[lvm-devel] [PATCH 4 of 5] LVM RAID: Add down-convert support for RAID1
Jonathan Brassow
jbrassow at redhat.com
Wed Aug 3 14:44:27 UTC 2011
Index: LVM2/tools/lvconvert.c
===================================================================
--- LVM2.orig/tools/lvconvert.c
+++ LVM2/tools/lvconvert.c
@@ -39,7 +39,7 @@ struct lvconvert_params {
uint32_t stripes;
uint32_t stripe_size;
- struct segment_type *segtype;
+ const struct segment_type *segtype;
alloc_policy_t alloc;
@@ -1366,6 +1366,62 @@ static int _lvconvert_mirrors(struct cmd
return 1;
}
+static int is_valid_raid_conversion(const struct segment_type *from_segtype,
+ const struct segment_type *to_segtype)
+{
+ if (from_segtype == to_segtype)
+ return 1;
+
+ if (!segtype_is_raid(from_segtype) && !segtype_is_raid(to_segtype))
+ return_0; /* Not converting to or from RAID? */
+
+ return 0;
+}
+
+static int lvconvert_raid(struct logical_volume *lv, struct lvconvert_params *lp)
+{
+ int image_count;
+ struct cmd_context *cmd = lv->vg->cmd;
+ struct lv_segment *seg = first_seg(lv);
+
+ if (!arg_count(cmd, type_ARG))
+ lp->segtype = seg->segtype;
+
+ if (arg_count(cmd, mirrors_ARG) && !seg_is_mirrored(seg)) {
+ log_error("'--mirrors/-m' is not compatible with %s",
+ seg->segtype->name);
+ return 0;
+ }
+
+ if (!is_valid_raid_conversion(seg->segtype, lp->segtype)) {
+ log_error("Unable to convert %s/%s from %s to %s",
+ lv->vg->name, lv->name,
+ seg->segtype->name, lp->segtype->name);
+ return 0;
+ }
+
+ /* Change number of RAID1 images */
+ if (arg_count(cmd, mirrors_ARG)) {
+ image_count = lv_raid_image_count(lv);
+ if (lp->mirrors_sign == SIGN_PLUS)
+ image_count += lp->mirrors;
+ else if (lp->mirrors_sign == SIGN_MINUS)
+ image_count -= lp->mirrors;
+ else
+ image_count = lp->mirrors + 1;
+
+ if (image_count < 1) {
+ log_error("Unable to reduce images by specified amount");
+ return 0;
+ }
+
+ return lv_raid_change_image_count(lv, image_count, lp->pvh);
+ }
+
+ log_error("Conversion operation not yet supported.");
+ return 0;
+}
+
static int lvconvert_snapshot(struct cmd_context *cmd,
struct logical_volume *lv,
struct lvconvert_params *lp)
@@ -1580,6 +1636,24 @@ static int _lvconvert_single(struct cmd_
stack;
return ECMD_FAILED;
}
+ } else if (segtype_is_raid(lp->segtype) || (lv->status & RAID)) {
+ if (!archive(lv->vg)) {
+ stack;
+ return ECMD_FAILED;
+ }
+ if (!lvconvert_raid(lv, lp)) {
+ stack;
+ return ECMD_FAILED;
+ }
+
+ if (!(failed_pvs = _failed_pv_list(lv->vg))) {
+ stack;
+ return ECMD_FAILED;
+ }
+
+ /* If repairing and using policies, remove missing PVs from VG */
+ if (arg_count(cmd, repair_ARG) && arg_count(cmd, use_policies_ARG))
+ _remove_missing_empty_pv(lv->vg, failed_pvs);
} else if (arg_count(cmd, mirrors_ARG) ||
arg_count(cmd, splitmirrors_ARG) ||
(lv->status & MIRRORED)) {
Index: LVM2/lib/metadata/raid_manip.c
===================================================================
--- /dev/null
+++ LVM2/lib/metadata/raid_manip.c
@@ -0,0 +1,418 @@
+/*
+ * Copyright (C) 2011 Red Hat, Inc. All rights reserved.
