid* LV. + * lvconvert --repair LV + * + * Auxiliary operation: + * Removes missing, empty PVs from the VG, like vgreduce. + */ + static int _convert_raid_repair(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3512,6 +3681,11 @@ static int _convert_raid_repair(struct cmd_context *cmd, struct logical_volume * return ret; }
+/* + * Replace a specific PV in a raid* LV with another PV. + * lvconvert --replace PV LV + */ + static int _convert_raid_replace(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3519,12 +3693,35 @@ static int _convert_raid_replace(struct cmd_context *cmd, struct logical_volume return _lvconvert_raid(lv, lp); }
+/* + * Combine a raid* LV with a snapshot LV that was previously + * split from the raid* LV using --splitsnapshot. + * lvconvert --type snapshot LV SnapshotLV + * + * Alternate syntax: + * lvconvert --snapshot LV SnapshotLV + */ + static int _convert_raid_snapshot(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_snapshot(cmd, lv, lp); }
+/* + * Convert a raid* LV to a thin LV with an external origin. + * lvconvert --type thin LV + * + * Required options: + * --thinpool LV + * + * Auxiliary operation: + * Converts the --thinpool arg to a thin pool if it is not already. + * + * Alternate syntax: + * lvconvert --thin LV + */ + static int _convert_raid_thin(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3537,10 +3734,24 @@ static int _convert_raid_thin(struct cmd_context *cmd, struct logical_volume *lv return _lvconvert_thin(cmd, lv, lp); }
+/* + * Convert a raid* LV to a cache LV. + * lvconvert --type cache LV + * + * Required options: + * --cachepool LV + * + * Auxiliary operation: + * Converts the --cachepool arg to a cache pool if it is not already. + * + * Alternate syntax: + * lvconvert --cache LV + */ + static int _convert_raid_cache(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { - /* lvconvert --cache includes an implicit conversion of the cachepool arg to type cache-pool. */ + /* lvconvert --type cache includes an implicit conversion of the cachepool arg to type cache-pool. */ if (!_lvconvert_pool(cmd, lv, lp)) { log_error("Implicit conversion of --cachepool arg to type cache-pool failed."); return 0; @@ -3549,41 +3760,74 @@ static int _convert_raid_cache(struct cmd_context *cmd, struct logical_volume *l return _lvconvert_cache(cmd, lv, lp); }
+/* + * Convert a raid* LV to a thin-pool LV. + * lvconvert --type thin-pool LV + * + * Alternate syntax: + * This is equivalent to above, but not preferred because it's ambiguous and inconsistent. + * lvconvert --thinpool LV + */ + static int _convert_raid_thin_pool(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_pool(cmd, lv, lp); }
+/* + * Convert a raid* LV to cache-pool LV. + * lvconvert --type cache-pool LV + */ + static int _convert_raid_cache_pool(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_pool(cmd, lv, lp); }
+/* + * Convert a raid* LV to use a different raid level. + * lvconvert --type raid* LV + */ + static int _convert_raid_raid(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_raid(lv, lp); }
+/* + * Convert a raid* LV to a striped LV. + * lvconvert --type striped LV + * + * FIXME: this is not yet implemented in the raid code. + */ + static int _convert_raid_striped(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_raid(lv, lp); }
+/* + * Convert a raid* LV to a linear LV. + * lvconvert --type linear LV + * + * FIXME: this is not yet implemented in the raid code. + */ + static int _convert_raid_linear(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_raid(lv, lp); }
-static int _convert_striped_snapshot(struct cmd_context *cmd, struct logical_volume *lv, - struct lvconvert_params *lp) -{ - return _lvconvert_snapshot(cmd, lv, lp); -} +/* + * Merge a striped/linear LV into a raid1 LV if the striped/linear LV was + * previously split from the raid1 LV using --trackchanges. + * lvconvert --merge LV + */
static int _convert_striped_merge(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) @@ -3591,6 +3835,35 @@ static int _convert_striped_merge(struct cmd_context *cmd, struct logical_volume return _lvconvert_raid(lv, lp); }
