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mirror of git://sourceware.org/git/lvm2.git synced 2025-03-11 20:58:50 +03:00

cache: support activation of empty cache-pool

When the cache pool is unused, lvm2 code will internally
allow to activate such cache-pool.

Cache-pool is activate as metadata LV, so lvm2 could easily
wipe such volume before cache-pool is reused.
This commit is contained in:
Zdenek Kabelac 2014-11-02 19:34:50 +01:00
parent ab49120465
commit 29bd3cccc8

View File

@ -1867,12 +1867,15 @@ static int _add_lv_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
const char *uuid; const char *uuid;
if (lv_is_cache_pool(lv)) { if (lv_is_cache_pool(lv)) {
/* origin_only is ignored */ if (!dm_list_empty(&lv->segs_using_this_lv)) {
/* cache pool is 'meta' LV and does not have a real device node */ /* origin_only is ignored */
if (!_add_lv_to_dtree(dm, dtree, seg_lv(first_seg(lv), 0), 0)) /* cache pool is 'meta' LV and does not have a real device node */
return_0; if (!_add_lv_to_dtree(dm, dtree, seg_lv(first_seg(lv), 0), 0))
if (!_add_lv_to_dtree(dm, dtree, first_seg(lv)->metadata_lv, 0)) return_0;
return_0; if (!_add_lv_to_dtree(dm, dtree, first_seg(lv)->metadata_lv, 0))
return_0;
} else if (!_add_dev_to_dtree(dm, dtree, lv, NULL))
return_0; /* For internal use - empty pool makes meta visible */
return 1; return 1;
} }
@ -2560,7 +2563,8 @@ static int _add_new_lv_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
uint32_t read_ahead = lv->read_ahead; uint32_t read_ahead = lv->read_ahead;
uint32_t read_ahead_flags = UINT32_C(0); uint32_t read_ahead_flags = UINT32_C(0);
if (lv_is_cache_pool(lv)) { if (lv_is_cache_pool(lv) &&
!dm_list_empty(&lv->segs_using_this_lv)) {
/* cache pool is 'meta' LV and does not have a real device node */ /* cache pool is 'meta' LV and does not have a real device node */
if (!_add_new_lv_to_dtree(dm, dtree, seg_lv(first_seg(lv), 0), laopts, NULL)) if (!_add_new_lv_to_dtree(dm, dtree, seg_lv(first_seg(lv), 0), laopts, NULL))
return_0; return_0;
@ -2637,6 +2641,10 @@ static int _add_new_lv_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
/* Create table */ /* Create table */
dm->pvmove_mirror_count = 0u; dm->pvmove_mirror_count = 0u;
/* This is unused cache-pool - make metadata accessible */
if (lv_is_cache_pool(lv))
lv = first_seg(lv)->metadata_lv;
/* If this is a snapshot origin, add real LV */ /* If this is a snapshot origin, add real LV */
/* If this is a snapshot origin + merging snapshot, add cow + real LV */ /* If this is a snapshot origin + merging snapshot, add cow + real LV */
/* Snapshot origin could be also external origin */ /* Snapshot origin could be also external origin */
@ -2853,7 +2861,7 @@ static int _tree_action(struct dev_manager *dm, const struct logical_volume *lv,
/* Some LV can be used for top level tree */ /* Some LV can be used for top level tree */
/* TODO: add more.... */ /* TODO: add more.... */
if (lv_is_cache_pool(lv)) { if (lv_is_cache_pool(lv) && !dm_list_empty(&lv->segs_using_this_lv)) {
log_error(INTERNAL_ERROR "Cannot create tree for %s.", lv->name); log_error(INTERNAL_ERROR "Cannot create tree for %s.", lv->name);
return 0; return 0;
} }