On Fri, Dec 05 2014 at 6:25pm -0500, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > On Tue, Oct 28 2014 at 2:26pm -0400, > Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > > > On Tue, Oct 28 2014 at 2:13pm -0400, > > Keith Busch <keith.busch@xxxxxxxxx> wrote: > > > > > No comments this time. Did I totally botch this in the wrong direction, > > > or was the timing bad with the linux con/plumbers that week? > > > > I've just been busy with other things. Reviewing this is on my > > near-term TODO (for 3.19 merge consideration). > > Hi Keith, > > I've found a few issues with your v2. I've been working through the > code and fixing things as I see them. Please see this branch: > https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/log/?h=dm-for-3.19-blk-mq > > My changes build on your v2 baseline. > > How much testing have you done? It could be that my changes screwed > something up but... I just tried simply creating a normal request-based > DM multipath device (using non blk-mq devices) and hit this crash: > > [ 1179.088841] BUG: unable to handle kernel NULL pointer dereference at 0000000000000378 > [ 1179.097587] IP: [<ffffffff8142091a>] scsi_setup_cmnd+0xea/0x170 map_tio_request -> map_request -> dm_dispatch_request -> blk_insert_cloned_request -> scsi_setup_cmnd -> scsi_setup_fs_cmnd -> scsi_cmd_to_driver static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd) { return *(struct scsi_driver **)cmd->request->rq_disk->private_data; } We're crashing because rq_disk is NULL. This fixed the crash for me: https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-for-3.19-blk-mq&id=0373233d9a9ca72a90394ed1770b21a8b7431abc But in general this code needs _a lot_ more testing/review. Sadly I cannot stage it for 3.19 inclusion. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
