On Tue, 7 Aug 2007, James Bottomley wrote: > On Tue, 2007-08-07 at 12:54 -0400, Alan Stern wrote: > > Can somebody explain the reason for calling a separate > > scsi_sysfs_add_devices() routine in the async scanning code instead of > > just calling scsi_sysfs_add_sdev() normally from within scsi_add_lun()? > > Matthew's away at the moment, so I'll speak for him. > > The reason is so that the order of device enumeration remains > approximately constant. We didn't necessarily want completely random > and timing related enumerations with the async scanning patch. If you say so. But aren't synchronous enumerations just about as random and timing-related? I guess you're concerned about cases where multiple SCSI buses are scanned in parallel. > > This peculiar delayed approach has introduced a bug. It evades the > > protection provided by shost->scan_mutex and as a result, if a host is > > hot-unplugged in the middle of an async scan, the SCSI core will > > attempt to unregister the host's devices before they have been > > registered! Obviously this is not good. > > Does this patch fix it: > > http://marc.info/?l=linux-scsi&m=118289275414202 > > ? it's one of a number designed to address the problems. Yes it does, thank you very much. I urge you to send the patch upstream in time for 2.6.23 and also to submit it for the 2.6.22-stable branch (if you haven't done so already). Alan Stern - 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
