1 /* 2 * zfcp device driver 3 * 4 * Tracking of manually configured LUNs and helper functions to 5 * register the LUNs with the SCSI midlayer. 6 * 7 * Copyright IBM Corp. 2010 8 */ 9 10 #include "zfcp_def.h" 11 #include "zfcp_ext.h" 12 13 /** 14 * zfcp_unit_scsi_scan - Register LUN with SCSI midlayer 15 * @unit: The zfcp LUN/unit to register 16 * 17 * When the SCSI midlayer is not allowed to automatically scan and 18 * attach SCSI devices, zfcp has to register the single devices with 19 * the SCSI midlayer. 20 */ 21 void zfcp_unit_scsi_scan(struct zfcp_unit *unit) 22 { 23 struct fc_rport *rport = unit->port->rport; 24 unsigned int lun; 25 26 lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun); 27 28 if (rport && rport->port_state == FC_PORTSTATE_ONLINE) 29 scsi_scan_target(&rport->dev, 0, rport->scsi_target_id, lun, 1); 30 } 31 32 static void zfcp_unit_scsi_scan_work(struct work_struct *work) 33 { 34 struct zfcp_unit *unit = container_of(work, struct zfcp_unit, 35 scsi_work); 36 37 zfcp_unit_scsi_scan(unit); 38 put_device(&unit->dev); 39 } 40 41 /** 42 * zfcp_unit_queue_scsi_scan - Register configured units on port 43 * @port: The zfcp_port where to register units 44 * 45 * After opening a port, all units configured on this port have to be 46 * registered with the SCSI midlayer. This function should be called 47 * after calling fc_remote_port_add, so that the fc_rport is already 48 * ONLINE and the call to scsi_scan_target runs the same way as the 49 * call in the FC transport class. 50 */ 51 void zfcp_unit_queue_scsi_scan(struct zfcp_port *port) 52 { 53 struct zfcp_unit *unit; 54 55 read_lock_irq(&port->unit_list_lock); 56 list_for_each_entry(unit, &port->unit_list, list) { 57 get_device(&unit->dev); 58 if (scsi_queue_work(port->adapter->scsi_host, 59 &unit->scsi_work) <= 0) 60 put_device(&unit->dev); 61 } 62 read_unlock_irq(&port->unit_list_lock); 63 } 64 65 static struct zfcp_unit *_zfcp_unit_find(struct zfcp_port *port, u64 fcp_lun) 66 { 67 struct zfcp_unit *unit; 68 69 list_for_each_entry(unit, &port->unit_list, list) 70 if (unit->fcp_lun == fcp_lun) { 71 get_device(&unit->dev); 72 return unit; 73 } 74 75 return NULL; 76 } 77 78 /** 79 * zfcp_unit_find - Find and return zfcp_unit with specified FCP LUN 80 * @port: zfcp_port where to look for the unit 81 * @fcp_lun: 64 Bit FCP LUN used to identify the zfcp_unit 82 * 83 * If zfcp_unit is found, a reference is acquired that has to be 84 * released later. 85 * 86 * Returns: Pointer to the zfcp_unit, or NULL if there is no zfcp_unit 87 * with the specified FCP LUN. 88 */ 89 struct zfcp_unit *zfcp_unit_find(struct zfcp_port *port, u64 fcp_lun) 90 { 91 struct zfcp_unit *unit; 92 93 read_lock_irq(&port->unit_list_lock); 94 unit = _zfcp_unit_find(port, fcp_lun); 95 read_unlock_irq(&port->unit_list_lock); 96 return unit; 97 } 98 99 /** 100 * zfcp_unit_release - Drop reference to zfcp_port and free memory of zfcp_unit. 101 * @dev: pointer to device in zfcp_unit 102 */ 103 static void zfcp_unit_release(struct device *dev) 104 { 105 struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev); 106 107 atomic_dec(&unit->port->units); 108 kfree(unit); 109 } 110 111 /** 112 * zfcp_unit_enqueue - enqueue unit to unit list of a port. 113 * @port: pointer to port where unit is added 114 * @fcp_lun: FCP LUN of unit to be enqueued 115 * Returns: 0 success 116 * 117 * Sets up some unit internal structures and creates sysfs entry. 