Viewing: jobid.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
* Copyright (c) 2011, 2014, Intel Corporation.
*
* Copyright 2017 Cray Inc, all rights reserved.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
*
* Store PID->JobID mappings
*
* Author: Ben Evans.
*/
#define DEBUG_SUBSYSTEM S_RPC
#include <linux/user_namespace.h>
#include <linux/uidgid.h>
#include <linux/utsname.h>
#include <cfs_hash.h>
#include <obd_support.h>
#include <obd_class.h>
#include <lustre_net.h>
static struct cfs_hash *jobid_hash;
static struct cfs_hash_ops jobid_hash_ops;
static spinlock_t jobid_hash_lock;
#define RESCAN_INTERVAL 30
#define DELETE_INTERVAL 300
char obd_jobid_var[JOBSTATS_JOBID_VAR_MAX_LEN + 1] = JOBSTATS_DISABLE;
char obd_jobid_name[LUSTRE_JOBID_SIZE] = "%e.%u";
/**
* Structure to store a single PID->JobID mapping
*/
struct jobid_pid_map {
struct hlist_node jp_hash;
time64_t jp_time;
spinlock_t jp_lock; /* protects jp_jobid */
char jp_jobid[LUSTRE_JOBID_SIZE];
unsigned int jp_joblen;
struct kref jp_refcount;
pid_t jp_pid;
};
/*
* Jobid can be set for a session (see setsid(2)) by writing to
* a sysfs file from any process in that session.
* The jobids are stored in a hash table indexed by the relevant
* struct pid. We periodically look for entries where the pid has
* no PIDTYPE_SID tasks any more, and prune them. This happens within
* 5 seconds of a jobid being added, and every 5 minutes when jobids exist,
* but none are added.
*/
#define JOBID_EXPEDITED_CLEAN (5)
#define JOBID_BACKGROUND_CLEAN (5 * 60)
struct session_jobid {
struct pid *sj_session;
struct rhash_head sj_linkage;
struct rcu_head sj_rcu;
char sj_jobid[];
};
static const struct rhashtable_params jobid_params = {
.key_len = sizeof(struct pid *),
.key_offset = offsetof(struct session_jobid, sj_session),
.head_offset = offsetof(struct session_jobid, sj_linkage),
};
static struct rhashtable session_jobids;
/*
* jobid_current must be called with rcu_read_lock held.
* if it returns non-NULL, the string can only be used
* until rcu_read_unlock is called.
*/
char *jobid_current(void)
{
struct pid *sid = task_session(current);
struct session_jobid *sj;
sj = rhashtable_lookup_fast(&session_jobids, &sid, jobid_params);
if (sj)
return sj->sj_jobid;
return NULL;
}
static void jobid_prune_expedite(void);
/*
* jobid_set_current will try to add a new entry
* to the table. If one exists with the same key, the
* jobid will be replaced
*/
int jobid_set_current(char *jobid)
{
struct pid *sid;
struct session_jobid *sj, *origsj;
int ret;
int len = strlen(jobid);
OBD_ALLOC(sj, sizeof(*sj) + len + 1);
if (!sj)
return -ENOMEM;
rcu_read_lock();
sid = task_session(current);
sj->sj_session = get_pid(sid);
strncpy(sj->sj_jobid, jobid, len + 1);
origsj = rhashtable_lookup_get_insert_fast(&session_jobids,
&sj->sj_linkage,
jobid_params);
if (origsj == NULL) {
/* successful insert */
rcu_read_unlock();
jobid_prune_expedite();
return 0;
}
if (IS_ERR(origsj)) {
put_pid(sj->sj_session);
OBD_FREE(sj, sizeof(*sj) + strlen(sj->sj_jobid) + 1);
rcu_read_unlock();
return PTR_ERR(origsj);
}
ret = rhashtable_replace_fast(&session_jobids,
&origsj->sj_linkage,
&sj->sj_linkage,
jobid_params);
if (ret) {
put_pid(sj->sj_session);
OBD_FREE(sj, sizeof(*sj) + strlen(sj->sj_jobid) + 1);
rcu_read_unlock();
return ret;
}
put_pid(origsj->sj_session);
rcu_read_unlock();
OBD_FREE_RCU(origsj, sizeof(*sj) + strlen(origsj->sj_jobid) + 1, sj_rcu);
jobid_prune_expedite();
return 0;
}
static void jobid_free(void *vsj, void *arg)
{
struct session_jobid *sj = vsj;
put_pid(sj->sj_session);
OBD_FREE(sj, sizeof(*sj) + strlen(sj->sj_jobid) + 1);;
}
static void jobid_prune(struct work_struct *work);
