On 27/06/2017 17:32, Vladimir Sementsov-Ogievskiy wrote: >>>> >>>> >>>> - we protect inserting into list from other threads, but what prevent >>>> creating bitmap with the same name from other thread after >>>> bdrv_find_dirty_bitmap() and before bdrv_dirty_bitmaps_lock() ? >>> It's like a read-write lock. >> >> Ok, finally I understand (not all, but the main idea=), sorry for >> annoying. > > Is there any example of accessing dirty bitmaps for read not under BQL > but only under dirty bitmap lock?
Yes, search for bdrv_dirty_bitmap_lock...unlock in block/mirror.c. There is also block/backup.c, which operates on a frozen bitmap. Paolo
