+ if (!scsi_mpath_head)
+ return NULL;
+
+ ida_init(&scsi_mpath_head->ida);
+ mutex_init(&scsi_mpath_head->lock);
+
+ scsi_mpath_head->mpath_head = mpath_alloc_head();
+ if (IS_ERR(scsi_mpath_head->mpath_head))
+ goto out_free;
+ scsi_mpath_head->mpath_head->mpdt = &smpdt_pr;
mpdt?
What's that supposed to mean?
multipath device template, like scsi host template
Please check it in the libmultipath series
Seems to be like a persistent reservation thing, so why don't
you introduce it together with PR suppoer?
+ scsi_mpath_head->mpath_head->drvdata = scsi_mpath_head;
+
+ scsi_mpath_head->index = ida_alloc(&scsi_multipath_dev_ida,
GFP_KERNEL);
+ if (scsi_mpath_head->index < 0)
+ goto out_put_head;
+
+ device_initialize(&scsi_mpath_head->dev);
+ ret = dev_set_name(&scsi_mpath_head->dev, "%d", scsi_mpath_head-
>index);
Huh? The name is just the number? So we will have a device
/sys/devices/virtual/1 ?
The sysfs registration looks decidedly odd.
I guess we should add a scsi multipath class to sort the devices under.
We do, check the later patches.
I have to admit that I am not a huge fan of the naming, but it's hard to
find something very good.
There is no common host. Further more, if I wanted to use HCIL SCSI
naming, then the CIL may not be consistent or unique. I did consider
using the wwid/vpd id, but that seems so inconsistent.
+ if (ret) {
+ put_device(&scsi_mpath_head->dev);
+ goto out_free_ida;
+ }
+
+ return scsi_mpath_head;
+
+out_free_ida:
+ ida_free(&scsi_multipath_dev_ida, scsi_mpath_head->index);
+out_put_head:
+ mpath_put_head(scsi_mpath_head->mpath_head);
+out_free:
+ kfree(scsi_mpath_head);
+ return NULL;
+}
+
+static struct scsi_mpath_head *scsi_mpath_find_head(
+ struct scsi_mpath_device *scsi_mpath_dev)
+{
+ struct scsi_mpath_head *scsi_mpath_head;
+ int ret;
+
+ mutex_lock(&scsi_mpath_heads_lock);
+ list_for_each_entry(scsi_mpath_head, &scsi_mpath_heads_list,
entry) {
+ ret = scsi_mpath_get_head(scsi_mpath_head);
+ if (ret)
+ continue;
+ if (strncmp(scsi_mpath_head->wwid,
+ scsi_mpath_dev->device_id_str,
+ SCSI_MPATH_DEVICE_ID_LEN) == 0) {
+
+ mutex_unlock(&scsi_mpath_heads_lock);
+ return scsi_mpath_head;
+ }
+ scsi_mpath_put_head(scsi_mpath_head);
+ }
+
+ return NULL;
+}
+
static void scsi_multipath_sdev_uninit(struct scsi_device *sdev)
{
kfree(sdev->scsi_mpath_dev);
@@ -107,6 +178,7 @@ static void scsi_multipath_sdev_uninit(struct
scsi_device *sdev)
int scsi_mpath_dev_alloc(struct scsi_device *sdev)
{
+ struct scsi_mpath_head *scsi_mpath_head;
int ret;
if (!scsi_multipath)
@@ -127,13 +199,75 @@ int scsi_mpath_dev_alloc(struct scsi_device *sdev)
goto out_uninit;
}
+ scsi_mpath_head = scsi_mpath_find_head(sdev->scsi_mpath_dev);
+ if (scsi_mpath_head)
+ goto found;
+ /* scsi_mpath_disks_list lock held */
+ scsi_mpath_head = scsi_mpath_alloc_head();
+ if (!scsi_mpath_head)
+ goto out_uninit;
+
+ strcpy(scsi_mpath_head->wwid, sdev->scsi_mpath_dev->device_id_str);
+
Do we have a sysfs attribute for this?
