Merge commit 'v2.6.26' into bkl-removal

[linux-2.6-omap-h63xx.git] / drivers / infiniband / core / user_mad.c

diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 840ede9ae965e2cfafd9766a91292e60910b2f1c..208c7f34323ccc372c4618dac9808badff6151b2 100644 (file)
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -777,6 +777,19 @@ static long ib_umad_compat_ioctl(struct file *filp, unsigned int cmd,
 }
 #endif
 
+/*
+ * ib_umad_open() does not need the BKL:
+ *
+ *  - umad_port[] accesses are protected by port_lock, the
+ *    ib_umad_port structures are properly reference counted, and
+ *    everything else is purely local to the file being created, so
+ *    races against other open calls are not a problem;
+ *  - the ioctl method does not affect any global state outside of the
+ *    file structure being operated on;
+ *  - the port is added to umad_port[] as the last part of module
+ *    initialization so the open method will either immediately run
+ *    -ENXIO, or all required initialization will be done.
+ */
 static int ib_umad_open(struct inode *inode, struct file *filp)
 {
        struct ib_umad_port *port;