diff options
| -rw-r--r-- | WHATS_NEW | 1 | ||||
| -rw-r--r-- | lib/metadata/metadata-exported.h | 1 | ||||
| -rw-r--r-- | lib/metadata/mirror.c | 54 | ||||
| -rw-r--r-- | tools/vgreduce.c | 5 |
4 files changed, 54 insertions, 7 deletions
@@ -1,5 +1,6 @@ Version 2.02.40 - ================================ + Avoid shuffling remaining mirror images when removing one, retaining primary. Add missing LV error target activation in _remove_mirror_images. Prevent resizing an LV while lvconvert is using it. Avoid repeatedly wiping cache while VG_GLOBAL is held in vgscan & pvscan. diff --git a/lib/metadata/metadata-exported.h b/lib/metadata/metadata-exported.h index e42597a2..a5390595 100644 --- a/lib/metadata/metadata-exported.h +++ b/lib/metadata/metadata-exported.h @@ -532,6 +532,7 @@ int add_mirror_log(struct cmd_context *cmd, struct logical_volume *lv, int reconfigure_mirror_images(struct lv_segment *mirrored_seg, uint32_t num_mirrors, struct list *removable_pvs, unsigned remove_log); int collapse_mirrored_lv(struct logical_volume *lv); +int shift_mirror_images(struct lv_segment *mirrored_seg, unsigned mimage); struct logical_volume *find_pvmove_lv(struct volume_group *vg, struct device *dev, uint32_t lv_type); diff --git a/lib/metadata/mirror.c b/lib/metadata/mirror.c index 5d9b355c..0e4afe76 100644 --- a/lib/metadata/mirror.c +++ b/lib/metadata/mirror.c @@ -136,6 +136,53 @@ uint32_t adjusted_mirror_region_size(uint32_t extent_size, uint32_t extents, } /* + * shift_mirror_images + * @mirrored_seg + * @mimage: The position (index) of the image to move to the end + * + * When dealing with removal of legs, we often move a 'removable leg' + * to the back of the 'areas' array. It is critically important not + * to simply swap it for the last area in the array. This would have + * the affect of reordering the remaining legs - altering position of + * the primary. So, we must shuffle all of the areas in the array + * to maintain their relative position before moving the 'removable + * leg' to the end. + * + * Short illustration of the problem: + * - Mirror consists of legs A, B, C and we want to remove A + * - We swap A and C and then remove A, leaving C, B + * This scenario is problematic in failure cases where A dies, because + * B becomes the primary. If the above happens, we effectively throw + * away any changes made between the time of failure and the time of + * restructuring the mirror. + * + * So, any time we want to move areas to the end to be removed, use + * this function. + */ +int shift_mirror_images(struct lv_segment *mirrored_seg, unsigned mimage) +{ + int i; + struct lv_segment_area area; + + if (mimage >= mirrored_seg->area_count) { + log_error("Invalid index (%u) of mirror image supplied " + "to shift_mirror_images()", mimage); + return 0; + } + + area = mirrored_seg->areas[mimage]; + + /* Shift remaining images down to fill the hole */ + for (i = mimage + 1; i < mirrored_seg->area_count; i++) + mirrored_seg->areas[i-1] = mirrored_seg->areas[i]; + + /* Place this one at the end */ + mirrored_seg->areas[i-1] = area; + + return 0; +} + +/* * This function writes a new header to the mirror log header to the lv * * Returns: 1 on success, 0 on failure @@ -469,13 +516,12 @@ static int _remove_mirror_images(struct logical_volume *lv, for (s = 0; s < mirrored_seg->area_count && old_area_count - new_area_count < num_removed; s++) { sub_lv = seg_lv(mirrored_seg, s); + if (!is_temporary_mirror_layer(sub_lv) && _is_mirror_image_removable(sub_lv, removable_pvs)) { - /* Swap segment to end */ + if (!shift_mirror_images(mirrored_seg, s)) + return_0; new_area_count--; - area = mirrored_seg->areas[new_area_count]; - mirrored_seg->areas[new_area_count] = mirrored_seg->areas[s]; - mirrored_seg->areas[s] = area; } } if (num_removed && old_area_count == new_area_count) diff --git a/tools/vgreduce.c b/tools/vgreduce.c index 5e613824..f2a5e218 100644 --- a/tools/vgreduce.c +++ b/tools/vgreduce.c @@ -250,9 +250,8 @@ static int _make_vg_consistent(struct cmd_context *cmd, struct volume_group *vg) lvl2->lv != seg_lv(mirrored_seg, s)) continue; list_del(&lvl2->list); - area = mirrored_seg->areas[mimages - 1]; - mirrored_seg->areas[mimages - 1] = mirrored_seg->areas[s]; - mirrored_seg->areas[s] = area; + if (!shift_mirror_images(mirrored_seg, s)) + return_0; mimages--; /* FIXME Assumes uniqueness */ } } |