static DECLARE_DELAYED_WORK(jobid_prune_work, jobid_prune);
static int jobid_prune_expedited;
static void jobid_prune(struct work_struct *work)
{
int remaining = 0;
struct rhashtable_iter iter;
struct session_jobid *sj;
jobid_prune_expedited = 0;
rhashtable_walk_enter(&session_jobids, &iter);
rhashtable_walk_start(&iter);
while ((sj = rhashtable_walk_next(&iter)) != NULL) {
if (IS_ERR(sj)) {
if (PTR_ERR(sj) == -EAGAIN)
continue;
break;
}
if (!hlist_empty(&sj->sj_session->tasks[PIDTYPE_SID])) {
remaining++;
continue;
}
if (rhashtable_remove_fast(&session_jobids,
&sj->sj_linkage,
jobid_params) == 0) {
put_pid(sj->sj_session);
OBD_FREE_RCU(sj, sizeof(*sj) + strlen(sj->sj_jobid) + 1,
sj_rcu);
}
}
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
if (remaining)
schedule_delayed_work(&jobid_prune_work,
cfs_time_seconds(JOBID_BACKGROUND_CLEAN));
}
static void jobid_prune_expedite(void)
{
/* submit the work only once */
if (!cmpxchg(&jobid_prune_expedited, 0, 1))
mod_delayed_work(system_wq, &jobid_prune_work,
cfs_time_seconds(JOBID_EXPEDITED_CLEAN));
}
static int cfs_access_process_vm(struct task_struct *tsk,
struct mm_struct *mm,
unsigned long addr,
void *buf, int len, int write)
{
/* Just copied from kernel for the kernels which doesn't
* have access_process_vm() exported
*/
struct vm_area_struct *vma = NULL;
struct page *page;
void *old_buf = buf;
/* Avoid deadlocks on mmap_sem if called from sys_mmap_pgoff(),
* which is already holding mmap_sem for writes. If some other
* thread gets the write lock in the meantime, this thread will
* block, but at least it won't deadlock on itself. LU-1735
*/
if (!mmap_read_trylock(mm))
return -EDEADLK;
/* ignore errors, just check how much was successfully transferred */
while (len) {
int bytes, rc, offset;
void *maddr;
#if defined(HAVE_GET_USER_PAGES_WITHOUT_VMA)
rc = get_user_pages(addr, 1, write ? FOLL_WRITE : 0, &page);
if (rc > 0)
vma = vma_lookup(mm, addr);
#else
rc = get_user_pages(addr, 1, write ? FOLL_WRITE : 0, &page,
&vma);
#endif
if (rc <= 0 || !vma)
break;
bytes = len;
offset = addr & (PAGE_SIZE-1);
if (bytes > PAGE_SIZE-offset)
bytes = PAGE_SIZE-offset;
maddr = kmap(page);
if (write) {
copy_to_user_page(vma, page, addr,
maddr + offset, buf, bytes);
set_page_dirty_lock(page);
} else {
copy_from_user_page(vma, page, addr,
buf, maddr + offset, bytes);
}
kunmap(kmap_to_page(maddr));
put_page(page);
len -= bytes;
buf += bytes;
addr += bytes;
}
mmap_read_unlock(mm);
return buf - old_buf;
}
/* Read the environment variable of current process specified by @key. */
static int cfs_get_environ(const char *key, char *value, int *val_len)
{
struct mm_struct *mm;
char *buffer;
int buf_len = PAGE_SIZE;
int key_len = strlen(key);
unsigned long addr;
int rc;
bool skip = false;
ENTRY;
buffer = kmalloc(buf_len, GFP_USER);
if (!buffer)
RETURN(-ENOMEM);
mm = get_task_mm(current);
if (!mm) {
kfree(buffer);
RETURN(-EINVAL);
}
addr = mm->env_start;
while (addr < mm->env_end) {
int this_len, retval, scan_len;
char *env_start, *env_end;
memset(buffer, 0, buf_len);
this_len = min_t(int, mm->env_end - addr, buf_len);
retval = cfs_access_process_vm(current, mm, addr, buffer,
this_len, 0);
if (retval < 0)
GOTO(out, rc = retval);
else if (retval != this_len)
break;
addr += retval;
/* Parse the buffer to find out the specified key/value pair.
* The "key=value" entries are separated by '\0'.
*/
env_start = buffer;
scan_len = this_len;
while (scan_len) {
char *entry;
int entry_len;
env_end = memscan(env_start, '\0', scan_len);
LASSERT(env_end >= env_start &&
env_end <= env_start + scan_len);
/* The last entry of this buffer cross the buffer
* boundary, reread it in next cycle.
