Chandra Seetharaman wrote:
Resending the patch to get in patchwork... ------- The problem reported by Moger Babu was caused due to the architectural change made when we moved from dm hardware handler to SCSI hardware handler. Thanks Babu for finding and reporting the bug. All of the hardware handlers, do have a state now, and they are set to active and (some form of) inactive. All of them have prep_fn, which use this "state" to fail the I/O without it ever being sent to the device. As Babu has noted in his email, the pg_init/activate is sent on only one path and the "state" of that path is changed appropriately to "active" while other paths in the same path group are never changed as they never got an "activate". Attached is a patch (compiled, tested, but not clean yet), which makes changes in the dm-multipath layer to send an "activate" on each paths in the path groups. Mike (Anderson) and I had a discussion about whether to implement this in the dm-mulitpath layer or in the SCSI hardware handler layer and we came to a conclusion that it is best suited to be in the dm-mulitpath layer as it is the one that knows the relationship between different paths. If it were to be done at the Hardware handler layer, then the hardware handler may end up having a different notion of the path relationship and hence may not work as expected by the dm-multipath layer. This patch has been tested by Hannes in EMC storage. Babu and I tested it in LSI storage. ---------- Signed-off-by: Chandra Seetharaman <sekharan@xxxxxxxxxx>
Acked-by: Hannes Reinecke <hare@xxxxxxx> Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