+ *
+ * This file is part of LVM2.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU Lesser General Public License v.2.1.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "lib.h"
+#include "metadata.h"
+#include "toolcontext.h"
+#include "segtype.h"
+#include "display.h"
+#include "archiver.h"
+#include "activate.h"
+#include "lv_alloc.h"
+#include "lvm-string.h"
+#include "str_list.h"
+#include "memlock.h"
+
+/* Useful macros that I don't think would be useful elsewhere */
+#define seg_metatype(seg, s) (seg)->meta_areas[(s)].type
+
+uint32_t lv_raid_image_count(const struct logical_volume *lv)
+{
+ struct lv_segment *seg = first_seg(lv);
+
+ if (!seg_is_raid(seg))
+ return 1;
+
+ return seg->area_count;
+}
+
+static int lv_is_on_pvs(struct logical_volume *lv, struct dm_list *pvs)
+{
+ struct pv_list *pvl;
+
+ dm_list_iterate_items(pvl, pvs)
+ if (pv_is_in_lv(lv, pvl->pv)) {
+ log_very_verbose("%s is on %s", lv->name,
+ pv_dev_name(pvl->pv));
+ return 1;
+ } else
+ log_very_verbose("%s is not on %s", lv->name,
+ pv_dev_name(pvl->pv));
+ return 0;
+}
+
+static int raid_in_sync(struct logical_volume *lv)
+{
+ percent_t sync_percent;
+
+ if (!lv_raid_percent(lv, &sync_percent)) {
+ log_error("Unable to determine sync status of %s/%s.",
+ lv->vg->name, lv->name);
+ return 0;
+ }
+
+ return (sync_percent == PERCENT_100) ? 1 : 0;
+}
+
+/*
+ * _shift_and_rename_image_components
+ * @seg: Top-level RAID segment
+ *
+ * Shift all higher indexed segment areas down to fill in gaps where
+ * there are 'AREA_UNASSIGNED' areas and rename data/metadata LVs so
+ * that their names match their new index. When finished, set
+ * seg->area_count to new reduced total.
+ *
+ * Returns: 1 on success, 0 on failure
+ */
+static int _shift_and_rename_image_components(struct lv_segment *seg)
+{
+ int len;
+ char *shift_name;
+ uint32_t s, missing;
+ struct cmd_context *cmd = seg->lv->vg->cmd;
+
+ /*
+ * All LVs must be properly named for their index before
+ * shifting begins. (e.g. Index '0' must contain *_rimage_0 and
+ * *_rmeta_0. Index 'n' must contain *_rimage_n and *_rmeta_n.)
+ */
+
+ if (!seg_is_raid(seg))
+ return_0;
+
+ if (seg->area_count > 10) {
+ /* Handling more would mean I'd have to handle double digits */
+ log_error("Unable handle arrays with more than 10 devices");
+ return 0;
+ }
+
+ log_very_verbose("Shifting images in %s", seg->lv->name);
+
+ for (s = 0, missing = 0; s < seg->area_count; s++) {
+ if (seg_type(seg, s) == AREA_UNASSIGNED) {
+ if (seg_metatype(seg, s) != AREA_UNASSIGNED) {
+ log_error(INTERNAL_ERROR "Metadata segment area"
+ " #%d should be AREA_UNASSIGNED", s);
+ return 0;
+ }
+ missing++;
+ continue;
+ }
+ if (!missing)
+ continue;
+
+ log_very_verbose("Shifting %s and %s by %u",
+ seg_metalv(seg, s)->name,
+ seg_lv(seg, s)->name, missing);
+
+ /* Alter rmeta name */
+ shift_name = dm_pool_strdup(cmd->mem, seg_metalv(seg, s)->name);
+ if (!shift_name)
+ return_0;
+ len = strlen(shift_name) - 1;
+ shift_name[len] -= missing;
+ seg_metalv(seg, s)->name = shift_name;
+
+ /* Alter rimage name */
+ shift_name = dm_pool_strdup(cmd->mem, seg_lv(seg, s)->name);
+ if (!shift_name)
+ return_0;
+ len = strlen(shift_name) - 1;
+ shift_name[len] -= missing;
+ seg_lv(seg, s)->name = shift_name;
+
+ seg->areas[s - missing] = seg->areas[s];
+ seg->meta_areas[s - missing] = seg->meta_areas[s];
+ }
+
+ seg->area_count -= missing;
+ return 1;
+}
+
+static int raid_add_images(struct logical_volume *lv,
+ uint32_t new_count, struct dm_list *pvs)
+{
+ /* Not implemented */
+ log_error("Unable to add images to LV, %s/%s",
+ lv->vg->name, lv->name);
+
+ return 0;
+}
+
+/*
+ * _extract_image_components
+ * @seg
+ * @idx: The index in the areas array to remove
+ * @extracted_rmeta: The displaced metadata LV
+ * @extracted_rimage: The displaced data LV
+ *
+ * This function extracts the image components - setting the respective
+ * 'extracted' pointers. It appends 'EXTRACTED' to the LVs' names, so that
+ * there are not future conflicts. It does /not/ commit the results.
