Rather than having the device created by scsi_get_host_dev() as
a weird semi-initialized device make it a first class citizen by
implementing a minimal command emulation and provide (static)
inquiry data.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/scsi/scsi_lib.c | 24 +++++++++++++++++++
drivers/scsi/scsi_scan.c | 60 +++++++++++++++++++++++++++++++++++-----------
drivers/scsi/scsi_sysfs.c | 3 ++-
include/scsi/scsi_device.h | 1 +
include/scsi/scsi_host.h | 3 +++
5 files changed, 76 insertions(+), 15 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 30f9ca9fce22..ce9f1d83aaee 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1528,6 +1528,30 @@ static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
}
+ if (unlikely(scsi_device_is_virtual(cmd->device))) {
+ unsigned char null_report_luns[16];
+
+ switch (cmd->cmnd[0]) {
+ case TEST_UNIT_READY:
+ cmd->result = (DID_OK << 16);
+ goto done;
+ case INQUIRY:
+ scsi_sg_copy_from_buffer(cmd, cmd->device->inquiry, 36);
+ cmd->result = (DID_OK << 16);
+ goto done;
+ case REPORT_LUNS:
+ memset(null_report_luns, 0, 16);
+ null_report_luns[3] = 0x08;
+ scsi_sg_copy_from_buffer(cmd, null_report_luns, 16);
+ cmd->result = (DID_OK << 16);
+ goto done;
+ default:
+ scsi_build_sense_buffer(0, cmd->sense_buffer,
+ ILLEGAL_REQUEST, 0x20, 0x00);
+ cmd->result = (DID_NO_CONNECT << 16);
+ goto done;
+ }
+ }
trace_scsi_dispatch_cmd_start(cmd);
rtn = host->hostt->queuecommand(host, cmd);
if (rtn) {
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 4648fd3f80d9..fdc291c47b9b 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1080,6 +1080,9 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
if (!sdev)
goto out;
+ if (sdev->hidden)
+ return SCSI_SCAN_LUN_PRESENT;
+
result = kmalloc(result_len, GFP_KERNEL |
((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
if (!result)
@@ -1325,6 +1328,8 @@ static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflag
sdev = scsi_alloc_sdev(starget, 0, NULL);
if (!sdev)
return 0;
+ if (sdev->hidden)
+ return 0;
if (scsi_device_get(sdev)) {
__scsi_remove_device(sdev);
return 0;
@@ -1698,6 +1703,8 @@ static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
/* If device is already visible, skip adding it to sysfs */
if (sdev->is_visible)
continue;
+ if (sdev->hidden)
+ continue;
if (!scsi_host_scan_allowed(shost) ||
scsi_sysfs_add_sdev(sdev) != 0)
__scsi_remove_device(sdev);
@@ -1861,39 +1868,48 @@ EXPORT_SYMBOL(scsi_scan_host);
void scsi_forget_host(struct Scsi_Host *shost)
{
- struct scsi_device *sdev;
+ struct scsi_device *sdev, *virtual_sdev = NULL;
unsigned long flags;
restart:
spin_lock_irqsave(shost->host_lock, flags);
list_for_each_entry(sdev, &shost->__devices, siblings) {
+ if (scsi_device_is_virtual(sdev)) {
+ virtual_sdev = sdev;
+ continue;
+ }
if (sdev->sdev_state == SDEV_DEL)
continue;
spin_unlock_irqrestore(shost->host_lock, flags);
__scsi_remove_device(sdev);
goto restart;
}
+ /* Remove virtual device last, might be needed to send commands */
+ if (virtual_sdev)
+ __scsi_remove_device(virtual_sdev);
spin_unlock_irqrestore(shost->host_lock, flags);
}
/**
- * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself
+ * scsi_get_virtual_dev - Create a virtual scsi_device to the host adapter
* @shost: Host that needs a scsi_device
+ * @channel: SCSI channel number for the virtual device
+ * @id: SCSI target number for the virtual device
*
* Lock status: None assumed.
