diff options
| -rw-r--r-- | block/dirty-bitmap.c | 36 | ||||
| -rw-r--r-- | block/io.c | 8 | ||||
| -rw-r--r-- | blockdev.c | 6 | ||||
| -rw-r--r-- | include/block/dirty-bitmap.h | 4 |
4 files changed, 54 insertions, 0 deletions
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index a8fe149c4a..17d3068336 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -46,6 +46,12 @@ struct BdrvDirtyBitmap { bool disabled; /* Bitmap is disabled. It ignores all writes to the device */ int active_iterators; /* How many iterators are active */ + bool readonly; /* Bitmap is read-only. This field also + prevents the respective image from being + modified (i.e. blocks writes and discards). + Such operations must fail and both the image + and this bitmap must remain unchanged while + this flag is set. */ QLIST_ENTRY(BdrvDirtyBitmap) list; }; @@ -505,6 +511,7 @@ void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap, int64_t cur_sector, int64_t nr_sectors) { assert(bdrv_dirty_bitmap_enabled(bitmap)); + assert(!bdrv_dirty_bitmap_readonly(bitmap)); hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); } @@ -521,6 +528,7 @@ void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap, int64_t cur_sector, int64_t nr_sectors) { assert(bdrv_dirty_bitmap_enabled(bitmap)); + assert(!bdrv_dirty_bitmap_readonly(bitmap)); hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors); } @@ -535,6 +543,7 @@ void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap, void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out) { assert(bdrv_dirty_bitmap_enabled(bitmap)); + assert(!bdrv_dirty_bitmap_readonly(bitmap)); bdrv_dirty_bitmap_lock(bitmap); if (!out) { hbitmap_reset_all(bitmap->bitmap); @@ -551,6 +560,7 @@ void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in) { HBitmap *tmp = bitmap->bitmap; assert(bdrv_dirty_bitmap_enabled(bitmap)); + assert(!bdrv_dirty_bitmap_readonly(bitmap)); bitmap->bitmap = in; hbitmap_free(tmp); } @@ -613,6 +623,7 @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, if (!bdrv_dirty_bitmap_enabled(bitmap)) { continue; } + assert(!bdrv_dirty_bitmap_readonly(bitmap)); hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); } bdrv_dirty_bitmaps_unlock(bs); @@ -635,3 +646,28 @@ int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap) { return hbitmap_count(bitmap->meta); } + +bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap) +{ + return bitmap->readonly; +} + +/* Called with BQL taken. */ +void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value) +{ + qemu_mutex_lock(bitmap->mutex); + bitmap->readonly = value; + qemu_mutex_unlock(bitmap->mutex); +} + +bool bdrv_has_readonly_bitmaps(BlockDriverState *bs) +{ + BdrvDirtyBitmap *bm; + QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { + if (bm->readonly) { + return true; + } + } + + return false; +} diff --git a/block/io.c b/block/io.c index 23170a57ee..b413727524 100644 --- a/block/io.c +++ b/block/io.c @@ -1315,6 +1315,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child, uint64_t bytes_remaining = bytes; int max_transfer; + if (bdrv_has_readonly_bitmaps(bs)) { + return -EPERM; + } + assert(is_power_of_2(align)); assert((offset & (align - 1)) == 0); assert((bytes & (align - 1)) == 0); @@ -2287,6 +2291,10 @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, return -ENOMEDIUM; } + if (bdrv_has_readonly_bitmaps(bs)) { + return -EPERM; + } + ret = bdrv_check_byte_request(bs, offset, bytes); if (ret < 0) { return ret; diff --git a/blockdev.c b/blockdev.c index 92c59910fc..edeb36bd3b 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2033,6 +2033,9 @@ static void block_dirty_bitmap_clear_prepare(BlkActionState *common, } else if (!bdrv_dirty_bitmap_enabled(state->bitmap)) { error_setg(errp, "Cannot clear a disabled bitmap"); return; + } else if (bdrv_dirty_bitmap_readonly(state->bitmap)) { + error_setg(errp, "Cannot clear a readonly bitmap"); + return; } bdrv_clear_dirty_bitmap(state->bitmap, &state->backup); @@ -2779,6 +2782,9 @@ void qmp_block_dirty_bitmap_clear(const char *node, const char *name, "Bitmap '%s' is currently disabled and cannot be cleared", name); return; + } else if (bdrv_dirty_bitmap_readonly(bitmap)) { + error_setg(errp, "Bitmap '%s' is readonly and cannot be cleared", name); + return; } bdrv_clear_dirty_bitmap(bitmap, NULL); diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h index 05451c727d..cb43fa37e2 100644 --- a/include/block/dirty-bitmap.h +++ b/include/block/dirty-bitmap.h @@ -71,6 +71,8 @@ void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap, bool finish); void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap); +void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value); + /* Functions that require manual locking. */ void bdrv_dirty_bitmap_lock(BdrvDirtyBitmap *bitmap); void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap); @@ -85,5 +87,7 @@ void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *hbi, int64_t sector_num); int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap); int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap); void bdrv_dirty_bitmap_truncate(BlockDriverState *bs); +bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap); +bool bdrv_has_readonly_bitmaps(BlockDriverState *bs); #endif |