+/* + * Combine a linear/striped LV with a snapshot LV that was previously + * split from the linear/striped LV using --splitsnapshot. + * lvconvert --type snapshot LV SnapshotLV + * + * Alternate syntax: + * lvconvert --snapshot LV SnapshotLV + */ + +static int _convert_striped_snapshot(struct cmd_context *cmd, struct logical_volume *lv, + struct lvconvert_params *lp) +{ + return _lvconvert_snapshot(cmd, lv, lp); +} + +/* + * Convert a striped/linear LV to a thin LV with an external origin. + * lvconvert --type thin LV + * + * Required options: + * --thinpool LV + * + * Auxiliary operation: + * Converts the --thinpool arg to a thin pool if it is not already. + * + * Alternate syntax: + * lvconvert --thin LV + */ + static int _convert_striped_thin(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3603,6 +3876,20 @@ static int _convert_striped_thin(struct cmd_context *cmd, struct logical_volume return _lvconvert_thin(cmd, lv, lp); }
+/* + * Convert a striped/linear LV to a cache LV. + * lvconvert --type cache LV + * + * Required options: + * --cachepool LV + * + * Auxiliary operation: + * Converts the --cachepool arg to a cache pool if it is not already. + * + * Alternate syntax: + * lvconvert --cache LV + */ + static int _convert_striped_cache(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3615,24 +3902,62 @@ static int _convert_striped_cache(struct cmd_context *cmd, struct logical_volume return _lvconvert_cache(cmd, lv, lp); }
+/* + * Convert a striped/linear LV to a thin-pool LV. + * lvconvert --type thin-pool LV + * + * Alternate syntax: + * This is equivalent to above, but not preferred because it's ambiguous and inconsistent. + * lvconvert --thinpool LV + */ + static int _convert_striped_thin_pool(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_pool(cmd, lv, lp); }
+/* + * Convert a striped/linear LV to a cache-pool LV. + * lvconvert --type cache-pool LV + */ + static int _convert_striped_cache_pool(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_pool(cmd, lv, lp); }
+/* + * Convert a striped/linear LV to a mirror LV. + * lvconvert --type mirror LV + * + * Required options: + * --mirrors Number + * + * Alternate syntax: + * This is equivalent to above when global/mirror_segtype_default="mirror". + * lvconvert --mirrors Number LV + */ + static int _convert_striped_mirror(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { return _lvconvert_mirrors(cmd, lv, lp); }
+/* + * Convert a striped/linear LV to a raid* LV. + * lvconvert --type raid* LV + * + * Required options: + * --mirrors Number + * + * Alternate syntax: + * This is equivalent to above when global/mirror_segtype_default="raid1". + * lvconvert --mirrors Number LV + */ + static int _convert_striped_raid(struct cmd_context *cmd, struct logical_volume *lv, struct lvconvert_params *lp) { @@ -3696,9 +4021,9 @@ static int _convert_thin_pool(struct cmd_context *cmd, struct logical_volume *lv
log_error("Operation not permitted on thin pool LV %s", display_lvname(lv)); log_error("Operations permitted on a thin pool LV are:\n" - " --splitcache (operates on cache sub LV)\n" - " --uncache (operates on cache sub LV)\n" - " --cache (operates on data sub LV)\n" + " --splitcache (operates on cache sub LV)\n" + " --uncache (operates on cache sub LV)\n" + " --type cache | --cache (operates on data sub LV)\n" " --repair\n"); return 0; } @@ -3718,12 +4043,12 @@ static int _convert_cache_volume(struct cmd_context *cmd, struct logical_volume if (arg_is_set(cmd, splitmirrors_ARG)) return _convert_cache_volume_splitmirrors(cmd, lv, lp);
- /* The --thinpool alias is ambiguous and not preferred. */ + /* Using --thinpool is ambiguous and not preferred. */
if ((new_type && !strcmp(new_type, "thin-pool")) || arg_is_set(cmd, thinpool_ARG)) return _convert_cache_volume_thin_pool(cmd, lv, lp);
- /* The --thinpool alias for --type thin-pool is not preferred, so not shown. */ + /* The --thinpool alternative for --type thin-pool is not preferred, so not shown. */
