> -----Original Message----- > From: Mike Christie [mailto:michael.christie@xxxxxxxxxx] > Sent: Friday, April 8, 2022 8:13 AM > To: skashyap@xxxxxxxxxxx; lduncan@xxxxxxxx; cleech@xxxxxxxxxx; > njavali@xxxxxxxxxxx; mrangankar@xxxxxxxxxxx; > GR-QLogic-Storage-Upstream@xxxxxxxxxxx; martin.petersen@xxxxxxxxxx; > linux-scsi@xxxxxxxxxxxxxxx; jejb@xxxxxxxxxxxxx > Cc: Mike Christie <michael.christie@xxxxxxxxxx> > Subject: [PATCH 03/10] scsi: iscsi: Release endpoint ID when its freed. > > 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. > > Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx> > --- > drivers/scsi/scsi_transport_iscsi.c | 71 ++++++++++++++--------------- > include/scsi/scsi_transport_iscsi.h | 2 +- > 2 files changed, 36 insertions(+), 37 deletions(-) > > diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c > index bf39fb5569b6..1fc7c6bfbd67 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_conn_cleanup_workq; > @@ -168,6 +171,11 @@ 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); > } > > @@ -180,7 +188,7 @@ 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); > > @@ -193,48 +201,32 @@ 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) > @@ -248,6 +240,10 @@ 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; > @@ -275,14 +271,17 @@ 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 38e4a67f5922..fdd486047404 100644 > --- a/include/scsi/scsi_transport_iscsi.h > +++ b/include/scsi/scsi_transport_iscsi.h > @@ -295,7 +295,7 @@ 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; > }; > > -- Reviewed-by: Wu Bo <wubo40@xxxxxxxxxx>
