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 Corporation 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 */
zfcp_unit_scsi_scan(struct zfcp_unit * unit)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
zfcp_unit_scsi_scan_work(struct work_struct * work)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 */
zfcp_unit_queue_scsi_scan(struct zfcp_port * port)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
_zfcp_unit_find(struct zfcp_port * port,u64 fcp_lun)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 */
zfcp_unit_find(struct zfcp_port * port,u64 fcp_lun)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 */
zfcp_unit_release(struct device * dev)103 static void zfcp_unit_release(struct device *dev)
104 {
105 struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev);
106
107 put_device(&unit->port->dev);
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 */
zfcp_unit_add(struct zfcp_port * port,u64 fcp_lun)119 int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun)
120 {
121 struct zfcp_unit *unit;
122
123 unit = zfcp_unit_find(port, fcp_lun);
124 if (unit) {
125 put_device(&unit->dev);
126 return -EEXIST;
127 }
128
129 unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
130 if (!unit)
131 return -ENOMEM;
132
133 unit->port = port;
134 unit->fcp_lun = fcp_lun;
135 unit->dev.parent = &port->dev;
136 unit->dev.release = zfcp_unit_release;
137 INIT_WORK(&unit->scsi_work, zfcp_unit_scsi_scan_work);
138
139 if (dev_set_name(&unit->dev, "0x%016llx",
140 (unsigned long long) fcp_lun)) {
141 kfree(unit);
142 return -ENOMEM;
143 }
144
145 get_device(&port->dev);
146
147 if (device_register(&unit->dev)) {
148 put_device(&unit->dev);
149 return -ENOMEM;
150 }
151
152 if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs)) {
153 device_unregister(&unit->dev);
154 return -EINVAL;
155 }
156
157 write_lock_irq(&port->unit_list_lock);
158 list_add_tail(&unit->list, &port->unit_list);
159 write_unlock_irq(&port->unit_list_lock);
160
161 zfcp_unit_scsi_scan(unit);
162
163 return 0;
164 }
165
166 /**
167 * zfcp_unit_sdev - Return SCSI device for zfcp_unit
168 * @unit: The zfcp_unit where to get the SCSI device for
169 *
170 * Returns: scsi_device pointer on success, NULL if there is no SCSI
171 * device for this zfcp_unit
172 *
173 * On success, the caller also holds a reference to the SCSI device
174 * that must be released with scsi_device_put.
175 */
zfcp_unit_sdev(struct zfcp_unit * unit)176 struct scsi_device *zfcp_unit_sdev(struct zfcp_unit *unit)
177 {
178 struct Scsi_Host *shost;
179 struct zfcp_port *port;
180 unsigned int lun;
181
182 lun = scsilun_to_int((struct scsi_lun *) &unit->fcp_lun);
183 port = unit->port;
184 shost = port->adapter->scsi_host;
185 return scsi_device_lookup(shost, 0, port->starget_id, lun);
186 }
187
188 /**
189 * zfcp_unit_sdev_status - Return zfcp LUN status for SCSI device
190 * @unit: The unit to lookup the SCSI device for
191 *
192 * Returns the zfcp LUN status field of the SCSI device if the SCSI device
193 * for the zfcp_unit exists, 0 otherwise.
194 */
zfcp_unit_sdev_status(struct zfcp_unit * unit)195 unsigned int zfcp_unit_sdev_status(struct zfcp_unit *unit)
196 {
197 unsigned int status = 0;
198 struct scsi_device *sdev;
199 struct zfcp_scsi_dev *zfcp_sdev;
200
201 sdev = zfcp_unit_sdev(unit);
202 if (sdev) {
203 zfcp_sdev = sdev_to_zfcp(sdev);
204 status = atomic_read(&zfcp_sdev->status);
205 scsi_device_put(sdev);
206 }
207
208 return status;
209 }
210
211 /**
212 * zfcp_unit_remove - Remove entry from list of configured units
213 * @port: The port where to remove the unit from the configuration
214 * @fcp_lun: The 64 bit LUN of the unit to remove
215 *
216 * Returns: -EINVAL if a unit with the specified LUN does not exist,
217 * 0 on success.
218 */
zfcp_unit_remove(struct zfcp_port * port,u64 fcp_lun)219 int zfcp_unit_remove(struct zfcp_port *port, u64 fcp_lun)
220 {
221 struct zfcp_unit *unit;
222 struct scsi_device *sdev;
223
224 write_lock_irq(&port->unit_list_lock);
225 unit = _zfcp_unit_find(port, fcp_lun);
226 if (unit)
227 list_del(&unit->list);
228 write_unlock_irq(&port->unit_list_lock);
229
230 if (!unit)
231 return -EINVAL;
232
233 sdev = zfcp_unit_sdev(unit);
234 if (sdev) {
235 scsi_remove_device(sdev);
236 scsi_device_put(sdev);
237 }
238
239 put_device(&unit->dev);
240
241 zfcp_device_unregister(&unit->dev, &zfcp_sysfs_unit_attrs);
242
243 return 0;
244 }
245