Messages in this thread Patch in this message | | | Date | Tue, 04 Mar 2008 14:07:22 +0200 | From | Erez Zilber <> | Subject | Re: [PATCH 1/2] IB/iSER: fix list iteration bug |
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Arne Redlich wrote: > The iteration through the list of "iser_device"s during device > lookup/creation is broken - it might result in an infinite loop if more > than 1 HCA is used with iSER. Use list_for_each_entry() instead of the > custom, flawed list iteration code. > > Signed-off-by: Arne Redlich <arne.redlich@xiranet.com> > --- > drivers/infiniband/ulp/iser/iser_verbs.c | 36 ++++++++++++----------------- > 1 files changed, 15 insertions(+), 21 deletions(-) > > diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c > index 714b8db..1c0f968 100644 > --- a/drivers/infiniband/ulp/iser/iser_verbs.c > +++ b/drivers/infiniband/ulp/iser/iser_verbs.c > @@ -237,33 +237,27 @@ static int iser_free_ib_conn_res(struct iser_conn *ib_conn) > static > struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id) > { > - struct list_head *p_list; > - struct iser_device *device = NULL; > + struct iser_device *device; > > mutex_lock(&ig.device_list_mutex); > > - p_list = ig.device_list.next; > - while (p_list != &ig.device_list) { > - device = list_entry(p_list, struct iser_device, ig_list); > - /* find if there's a match using the node GUID */ > + list_for_each_entry(device, &ig.device_list, ig_list)
I've just added the original comments that are missing in your patch.
> if (device->ib_device->node_guid == cma_id->device->node_guid) > - break; > - } > - > - if (device == NULL) { > - device = kzalloc(sizeof *device, GFP_KERNEL); > - if (device == NULL) > goto out; > - /* assign this device to the device */ > - device->ib_device = cma_id->device; > - /* init the device and link it into ig device list */ > - if (iser_create_device_ib_res(device)) { > - kfree(device); > - device = NULL; > - goto out; > - } > - list_add(&device->ig_list, &ig.device_list); > + > + device = kzalloc(sizeof *device, GFP_KERNEL); > + if (device == NULL) > + goto out; > + > + device->ib_device = cma_id->device; > + /* init the device and link it into ig device list */ > + if (iser_create_device_ib_res(device)) { > + kfree(device); > + device = NULL; > + goto out; > } > + list_add(&device->ig_list, &ig.device_list); > + > out: > BUG_ON(device == NULL); > device->refcount++;
The iteration through the list of "iser_device"s during device lookup/creation is broken - it might result in an infinite loop if more than 1 HCA is used with iSER. Use list_for_each_entry() instead of the custom, flawed list iteration code.
Signed-off-by: Arne Redlich <arne.redlich@xiranet.com> Signed-off-by: Erez Zilber <erezz@voltaire.com> --- drivers/infiniband/ulp/iser/iser_verbs.c | 36 +++++++++++++---------------- 1 files changed, 16 insertions(+), 20 deletions(-)
diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c index 714b8db..768ba69 100644 --- a/drivers/infiniband/ulp/iser/iser_verbs.c +++ b/drivers/infiniband/ulp/iser/iser_verbs.c @@ -237,33 +237,29 @@ static int iser_free_ib_conn_res(struct iser_conn *ib_conn) static struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id) { - struct list_head *p_list; - struct iser_device *device = NULL; + struct iser_device *device; mutex_lock(&ig.device_list_mutex); - p_list = ig.device_list.next; - while (p_list != &ig.device_list) { - device = list_entry(p_list, struct iser_device, ig_list); + list_for_each_entry(device, &ig.device_list, ig_list) /* find if there's a match using the node GUID */ if (device->ib_device->node_guid == cma_id->device->node_guid) - break; - } - - if (device == NULL) { - device = kzalloc(sizeof *device, GFP_KERNEL); - if (device == NULL) goto out; - /* assign this device to the device */ - device->ib_device = cma_id->device; - /* init the device and link it into ig device list */ - if (iser_create_device_ib_res(device)) { - kfree(device); - device = NULL; - goto out; - } - list_add(&device->ig_list, &ig.device_list); + + device = kzalloc(sizeof *device, GFP_KERNEL); + if (device == NULL) + goto out; + + /* assign this device to the device */ + device->ib_device = cma_id->device; + /* init the device and link it into ig device list */ + if (iser_create_device_ib_res(device)) { + kfree(device); + device = NULL; + goto out; } + list_add(&device->ig_list, &ig.device_list); + out: BUG_ON(device == NULL); device->refcount++; -- 1.5.3.6
I agree with your patch. It seems that we forgot to add something like p_list=p_list->next. Anyway, using list_for_each_entry is better than what we had.
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