log_error("Operation not permitted on cache LV %s", display_lvname(lv)); log_error("Operations permitted on a cache LV are:\n" @@ -3782,6 +4107,7 @@ static int _convert_mirror(struct cmd_context *cmd, struct logical_volume *lv, * explicit option should be added to enable this case, * rather than making it the result of an ambiguous * "lvconvert vg/lv" command. + * Add 'lvconvert --poll-mirror vg/lv' for this case. * * Old behavior was described as: * "Collapsing a stack of mirrors. @@ -3837,7 +4163,7 @@ static int _convert_raid(struct cmd_context *cmd, struct logical_volume *lv, if (lp->cache) return _convert_raid_cache(cmd, lv, lp);
- /* The --thinpool alias is ambiguous and not preferred. */ + /* Using --thinpool is ambiguous and not preferred. */
if ((new_type && !strcmp(new_type, "thin-pool")) || arg_is_set(cmd, thinpool_ARG)) return _convert_raid_thin_pool(cmd, lv, lp); @@ -3854,7 +4180,7 @@ static int _convert_raid(struct cmd_context *cmd, struct logical_volume *lv, if (new_type && !strcmp(new_type, "linear")) return _convert_raid_linear(cmd, lv, lp);
- /* The --thinpool alias for --type thin-pool is not preferred, so not shown. */ + /* The --thinpool alternative for --type thin-pool is not preferred, so not shown. */
log_error("Operation not permitted on raid LV %s", display_lvname(lv)); log_error("Operations permitted on a raid LV are:\n" @@ -3863,9 +4189,9 @@ static int _convert_raid(struct cmd_context *cmd, struct logical_volume *lv, " --merge\n" " --repair\n" " --replace\n" - " --snapshot\n" - " --thin\n" - " --cache\n" + " --type snapshot | --snapshot\n" + " --type thin | --thin\n" + " --type cache | --cache\n" " --type thin-pool\n" " --type cache-pool\n" " --type raid*\n" @@ -3884,20 +4210,20 @@ static int _convert_striped(struct cmd_context *cmd, struct logical_volume *lv, if (new_type) new_segtype = get_segtype_from_string(cmd, new_type);
- if (lp->snapshot) - return _convert_striped_snapshot(cmd, lv, lp); - /* FIXME: add a new option to make this case more clear, e.g. --merge-splitmirror */ if (lp->merge) return _convert_striped_merge(cmd, lv, lp);
+ if (lp->snapshot) + return _convert_striped_snapshot(cmd, lv, lp); + if (lp->thin) return _convert_striped_thin(cmd, lv, lp);
if (lp->cache) return _convert_striped_cache(cmd, lv, lp);
- /* The --thinpool alias is ambiguous and not preferred. */ + /* Using --thinpool is ambiguous and not preferred. */
if ((new_type && !strcmp(new_type, "thin-pool")) || arg_is_set(cmd, thinpool_ARG)) return _convert_striped_thin_pool(cmd, lv, lp); @@ -3919,14 +4245,14 @@ static int _convert_striped(struct cmd_context *cmd, struct logical_volume *lv, if (arg_is_set(cmd, mirrors_ARG) && mirrors_type && !strcmp(mirrors_type, "raid1")) return _convert_striped_raid(cmd, lv, lp);
- /* The --thinpool alias for --type thin-pool is not preferred, so not shown. */ + /* The --thinpool alternative for --type thin-pool is not preferred, so not shown. */
log_error("Operation not permitted on striped or linear LV %s", display_lvname(lv)); log_error("Operations permitted on a striped or linear LV are:\n" - " --snapshot\n" " --merge\n" - " --thin\n" - " --cache\n" + " --type snapshot | --snapshot\n" + " --type thin | --thin\n" + " --type cache | --cache\n" " --type thin-pool\n" " --type cache-pool\n" " --type mirror | --mirrors\n" @@ -3949,6 +4275,7 @@ static int _convert_striped(struct cmd_context *cmd, struct logical_volume *lv, * _convert_lvtype(); * for each lp->operation * _convert_lvtype_operation(); + * */
static int _lvconvert(struct cmd_context *cmd, struct logical_volume *lv, @@ -3957,12 +4284,6 @@ static int _lvconvert(struct cmd_context *cmd, struct logical_volume *lv, struct lv_segment *lv_seg = first_seg(lv); int ret = 0;
- log_debug("lvconvert lv %s is type %s status %llx to type %s", - display_lvname(lv), - lv_seg->segtype->name, - (unsigned long long)lv->status, - arg_str_value(cmd, type_ARG, "")); - /* * Check some conditions that can never be processed. */ @@ -4048,10 +4369,6 @@ static int _lvconvert(struct cmd_context *cmd, struct logical_volume *lv, }
/* - * Check for LV types that cannot be converted and print an error. - */ - - /* * The intention is to explicitly check all cases above and never * reach here, but this covers anything that was missed. */
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