From 0c99cb6d5fe77872c5a32cff837c05f70158ce15 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Thu, 3 Nov 2005 12:01:18 -0800 Subject: [PATCH] [IB] umad: fix hot remove of IB devices Fix hotplug of devices for ib_umad module: when a device goes away, kill off all MAD agents for open files associated with that device, and make sure that the device is not touched again after ib_umad returns from its remove_one function. Signed-off-by: Roland Dreier --- drivers/infiniband/core/user_mad.c | 80 ++++++++++++++++++++++++------ 1 file changed, 64 insertions(+), 16 deletions(-) diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c index 97128e25f78b..aed5ca23fb22 100644 --- a/drivers/infiniband/core/user_mad.c +++ b/drivers/infiniband/core/user_mad.c @@ -94,6 +94,9 @@ struct ib_umad_port { struct class_device *sm_class_dev; struct semaphore sm_sem; + struct rw_semaphore mutex; + struct list_head file_list; + struct ib_device *ib_dev; struct ib_umad_device *umad_dev; int dev_num; @@ -108,10 +111,10 @@ struct ib_umad_device { struct ib_umad_file { struct ib_umad_port *port; - spinlock_t recv_lock; struct list_head recv_list; + struct list_head port_list; + spinlock_t recv_lock; wait_queue_head_t recv_wait; - struct rw_semaphore agent_mutex; struct ib_mad_agent *agent[IB_UMAD_MAX_AGENTS]; struct ib_mr *mr[IB_UMAD_MAX_AGENTS]; }; @@ -148,7 +151,7 @@ static int queue_packet(struct ib_umad_file *file, { int ret = 1; - down_read(&file->agent_mutex); + down_read(&file->port->mutex); for (packet->mad.hdr.id = 0; packet->mad.hdr.id < IB_UMAD_MAX_AGENTS; packet->mad.hdr.id++) @@ -161,7 +164,7 @@ static int queue_packet(struct ib_umad_file *file, break; } - up_read(&file->agent_mutex); + up_read(&file->port->mutex); return ret; } @@ -322,7 +325,7 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf, goto err; } - down_read(&file->agent_mutex); + down_read(&file->port->mutex); agent = file->agent[packet->mad.hdr.id]; if (!agent) { @@ -419,7 +422,7 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf, if (ret) goto err_msg; - up_read(&file->agent_mutex); + up_read(&file->port->mutex); return count; @@ -430,7 +433,7 @@ err_ah: ib_destroy_ah(ah); err_up: - up_read(&file->agent_mutex); + up_read(&file->port->mutex); err: kfree(packet); @@ -460,7 +463,12 @@ static int ib_umad_reg_agent(struct ib_umad_file *file, unsigned long arg) int agent_id; int ret; - down_write(&file->agent_mutex); + down_write(&file->port->mutex); + + if (!file->port->ib_dev) { + ret = -EPIPE; + goto out; + } if (copy_from_user(&ureq, (void __user *) arg, sizeof ureq)) { ret = -EFAULT; @@ -522,7 +530,7 @@ err: ib_unregister_mad_agent(agent); out: - up_write(&file->agent_mutex); + up_write(&file->port->mutex); return ret; } @@ -531,7 +539,7 @@ static int ib_umad_unreg_agent(struct ib_umad_file *file, unsigned long arg) u32 id; int ret = 0; - down_write(&file->agent_mutex); + down_write(&file->port->mutex); if (get_user(id, (u32 __user *) arg)) { ret = -EFAULT; @@ -548,7 +556,7 @@ static int ib_umad_unreg_agent(struct ib_umad_file *file, unsigned long arg) file->agent[id] = NULL; out: - up_write(&file->agent_mutex); + up_write(&file->port->mutex); return ret; } @@ -569,6 +577,7 @@ static int ib_umad_open(struct inode *inode, struct file *filp) { struct ib_umad_port *port; struct ib_umad_file *file; + int ret = 0; spin_lock(&port_lock); port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE]; @@ -579,21 +588,32 @@ static int ib_umad_open(struct inode *inode, struct file *filp) if (!port) return -ENXIO; + down_write(&port->mutex); + + if (!port->ib_dev) { + ret = -ENXIO; + goto out; + } + file = kzalloc(sizeof *file, GFP_KERNEL); if (!file) { kref_put(&port->umad_dev->ref, ib_umad_release_dev); - return -ENOMEM; + ret = -ENOMEM; + goto out; } spin_lock_init(&file->recv_lock); - init_rwsem(&file->agent_mutex); INIT_LIST_HEAD(&file->recv_list); init_waitqueue_head(&file->recv_wait); file->port = port; filp->private_data = file; - return 0; + list_add_tail(&file->port_list, &port->file_list); + +out: + up_write(&port->mutex); + return ret; } static int ib_umad_close(struct inode *inode, struct file *filp) @@ -603,6 +623,7 @@ static int ib_umad_close(struct inode *inode, struct file *filp) struct ib_umad_packet *packet, *tmp; int i; + down_write(&file->port->mutex); for (i = 0; i < IB_UMAD_MAX_AGENTS; ++i) if (file->agent[i]) { ib_dereg_mr(file->mr[i]); @@ -612,6 +633,9 @@ static int ib_umad_close(struct inode *inode, struct file *filp) list_for_each_entry_safe(packet, tmp, &file->recv_list, list) kfree(packet); + list_del(&file->port_list); + up_write(&file->port->mutex); + kfree(file); kref_put(&dev->ref, ib_umad_release_dev); @@ -680,9 +704,13 @@ static int ib_umad_sm_close(struct inode *inode, struct file *filp) struct ib_port_modify props = { .clr_port_cap_mask = IB_PORT_SM }; - int ret; + int ret = 0; + + down_write(&port->mutex); + if (port->ib_dev) + ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props); + up_write(&port->mutex); - ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props); up(&port->sm_sem); kref_put(&port->umad_dev->ref, ib_umad_release_dev); @@ -745,6 +773,8 @@ static int ib_umad_init_port(struct ib_device *device, int port_num, port->ib_dev = device; port->port_num = port_num; init_MUTEX(&port->sm_sem); + init_rwsem(&port->mutex); + INIT_LIST_HEAD(&port->file_list); port->dev = cdev_alloc(); if (!port->dev) @@ -813,6 +843,9 @@ err_cdev: static void ib_umad_kill_port(struct ib_umad_port *port) { + struct ib_umad_file *file; + int id; + class_set_devdata(port->class_dev, NULL); class_set_devdata(port->sm_class_dev, NULL); @@ -826,6 +859,21 @@ static void ib_umad_kill_port(struct ib_umad_port *port) umad_port[port->dev_num] = NULL; spin_unlock(&port_lock); + down_write(&port->mutex); + + port->ib_dev = NULL; + + list_for_each_entry(file, &port->file_list, port_list) + for (id = 0; id < IB_UMAD_MAX_AGENTS; ++id) { + if (!file->agent[id]) + continue; + ib_dereg_mr(file->mr[id]); + ib_unregister_mad_agent(file->agent[id]); + file->agent[id] = NULL; + } + + up_write(&port->mutex); + clear_bit(port->dev_num, dev_map); }