staging/rdma/hfi1: Reduce snoop locking scope in IOCTL handler.

This patch avoids issues while calling into copy from/to user while holding the
lock by only taking the lock when it is absolutely required.

The only commands which require the snoop lock are: *Set Filter *Clear Filter
*Clear Queue

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/rdma/hfi1/diag.c b/drivers/staging/rdma/hfi1/diag.c
index ccc5aec..b0b7e28 100644 (file)
--- a/drivers/staging/rdma/hfi1/diag.c
+++ b/drivers/staging/rdma/hfi1/diag.c
@@ -1012,8 +1012,6 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
                 */
                return -EINVAL;
 
-       spin_lock_irqsave(&dd->hfi1_snoop.snoop_lock, flags);
-
        switch (cmd) {
        case HFI1_SNOOP_IOCSETLINKSTATE_EXTRA:
                memset(&link_info, 0, sizeof(link_info));
@@ -1130,11 +1128,14 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 
        case HFI1_SNOOP_IOCCLEARQUEUE:
                snoop_dbg("Clearing snoop queue");
+               spin_lock_irqsave(&dd->hfi1_snoop.snoop_lock, flags);
                drain_snoop_list(&dd->hfi1_snoop.queue);
+               spin_unlock_irqrestore(&dd->hfi1_snoop.snoop_lock, flags);
                break;
 
        case HFI1_SNOOP_IOCCLEARFILTER:
                snoop_dbg("Clearing filter");
+               spin_lock_irqsave(&dd->hfi1_snoop.snoop_lock, flags);
                if (dd->hfi1_snoop.filter_callback) {
                        /* Drain packets first */
                        drain_snoop_list(&dd->hfi1_snoop.queue);
@@ -1142,6 +1143,7 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
                }
                kfree(dd->hfi1_snoop.filter_value);
                dd->hfi1_snoop.filter_value = NULL;
+               spin_unlock_irqrestore(&dd->hfi1_snoop.snoop_lock, flags);
                break;
 
        case HFI1_SNOOP_IOCSETFILTER:
@@ -1178,13 +1180,14 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
                        break;
                }
                /* Drain packets first */
+               spin_lock_irqsave(&dd->hfi1_snoop.snoop_lock, flags);
                drain_snoop_list(&dd->hfi1_snoop.queue);
                dd->hfi1_snoop.filter_callback =
                        hfi1_filters[filter_cmd.opcode].filter;
                /* just in case we see back to back sets */
                kfree(dd->hfi1_snoop.filter_value);
                dd->hfi1_snoop.filter_value = filter_value;
-
+               spin_unlock_irqrestore(&dd->hfi1_snoop.snoop_lock, flags);
                break;
        case HFI1_SNOOP_IOCGETVERSION:
                value = SNOOP_CAPTURE_VERSION;
@@ -1208,7 +1211,6 @@ static long hfi1_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
                break;
        }
 done:
-       spin_unlock_irqrestore(&dd->hfi1_snoop.snoop_lock, flags);
        return ret;
 }