4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, 2014, Intel Corporation.
28 * Copyright 2017 Cray Inc, all rights reserved.
31 * Store PID->JobID mappings
34 #define DEBUG_SUBSYSTEM S_RPC
35 #include <linux/user_namespace.h>
36 #ifdef HAVE_UIDGID_HEADER
37 #include <linux/uidgid.h>
39 #include <linux/utsname.h>
41 #include <libcfs/libcfs.h>
42 #include <obd_support.h>
43 #include <obd_class.h>
44 #include <lustre_net.h>
46 static struct cfs_hash *jobid_hash;
47 static struct cfs_hash_ops jobid_hash_ops;
48 spinlock_t jobid_hash_lock;
50 #define RESCAN_INTERVAL 30
51 #define DELETE_INTERVAL 300
53 char obd_jobid_var[JOBSTATS_JOBID_VAR_MAX_LEN + 1] = JOBSTATS_DISABLE;
54 char obd_jobid_name[LUSTRE_JOBID_SIZE] = "%e.%u";
57 * Structure to store a single PID->JobID mapping
59 struct jobid_pid_map {
60 struct hlist_node jp_hash;
62 spinlock_t jp_lock; /* protects jp_jobid */
63 char jp_jobid[LUSTRE_JOBID_SIZE];
64 unsigned int jp_joblen;
70 * Get jobid of current process by reading the environment variable
71 * stored in between the "env_start" & "env_end" of task struct.
73 * If some job scheduler doesn't store jobid in the "env_start/end",
74 * then an upcall could be issued here to get the jobid by utilizing
75 * the userspace tools/API. Then, the jobid must be cached.
77 int jobid_get_from_environ(char *jobid_var, char *jobid, int *jobid_len)
82 rc = cfs_get_environ(jobid_var, jobid, jobid_len);
86 if (unlikely(rc == -EOVERFLOW && !printed)) {
87 /* For the PBS_JOBID and LOADL_STEP_ID keys (which are
88 * variable length strings instead of just numbers), it
89 * might make sense to keep the unique parts for JobID,
90 * instead of just returning an error. That means a
91 * larger temp buffer for cfs_get_environ(), then
92 * truncating the string at some separator to fit into
93 * the specified jobid_len. Fix later if needed. */
94 LCONSOLE_WARN("jobid: '%s' value too large (%d)\n",
95 obd_jobid_var, *jobid_len);
100 CDEBUG((rc == -ENOENT || rc == -EINVAL ||
101 rc == -EDEADLK) ? D_INFO : D_ERROR,
102 "jobid: get '%s' failed: rc = %d\n",
111 * jobid_should_free_item
113 * Each item is checked to see if it should be released
114 * Removed from hash table by caller
115 * Actually freed in jobid_put_locked
117 * Returns 1 if item is to be freed, 0 if it is to be kept
120 static int jobid_should_free_item(void *obj, void *data)
123 struct jobid_pid_map *pidmap = obj;
129 spin_lock(&pidmap->jp_lock);
132 else if (jobid[0] == '\0')
134 else if (ktime_get_real_seconds() - pidmap->jp_time > DELETE_INTERVAL)
136 else if (strcmp(pidmap->jp_jobid, jobid) == 0)
138 spin_unlock(&pidmap->jp_lock);
144 * jobid_name_is_valid
146 * Checks if the jobid is a Lustre process
148 * Returns true if jobid is valid
149 * Returns false if jobid looks like it's a Lustre process
151 static bool jobid_name_is_valid(char *jobid)
153 const char *const lustre_reserved[] = { "ll_ping", "ptlrpc",
154 "ldlm", "ll_sa", NULL };
157 if (jobid[0] == '\0')
160 for (i = 0; lustre_reserved[i] != NULL; i++) {
161 if (strncmp(jobid, lustre_reserved[i],
162 strlen(lustre_reserved[i])) == 0)
169 * jobid_get_from_cache()
171 * Returns contents of jobid_var from process environment for current PID.
172 * This will be cached for some time to avoid overhead scanning environment.
174 * Return: -ENOMEM if allocating a new pidmap fails
175 * -ENOENT if no entry could be found
176 * +ve string length for success (something was returned in jobid)
178 static int jobid_get_from_cache(char *jobid, size_t joblen)
180 static time64_t last_expire;
181 bool expire_cache = false;
182 pid_t pid = current_pid();
183 struct jobid_pid_map *pidmap = NULL;
184 time64_t now = ktime_get_real_seconds();
188 LASSERT(jobid_hash != NULL);
190 /* scan hash periodically to remove old PID entries from cache */
191 spin_lock(&jobid_hash_lock);
192 if (unlikely(last_expire + DELETE_INTERVAL <= now)) {
196 spin_unlock(&jobid_hash_lock);
199 cfs_hash_cond_del(jobid_hash, jobid_should_free_item,
200 "intentionally_bad_jobid");
202 /* first try to find PID in the hash and use that value */
203 pidmap = cfs_hash_lookup(jobid_hash, &pid);
204 if (pidmap == NULL) {
205 struct jobid_pid_map *pidmap2;
207 OBD_ALLOC_PTR(pidmap);
209 GOTO(out, rc = -ENOMEM);
211 pidmap->jp_pid = pid;
213 pidmap->jp_jobid[0] = '\0';
214 spin_lock_init(&pidmap->jp_lock);
215 INIT_HLIST_NODE(&pidmap->jp_hash);
218 * Add the newly created map to the hash, on key collision we
219 * lost a racing addition and must destroy our newly allocated
220 * map. The object which exists in the hash will be returned.
