While accessing a scsi_device, the use count of the underlying LLDD module
is incremented. The module reference is retrieved through .module field of
struct scsi_host_template.
This mapping between scsi_device and underlying LLDD module works well
except some scsi drivers (ufs and unusual usb storage drivers). These
drivers consist with core driver and actual LLDDs, and scsi_host_template
is defined in the core driver. So the actual LLDDs can be unloaded even if
the scsi_device is being accessed.
This adds .module field in struct Scsi_Host and let the module reference
be retrieved though it instead of struct scsi_host_template. This allows
the actual LLDDs adjust module reference.
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Vinayak Holikatti <vinholikatti@xxxxxxxxx>
Cc: Dolev Raviv <draviv@xxxxxxxxxxxxxx>
Cc: Sujit Reddy Thumma <sthumma@xxxxxxxxxxxxxx>
Cc: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: "James E.J. Bottomley" <JBottomley@xxxxxxxxxxxxx>
Cc: Matthew Dharm <mdharm-usb@xxxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: usb-storage@xxxxxxxxxxxxxxxxxxxxxxxx
Cc: linux-scsi@xxxxxxxxxxxxxxx
---
drivers/scsi/hosts.c | 1 +
drivers/scsi/scsi.c | 4 ++--
include/scsi/scsi_host.h | 1 +
3 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 8bb173e..21f1442 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -411,6 +411,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
*/
shost->max_cmd_len = 12;
shost->hostt = sht;
+ shost->module = sht->module;
shost->this_id = sht->this_id;
shost->can_queue = sht->can_queue;
shost->sg_tablesize = sht->sg_tablesize;
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index e028854..5905b83 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -988,7 +988,7 @@ int scsi_device_get(struct scsi_device *sdev)
return -ENXIO;
/* We can fail this if we're doing SCSI operations
* from module exit (like cache flush) */
- try_module_get(sdev->host->hostt->module);
+ try_module_get(sdev->host->module);
return 0;
}
@@ -1005,7 +1005,7 @@ EXPORT_SYMBOL(scsi_device_get);
void scsi_device_put(struct scsi_device *sdev)
{
#ifdef CONFIG_MODULE_UNLOAD
- struct module *module = sdev->host->hostt->module;
+ struct module *module = sdev->host->module;
/* The module refcount will be zero if scsi_device_get()
* was called from a module removal routine */
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 019e668..5133f2f 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -617,6 +617,7 @@ struct Scsi_Host {
*/
unsigned short max_cmd_len;
+ struct module *module;
int this_id;
int can_queue;
short cmd_per_lun;
--
1.9.1
--
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