This is a note to let you know that I've just added the patch titled
scsi: iscsi: Release endpoint ID when its freed
to the 5.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-iscsi-release-endpoint-id-when-its-freed.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5ce21d37954b3524d2bc12398c6be2608a6a89de
Author: Mike Christie <michael.christie@xxxxxxxxxx>
Date: Thu Apr 7 19:13:07 2022 -0500
scsi: iscsi: Release endpoint ID when its freed
[ Upstream commit 3c6ae371b8a1ffba1fc415989fd581ebf841ed0a ]
We can't release the endpoint ID until all references to the endpoint have
been dropped or it could be allocated while in use. This has us use an idr
instead of looping over all conns to find a free ID and then free the ID
when all references have been dropped instead of when the device is only
deleted.
Link: https://lore.kernel.org/r/20220408001314.5014-4-michael.christie@xxxxxxxxxx
Tested-by: Manish Rangankar <mrangankar@xxxxxxxxxxx>
Reviewed-by: Lee Duncan <lduncan@xxxxxxxx>
Reviewed-by: Chris Leech <cleech@xxxxxxxxxx>
Reviewed-by: Wu Bo <wubo40@xxxxxxxxxx>
Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index c7b1b2e8bb02..bcdfcb25349a 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -86,6 +86,9 @@ struct iscsi_internal {
struct transport_container session_cont;
};
+static DEFINE_IDR(iscsi_ep_idr);
+static DEFINE_MUTEX(iscsi_ep_idr_mutex);
+
static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
static struct workqueue_struct *iscsi_eh_timer_workq;
@@ -169,6 +172,11 @@ struct device_attribute dev_attr_##_prefix##_##_name = \
static void iscsi_endpoint_release(struct device *dev)
{
struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
+
+ mutex_lock(&iscsi_ep_idr_mutex);
+ idr_remove(&iscsi_ep_idr, ep->id);
+ mutex_unlock(&iscsi_ep_idr_mutex);
+
kfree(ep);
}
@@ -181,7 +189,7 @@ static ssize_t
show_ep_handle(struct device *dev, struct device_attribute *attr, char *buf)
{
struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
- return sysfs_emit(buf, "%llu\n", (unsigned long long) ep->id);
+ return sysfs_emit(buf, "%d\n", ep->id);
}
static ISCSI_ATTR(ep, handle, S_IRUGO, show_ep_handle, NULL);
@@ -194,48 +202,32 @@ static struct attribute_group iscsi_endpoint_group = {
.attrs = iscsi_endpoint_attrs,
};
-#define ISCSI_MAX_EPID -1
-
-static int iscsi_match_epid(struct device *dev, const void *data)
-{
- struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
- const uint64_t *epid = data;
-
- return *epid == ep->id;
-}
-
struct iscsi_endpoint *
iscsi_create_endpoint(int dd_size)
{
- struct device *dev;
struct iscsi_endpoint *ep;
- uint64_t id;
- int err;
-
- for (id = 1; id < ISCSI_MAX_EPID; id++) {
- dev = class_find_device(&iscsi_endpoint_class, NULL, &id,
- iscsi_match_epid);
- if (!dev)
- break;
- else
- put_device(dev);
- }
- if (id == ISCSI_MAX_EPID) {
- printk(KERN_ERR "Too many connections. Max supported %u\n",
- ISCSI_MAX_EPID - 1);
- return NULL;
- }
+ int err, id;
ep = kzalloc(sizeof(*ep) + dd_size, GFP_KERNEL);
if (!ep)
return NULL;
+ mutex_lock(&iscsi_ep_idr_mutex);
+ id = idr_alloc(&iscsi_ep_idr, ep, 0, -1, GFP_NOIO);
+ if (id < 0) {
+ mutex_unlock(&iscsi_ep_idr_mutex);
+ printk(KERN_ERR "Could not allocate endpoint ID. Error %d.\n",
+ id);
+ goto free_ep;
+ }
+ mutex_unlock(&iscsi_ep_idr_mutex);
+
ep->id = id;
ep->dev.class = &iscsi_endpoint_class;
- dev_set_name(&ep->dev, "ep-%llu", (unsigned long long) id);
+ dev_set_name(&ep->dev, "ep-%d", id);
err = device_register(&ep->dev);
if (err)
- goto free_ep;
+ goto free_id;
err = sysfs_create_group(&ep->dev.kobj, &iscsi_endpoint_group);
if (err)
@@ -249,6 +241,10 @@ iscsi_create_endpoint(int dd_size)
device_unregister(&ep->dev);
return NULL;
+free_id:
+ mutex_lock(&iscsi_ep_idr_mutex);
+ idr_remove(&iscsi_ep_idr, id);
+ mutex_unlock(&iscsi_ep_idr_mutex);
free_ep:
kfree(ep);
return NULL;
@@ -276,14 +272,17 @@ EXPORT_SYMBOL_GPL(iscsi_put_endpoint);
*/
struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle)
{
- struct device *dev;
+ struct iscsi_endpoint *ep;
- dev = class_find_device(&iscsi_endpoint_class, NULL, &handle,
- iscsi_match_epid);
- if (!dev)
- return NULL;
+ mutex_lock(&iscsi_ep_idr_mutex);
+ ep = idr_find(&iscsi_ep_idr, handle);
+ if (!ep)
+ goto unlock;
- return iscsi_dev_to_endpoint(dev);
+ get_device(&ep->dev);
+unlock:
+ mutex_unlock(&iscsi_ep_idr_mutex);
+ return ep;
}
EXPORT_SYMBOL_GPL(iscsi_lookup_endpoint);
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index 037c77fb5dc5..3ecf9702287b 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -296,7 +296,7 @@ extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
struct iscsi_endpoint {
void *dd_data; /* LLD private data */
struct device dev;
- uint64_t id;
+ int id;
struct iscsi_cls_conn *conn;
};
