>>>>> "Nicolai" == Nicolai Stange <nicstange@xxxxxxxxx> writes: Nicolai, Nicolai> 1.) Do these older SCSI devices have a way to report Nicolai> ->max_ws_blocks? I'm afraid not. Nicolai> 3.) Those older devices that have ->max_ws_blocks > Nicolai> SD_MAX_WS10_BLOCKS but ->ws16 == ->ws10 == 0, i.e. the Nicolai> heuristicated ones would always be given WRITE_SAME, not Nicolai> WRITE_SAME_16 commands? C.f. sd_setup_write_same_cmnd(): Nicolai> if ->ws16 is not set, do WRITE_SAME. Isn't this a little Nicolai> bit odd given that the reported -> max_ws_blocks would be Nicolai> greater than SD_MAX_WS10_BLOCKS? The check looks confusing because it caps the number of blocks to 0xFFFF (the WRITE SAME(10) limit) for WRITE SAME(16) commands. Several older devices accept the 16-byte command which allows for a bigger block range but they only actually check the lower two bytes. This will cause data corruption as parts of a block range may not be zeroed as requested. FWIW, I'm in agreement with your patch to disable write same in libata as a quick fix for 4.9. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
