On Thu, 2008-01-31 at 20:14 +0100, Geert Uytterhoeven wrote: > On Thu, 31 Jan 2008, Nicholas A. Bellinger wrote: > > On Thu, 2008-01-31 at 11:53 -0600, James Bottomley wrote: > > > On Thu, 2008-01-31 at 09:28 -0800, Nicholas A. Bellinger wrote: > > > > The problem case is a SCSI Target Mode engine that receives a 2048 Byte > > > > single sector ATAPI READ_10 request from the storage fabric, and uses > > > > scsi_execute_async() (the only option >= 2.6.18) to issue said request > > > > to the underlying struct scsi_device. Because the underlying bio code > > > > assumes 512 byte only sectors, the check in __bio_add_page() incorrectly > > > > determines that max_sectors (max_sectors has to be low, as with 32 from > > > > ps3rom.c) has been exceeded, and fails the request back up the stack. > > > > > > OK, so this is a totally separate issue from the one you actually posted > > > it as a patch to fix? > > > > > > the queue max_sectors parameter is also counted in the block internal of > > > 512 byte sectors. If you set it to 32 that means you were only > > > expecting 16k of transfers per command maximum. If that's not right, > > > then set the limit correctly. > > > > > > In short, and to repeat: almost every internal size counter to block is > > > in units of 512 byte sectors ... that includes capacity, maximum etc ... > > > > > > > Ok, after reading your followup with Geert I see that this looks like a > > bug in ps3rom.c assuming 2048 byte sectors to calculate .max_sectors > > (which was originally set to 32 as I mentioned). Using the setting > > BOUNCE_SIZE << 9 where BOUNCE_SIZE is the request size in bytes looks > > like this will solve the issue. My misunderstanding was > > that .max_sectors was allowed to be calcuated in non 512 byte sectors, > > so please disregard my patch. > > > > Geert, .max_sectors for ps3rom.c using 512 byte sectors ends up being > > 128, yes.? > > Yes. > > With kind regards, > > Geert Uytterhoeven > Software Architect > Great! I will update my ps3 to the latest 2.6.24 from ps3-linux.git and get some new Linux/iSCSI.org Target builds made this weekend once ps3rom-use-128-max-sector.patch is committed. Also, I will be updating my userspace to FC8 PPC, and would like to get a target build for the current stable 2.6.23 PPC64 from the addon CDs. I also would not mind providing a ps3rom.ko with said patch for interested parties using the default FC-8 Ps3-Linux kernel who are not adventurous enough to build their own kernel until the Addon CDs are reved again. --nab - 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