*/
if (unlikely(env_end - env_start == scan_len)) {
/* Just skip the entry larger than page size,
* it can't be jobID env variable.
*/
if (unlikely(scan_len == this_len))
skip = true;
else
addr -= scan_len;
break;
} else if (unlikely(skip)) {
skip = false;
goto skip;
}
entry = env_start;
entry_len = env_end - env_start;
CDEBUG(D_INFO, "key: %s, entry: %s\n", key, entry);
/* Key length + length of '=' */
if (entry_len > key_len + 1 &&
entry[key_len] == '=' &&
!memcmp(entry, key, key_len)) {
entry += key_len + 1;
entry_len -= key_len + 1;
/* The 'value' buffer passed in is too small.
* Copy what fits, but return -EOVERFLOW.
*/
if (entry_len >= *val_len) {
memcpy(value, entry, *val_len);
value[*val_len - 1] = 0;
GOTO(out, rc = -EOVERFLOW);
}
memcpy(value, entry, entry_len);
*val_len = entry_len;
GOTO(out, rc = 0);
}
skip:
scan_len -= (env_end - env_start + 1);
env_start = env_end + 1;
}
}
GOTO(out, rc = -ENOENT);
out:
mmput(mm);
kfree((void *)buffer);
return rc;
}
/*
* Get jobid of current process by reading the environment variable
* stored in between the "env_start" & "env_end" of task struct.
*
* If some job scheduler doesn't store jobid in the "env_start/end",
* then an upcall could be issued here to get the jobid by utilizing
* the userspace tools/API. Then, the jobid must be cached.
*/
static int jobid_get_from_environ(char *jobid_var, char *jobid, int *jobid_len)
{
int rc;
rc = cfs_get_environ(jobid_var, jobid, jobid_len);
if (!rc)
goto out;
if (rc == -EOVERFLOW) {
/* For the PBS_JOBID and LOADL_STEP_ID keys (which are
* variable length strings instead of just numbers), it
* might make sense to keep the unique parts for JobID,
* instead of just returning an error. That means a
* larger temp buffer for cfs_get_environ(), then
* truncating the string at some separator to fit into
* the specified jobid_len. Fix later if needed. */
static ktime_t printed;
if (unlikely(ktime_to_ns(printed) == 0 ||
ktime_after(ktime_get(),
ktime_add_ns(printed,
3600ULL * 24 * NSEC_PER_SEC)))) {
LCONSOLE_WARN("jobid: '%s' value too large (%d)\n",
obd_jobid_var, *jobid_len);
printed = ktime_get();
}
rc = 0;
} else {
CDEBUG_LIMIT((rc == -ENOENT || rc == -EINVAL ||
rc == -EDEADLK) ? D_INFO : D_ERROR,
"jobid: get '%s' failed: rc = %d\n",
obd_jobid_var, rc);
}
out:
return rc;
}
/*
* jobid_should_free_item
*
* Each item is checked to see if it should be released
* Removed from hash table by caller
* Actually freed in jobid_put_locked
*
* Returns 1 if item is to be freed, 0 if it is to be kept
*/
static int jobid_should_free_item(void *obj, void *data)
{
char *jobid = data;
struct jobid_pid_map *pidmap = obj;
int rc = 0;
if (obj == NULL)
return 0;
if (jobid == NULL) {
WARN_ON_ONCE(kref_read(&pidmap->jp_refcount) != 1);
return 1;
}
spin_lock(&pidmap->jp_lock);
/* prevent newly inserted items from deleting */
if (jobid[0] == '\0' && kref_read(&pidmap->jp_refcount) == 1)
rc = 1;
else if (ktime_get_real_seconds() - pidmap->jp_time > DELETE_INTERVAL)
rc = 1;
else if (strcmp(pidmap->jp_jobid, jobid) == 0)
rc = 1;
spin_unlock(&pidmap->jp_lock);
return rc;
}
static void jobid_pidmap_gc(struct work_struct *work);
static DECLARE_DELAYED_WORK(jobid_pidmap_gc_work, jobid_pidmap_gc);
static int jobid_pidmap_gc_started;
static void jobid_pidmap_gc(struct work_struct *work)
{
struct cfs_hash *hash;
hash = cfs_hash_getref(jobid_hash);
if (!hash)
return;
CDEBUG(D_INFO, "jobid: running the PID map GC (count: %d)\n",
atomic_read(&jobid_hash->hs_count));
cfs_hash_cond_del(jobid_hash, jobid_should_free_item,
"intentionally_bad_jobid");
if (atomic_read(&jobid_hash->hs_count) == 0)
jobid_pidmap_gc_started = 0;
else
schedule_delayed_work(&jobid_pidmap_gc_work,
cfs_time_seconds(DELETE_INTERVAL));
cfs_hash_putref(hash);
