---

yaml
---
r: 292978
b: refs/heads/master
c: 18a4d0a
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a78e21dc5e9f896ecee5b1fbe189690dfcca38e1
+refs/heads/master: 18a4d0a22ed6c54b67af7718c305cd010f09ddf8

trunk/drivers/scsi/scsi.c

@@ -782,12 +782,6 @@ static void scsi_done(struct scsi_cmnd *cmd)
 	blk_complete_request(cmd->request);
 }
 
-/* Move this to a header if it becomes more generally useful */
-static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
-{
-	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
-}
-
 /**
  * scsi_finish_command - cleanup and pass command back to upper layer
  * @cmd: the command

trunk/drivers/scsi/scsi_debug.c

@@ -126,6 +126,7 @@ static const char * scsi_debug_version_date = "20100324";
 #define SCSI_DEBUG_OPT_TRANSPORT_ERR   16
 #define SCSI_DEBUG_OPT_DIF_ERR   32
 #define SCSI_DEBUG_OPT_DIX_ERR   64
+#define SCSI_DEBUG_OPT_MAC_TIMEOUT  128
 /* When "every_nth" > 0 then modulo "every_nth" commands:
  *   - a no response is simulated if SCSI_DEBUG_OPT_TIMEOUT is set
  *   - a RECOVERED_ERROR is simulated on successful read and write
@@ -3615,6 +3616,9 @@ int scsi_debug_queuecommand_lck(struct scsi_cmnd *SCpnt, done_funct_t done)
 			scsi_debug_every_nth = -1;
 		if (SCSI_DEBUG_OPT_TIMEOUT & scsi_debug_opts)
 			return 0; /* ignore command causing timeout */
+		else if (SCSI_DEBUG_OPT_MAC_TIMEOUT & scsi_debug_opts &&
+			 scsi_medium_access_command(SCpnt))
+			return 0; /* time out reads and writes */
 		else if (SCSI_DEBUG_OPT_RECOVERED_ERR & scsi_debug_opts)
 			inj_recovered = 1; /* to reads and writes below */
 		else if (SCSI_DEBUG_OPT_TRANSPORT_ERR & scsi_debug_opts)

trunk/drivers/scsi/scsi_error.c

@@ -30,6 +30,7 @@
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_dbg.h>
 #include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_transport.h>
 #include <scsi/scsi_host.h>
@@ -141,11 +142,11 @@ enum blk_eh_timer_return scsi_times_out(struct request *req)
 	else if (host->hostt->eh_timed_out)
 		rtn = host->hostt->eh_timed_out(scmd);
 
+	scmd->result |= DID_TIME_OUT << 16;
+
 	if (unlikely(rtn == BLK_EH_NOT_HANDLED &&
-		     !scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
-		scmd->result |= DID_TIME_OUT << 16;
+		     !scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD)))
 		rtn = BLK_EH_HANDLED;
-	}
 
 	return rtn;
 }
@@ -778,6 +779,7 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 			     int cmnd_size, int timeout, unsigned sense_bytes)
 {
 	struct scsi_device *sdev = scmd->device;
+	struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
 	struct Scsi_Host *shost = sdev->host;
 	DECLARE_COMPLETION_ONSTACK(done);
 	unsigned long timeleft;
@@ -832,6 +834,10 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 	}
 
 	scsi_eh_restore_cmnd(scmd, &ses);
+
+	if (sdrv->eh_action)
+		rtn = sdrv->eh_action(scmd, cmnd, cmnd_size, rtn);
+
 	return rtn;
 }
 

trunk/drivers/scsi/sd.c

@@ -107,6 +107,7 @@ static int sd_suspend(struct device *, pm_message_t state);
 static int sd_resume(struct device *);
 static void sd_rescan(struct device *);
 static int sd_done(struct scsi_cmnd *);
+static int sd_eh_action(struct scsi_cmnd *, unsigned char *, int, int);
 static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
 static void scsi_disk_release(struct device *cdev);
 static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
@@ -346,6 +347,31 @@ sd_store_provisioning_mode(struct device *dev, struct device_attribute *attr,
 	return count;
 }
 
+static ssize_t
+sd_show_max_medium_access_timeouts(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct scsi_disk *sdkp = to_scsi_disk(dev);
+
+	return snprintf(buf, 20, "%u\n", sdkp->max_medium_access_timeouts);
+}
+
+static ssize_t
+sd_store_max_medium_access_timeouts(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct scsi_disk *sdkp = to_scsi_disk(dev);
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	err = kstrtouint(buf, 10, &sdkp->max_medium_access_timeouts);
+
+	return err ? err : count;
+}
+
 static struct device_attribute sd_disk_attrs[] = {
 	__ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
 	       sd_store_cache_type),
@@ -360,6 +386,9 @@ static struct device_attribute sd_disk_attrs[] = {
 	__ATTR(thin_provisioning, S_IRUGO, sd_show_thin_provisioning, NULL),
 	__ATTR(provisioning_mode, S_IRUGO|S_IWUSR, sd_show_provisioning_mode,
 	       sd_store_provisioning_mode),
+	__ATTR(max_medium_access_timeouts, S_IRUGO|S_IWUSR,
+	       sd_show_max_medium_access_timeouts,
+	       sd_store_max_medium_access_timeouts),
 	__ATTR_NULL,
 };
 