+ * (IOW, erroring-out requires no unwinding of operations.)
+ *
+ * This function does /not/ attempt to:
+ * 1) shift the 'areas' or 'meta_areas' arrays.
+ * The '[meta_]areas' are left as AREA_UNASSIGNED.
+ * 2) Adjust the seg->area_count
+ * 3) Name the extracted LVs appropriately (appends 'EXTRACTED' to names)
+ * These actions must be performed by the caller.
+ *
+ * Returns: 1 on success, 0 on failure
+ */
+static int _extract_image_components(struct lv_segment *seg, uint32_t idx,
+ struct logical_volume **extracted_rmeta,
+ struct logical_volume **extracted_rimage)
+{
+ int len;
+ char *tmp_name;
+ struct cmd_context *cmd = seg->lv->vg->cmd;
+ struct logical_volume *data_lv = seg_lv(seg, idx);
+ struct logical_volume *meta_lv = seg_metalv(seg, idx);
+
+ log_very_verbose("Extracting image components %s and %s from %s",
+ data_lv->name, meta_lv->name, seg->lv->name);
+
+ data_lv->status &= ~RAID_IMAGE;
+ meta_lv->status &= ~RAID_META;
+ lv_set_visible(data_lv);
+ lv_set_visible(meta_lv);
+
+ /* release removes data and meta areas */
+ remove_seg_from_segs_using_this_lv(data_lv, seg);
+ remove_seg_from_segs_using_this_lv(meta_lv, seg);
+
+ seg_type(seg, idx) = AREA_UNASSIGNED;
+ seg_metatype(seg, idx) = AREA_UNASSIGNED;
+
+ len = strlen(meta_lv->name) + strlen("EXTRACTED") + 1;
+ tmp_name = dm_pool_alloc(cmd->mem, len);
+ if (!tmp_name)
+ return_0;
+ sprintf(tmp_name, "%sEXTRACTED", meta_lv->name);
+ meta_lv->name = tmp_name;
+
+ len = strlen(data_lv->name) + strlen("EXTRACTED") + 1;
+ tmp_name = dm_pool_alloc(cmd->mem, len);
+ if (!tmp_name)
+ return_0;
+ sprintf(tmp_name, "%sEXTRACTED", data_lv->name);
+ data_lv->name = tmp_name;
+
+ *extracted_rmeta = meta_lv;
+ *extracted_rimage = data_lv;
+
+ return 1;
+}
+
+/*
+ * raid_extract_images
+ * @lv
+ * @new_count: The absolute count of images (e.g. '2' for a 2-way mirror)
+ * @target_pvs: The list of PVs that are candidates for removal
+ * @shift: If set, use _shift_and_rename_image_components().
+ * Otherwise, leave the [meta_]areas as AREA_UNASSIGNED and
+ * seg->area_count unchanged.
+ * @extracted_[meta|data]_lvs: The LVs removed from the array. If 'shift'
+ * is set, then there will likely be name conflicts.
+ *
+ * This function extracts _both_ portions of the indexed image. It
+ * does /not/ commit the results. (IOW, erroring-out requires no unwinding
+ * of operations.)
