On Maw, 2005-12-20 at 15:55 -0600, John Treubig wrote: > Where would I look in the LibATA/SCSI chain to permit Write Error and > Time-out notification to be passed back to user space without hanging the > system? Some background first: The 2.6 block layer can generally handle passing errors back up. It has a load of problems with EOF on media that is variable size but block that need fixing but the fundamental errors get back to the block layer. Unfortunately although they get back to the block request the full error is not propogated further up the stack. Thats actually tricky for the general file system case as I/O as asynchronous to the actual file system accesses and we may even hit errors on pages we didn't actually need. One result of that is that on write errors we generally mark a volume offline and processes accessing it get stuck. > drives. When a SCSI disks report errors, the SCSI handlers perform as > expected, reporting the error and recovering. When ATA drives report > errors, only read errors recover and we are able to capture the error. > Write and time-out errors hang the system. The problem with the file system layer at this point is it isn't clear how you get the device back. What you should see is a sequence of retries and then the volume going offline. I don't know how complete your log is but it doesn't end with the expected 'giving up' and volume offlining. Is that because the final messages don't hit the log or are they just not seen ? The promise devices have some "interesting" behaviour when you reset the chip. There is a second problem with PATA too. If the drive decides to keel over asserting IORDY its game over. The bus transactions will hang and the CPU get stuck. That would _not_ be my first suspicion however. - : 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