222 pidmap2 = cfs_hash_findadd_unique(jobid_hash, &pid,
224 if (unlikely(pidmap != pidmap2)) {
225 CDEBUG(D_INFO, "jobid: duplicate found for PID=%u\n",
227 OBD_FREE_PTR(pidmap);
230 cfs_hash_get(jobid_hash, &pidmap->jp_hash);
235 * If pidmap is old (this is always true for new entries) refresh it.
236 * If obd_jobid_var is not found, cache empty entry and try again
237 * later, to avoid repeat lookups for PID if obd_jobid_var missing.
239 spin_lock(&pidmap->jp_lock);
240 if (pidmap->jp_time + RESCAN_INTERVAL <= now) {
241 char env_jobid[LUSTRE_JOBID_SIZE] = "";
242 int env_len = sizeof(env_jobid);
244 pidmap->jp_time = now;
246 spin_unlock(&pidmap->jp_lock);
247 rc = jobid_get_from_environ(obd_jobid_var, env_jobid, &env_len);
249 CDEBUG(D_INFO, "jobid: PID mapping established: %d->%s\n",
250 pidmap->jp_pid, env_jobid);
251 spin_lock(&pidmap->jp_lock);
253 pidmap->jp_joblen = env_len;
254 strlcpy(pidmap->jp_jobid, env_jobid,
255 sizeof(pidmap->jp_jobid));
257 } else if (rc == -ENOENT) {
258 /* It might have been deleted, clear out old entry */
259 pidmap->jp_joblen = 0;
260 pidmap->jp_jobid[0] = '\0';
265 * Regardless of how pidmap was found, if it contains a valid entry
266 * use that for now. If there was a technical error (e.g. -ENOMEM)
267 * use the old cached value until it can be looked up again properly.
268 * If a cached missing entry was found, return -ENOENT.
270 if (pidmap->jp_joblen) {
271 strlcpy(jobid, pidmap->jp_jobid, joblen);
272 joblen = pidmap->jp_joblen;
277 spin_unlock(&pidmap->jp_lock);
279 cfs_hash_put(jobid_hash, &pidmap->jp_hash);
283 return rc < 0 ? rc : joblen;
287 * jobid_interpret_string()
289 * Interpret the jobfmt string to expand specified fields, like coredumps do:
293 * %j = jobid from environment
297 * Unknown escape strings are dropped. Other characters are copied through,
298 * excluding whitespace (to avoid making jobid parsing difficult).
300 * Return: -EOVERFLOW if the expanded string does not fit within @joblen
303 static int jobid_interpret_string(const char *jobfmt, char *jobid,
308 while ((c = *jobfmt++) && joblen > 1) {
312 if (isspace(c)) /* Don't allow embedded spaces */
322 switch ((f = *jobfmt++)) {
323 case 'e': /* executable name */
324 l = snprintf(jobid, joblen, "%s", current_comm());
326 case 'g': /* group ID */
327 l = snprintf(jobid, joblen, "%u",
328 from_kgid(&init_user_ns, current_fsgid()));
330 case 'h': /* hostname */
331 l = snprintf(jobid, joblen, "%s",
332 init_utsname()->nodename);
334 case 'j': /* jobid stored in process environment */
335 l = jobid_get_from_cache(jobid, joblen);
339 case 'p': /* process ID */
340 l = snprintf(jobid, joblen, "%u", current_pid());
342 case 'u': /* user ID */
343 l = snprintf(jobid, joblen, "%u",
344 from_kuid(&init_user_ns, current_fsuid()));
346 case '\0': /* '%' at end of format string */
349 default: /* drop unknown %x format strings */
357 * This points at the end of the buffer, so long as jobid is always
358 * incremented the same amount as joblen is decremented.
