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authorMartin K. Petersen <martin.petersen@oracle.com>2012-02-09 13:48:53 -0500
committerJames Bottomley <JBottomley@Parallels.com>2012-02-19 10:14:52 -0600
commit18a4d0a22ed6c54b67af7718c305cd010f09ddf8 (patch)
tree06e22a92290ff84b2c1d5abb09424493de384c4b /include
parenta78e21dc5e9f896ecee5b1fbe189690dfcca38e1 (diff)
[SCSI] Handle disk devices which can not process medium access commands
We have experienced several devices which fail in a fashion we do not currently handle gracefully in SCSI. After a failure these devices will respond to the SCSI primary command set (INQUIRY, TEST UNIT READY, etc.) but any command accessing the storage medium will time out. The following patch adds an callback that can be used by upper level drivers to inspect the results of an error handling command. This in turn has been used to implement additional checking in the SCSI disk driver. If a medium access command fails twice but TEST UNIT READY succeeds both times in the subsequent error handling we will offline the device. The maximum number of failed commands required to take a device offline can be tweaked in sysfs. Also add a new error flag to scsi_debug which allows this scenario to be easily reproduced. [jejb: fix up integer parsing to use kstrtouint] Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'include')
-rw-r--r--include/scsi/scsi_cmnd.h6
-rw-r--r--include/scsi/scsi_driver.h1
2 files changed, 7 insertions, 0 deletions
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 9be0128bf30..377df4a2851 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -10,6 +10,7 @@
struct Scsi_Host;
struct scsi_device;
+struct scsi_driver;
/*
* MAX_COMMAND_SIZE is:
@@ -131,6 +132,11 @@ struct scsi_cmnd {
unsigned char tag; /* SCSI-II queued command tag */
};
+static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
+{
+ return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
+}
+
extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
extern void scsi_put_command(struct scsi_cmnd *);
diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h
index 9fd6702f02e..d443aa06a72 100644
--- a/include/scsi/scsi_driver.h
+++ b/include/scsi/scsi_driver.h
@@ -16,6 +16,7 @@ struct scsi_driver {
void (*rescan)(struct device *);
int (*done)(struct scsi_cmnd *);
+ int (*eh_action)(struct scsi_cmnd *, unsigned char *, int, int);
};
#define to_scsi_driver(drv) \
container_of((drv), struct scsi_driver, gendrv)