Hello upstream kernel team! A fix was recently published for drivers/s390/block/dasd_diag.c to fix a problem with an inability to get read-only minidisks online to Linux via the dasd_diag driver. This fix was published for kernel release 2.6.33. (See http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=22825ab7693fd29769518a0d25ba43c01a50092a for the git commit.) Here is a description of the problem: ---------- [S390] dasd: support DIAG access for read-only devices author Stefan Weinhuber <wein@xxxxxxxxxx> Mon, 7 Dec 2009 11:51:48 +0000 (12:51 +0100) committer Martin Schwidefsky <sky@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> Mon, 7 Dec 2009 11:51:34 +0000 (12:51 +0100) When a DASD device is used with the DIAG discipline, the DIAG initialization will indicate success or error with a respective return code. So far we have interpreted a return code of 4 as error, but it actually means that the initialization was successful, but the device is read-only. To allow read-only devices to be used with DIAG we need to accept a return code of 4 as success. Re-initialization of the DIAG access is also part of the DIAG error recovery. If we find that the access mode of a device has been changed from writable to read-only while the device was in use, we print an error message. Signed-off-by: Stefan Weinhuber <wein@xxxxxxxxxx> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> ---------- I am the one who originally reported this problem to my Linux distributor (Debian), and I'd like to thank you all for your quick response to this problem. However, I'd also like to make an appeal to have this fix backported to your next stable release update for 2.6.32. It appears likely at this point that 2.6.32 will be adopted as the kernel used by Debian's next release (6.0.0, codename "Squeeze"). Having this fix in the kernel when Squeeze is first released will be a great benefit. This is an important fix for the s390 architecture. Other distributions have recognized this and have backported the fix as far back as 2.6.16 kernels (SLES10). Regards, Steve Powell -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html