}
/* scan hash periodically to remove old PID entries from cache */
static inline void jobid_pidmap_gc_start(void)
{
/* submit the work only once */
if (!cmpxchg(&jobid_pidmap_gc_started, 0, 1))
schedule_delayed_work(&jobid_pidmap_gc_work,
cfs_time_seconds(DELETE_INTERVAL));
}
/*
* jobid_name_is_valid
*
* Checks if the jobid is a Lustre process
*
* Returns true if jobid is valid
* Returns false if jobid looks like it's a Lustre process
*/
static bool jobid_name_is_valid(char *jobid)
{
const char *const lustre_reserved[] = { "ll_ping", "ptlrpc",
"ldlm", "ll_sa", "kworker",
"kswapd", "writeback", "irq",
"ksoftirq", "ll_ucp", NULL };
int i;
if (jobid[0] == '\0')
return false;
for (i = 0; lustre_reserved[i] != NULL; i++) {
if (strncmp(jobid, lustre_reserved[i],
strlen(lustre_reserved[i])) == 0)
return false;
}
return true;
}
/*
* jobid_get_from_cache()
*
* Returns contents of jobid_var from process environment for current PID,
* or from the per-session jobid table.
* Values fetch from process environment will be cached for some time to avoid
* the overhead of scanning the environment.
*
* Return: -ENOMEM if allocating a new pidmap fails
* -ENOENT if no entry could be found
* +ve string length for success (something was returned in jobid)
*/
static int jobid_get_from_cache(char *jobid, size_t joblen)
{
pid_t pid = current->pid;
struct jobid_pid_map *pidmap = NULL;
time64_t now = ktime_get_real_seconds();
int rc = 0;
ENTRY;
if (strcmp(obd_jobid_var, JOBSTATS_SESSION) == 0) {
char *jid;
rcu_read_lock();
jid = jobid_current();
if (jid) {
strscpy(jobid, jid, joblen);
joblen = strlen(jobid);
} else {
rc = -ENOENT;
}
rcu_read_unlock();
GOTO(out, rc);
}
LASSERT(jobid_hash != NULL);
/* first try to find PID in the hash and use that value */
pidmap = cfs_hash_lookup(jobid_hash, &pid);
if (pidmap == NULL) {
struct jobid_pid_map *pidmap2;
OBD_ALLOC_PTR(pidmap);
if (pidmap == NULL)
GOTO(out, rc = -ENOMEM);
pidmap->jp_pid = pid;
pidmap->jp_time = 0;
pidmap->jp_jobid[0] = '\0';
spin_lock_init(&pidmap->jp_lock);
INIT_HLIST_NODE(&pidmap->jp_hash);
/*
* @pidmap might be reclaimed just after it is added into
* hash list, init @jp_refcount as 1 to make sure memory
* could be not freed during access.
*/
kref_init(&pidmap->jp_refcount);
/*
* Add the newly created map to the hash, on key collision we
* lost a racing addition and must destroy our newly allocated
* map. The object which exists in the hash will be returned.
*/
pidmap2 = cfs_hash_findadd_unique(jobid_hash, &pid,
&pidmap->jp_hash);
if (unlikely(pidmap != pidmap2)) {
CDEBUG(D_INFO, "jobid: duplicate found for PID=%u\n",
pid);
OBD_FREE_PTR(pidmap);
pidmap = pidmap2;
} else {
jobid_pidmap_gc_start();
}
}
/*
* If pidmap is old (this is always true for new entries) refresh it.
* If obd_jobid_var is not found, cache empty entry and try again
* later, to avoid repeat lookups for PID if obd_jobid_var missing.
*/
spin_lock(&pidmap->jp_lock);
if (pidmap->jp_time + RESCAN_INTERVAL <= now) {
char env_jobid[LUSTRE_JOBID_SIZE] = "";
int env_len = sizeof(env_jobid);
pidmap->jp_time = now;
spin_unlock(&pidmap->jp_lock);
rc = jobid_get_from_environ(obd_jobid_var, env_jobid, &env_len);
CDEBUG(D_INFO, "jobid: PID mapping established: %d->%s\n",
pidmap->jp_pid, env_jobid);
spin_lock(&pidmap->jp_lock);
if (!rc) {
pidmap->jp_joblen = env_len;
strscpy(pidmap->jp_jobid, env_jobid,
sizeof(pidmap->jp_jobid));
rc = 0;
} else if (rc == -ENOENT) {
/* It might have been deleted, clear out old entry */
pidmap->jp_joblen = 0;
pidmap->jp_jobid[0] = '\0';
}
}
/*
* Regardless of how pidmap was found, if it contains a valid entry
* use that for now. If there was a technical error (e.g. -ENOMEM)
* use the old cached value until it can be looked up again properly.
