On 1/11/23 21:23, Johannes Thumshirn wrote: > On 10.01.23 14:08, Damien Le Moal wrote: >> Using REQ_OP_ZONE_APPEND operations for synchronous writes to sequential >> files succeeds regardless of the zone write pointer position, as long as >> the target zone is not full. This means that if an external (buggy) >> application writes to the zone of a sequential file underneath the file >> system, subsequent file write() operation will succeed but the file size >> will not be correct and the file will contain invalid data written by >> another application. >> >> Modify zonefs_file_dio_append() to check the written sector of an append >> write (returned in bio->bi_iter.bi_sector) and return -EIO if there is a >> mismatch with the file zone wp offset field. This change triggers a call >> to zonefs_io_error() and a zone check. Modify zonefs_io_error_cb() to >> not expose the unexpected data after the current inode size when the >> errors=remount-ro mode is used. Other error modes are correctly handled >> already. > > This only happens on ZNS and null_blk, doesn't it? On SCSI the Zone Append > emulation should catch this error before. Yes. The zone append will fail with scsi sd emulation so this change is not useful in that case. But null_blk and ZNS drives will not fail the zone append, resulting in a bad file size without this check. -- Damien Le Moal Western Digital Research
