On 09/05/2022 13:28, John Garry wrote: > > For some reason I cannot fetch your git due to "error: RPC failed ..." > which I think is a timeout. I seem to have this problem recently > whenever a linux.git clone has branches based on linux-next.git . Maybe > a git config issue for me... Just to be sure - the link was not a git remote, but direct link for a web browser. The repo is: https://github.com/krzk/linux.git branch: n/qcom-ufs-opp-cleanups-v2 >> However this does not solve the problem. The SHT has "module" which gets >> incremented/decremented. Exactly like in case of other drivers >> (driver->owner). > > Ah, I missed that this could be a problem. So we have this member to > stop the SCSI host driver being removed when we have disks mounted, etc. > > But isn't scsi_host_template.module just a pointer to the local driver > module data (and that data gets incremented/decremented)? I am looking > at the THIS_MODULE definition in export.h: Yes, it is just a pointer, just like 'struct device_driver.owner' is. > > extern stuct module __this_module; > #define THIS_MODULE(&__this_module) > > However I do see scsi_device_dev_release(), which does: > > sdp->host->hostt->module = NULL > > I am not sure how necessary that really is. I would need to check further. > > Did you see if there other places which set hostt->module dynamically? I think all SHT set it statically. Then it is being dynamically incremented when needed and in scsi_device_dev_release() is being nullified (as you mentioned above). I guess this SHT->module is actually duplicating what most of drivers (e.g. PCI, platform, USB) are doing. If I understand correctly, the Scsi_Host is instantiated by the probe of a driver (pci_driver, virtio_driver etc), therefore the SHT->module could be simply stored in Scsi_Host. >> >> I started moving the SHT->module to a new field scsi_host->owner and >> trying to use the parent's driver (so PCI, USB) owner. >> I am not sure if it is correct approach, so before implementing such big >> change affecting multiple subsystems (USB, ATA, SCSI) - can you share >> ideas/opinion? >> >> The Work-in-Progress looks like this (last commit): >> https://github.com/krzk/linux/commit/17609caecd53df20f631703ea084a70e7735b5d7 Best regards, Krzysztof