+ *
+ * Returns: 1 on success, 0 on failure
+ */
+static int raid_extract_images(struct logical_volume *lv, uint32_t new_count,
+ struct dm_list *target_pvs, int shift,
+ struct dm_list *extracted_meta_lvs,
+ struct dm_list *extracted_data_lvs)
+{
+ int s, extract, lvl_idx = 0;
+ struct lv_list *lvl_array;
+ struct lv_segment *seg = first_seg(lv);
+ struct logical_volume *rmeta_lv, *rimage_lv;
+
+ extract = seg->area_count - new_count;
+ log_verbose("Extracting %u %s from %s/%s", extract,
+ (extract > 1) ? "images" : "image",
+ lv->vg->name, lv->name);
+
+ lvl_array = dm_pool_alloc(lv->vg->cmd->mem,
+ sizeof(*lvl_array) * extract * 2);
+ if (!lvl_array)
+ return_0;
+
+ for (s = seg->area_count - 1; (s >= 0) && extract; s--) {
+ if (!lv_is_on_pvs(seg_lv(seg, s), target_pvs) ||
+ !lv_is_on_pvs(seg_metalv(seg, s), target_pvs))
+ continue;
+ if (!raid_in_sync(lv) &&
+ (!seg_is_mirrored(seg) || (s == 0))) {
+ log_error("Unable to extract %sRAID image"
+ " while RAID array is not in-sync",
+ seg_is_mirrored(seg) ? "primary " : "");
+ return 0;
+ }
+
+ if (!_extract_image_components(seg, s, &rmeta_lv, &rimage_lv)) {
+ log_error("Failed to extract %s from %s",
+ seg_lv(seg, s)->name, lv->name);
+ return 0;
+ }
+
+ if (shift && !_shift_and_rename_image_components(seg)) {
+ log_error("Failed to shift and rename image components");
+ return 0;
+ }
+
+ lvl_array[lvl_idx].lv = rmeta_lv;
+ lvl_array[lvl_idx + 1].lv = rimage_lv;
+ dm_list_add(extracted_meta_lvs, &(lvl_array[lvl_idx++].list));
+ dm_list_add(extracted_data_lvs, &(lvl_array[lvl_idx++].list));
+
+ extract--;
+ }
+ if (extract) {
+ log_error("Unable to extract enough images to satisfy request");
+ return 0;
+ }
+
+ return 1;
+}
+
+/*
+ * lv_raid_change_image_count
+ * @lv
+ * @new_count: The absolute count of images (e.g. '2' for a 2-way mirror)
+ * @pvs: The list of PVs that are candidates for removal (or empty list)
+ *
+ * RAID arrays have 'images' which are composed of two parts, they are:
+ * - 'rimage': The data/parity holding portion
+ * - 'rmeta' : The metadata holding portion (i.e. superblock/bitmap area)
+ * This function adds or removes _both_ portions of the image and commits
+ * the results.
+ *
+ * Returns: 1 on success, 0 on failure
+ */
+int lv_raid_change_image_count(struct logical_volume *lv,
+ uint32_t new_count, struct dm_list *pvs)
+{
+ int r;
+ uint32_t old_count = lv_raid_image_count(lv);
+ struct lv_segment *seg = first_seg(lv);
+ struct dm_list removal_list;
+ struct lv_list *lvl_array, *lvl;
+
+ dm_list_init(&removal_list);
+
+ if (!seg_is_mirrored(seg)) {
+ log_error("Unable to change image count of non-mirrored RAID.");
+ return 0;
+ }
+
+ if (old_count == new_count) {
+ log_verbose("%s/%s already has image count of %d",
+ lv->vg->name, lv->name, new_count);
+ return 1;
+ }
+
+ if (old_count > new_count)
+ r = raid_extract_images(lv, new_count, pvs, 1,
+ &removal_list, &removal_list);
+ else
+ r = raid_add_images(lv, new_count, pvs);
+ if (!r)
+ return 0;
+
+ /* Convert to linear? */
+ if (new_count == 1) {
+ /* Add last metadata area to removal_list */
