Hello James Smart,
The patch e0063f4ad51c: "scsi: lpfc: Commonize VMID code location"
from May 10, 2022, leads to the following Smatch static checker
warning:
drivers/scsi/lpfc/lpfc_vmid.c:248 lpfc_vmid_get_appid()
warn: sleeping in atomic context
drivers/scsi/lpfc/lpfc_vmid.c
192 } else {
193 /* The VMID was not found in the hashtable. At this point, */
194 /* drop the read lock first before proceeding further */
195 read_unlock(&vport->vmid_lock);
196 /* start the process to obtain one as per the */
197 /* type of the VMID indicated */
198 write_lock(&vport->vmid_lock);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Holding a spin lock (write lock) disabled preemption
199 vmp = lpfc_get_vmid_from_hashtable(vport, hash, uuid);
200
201 /* while the read lock was released, in case the entry was */
202 /* added by other context or is in process of being added */
203 if (vmp && vmp->flag & LPFC_VMID_REGISTERED) {
204 lpfc_vmid_update_entry(vport, iodir, vmp, tag);
205 write_unlock(&vport->vmid_lock);
206 return 0;
207 } else if (vmp && vmp->flag & LPFC_VMID_REQ_REGISTER) {
208 write_unlock(&vport->vmid_lock);
209 return -EBUSY;
210 }
211
212 /* else search and allocate a free slot in the hash table */
213 if (vport->cur_vmid_cnt < vport->max_vmid) {
214 for (i = 0; i < vport->max_vmid; i++) {
215 vmp = vport->vmid + i;
216 if (vmp->flag == LPFC_VMID_SLOT_FREE)
217 break;
218 }
219 if (i == vport->max_vmid)
220 vmp = NULL;
221 } else {
222 vmp = NULL;
223 }
224
225 if (!vmp) {
226 write_unlock(&vport->vmid_lock);
227 return -ENOMEM;
228 }
229
230 /* Add the vmid and register */
231 lpfc_put_vmid_in_hashtable(vport, hash, vmp);
232 vmp->vmid_len = len;
233 memcpy(vmp->host_vmid, uuid, vmp->vmid_len);
234 vmp->io_rd_cnt = 0;
235 vmp->io_wr_cnt = 0;
236 vmp->flag = LPFC_VMID_SLOT_USED;
237
238 vmp->delete_inactive =
239 vport->vmid_inactivity_timeout ? 1 : 0;
240
241 /* if type priority tag, get next available VMID */
242 if (vport->phba->pport->vmid_flag & LPFC_VMID_TYPE_PRIO)
243 lpfc_vmid_assign_cs_ctl(vport, vmp);
244
245 /* allocate the per cpu variable for holding */
246 /* the last access time stamp only if VMID is enabled */
247 if (!vmp->last_io_time)
--> 248 vmp->last_io_time = __alloc_percpu(sizeof(u64),
^^^^^^^^^^^^^^^
Sleeps
249 __alignof__(struct
250 lpfc_vmid));
251 if (!vmp->last_io_time) {
252 hash_del(&vmp->hnode);
253 vmp->flag = LPFC_VMID_SLOT_FREE;
254 write_unlock(&vport->vmid_lock);
255 return -EIO;
256 }
257
258 write_unlock(&vport->vmid_lock);
259
260 /* complete transaction with switch */
261 if (vport->phba->pport->vmid_flag & LPFC_VMID_TYPE_PRIO)
262 rc = lpfc_vmid_uvem(vport, vmp, true);
263 else if (vport->phba->cfg_vmid_app_header)
264 rc = lpfc_vmid_cmd(vport, SLI_CTAS_RAPP_IDENT, vmp);
265 if (!rc) {
266 write_lock(&vport->vmid_lock);
267 vport->cur_vmid_cnt++;
268 vmp->flag |= LPFC_VMID_REQ_REGISTER;
269 write_unlock(&vport->vmid_lock);
270 } else {
271 write_lock(&vport->vmid_lock);
272 hash_del(&vmp->hnode);
273 vmp->flag = LPFC_VMID_SLOT_FREE;
274 free_percpu(vmp->last_io_time);
275 write_unlock(&vport->vmid_lock);
276 return -EIO;
277 }
278
279 /* finally, enable the idle timer once */
280 if (!(vport->phba->pport->vmid_flag & LPFC_VMID_TIMER_ENBLD)) {
281 mod_timer(&vport->phba->inactive_vmid_poll,
282 jiffies +
283 msecs_to_jiffies(1000 * LPFC_VMID_TIMER));
284 vport->phba->pport->vmid_flag |= LPFC_VMID_TIMER_ENBLD;
285 }
286 }
287 return rc;
288 }
regards,
dan carpenter