118 */ 119 int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun) 120 { 121 struct zfcp_unit *unit; 122 int retval = 0; 123 124 mutex_lock(&zfcp_sysfs_port_units_mutex); 125 if (atomic_read(&port->units) == -1) { 126 /* port is already gone */ 127 retval = -ENODEV; 128 goto out; 129 } 130 131 unit = zfcp_unit_find(port, fcp_lun); 132 if (unit) { 133 put_device(&unit->dev); 134 retval = -EEXIST; 135 goto out; 136 } 137 138 unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL); 139 if (!unit) { 140 retval = -ENOMEM; 141 goto out; 142 } 143 144 unit->port = port; 145 unit->fcp_lun = fcp_lun; 146 unit->dev.parent = &port->dev; 147 unit->dev.release = zfcp_unit_release; 148 unit->dev.groups = zfcp_unit_attr_groups; 149 INIT_WORK(&unit->scsi_work, zfcp_unit_scsi_scan_work); 150 151 if (dev_set_name(&unit->dev, "0x%016llx", 152 (unsigned long long) fcp_lun)) { 153 kfree(unit); 154 retval = -ENOMEM; 155 goto out; 156 } 157 158 if (device_register(&unit->dev)) { 159 put_device(&unit->dev); 160 retval = -ENOMEM; 161 goto out; 162 } 163 164 atomic_inc(&port->units); /* under zfcp_sysfs_port_units_mutex ! */ 165 166 write_lock_irq(&port->unit_list_lock); 167 list_add_tail(&unit->list, &port->unit_list); 168 write_unlock_irq(&port->unit_list_lock); 169 170 zfcp_unit_scsi_scan(unit); 171 172 out: 173 mutex_unlock(&zfcp_sysfs_port_units_mutex); 174 return retval; 175 } 176 177 /** 178 * zfcp_unit_sdev - Return SCSI device for zfcp_unit 179 * @unit: The zfcp_unit where to get the SCSI device for 180 * 181 * Returns: scsi_device pointer on success, NULL if there is no SCSI 182 * device for this zfcp_unit 183 * 184 * On success, the caller also holds a reference to the SCSI device 185 * that must be released with scsi_device_put. 186 */ 187 struct scsi_device *zfcp_unit_sdev(struct zfcp_unit *unit) 188 { 189 struct Scsi_Host *shost; 190 struct zfcp_port *port; 191 unsigned int lun; 192 193 lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun); 194 port = unit->port; 195 shost = port->adapter->scsi_host; 196 return scsi_device_lookup(shost, 0, port->starget_id, lun); 197 } 198 199 /** 200 * zfcp_unit_sdev_status - Return zfcp LUN status for SCSI device 201 * @unit: The unit to lookup the SCSI device for 202 * 203 * Returns the zfcp LUN status field of the SCSI device if the SCSI device 204 * for the zfcp_unit exists, 0 otherwise. 205 */ 206 unsigned int zfcp_unit_sdev_status(struct zfcp_unit *unit) 207 { 208 unsigned int status = 0; 209 struct scsi_device *sdev; 210 struct zfcp_scsi_dev *zfcp_sdev; 211 212 sdev = zfcp_unit_sdev(unit); 213 if (sdev) { 214 zfcp_sdev = sdev_to_zfcp(sdev); 215 status = atomic_read(&zfcp_sdev->status); 216 scsi_device_put(sdev); 217 } 218 219 return status; 220 } 221 222 /** 223 * zfcp_unit_remove - Remove entry from list of configured units 224 * @port: The port where to remove the unit from the configuration 225 * @fcp_lun: The 64 bit LUN of the unit to remove 226 * 227 * Returns: -EINVAL if a unit with the specified LUN does not exist, 228 * 0 on success. 229 */ 230 int zfcp_unit_remove(struct zfcp_port *port, u64 fcp_lun) 231 { 232 struct zfcp_unit *unit; 233 struct scsi_device *sdev; 234 235 write_lock_irq(&port->unit_list_lock); 236 unit = _zfcp_unit_find(port, fcp_lun); 237 if (unit) 238 list_del(&unit->list); 239 write_unlock_irq(&port->unit_list_lock); 240 241 if (!unit) 242 return -EINVAL; 243 244 sdev = zfcp_unit_sdev(unit); 245 if (sdev) { 246 scsi_remove_device(sdev); 247 scsi_device_put(sdev); 248 } 249 250 put_device(&unit->dev); 251 252 device_unregister(&unit->dev); 253 254 return 0; 255 } 256