diff options
Diffstat (limited to 'migration/block-dirty-bitmap.c')
| -rw-r--r-- | migration/block-dirty-bitmap.c | 412 |
1 files changed, 358 insertions, 54 deletions
diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c index 784330ebe1..549e14daba 100644 --- a/migration/block-dirty-bitmap.c +++ b/migration/block-dirty-bitmap.c @@ -29,10 +29,10 @@ * * # Header (shared for different chunk types) * 1, 2 or 4 bytes: flags (see qemu_{put,put}_flags) - * [ 1 byte: node name size ] \ flags & DEVICE_NAME - * [ n bytes: node name ] / - * [ 1 byte: bitmap name size ] \ flags & BITMAP_NAME - * [ n bytes: bitmap name ] / + * [ 1 byte: node alias size ] \ flags & DEVICE_NAME + * [ n bytes: node alias ] / + * [ 1 byte: bitmap alias size ] \ flags & BITMAP_NAME + * [ n bytes: bitmap alias ] / * * # Start of bitmap migration (flags & START) * header @@ -72,7 +72,9 @@ #include "migration/register.h" #include "qemu/hbitmap.h" #include "qemu/cutils.h" +#include "qemu/id.h" #include "qapi/error.h" +#include "qapi/qapi-commands-migration.h" #include "trace.h" #define CHUNK_SIZE (1 << 10) @@ -104,7 +106,8 @@ typedef struct SaveBitmapState { /* Written during setup phase. */ BlockDriverState *bs; - const char *node_name; + char *node_alias; + char *bitmap_alias; BdrvDirtyBitmap *bitmap; uint64_t total_sectors; uint64_t sectors_per_chunk; @@ -138,8 +141,9 @@ typedef struct LoadBitmapState { /* State of the dirty bitmap migration (DBM) during load process */ typedef struct DBMLoadState { uint32_t flags; - char node_name[256]; - char bitmap_name[256]; + char node_alias[256]; + char bitmap_alias[256]; + char bitmap_name[BDRV_BITMAP_MAX_NAME_SIZE + 1]; BlockDriverState *bs; BdrvDirtyBitmap *bitmap; @@ -165,6 +169,188 @@ typedef struct DBMState { static DBMState dbm_state; +/* For hash tables that map node/bitmap names to aliases */ +typedef struct AliasMapInnerNode { + char *string; + GHashTable *subtree; +} AliasMapInnerNode; + +static void free_alias_map_inner_node(void *amin_ptr) +{ + AliasMapInnerNode *amin = amin_ptr; + + g_free(amin->string); + g_hash_table_unref(amin->subtree); + g_free(amin); +} + +/** + * Construct an alias map based on the given QMP structure. + * + * (Note that we cannot store such maps in the MigrationParameters + * object, because that struct is defined by the QAPI schema, which + * makes it basically impossible to have dicts with arbitrary keys. + * Therefore, we instead have to construct these maps when migration + * starts.) + * + * @bbm is the block_bitmap_mapping from the migration parameters. + * + * If @name_to_alias is true, the returned hash table will map node + * and bitmap names to their respective aliases (for outgoing + * migration). + * + * If @name_to_alias is false, the returned hash table will map node + * and bitmap aliases to their respective names (for incoming + * migration). + * + * The hash table maps node names/aliases to AliasMapInnerNode + * objects, whose .string is the respective node alias/name, and whose + * .subtree table maps bitmap names/aliases to the respective bitmap + * alias/name. + */ +static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm, + bool name_to_alias, + Error **errp) +{ + GHashTable *alias_map; + size_t max_node_name_len = sizeof_field(BlockDriverState, node_name) - 1; + + alias_map = g_hash_table_new_full(g_str_hash, g_str_equal, + g_free, free_alias_map_inner_node); + + for (; bbm; bbm = bbm->next) { + const BitmapMigrationNodeAlias *bmna = bbm->value; + const BitmapMigrationBitmapAliasList *bmbal; + AliasMapInnerNode *amin; + GHashTable *bitmaps_map; + const char *node_map_from, *node_map_to; + + if (!id_wellformed(bmna->alias)) { + error_setg(errp, "The node alias '%s' is not well-formed", + bmna->alias); + goto fail; + } + + if (strlen(bmna->alias) > UINT8_MAX) { + error_setg(errp, "The node alias '%s' is longer than %u bytes", + bmna->alias, UINT8_MAX); + goto fail; + } + + if (strlen(bmna->node_name) > max_node_name_len) { + error_setg(errp, "The node name '%s' is longer than %zu bytes", + bmna->node_name, max_node_name_len); + goto fail; + } + + if (name_to_alias) { + if (g_hash_table_contains(alias_map, bmna->node_name)) { + error_setg(errp, "The node name '%s' is mapped twice", + bmna->node_name); + goto fail; + } + + node_map_from = bmna->node_name; + node_map_to = bmna->alias; + } else { + if (g_hash_table_contains(alias_map, bmna->alias)) { + error_setg(errp, "The node alias '%s' is used twice", + bmna->alias); + goto fail; + } + + node_map_from = bmna->alias; + node_map_to = bmna->node_name; + } + + bitmaps_map = g_hash_table_new_full(g_str_hash, g_str_equal, + g_free, g_free); + + amin = g_new(AliasMapInnerNode, 1); + *amin = (AliasMapInnerNode){ + .string = g_strdup(node_map_to), + .subtree = bitmaps_map, + }; + + g_hash_table_insert(alias_map, g_strdup(node_map_from), amin); + + for (bmbal = bmna->bitmaps; bmbal; bmbal = bmbal->next) { + const BitmapMigrationBitmapAlias *bmba = bmbal->value; + const char *bmap_map_from, *bmap_map_to; + + if (strlen(bmba->alias) > UINT8_MAX) { + error_setg(errp, + "The bitmap alias '%s' is longer than %u bytes", + bmba->alias, UINT8_MAX); + goto fail; + } + + if (strlen(bmba->name) > BDRV_BITMAP_MAX_NAME_SIZE) { + error_setg(errp, "The bitmap name '%s' is longer than %d bytes", + bmba->name, BDRV_BITMAP_MAX_NAME_SIZE); + goto fail; + } + + if (name_to_alias) { + bmap_map_from = bmba->name; + bmap_map_to = bmba->alias; + + if (g_hash_table_contains(bitmaps_map, bmba->name)) { + error_setg(errp, "The bitmap '%s'/'%s' is mapped twice", + bmna->node_name, bmba->name); + goto fail; + } + } else { + bmap_map_from = bmba->alias; + bmap_map_to = bmba->name; + + if (g_hash_table_contains(bitmaps_map, bmba->alias)) { + error_setg(errp, "The bitmap alias '%s'/'%s' is used twice", + bmna->alias, bmba->alias); + goto fail; + } + } + + g_hash_table_insert(bitmaps_map, + g_strdup(bmap_map_from), g_strdup(bmap_map_to)); + } + } + + return alias_map; + +fail: + g_hash_table_destroy(alias_map); + return NULL; +} + +/** + * Run construct_alias_map() in both directions to check whether @bbm + * is valid. + * (This function is to be used by migration/migration.c to validate + * the user-specified block-bitmap-mapping migration parameter.) + * + * Returns true if and only if the mapping is valid. + */ +bool check_dirty_bitmap_mig_alias_map(const BitmapMigrationNodeAliasList *bbm, + Error **errp) +{ + GHashTable *alias_map; + + alias_map = construct_alias_map(bbm, true, errp); + if (!alias_map) { + return false; + } + g_hash_table_destroy(alias_map); + + alias_map = construct_alias_map(bbm, false, errp); + if (!alias_map) { + return