@@ -382,6 +411,7 @@ static struct scsi_driver sd_template = {
 	},
 	.rescan			= sd_rescan,
 	.done			= sd_done,
+	.eh_action		= sd_eh_action,
 };
 
 /*
@@ -1313,6 +1343,55 @@ static const struct block_device_operations sd_fops = {
 	.unlock_native_capacity	= sd_unlock_native_capacity,
 };
 
+/**
+ *	sd_eh_action - error handling callback
+ *	@scmd:		sd-issued command that has failed
+ *	@eh_cmnd:	The command that was sent during error handling
+ *	@eh_cmnd_len:	Length of eh_cmnd in bytes
+ *	@eh_disp:	The recovery disposition suggested by the midlayer
+ *
+ *	This function is called by the SCSI midlayer upon completion of
+ *	an error handling command (TEST UNIT READY, START STOP UNIT,
+ *	etc.) The command sent to the device by the error handler is
+ *	stored in eh_cmnd. The result of sending the eh command is
+ *	passed in eh_disp.
+ **/
+static int sd_eh_action(struct scsi_cmnd *scmd, unsigned char *eh_cmnd,
+			int eh_cmnd_len, int eh_disp)
+{
+	struct scsi_disk *sdkp = scsi_disk(scmd->request->rq_disk);
+
+	if (!scsi_device_online(scmd->device) ||
+	    !scsi_medium_access_command(scmd))
+		return eh_disp;
+
+	/*
+	 * The device has timed out executing a medium access command.
+	 * However, the TEST UNIT READY command sent during error
+	 * handling completed successfully. Either the device is in the
+	 * process of recovering or has it suffered an internal failure
+	 * that prevents access to the storage medium.
+	 */
+	if (host_byte(scmd->result) == DID_TIME_OUT && eh_disp == SUCCESS &&
+	    eh_cmnd_len && eh_cmnd[0] == TEST_UNIT_READY)
+		sdkp->medium_access_timed_out++;
+
+	/*
+	 * If the device keeps failing read/write commands but TEST UNIT
+	 * READY always completes successfully we assume that medium
+	 * access is no longer possible and take the device offline.
+	 */
+	if (sdkp->medium_access_timed_out >= sdkp->max_medium_access_timeouts) {
+		scmd_printk(KERN_ERR, scmd,
+			    "Medium access timeout failure. Offlining disk!\n");
+		scsi_device_set_state(scmd->device, SDEV_OFFLINE);
+
+		return FAILED;
+	}
+
+	return eh_disp;
+}
+
 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
 {
 	u64 start_lba = blk_rq_pos(scmd->request);
@@ -1402,6 +1481,8 @@ static int sd_done(struct scsi_cmnd *SCpnt)
 	    (!sense_valid || sense_deferred))
 		goto out;
 
+	sdkp->medium_access_timed_out = 0;
+
 	switch (sshdr.sense_key) {
 	case HARDWARE_ERROR:
 	case MEDIUM_ERROR:
@@ -2523,6 +2604,7 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
 	sdkp->RCD = 0;
 	sdkp->ATO = 0;
 	sdkp->first_scan = 1;
+	sdkp->max_medium_access_timeouts = SD_MAX_MEDIUM_TIMEOUTS;
 
 	sd_revalidate_disk(gd);
 

trunk/drivers/scsi/sd.h

@@ -20,6 +20,7 @@
  */
 #define SD_MAX_RETRIES		5
 #define SD_PASSTHROUGH_RETRIES	1
+#define SD_MAX_MEDIUM_TIMEOUTS	2
 
 /*
  * Size of the initial data buffer for mode and read capacity data
@@ -59,6 +60,8 @@ struct scsi_disk {
 	u32		unmap_alignment;
 	u32		index;
 	unsigned int	physical_block_size;
+	unsigned int	max_medium_access_timeouts;
+	unsigned int	medium_access_timed_out;
 	u8		media_present;
 	u8		write_prot;
 	u8		protection_type;/* Data Integrity Field */
@@ -88,6 +91,38 @@ static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
 		    (sdsk)->disk->disk_name, ##a) :			\
 	sdev_printk(prefix, (sdsk)->device, fmt, ##a)
 
+static inline int scsi_medium_access_command(struct scsi_cmnd *scmd)
+{
+	switch (scmd->cmnd[0]) {
+	case READ_6:
+	case READ_10:
+	case READ_12:
+	case READ_16:
+	case SYNCHRONIZE_CACHE:
+	case VERIFY:
+	case VERIFY_12:
+	case VERIFY_16:
+	case WRITE_6:
+	case WRITE_10:
+	case WRITE_12:
+	case WRITE_16:
+	case WRITE_SAME:
+	case WRITE_SAME_16:
+	case UNMAP:
+		return 1;
+	case VARIABLE_LENGTH_CMD:
+		switch (scmd->cmnd[9]) {
+		case READ_32:
+		case VERIFY_32:
+		case WRITE_32:
+		case WRITE_SAME_32:
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 /*
  * A DIF-capable target device can be formatted with different
  * protection schemes.  Currently 0 through 3 are defined:

trunk/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 *);

trunk/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)