361 jobid[joblen - 1] = '\0';
363 return joblen < 0 ? -EOVERFLOW : 0;
367 * Hash initialization, copied from server-side job stats bucket sizes
369 #define HASH_JOBID_BKT_BITS 5
370 #define HASH_JOBID_CUR_BITS 7
371 #define HASH_JOBID_MAX_BITS 12
373 int jobid_cache_init(void)
381 spin_lock_init(&jobid_hash_lock);
382 jobid_hash = cfs_hash_create("JOBID_HASH", HASH_JOBID_CUR_BITS,
383 HASH_JOBID_MAX_BITS, HASH_JOBID_BKT_BITS,
384 0, CFS_HASH_MIN_THETA, CFS_HASH_MAX_THETA,
385 &jobid_hash_ops, CFS_HASH_DEFAULT);
391 EXPORT_SYMBOL(jobid_cache_init);
393 void jobid_cache_fini(void)
395 struct cfs_hash *tmp_hash;
398 spin_lock(&jobid_hash_lock);
399 tmp_hash = jobid_hash;
401 spin_unlock(&jobid_hash_lock);
403 if (tmp_hash != NULL) {
404 cfs_hash_cond_del(tmp_hash, jobid_should_free_item, NULL);
405 cfs_hash_putref(tmp_hash);
410 EXPORT_SYMBOL(jobid_cache_fini);
413 * Hash operations for pid<->jobid
415 static unsigned jobid_hashfn(struct cfs_hash *hs, const void *key,
418 return cfs_hash_djb2_hash(key, sizeof(pid_t), mask);
421 static void *jobid_key(struct hlist_node *hnode)
423 struct jobid_pid_map *pidmap;
425 pidmap = hlist_entry(hnode, struct jobid_pid_map, jp_hash);
426 return &pidmap->jp_pid;
429 static int jobid_keycmp(const void *key, struct hlist_node *hnode)
431 const pid_t *pid_key1;
432 const pid_t *pid_key2;
434 LASSERT(key != NULL);
435 pid_key1 = (pid_t *)key;
436 pid_key2 = (pid_t *)jobid_key(hnode);
438 return *pid_key1 == *pid_key2;
441 static void *jobid_object(struct hlist_node *hnode)
443 return hlist_entry(hnode, struct jobid_pid_map, jp_hash);
446 static void jobid_get(struct cfs_hash *hs, struct hlist_node *hnode)
448 struct jobid_pid_map *pidmap;
450 pidmap = hlist_entry(hnode, struct jobid_pid_map, jp_hash);
452 atomic_inc(&pidmap->jp_refcount);
455 static void jobid_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
457 struct jobid_pid_map *pidmap;
462 pidmap = hlist_entry(hnode, struct jobid_pid_map, jp_hash);
463 LASSERT(atomic_read(&pidmap->jp_refcount) > 0);
464 if (atomic_dec_and_test(&pidmap->jp_refcount)) {
465 CDEBUG(D_INFO, "Freeing: %d->%s\n",
466 pidmap->jp_pid, pidmap->jp_jobid);
468 OBD_FREE_PTR(pidmap);
472 static struct cfs_hash_ops jobid_hash_ops = {
473 .hs_hash = jobid_hashfn,
474 .hs_keycmp = jobid_keycmp,
476 .hs_object = jobid_object,
478 .hs_put = jobid_put_locked,
479 .hs_put_locked = jobid_put_locked,
483 * Generate the job identifier string for this process for tracking purposes.
485 * Fill in @jobid string based on the value of obd_jobid_var:
486 * JOBSTATS_DISABLE: none
487 * JOBSTATS_NODELOCAL: content of obd_jobid_node (jobid_interpret_string())
488 * JOBSTATS_PROCNAME_UID: process name/UID
489 * anything else: look up obd_jobid_var in the processes environment
491 * Return -ve error number, 0 on success.
493 int lustre_get_jobid(char *jobid, size_t joblen)
498 if (unlikely(joblen < 2)) {
504 if (strcmp(obd_jobid_var, JOBSTATS_DISABLE) == 0) {
505 /* Jobstats isn't enabled */
506 memset(jobid, 0, joblen);
507 } else if (strcmp(obd_jobid_var, JOBSTATS_NODELOCAL) == 0) {
508 /* Whole node dedicated to single job */
509 rc = jobid_interpret_string(obd_jobid_name, jobid, joblen);
510 } else if (strcmp(obd_jobid_var, JOBSTATS_PROCNAME_UID) == 0) {
511 rc = jobid_interpret_string("%e.%u", jobid, joblen);
512 } else if (jobid_name_is_valid(current_comm())) {
514 * obd_jobid_var holds the jobid environment variable name.
515 * Skip initial check if obd_jobid_name already uses "%j",
516 * otherwise try just "%j" first, then fall back to whatever
517 * is in obd_jobid_name if obd_jobid_var is not found.
520 if (!strnstr(obd_jobid_name, "%j", joblen))
521 rc = jobid_get_from_cache(jobid, joblen);
523 /* fall back to jobid_node if jobid_var not in environment */
525 int rc2 = jobid_interpret_string(obd_jobid_name,
534 EXPORT_SYMBOL(lustre_get_jobid);
539 * Search cache for JobID given by @find_jobid.
540 * If any entries in the hash table match the value, they are removed
542 void lustre_jobid_clear(const char *find_jobid)
544 char jobid[LUSTRE_JOBID_SIZE];
547 if (jobid_hash == NULL)
550 strlcpy(jobid, find_jobid, sizeof(jobid));
551 /* trim \n off the end of the incoming jobid */
552 end = strchr(jobid, '\n');
553 if (end && *end == '\n')
556 CDEBUG(D_INFO, "Clearing Jobid: %s\n", jobid);
557 cfs_hash_cond_del(jobid_hash, jobid_should_free_item, jobid);
559 CDEBUG(D_INFO, "%d items remain in jobID table\n",
560 atomic_read(&jobid_hash->hs_count));