Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6

SCSI updates from James Bottomley:
 "The update includes the usual assortment of driver updates (lpfc,
  qla2xxx, qla4xxx, bfa, bnx2fc, bnx2i, isci, fcoe, hpsa) plus a huge
  amount of infrastructure work in the SAS library and transport class
  as well as an iSCSI update.  There's also a new SCSI based virtio
  driver."

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (177 commits)
  [SCSI] qla4xxx: Update driver version to 5.02.00-k15
  [SCSI] qla4xxx: trivial cleanup
  [SCSI] qla4xxx: Fix sparse warning
  [SCSI] qla4xxx: Add support for multiple session per host.
  [SCSI] qla4xxx: Export CHAP index as sysfs attribute
  [SCSI] scsi_transport: Export CHAP index as sysfs attribute
  [SCSI] qla4xxx: Add support to display CHAP list and delete CHAP entry
  [SCSI] iscsi_transport: Add support to display CHAP list and delete CHAP entry
  [SCSI] pm8001: fix endian issue with code optimization.
  [SCSI] pm8001: Fix possible racing condition.
  [SCSI] pm8001: Fix bogus interrupt state flag issue.
  [SCSI] ipr: update PCI ID definitions for new adapters
  [SCSI] qla2xxx: handle default case in qla2x00_request_firmware()
  [SCSI] isci: improvements in driver unloading routine
  [SCSI] isci: improve phy event warnings
  [SCSI] isci: debug, provide state-enum-to-string conversions
  [SCSI] scsi_transport_sas: 'enable' phys on reset
  [SCSI] libsas: don't recover end devices attached to disabled phys
  [SCSI] libsas: fixup target_port_protocols for expanders that don't report sata
  [SCSI] libsas: set attached device type and target protocols for local phys
  ...

1 files changed, 84 insertions, 2 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index d173b90b25e9..09e3df42a402 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;
 }
 
 /**
@@ -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);