Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 95 insertions, 8 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index c691fb50e6c..5ba5c2a9e8e 100644
--- a/drivers/scsi/sd.c
+++ b/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,
 };
 
 /*
@@ -497,6 +527,8 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
 		max(sdkp->physical_block_size,
 		    sdkp->unmap_granularity * logical_block_size);
 
+	sdkp->provisioning_mode = mode;
+
 	switch (mode) {
 
 	case SD_LBP_DISABLE:
@@ -524,8 +556,6 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
 
 	q->limits.max_discard_sectors = max_blocks * (logical_block_size >> 9);
 	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
-
-	sdkp->provisioning_mode = mode;
 }
 
 /**
@@ -634,7 +664,7 @@ static void sd_unprep_fn(struct request_queue *q, struct request *rq)
 }
 
 /**
- *	sd_init_command - build a scsi (read or write) command from
+ *	sd_prep_fn - build a scsi (read or write) command from
  *	information in the request structure.
  *	@SCpnt: pointer to mid-level's per scsi command structure that
  *	contains request and into which the scsi command is written
@@ -681,7 +711,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
 	ret = BLKPREP_KILL;
 
 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
-					"sd_init_command: block=%llu, "
+					"sd_prep_fn: block=%llu, "
 					"count=%d\n",
 					(unsigned long long)block,
 					this_count));
@@ -1182,9 +1212,14 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
 	retval = -ENODEV;
 
 	if (scsi_block_when_processing_errors(sdp)) {
+		retval = scsi_autopm_get_device(sdp);
+		if (retval)
+			goto out;
+
 		sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
 		retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
 					      sshdr);
+		scsi_autopm_put_device(sdp);
 	}
 
 	/* failed to execute TUR, assume media not present */
@@ -1313,6 +1348,55 @@ 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 +1486,8 @@ 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:
@@ -2349,7 +2435,7 @@ static int sd_try_extended_inquiry(struct scsi_device *sdp)
 	 * some USB ones crash on receiving them, and the pages
 	 * we currently ask for are for SPC-3 and beyond
 	 */
-	if (sdp->scsi_level > SCSI_SPC_2)
+	if (sdp->scsi_level > SCSI_SPC_2 && !sdp->skip_vpd_pages)
 		return 1;
 	return 0;
 }
@@ -2523,6 +2609,7 @@ 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);
 
@@ -2562,8 +2649,8 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
  *	(e.g. /dev/sda). More precisely it is the block device major 
  *	and minor number that is chosen here.
  *
- *	Assume sd_attach is not re-entrant (for time being)
- *	Also think about sd_attach() and sd_remove() running coincidentally.
+ *	Assume sd_probe is not re-entrant (for time being)
+ *	Also think about sd_probe() and sd_remove() running coincidentally.
  **/
 static int sd_probe(struct device *dev)
 {
@@ -2578,7 +2665,7 @@ static int sd_probe(struct device *dev)
 		goto out;
 
 	SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
-					"sd_attach\n"));
+					"sd_probe\n"));
 
 	error = -ENOMEM;
 	sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);