yes, it's introduced later
+ ret = device_add(&scsi_mpath_head->dev);
+ if (ret)
+ goto out_put_head;
+
+ list_add_tail(&scsi_mpath_head->entry, &scsi_mpath_heads_list);
+
+ mutex_unlock(&scsi_mpath_heads_lock);
+ sdev->scsi_mpath_dev->scsi_mpath_head = scsi_mpath_head;
+
+found:
+ sdev->scsi_mpath_dev->index = ida_alloc(&scsi_mpath_head->ida,
GFP_KERNEL);
+ if (sdev->scsi_mpath_dev->index < 0) {
+ ret = sdev->scsi_mpath_dev->index;
+ goto out_put_head;
+ }
+
+ mutex_lock(&scsi_mpath_head->lock);
+ scsi_mpath_head->dev_count++;
+ mutex_unlock(&scsi_mpath_head->lock);
+
+ sdev->scsi_mpath_dev->scsi_mpath_head = scsi_mpath_head;
return 0;
+out_put_head:
+ scsi_mpath_put_head(scsi_mpath_head);
out_uninit:
+ mutex_unlock(&scsi_mpath_heads_lock);
scsi_multipath_sdev_uninit(sdev);
return ret;
}
+static void scsi_mpath_remove_head(struct scsi_mpath_device
*scsi_mpath_dev)
+{
+ struct scsi_mpath_head *scsi_mpath_head =
+ scsi_mpath_dev->scsi_mpath_head;
+ bool last_path = false;
+
+ mutex_lock(&scsi_mpath_head->lock);
+ scsi_mpath_head->dev_count--;
+ if (scsi_mpath_head->dev_count == 0)
+ last_path = true;
+ mutex_unlock(&scsi_mpath_head->lock);
+
+ if (last_path)
+ device_del(&scsi_mpath_head->dev);
+
+ scsi_mpath_dev->scsi_mpath_head = NULL;
+ scsi_mpath_put_head(scsi_mpath_head);
+}
+
+void scsi_mpath_remove_device(struct scsi_mpath_device *scsi_mpath_dev)
+{
+ struct scsi_mpath_head *scsi_mpath_head = scsi_mpath_dev-
>scsi_mpath_head;
+
+ ida_free(&scsi_mpath_head->ida, scsi_mpath_dev->index);
+
+ scsi_mpath_remove_head(scsi_mpath_dev);
+}
+
void scsi_mpath_dev_release(struct scsi_device *sdev)
{
struct scsi_mpath_device *scsi_mpath_dev = sdev->scsi_mpath_dev;
@@ -142,8 +276,21 @@ void scsi_mpath_dev_release(struct scsi_device
*sdev)
return;
scsi_multipath_sdev_uninit(sdev);
+}
+
+int scsi_mpath_get_head(struct scsi_mpath_head *scsi_mpath_head)
+{
+ if (!get_device(&scsi_mpath_head->dev))
+ return -ENXIO;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(scsi_mpath_get_head);
+void scsi_mpath_put_head(struct scsi_mpath_head *scsi_mpath_head)
+{
+ put_device(&scsi_mpath_head->dev);
}
+EXPORT_SYMBOL_GPL(scsi_mpath_put_head);
int __init scsi_multipath_init(void)
{
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 0d69e27600a7a..287a683e89ae5 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1447,6 +1447,9 @@ void __scsi_remove_device(struct scsi_device *sdev)
} else
put_device(&sdev->sdev_dev);
+ if (sdev->scsi_mpath_dev)
+ scsi_mpath_remove_device(sdev->scsi_mpath_dev);
+
/*
* Stop accepting new requests and wait until all queuecommand()
and
* scsi_run_queue() invocations have finished before tearing
down the
diff --git a/include/scsi/scsi_multipath.h b/include/scsi/
scsi_multipath.h
index ca00ea10cd5db..38953b05a44dc 100644
--- a/include/scsi/scsi_multipath.h
+++ b/include/scsi/scsi_multipath.h
@@ -19,9 +19,22 @@
#ifdef CONFIG_SCSI_MULTIPATH
#define SCSI_MPATH_DEVICE_ID_LEN 40
+struct scsi_mpath_head {
+ char wwid[SCSI_MPATH_DEVICE_ID_LEN];
Don't name it WWID. That's an ATA thing. Make it vpd_id.
ok
Thanks!