+ lvl_array = dm_pool_alloc(lv->vg->cmd->mem, 2 * sizeof(*lvl));
+ if (!lvl_array)
+ return_0;
+ lvl_array[0].lv = seg_metalv(seg, 0);
+ remove_seg_from_segs_using_this_lv(seg_metalv(seg, 0), seg);
+ seg_metatype(seg, 0) = AREA_UNASSIGNED;
+ dm_list_add(&removal_list, &(lvl_array[0].list));
+
+ /* Remove RAID layer */
+ seg_lv(seg, 0)->status &= ~RAID_IMAGE;
+ lv_set_visible(seg_lv(seg, 0));
+ lvl_array[1].lv = seg_lv(seg, 0);
+ dm_list_add(&removal_list, &(lvl_array[1].list));
+
+ if (!remove_layer_from_lv(lv, seg_lv(seg, 0)))
+ return_0;
+ lv->status &= ~(MIRRORED | RAID);
+ }
+
+ if (!vg_write(lv->vg)) {
+ log_error("Failed to write changes to %s in %s",
+ lv->name, lv->vg->name);
+ return 0;
+ }
+
+ if (!suspend_lv(lv->vg->cmd, lv)) {
+ log_error("Failed to suspend %s/%s before committing changes",
+ lv->vg->name, lv->name);
+ return 0;
+ }
+
+ if (!vg_commit(lv->vg)) {
+ log_error("Failed to commit changes to %s in %s",
+ lv->name, lv->vg->name);
+ return 0;
+ }
+
+ /*
+ * Bring extracted LVs into existance, so there are no
+ * conflicts for the main RAID device's resume
+ */
+ if (!dm_list_empty(&removal_list)) {
+ dm_list_iterate_items(lvl, &removal_list) {
+ /* If top RAID was EX, use EX */
+ if (lv_is_active_exclusive_locally(lv)) {
+ if (!activate_lv_excl(lv->vg->cmd, lvl->lv))
+ return_0;
+ } else {
+ if (!activate_lv(lv->vg->cmd, lvl->lv))
+ return_0;
+ }
+ }
+ }
+
+ if (!resume_lv(lv->vg->cmd, lv)) {
+ log_error("Failed to resume %s/%s after committing changes",
+ lv->vg->name, lv->name);
+ return 0;
+ }
+
+ /*
+ * Eliminate the extracted LVs
+ */
+ if (!dm_list_empty(&removal_list)) {
+ dm_list_iterate_items(lvl, &removal_list) {
+ if (!deactivate_lv(lv->vg->cmd, lvl->lv))
+ return_0;
+ if (!lv_remove(lvl->lv))
+ return_0;
+ }
+
+ if (!vg_write(lv->vg) || !vg_commit(lv->vg))
+ return_0;
+ }
+
+ return 1;
+}
Index: LVM2/lib/Makefile.in
===================================================================
--- LVM2.orig/lib/Makefile.in
+++ LVM2/lib/Makefile.in
@@ -85,6 +85,7 @@ SOURCES =\
metadata/pv.c \
metadata/pv_manip.c \
metadata/pv_map.c \
+ metadata/raid_manip.c \
metadata/replicator_manip.c \
metadata/segtype.c \
metadata/snapshot_manip.c \
Index: LVM2/lib/metadata/metadata-exported.h
===================================================================
--- LVM2.orig/lib/metadata/metadata-exported.h
+++ LVM2/lib/metadata/metadata-exported.h
@@ -743,6 +743,13 @@ int lv_is_rlog(const struct logical_volu
int lv_is_slog(const struct logical_volume *lv);
struct logical_volume *first_replicator_dev(const struct logical_volume *lv);
/* -- metadata/replicator_manip.c */
+
+/* ++ metadata/raid_manip.c */
+uint32_t lv_raid_image_count(const struct logical_volume *lv);
+int lv_raid_change_image_count(struct logical_volume *lv,
+ uint32_t new_count, struct dm_list *pvs);
+/* -- metadata/raid_manip.c */
+
struct cmd_vg *cmd_vg_add(struct dm_pool *mem, struct dm_list *cmd_vgs,
const char *vg_name, const char *vgid,
uint32_t flags);
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