diff options
Diffstat (limited to 'qemu/block/dirty-bitmap.c')
| -rw-r--r-- | qemu/block/dirty-bitmap.c | 387 |
1 files changed, 0 insertions, 387 deletions
diff --git a/qemu/block/dirty-bitmap.c b/qemu/block/dirty-bitmap.c deleted file mode 100644 index 4902ca557..000000000 --- a/qemu/block/dirty-bitmap.c +++ /dev/null @@ -1,387 +0,0 @@ -/* - * Block Dirty Bitmap - * - * Copyright (c) 2016 Red Hat. Inc - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ -#include "qemu/osdep.h" -#include "qapi/error.h" -#include "qemu-common.h" -#include "trace.h" -#include "block/block_int.h" -#include "block/blockjob.h" - -/** - * A BdrvDirtyBitmap can be in three possible states: - * (1) successor is NULL and disabled is false: full r/w mode - * (2) successor is NULL and disabled is true: read only mode ("disabled") - * (3) successor is set: frozen mode. - * A frozen bitmap cannot be renamed, deleted, anonymized, cleared, set, - * or enabled. A frozen bitmap can only abdicate() or reclaim(). - */ -struct BdrvDirtyBitmap { - HBitmap *bitmap; /* Dirty sector bitmap implementation */ - BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */ - char *name; /* Optional non-empty unique ID */ - int64_t size; /* Size of the bitmap (Number of sectors) */ - bool disabled; /* Bitmap is read-only */ - QLIST_ENTRY(BdrvDirtyBitmap) list; -}; - -BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name) -{ - BdrvDirtyBitmap *bm; - - assert(name); - QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { - if (bm->name && !strcmp(name, bm->name)) { - return bm; - } - } - return NULL; -} - -void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap) -{ - assert(!bdrv_dirty_bitmap_frozen(bitmap)); - g_free(bitmap->name); - bitmap->name = NULL; -} - -BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, - uint32_t granularity, - const char *name, - Error **errp) -{ - int64_t bitmap_size; - BdrvDirtyBitmap *bitmap; - uint32_t sector_granularity; - - assert((granularity & (granularity - 1)) == 0); - - if (name && bdrv_find_dirty_bitmap(bs, name)) { - error_setg(errp, "Bitmap already exists: %s", name); - return NULL; - } - sector_granularity = granularity >> BDRV_SECTOR_BITS; - assert(sector_granularity); - bitmap_size = bdrv_nb_sectors(bs); - if (bitmap_size < 0) { - error_setg_errno(errp, -bitmap_size, "could not get length of device"); - errno = -bitmap_size; - return NULL; - } - bitmap = g_new0(BdrvDirtyBitmap, 1); - bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity)); - bitmap->size = bitmap_size; - bitmap->name = g_strdup(name); - bitmap->disabled = false; - QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list); - return bitmap; -} - -bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap) -{ - return bitmap->successor; -} - -bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap) -{ - return !(bitmap->disabled || bitmap->successor); -} - -DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap) -{ - if (bdrv_dirty_bitmap_frozen(bitmap)) { - return DIRTY_BITMAP_STATUS_FROZEN; - } else if (!bdrv_dirty_bitmap_enabled(bitmap)) { - return DIRTY_BITMAP_STATUS_DISABLED; - } else { - return DIRTY_BITMAP_STATUS_ACTIVE; - } -} - -/** - * Create a successor bitmap destined to replace this bitmap after an operation. - * Requires that the bitmap is not frozen and has no successor. - */ -int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs, - BdrvDirtyBitmap *bitmap, Error **errp) -{ - uint64_t granularity; - BdrvDirtyBitmap *child; - - if (bdrv_dirty_bitmap_frozen(bitmap)) { - error_setg(errp, "Cannot create a successor for a bitmap that is " - "currently frozen"); - return -1; - } - assert(!bitmap->successor); - - /* Create an anonymous successor */ - granularity = bdrv_dirty_bitmap_granularity(bitmap); - child = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); - if (!child) { - return -1; - } - - /* Successor will be on or off based on our current state. */ - child->disabled = bitmap->disabled; - - /* Install the successor and freeze the parent */ - bitmap->successor = child; - return 0; -} - -/** - * For a bitmap with a successor, yield our name to the successor, - * delete the old bitmap, and return a handle to the new bitmap. - */ -BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs, - BdrvDirtyBitmap *bitmap, - Error **errp) -{ - char *name; - BdrvDirtyBitmap *successor = bitmap->successor; - - if (successor == NULL) { - error_setg(errp, "Cannot relinquish control if " - "there's no successor present"); - return NULL; - } - - name = bitmap->name; - bitmap->name = NULL; - successor->name = name; - bitmap->successor = NULL; - bdrv_release_dirty_bitmap(bs, bitmap); - - return successor; -} - -/** - * In cases of failure where we can no longer safely delete the parent, - * we may wish to re-join the parent and child/successor. - * The merged parent will be un-frozen, but not explicitly re-enabled. - */ -BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs, - BdrvDirtyBitmap *parent, - Error **errp) -{ - BdrvDirtyBitmap *successor = parent->successor; - - if (!successor) { - error_setg(errp, "Cannot reclaim a successor when none is present"); - return NULL; - } - - if (!hbitmap_merge(parent->bitmap, successor->bitmap)) { - error_setg(errp, "Merging of parent and successor bitmap failed"); - return NULL; - } - bdrv_release_dirty_bitmap(bs, successor); - parent->successor = NULL; - - return parent; -} - -/** - * Truncates _all_ bitmaps attached to a BDS. - */ -void bdrv_dirty_bitmap_truncate(BlockDriverState *bs) -{ - BdrvDirtyBitmap *bitmap; - uint64_t size = bdrv_nb_sectors(bs); - - QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { - assert(!bdrv_dirty_bitmap_frozen(bitmap)); - hbitmap_truncate(bitmap->bitmap, size); - bitmap->size = size; - } -} - -static void bdrv_do_release_matching_dirty_bitmap(BlockDriverState *bs, - BdrvDirtyBitmap *bitmap, - bool only_named) -{ - BdrvDirtyBitmap *bm, *next; - QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) { - if ((!bitmap || bm == bitmap) && (!only_named || bm->name)) { - assert(!bdrv_dirty_bitmap_frozen(bm)); - QLIST_REMOVE(bm, list); - hbitmap_free(bm->bitmap); - g_free(bm->name); - g_free(bm); - - if (bitmap) { - return; - } - } - } -} - -void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) -{ - bdrv_do_release_matching_dirty_bitmap(bs, bitmap, false); -} - -/** - * Release all named dirty bitmaps attached to a BDS (for use in bdrv_close()). - * There must not be any frozen bitmaps attached. - */ -void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs) -{ - bdrv_do_release_matching_dirty_bitmap(bs, NULL, true); -} - -void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap) -{ - assert(!bdrv_dirty_bitmap_frozen(bitmap)); - bitmap->disabled = true; -} - -void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap) -{ - assert(!bdrv_dirty_bitmap_frozen(bitmap)); - bitmap->disabled = false; -} - -BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs) -{ - BdrvDirtyBitmap *bm; - BlockDirtyInfoList *list = NULL; - BlockDirtyInfoList **plist = &list; - - QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { - BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1); - BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1); - info->count = bdrv_get_dirty_count(bm); - info->granularity = bdrv_dirty_bitmap_granularity(bm); - info->has_name = !!bm->name; - info->name = g_strdup(bm->name); - info->status = bdrv_dirty_bitmap_status(bm); - entry->value = info; - *plist = entry; - plist = &entry->next; - } - - return list; -} - -int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, - int64_t sector) -{ - if (bitmap) { - return hbitmap_get(bitmap->bitmap, sector); - } else { - return 0; - } -} - -/** - * Chooses a default granularity based on the existing cluster size, - * but clamped between [4K, 64K]. Defaults to 64K in the case that there - * is no cluster size information available. - */ -uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs) -{ - BlockDriverInfo bdi; - uint32_t granularity; - - if (bdrv_get_info(bs, &bdi) >= 0 && bdi.cluster_size > 0) { - granularity = MAX(4096, bdi.cluster_size); - granularity = MIN(65536, granularity); - } else { - granularity = 65536; - } - - return granularity; -} - -uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap) -{ - return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap); -} - -void bdrv_dirty_iter_init(BdrvDirtyBitmap *bitmap, HBitmapIter *hbi) -{ - hbitmap_iter_init(hbi, bitmap->bitmap, 0); -} - -void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap, - int64_t cur_sector, int nr_sectors) -{ - assert(bdrv_dirty_bitmap_enabled(bitmap)); - hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); -} - -void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap, - int64_t cur_sector, int nr_sectors) -{ - assert(bdrv_dirty_bitmap_enabled(bitmap)); - hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors); -} - -void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out) -{ - assert(bdrv_dirty_bitmap_enabled(bitmap)); - if (!out) { - hbitmap_reset_all(bitmap->bitmap); - } else { - HBitmap *backup = bitmap->bitmap; - bitmap->bitmap = hbitmap_alloc(bitmap->size, - hbitmap_granularity(backup)); - *out = backup; - } -} - -void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in) -{ - HBitmap *tmp = bitmap->bitmap; - assert(bdrv_dirty_bitmap_enabled(bitmap)); - bitmap->bitmap = in; - hbitmap_free(tmp); -} - -void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, - int nr_sectors) -{ - BdrvDirtyBitmap *bitmap; - QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { - if (!bdrv_dirty_bitmap_enabled(bitmap)) { - continue; - } - hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); - } -} - -/** - * Advance an HBitmapIter to an arbitrary offset. - */ -void bdrv_set_dirty_iter(HBitmapIter *hbi, int64_t offset) -{ - assert(hbi->hb); - hbitmap_iter_init(hbi, hbi->hb, offset); -} - -int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap) -{ - return hbitmap_count(bitmap->bitmap); -} |