*
* Returns: The scsi_device or NULL
*
* Notes:
- * Attach a single scsi_device to the Scsi_Host - this should
- * be made to look like a "pseudo-device" that points to the
- * HA itself.
- *
- * Note - this device is not accessible from any high-level
- * drivers (including generics), which is probably not
- * optimal. We can add hooks later to attach.
+ * Attach a single scsi_device to the Scsi_Host. This device
+ * has a minimal command emulation, but will never submit commands
+ * to the LLDD. The primary aim for this device is to serve as a
+ * container from which command tags can be allocated from; each
+ * scsi command will carry an unused/free command tag, which then
+ * can be used by the LLDD to format internal or passthrough commands.
*/
-struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
+struct scsi_device *scsi_get_virtual_dev(struct Scsi_Host *shost,
+ unsigned int channel, unsigned int id)
{
struct scsi_device *sdev = NULL;
struct scsi_target *starget;
@@ -1901,22 +1917,38 @@ struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
mutex_lock(&shost->scan_mutex);
if (!scsi_host_scan_allowed(shost))
goto out;
- starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
+ starget = scsi_alloc_target(&shost->shost_gendev, channel, id);
if (!starget)
goto out;
sdev = scsi_alloc_sdev(starget, 0, NULL);
- if (sdev)
+ if (sdev) {
sdev->borken = 0;
- else
+ sdev->hidden = 1;
+ sdev->inquiry = (unsigned char *)scsi_null_inquiry;
+ sdev->inquiry_len = sizeof(scsi_null_inquiry);
+ scsi_device_set_state(sdev, SDEV_RUNNING);
+ } else
scsi_target_reap(starget);
put_device(&starget->dev);
out:
mutex_unlock(&shost->scan_mutex);
return sdev;
}
+EXPORT_SYMBOL_GPL(scsi_get_virtual_dev);
+
+struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
+{
+ return scsi_get_virtual_dev(shost, 0, shost->this_id);
+}
EXPORT_SYMBOL(scsi_get_host_dev);
+bool scsi_device_is_virtual(struct scsi_device *sdev)
+{
+ return ((const unsigned char *)sdev->inquiry == scsi_null_inquiry);
+}
+EXPORT_SYMBOL_GPL(scsi_device_is_virtual);
+
/**
* scsi_free_host_dev - Free a scsi_device that points to the host adapter itself
* @sdev: Host device to be freed
@@ -1927,7 +1959,7 @@ EXPORT_SYMBOL(scsi_get_host_dev);
*/
void scsi_free_host_dev(struct scsi_device *sdev)
{
- BUG_ON(sdev->id != sdev->host->this_id);
+ BUG_ON(!scsi_device_is_virtual(sdev));
__scsi_remove_device(sdev);
}
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 163dbcb741c1..c54011c2cdda 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -485,7 +485,8 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work)
kfree_rcu(vpd_pg80, rcu);
if (vpd_pg89)
kfree_rcu(vpd_pg89, rcu);
- kfree(sdev->inquiry);
+ if (!scsi_device_is_virtual(sdev))
+ kfree(sdev->inquiry);
kfree(sdev);
if (parent)
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index e74c7e671aa0..6039ce7d09d7 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -203,6 +203,7 @@ struct scsi_device {
unsigned unmap_limit_for_ws:1; /* Use the UNMAP limit for WRITE SAME */
unsigned rpm_autosuspend:1; /* Enable runtime autosuspend at device
* creation time */
+ unsigned hidden:1; /* Do not register with sysfs */
bool offline_already; /* Device offline message logged */
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 37bb7d74e4c4..6961cbc3b2c0 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -781,7 +781,10 @@ struct class_container;
* from any high-level drivers.
*/
extern void scsi_free_host_dev(struct scsi_device *);
+extern struct scsi_device *scsi_get_virtual_dev(struct Scsi_Host *,
+ unsigned int, unsigned int);
extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
+extern bool scsi_device_is_virtual(struct scsi_device *);
/*
* DIF defines the exchange of protection information between
--
2.16.4