false; + } + g_hash_table_destroy(alias_map); + + return true; +} + static uint32_t qemu_get_bitmap_flags(QEMUFile *f) { uint8_t flags = qemu_get_byte(f); @@ -207,11 +393,11 @@ static void send_bitmap_header(QEMUFile *f, DBMSaveState *s, qemu_put_bitmap_flags(f, flags); if (flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) { - qemu_put_counted_string(f, dbms->node_name); + qemu_put_counted_string(f, dbms->node_alias); } if (flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) { - qemu_put_counted_string(f, bdrv_dirty_bitmap_name(bitmap)); + qemu_put_counted_string(f, dbms->bitmap_alias); } } @@ -282,18 +468,25 @@ static void dirty_bitmap_do_save_cleanup(DBMSaveState *s) QSIMPLEQ_REMOVE_HEAD(&s->dbms_list, entry); bdrv_dirty_bitmap_set_busy(dbms->bitmap, false); bdrv_unref(dbms->bs); + g_free(dbms->node_alias); + g_free(dbms->bitmap_alias); g_free(dbms); } } /* Called with iothread lock taken. */ static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs, - const char *bs_name) + const char *bs_name, GHashTable *alias_map) { BdrvDirtyBitmap *bitmap; SaveBitmapState *dbms; + GHashTable *bitmap_aliases; + const char *node_alias, *bitmap_name, *bitmap_alias; Error *local_err = NULL; + /* When an alias map is given, @bs_name must be @bs's node name */ + assert(!alias_map || !strcmp(bs_name, bdrv_get_node_name(bs))); + FOR_EACH_DIRTY_BITMAP(bs, bitmap) { if (bdrv_dirty_bitmap_name(bitmap)) { break; @@ -303,21 +496,39 @@ static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs, return 0; } + bitmap_name = bdrv_dirty_bitmap_name(bitmap); + if (!bs_name || strcmp(bs_name, "") == 0) { error_report("Bitmap '%s' in unnamed node can't be migrated", - bdrv_dirty_bitmap_name(bitmap)); + bitmap_name); return -1; } - if (bs_name[0] == '#') { + if (alias_map) { + const AliasMapInnerNode *amin = g_hash_table_lookup(alias_map, bs_name); + + if (!amin) { + /* Skip bitmaps on nodes with no alias */ + return 0; + } + + node_alias = amin->string; + bitmap_aliases = amin->subtree; + } else { + node_alias = bs_name; + bitmap_aliases = NULL; + } + + if (node_alias[0] == '#') { error_report("Bitmap '%s' in a node with auto-generated " "name '%s' can't be migrated", - bdrv_dirty_bitmap_name(bitmap), bs_name); + bitmap_name, node_alias); return -1; } FOR_EACH_DIRTY_BITMAP(bs, bitmap) { - if (!bdrv_dirty_bitmap_name(bitmap)) { + bitmap_name = bdrv_dirty_bitmap_name(bitmap); + if (!bitmap_name) { continue; } @@ -326,12 +537,29 @@ static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs, return -1; } + if (bitmap_aliases) { + bitmap_alias = g_hash_table_lookup(bitmap_aliases, bitmap_name); + if (!bitmap_alias) { + /* Skip bitmaps with no alias */ + continue; + } + } else { + if (strlen(bitmap_name) > UINT8_MAX) { + error_report("Cannot migrate bitmap '%s' on node '%s': " + "Name is longer than %u bytes", + bitmap_name, bs_name, UINT8_MAX); + return -1; + } + bitmap_alias = bitmap_name; + } + bdrv_ref(bs); bdrv_dirty_bitmap_set_busy(bitmap, true); dbms = g_new0(SaveBitmapState, 1); dbms->bs = bs; - dbms->node_name = bs_name; + dbms->node_alias = g_strdup(node_alias); + dbms->bitmap_alias = g_strdup(bitmap_alias); dbms->bitmap = bitmap; dbms->total_sectors = bdrv_nb_sectors(bs); dbms->sectors_per_chunk = CHUNK_SIZE * 8 * @@ -356,43 +584,52 @@ static int init_dirty_bitmap_migration(DBMSaveState *s) SaveBitmapState *dbms; GHashTable *handled_by_blk = g_hash_table_new(NULL, NULL); BlockBackend *blk; + const MigrationParameters *mig_params = &migrate_get_current()->parameters; + GHashTable *alias_map = NULL; + + if (mig_params->has_block_bitmap_mapping) { + alias_map = construct_alias_map(mig_params->block_bitmap_mapping, true, + &error_abort); + } s->bulk_completed = false; s->prev_bs = NULL; s->prev_bitmap = NULL; s->no_bitmaps = false; - /* - * Use blockdevice name for direct (or filtered) children of named block - * backends. - */ - for (blk = blk_next(NULL); blk; blk = blk_next(blk)) { - const char *name = blk_name(blk); - - if (!name || strcmp(name, "") == 0) { - continue; - } + if (!alias_map) { + /* + * Use blockdevice name for direct (or filtered) children of named block + * backends. + */ + for (blk = blk_next(NULL); blk; blk = blk_next(blk)) { + const char *name = blk_name(blk); - bs = blk_bs(blk); + if (!name || strcmp(name, "") == 0) { + continue; + } - /* Skip filters without bitmaps */ - while (bs && bs->drv && bs->drv->is_filter && - !bdrv_has_named_bitmaps(bs)) - { - if (bs->backing) { - bs = bs->backing->bs; - } else if (bs->file) { - bs = bs->file->bs; - } else { - bs = NULL; + bs = blk_bs(blk); + + /* Skip filters without bitmaps */ + while (bs && bs->drv && bs->drv->is_filter && + !bdrv_has_named_bitmaps(bs)) + { + if (bs->backing) { + bs = bs->backing->bs; + } else if (bs->file) { + bs = bs->file->bs; + } else { + bs = NULL; + } } - } - if (bs && bs->drv && !bs->drv->is_filter) { - if (add_bitmaps_to_list(s, bs, name)) { - goto fail; + if (bs && bs->drv && !bs->drv->is_filter) { + if (add_bitmaps_to_list(s, bs, name, NULL)) { + goto fail; + } + g_hash_table_add(handled_by_blk, bs); } - g_hash_table_add(handled_by_blk, bs); } } @@ -401,7 +638,7 @@ static int init_dirty_bitmap_migration(DBMSaveState *s) continue; } - if (add_bitmaps_to_list(s, bs, bdrv_get_node_name(bs))) { + if (add_bitmaps_to_list(s, bs, bdrv_get_node_name(bs), alias_map)) { goto fail; } } @@ -416,11 +653,17 @@ static int init_dirty_bitmap_migration(DBMSaveState *s) } g_hash_table_destroy(handled_by_blk); + if (alias_map) { + g_hash_table_destroy(alias_map); + } return 0; fail: g_hash_table_destroy(handled_by_blk); + if (alias_map) { + g_hash_table_destroy(alias_map); + } dirty_bitmap_do_save_cleanup(s); return -1; @@ -770,8 +1013,10 @@ static int dirty_bitmap_load_bits(QEMUFile *f, DBMLoadState *s) return 0; } -static int dirty_bitmap_load_header(QEMUFile *f, DBMLoadState *s) +static int dirty_bitmap_load_header(QEMUFile *f, DBMLoadState *s, + GHashTable *alias_map) { + GHashTable *bitmap_alias_map = NULL; Error *local_err = NULL; bool nothing; s->flags = qemu_get_bitmap_flags(f); @@ -780,28 +1025,75 @@ static int dirty_bitmap_load_header(QEMUFile *f, DBMLoadState *s) nothing = s->flags == (s->flags & DIRTY_BITMAP_MIG_FLAG_EOS); if (s->flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) { - if (!qemu_get_counted_string(f, s->node_name)) { - error_report("Unable to read node name string"); + if (!qemu_get_counted_string(f, s->node_alias)) { + error_report("Unable to read node alias string"); return -EINVAL; } + if (!s->cancelled) { - s->bs = bdrv_lookup_bs(s->node_name, s->node_name, &local_err); + if (alias_map) { + const AliasMapInnerNode *amin; + + amin = g_hash_table_lookup(alias_map, s->node_alias); + if (!amin) { + error_setg(&local_err, "Error: Unknown node alias '%s'", + s->node_alias); + s->bs = NULL; + } else { + bitmap_alias_map = amin->subtree; + s->bs = bdrv_lookup_bs(NULL, amin->string, &local_err); + } + } else { + s->bs = bdrv_lookup_bs(s->node_alias, s->node_alias, + &local_err); + } if (!s->bs) { error_report_err(local_err); cancel_incoming_locked(s); } } - } else if (!s->bs && !nothing && !s->cancelled) { + } else if (s->bs) { + if (alias_map) { + const AliasMapInnerNode *amin; + + /* Must be present in the map, or s->bs would not be set */ + amin = g_hash_table_lookup(alias_map, s->node_alias); + assert(amin != NULL); + + bitmap_alias_map = amin->subtree; + } + } else if (!nothing && !s->cancelled) { error_report("Error: block device name is not set"); cancel_incoming_locked(s); } + assert(nothing || s->cancelled || !!alias_map == !!bitmap_alias_map); + if (s->flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) { - if (!qemu_get_counted_string(f, s->bitmap_name)) { - error_report("Unable to read bitmap name string"); + const char *bitmap_name; + + if (!qemu_get_counted_string(f, s->bitmap_alias)) { + error_report("Unable to read bitmap alias string"); return -EINVAL; } + + if (!s->cancelled) { + if (bitmap_alias_map) { + bitmap_name = g_hash_table_lookup(bitmap_alias_map, + s->bitmap_alias); + if (!bitmap_name) { + error_report("Error: Unknown bitmap alias '%s' on node " + "'%s' (alias '%s')", s->bitmap_alias, + s->bs->node_name, s->node_alias); + cancel_incoming_locked(s); + } + } else { + bitmap_name = s->bitmap_alias; + } + } + if (!s->cancelled) { + g_strlcpy(s->bitmap_name, bitmap_name, sizeof(s->bitmap_name)); s->bitmap = bdrv_find_dirty_bitmap(s->bs, s->bitmap_name); /* @@ -811,7 +1103,7 @@ static int dirty_bitmap_load_header(QEMUFile *f, DBMLoadState *s) if (!s->bitmap && !(s->flags & DIRTY_BITMAP_MIG_FLAG_START)) { error_report("Error: unknown dirty bitmap " "'%s' for block device '%s'", - s->bitmap_name, s->node_name); + s->bitmap_name, s->bs->node_name); cancel_incoming_locked(s); } } @@ -835,6 +1127,8 @@ static int dirty_bitmap_load_header(QEMUFile *f, DBMLoadState *s) */ static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id) { + GHashTable *alias_map = NULL; + const MigrationParameters *mig_params = &migrate_get_current()->parameters; DBMLoadState *s = &((DBMState *)opaque)->load; int ret = 0; @@ -846,13 +1140,18 @@ static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id) return -EINVAL; } + if (mig_params->has_block_bitmap_mapping) { + alias_map = construct_alias_map(mig_params->block_bitmap_mapping, + false, &error_abort); + } + do { QEMU_LOCK_GUARD(&s->lock); - ret = dirty_bitmap_load_header(f, s); + ret = dirty_bitmap_load_header(f, s, alias_map); if (ret < 0) { cancel_incoming_locked(s); - return ret; + goto fail; } if (s->flags & DIRTY_BITMAP_MIG_FLAG_START) { @@ -869,12 +1168,17 @@ static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id) if (ret) { cancel_incoming_locked(s); - return ret; + goto fail; } } while (!(s->flags & DIRTY_BITMAP_MIG_FLAG_EOS)); trace_dirty_bitmap_load_success(); - return 0; + ret = 0; +fail: + if (alias_map) { + g_hash_table_destroy(alias_map); + } + return ret; } static int dirty_bitmap_save_setup(QEMUFile *f, void *opaque) |