From: Alexander Chiang Date: Tue, 2 Feb 2010 19:08:30 +0000 (+0000) Subject: IB/umad: Remove port_table[] X-Git-Tag: v2.6.34-rc1~225^2~18 X-Git-Url: http://git.cascardo.eti.br/?a=commitdiff_plain;h=6aa2a86ec430fb1ae739bd065d7ea6596997a2cf;p=cascardo%2Flinux.git IB/umad: Remove port_table[] We no longer need this data structure, as it was used to associate an inode back to a struct ib_umad_port during ->open(). But now that we're embedding a struct cdev in struct ib_umad_port, we can use the container_of() macro to go from the inode back to the device instead. Signed-off-by: Alex Chiang Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c index 40440ef1b31c..46c88795cc75 100644 --- a/drivers/infiniband/core/user_mad.c +++ b/drivers/infiniband/core/user_mad.c @@ -65,12 +65,9 @@ enum { }; /* - * Our lifetime rules for these structs are the following: each time a - * device special file is opened, we look up the corresponding struct - * ib_umad_port by minor in the umad_port[] table while holding the - * port_lock. If this lookup succeeds, we take a reference on the - * ib_umad_port's struct ib_umad_device while still holding the - * port_lock; if the lookup fails, we fail the open(). We drop these + * Our lifetime rules for these structs are the following: + * device special file is opened, we take a reference on the + * ib_umad_port's struct ib_umad_device. We drop these * references in the corresponding close(). * * In addition to references coming from open character devices, there @@ -78,12 +75,7 @@ enum { * module's reference taken when allocating the ib_umad_device in * ib_umad_add_one(). * - * When destroying an ib_umad_device, we clear all of its - * ib_umad_ports from umad_port[] while holding port_lock before - * dropping the module's reference to the ib_umad_device. This is - * always safe because any open() calls will either succeed and obtain - * a reference before we clear the umad_port[] entries, or fail after - * we clear the umad_port[] entries. + * When destroying an ib_umad_device, we drop the module's reference. */ struct ib_umad_port { @@ -136,7 +128,6 @@ static struct class *umad_class; static const dev_t base_dev = MKDEV(IB_UMAD_MAJOR, IB_UMAD_MINOR_BASE); static DEFINE_SPINLOCK(port_lock); -static struct ib_umad_port *umad_port[IB_UMAD_MAX_PORTS]; static DECLARE_BITMAP(dev_map, IB_UMAD_MAX_PORTS); static void ib_umad_add_one(struct ib_device *device); @@ -779,15 +770,11 @@ static long ib_umad_compat_ioctl(struct file *filp, unsigned int cmd, /* * 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 + * - 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) { @@ -795,13 +782,10 @@ static int ib_umad_open(struct inode *inode, struct file *filp) struct ib_umad_file *file; int ret = 0; - spin_lock(&port_lock); - port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE]; + port = container_of(inode->i_cdev, struct ib_umad_port, cdev); if (port) kref_get(&port->umad_dev->ref); - spin_unlock(&port_lock); - - if (!port) + else return -ENXIO; mutex_lock(&port->file_mutex); @@ -892,13 +876,10 @@ static int ib_umad_sm_open(struct inode *inode, struct file *filp) }; int ret; - spin_lock(&port_lock); - port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE - IB_UMAD_MAX_PORTS]; + port = container_of(inode->i_cdev, struct ib_umad_port, sm_cdev); if (port) kref_get(&port->umad_dev->ref); - spin_unlock(&port_lock); - - if (!port) + else return -ENXIO; if (filp->f_flags & O_NONBLOCK) { @@ -1042,10 +1023,6 @@ static int ib_umad_init_port(struct ib_device *device, int port_num, if (device_create_file(port->sm_dev, &dev_attr_port)) goto err_sm_dev; - spin_lock(&port_lock); - umad_port[port->dev_num] = port; - spin_unlock(&port_lock); - return 0; err_sm_dev: @@ -1079,10 +1056,6 @@ static void ib_umad_kill_port(struct ib_umad_port *port) cdev_del(&port->cdev); cdev_del(&port->sm_cdev); - spin_lock(&port_lock); - umad_port[port->dev_num] = NULL; - spin_unlock(&port_lock); - mutex_lock(&port->file_mutex); port->ib_dev = NULL;