On 2020-04-17 05:15, Johannes Thumshirn wrote: > In order to reduce memory consumption, the only cached item is the offset > of the write pointer from the start of the zone, everything else can be > calculated. On an example drive with 52156 zones, the additional memory > consumption of the cache is thus 52156 * 4 = 208624 Bytes or 51 4k Byte > pages. The performance impact is neglectable for a spinning drive. What will happen if e.g. syzkaller mixes write() system calls with SG_IO writes? Can that cause a mismatch between the cached write pointer and the write pointer maintained by the drive? If so, should SG_IO perhaps be disallowed if the write pointer is cached? Thanks, Bart.