* If a cached missing entry was found, return -ENOENT.
*/
if (pidmap->jp_joblen) {
strscpy(jobid, pidmap->jp_jobid, joblen);
joblen = pidmap->jp_joblen;
rc = 0;
} else if (!rc) {
rc = -ENOENT;
}
spin_unlock(&pidmap->jp_lock);
cfs_hash_put(jobid_hash, &pidmap->jp_hash);
EXIT;
out:
return rc < 0 ? rc : joblen;
}
/*
* jobid_print_current_comm()
*
* Print current comm name into the provided jobid buffer, and trim names of
* kernel threads like "kworker/0:0" to "kworker" or "ll_sa_12345" to "ll_sa"
*
* Return: number of chars printed to jobid
*/
static int jobid_print_current_comm(char *jobid, ssize_t joblen)
{
const char *const names[] = {"kworker", "kswapd", "ll_sa", "ll_agl",
"ldlm_bl", "ll_ucp", NULL};
int i;
if (current->flags & PF_KTHREAD) {
for (i = 0; names[i] != NULL; i++) {
if (strncmp(current->comm, names[i],
strlen(names[i])) == 0)
return snprintf(jobid, joblen, "%s", names[i]);
}
}
return snprintf(jobid, joblen, "%s", current->comm);
}
/*
* jobid_interpret_string()
*
* Interpret the jobfmt string to expand specified fields, like coredumps do:
* %e = executable
* %g = gid
* %h = hostname
* %H = short hostname
* %j = jobid from environment
* ? = for use between %j and %H. Uses jobid if set, otherwise use Hostname
* %p = pid
* %u = uid
*
* Truncation can also be interpreted by writing .n between % and field, for
* example %.3h to print only the 3 first characaters.
*
* Unknown escape strings are dropped. Other characters are copied through,
* excluding whitespace (to avoid making jobid parsing difficult).
*
* Return: -EOVERFLOW if the expanded string does not fit within @joblen
* 0 for success
*/
static int jobid_interpret_string(const char *jobfmt, char *jobid,
ssize_t joblen)
{
char c;
while ((c = *jobfmt++) && joblen > 1) {
long width = joblen;
char *p;
int l;
if (isspace(c)) /* Don't allow embedded spaces */
continue;
if (c != '%') {
*jobid = c;
joblen--;
jobid++;
*jobid = '\0';
continue;
}
if (*jobfmt == '.') {
long w = 0;
int size = 0;
jobfmt++;
if (sscanf(jobfmt, "%ld%n", &w, &size) == 1)
jobfmt += size;
if (w > 0)
width = min(w+1, joblen);
}
switch (*jobfmt++) {
case 'e': /* executable name */
l = jobid_print_current_comm(jobid, width);
break;
case 'g': /* group ID */
l = snprintf(jobid, width, "%u",
from_kgid(&init_user_ns, current_fsgid()));
break;
case 'h': /* hostname */
l = snprintf(jobid, width, "%s",
init_utsname()->nodename);
break;
case 'H': /* short hostname. Cut at first dot */
l = snprintf(jobid, width, "%s",
init_utsname()->nodename);
p = strnchr(jobid, width, '.');
if (p) {
*p = '\0';
l = p - jobid;
}
break;
case 'j': /* jobid stored in process environment */
l = jobid_get_from_cache(jobid, width);
if (l < 0)
l = 0;
if (*jobfmt == '?') {
if (l == 0)
jobfmt++;
else
jobfmt += 3;
}
break;
case 'p': /* process ID */
l = snprintf(jobid, width, "%u", current->pid);
break;
case 'u': /* user ID */
l = snprintf(jobid, width, "%u",
from_kuid(&init_user_ns, current_fsuid()));
break;
case '\0': /* '%' at end of format string */
l = 0;
goto out;
default: /* drop unknown %x format strings */
l = 0;
break;
}
if (l >= width)
l = width-1;
jobid += l;
joblen -= l;
}
/*
* This points at the end of the buffer, so long as jobid is always
* incremented the same amount as joblen is decremented.
*/
out:
jobid[joblen - 1] = '\0';
return joblen < 0 ? -EOVERFLOW : 0;
}
/*
* Hash initialization, copied from server-side job stats bucket sizes
*/
#define HASH_JOBID_BKT_BITS 5
#define HASH_JOBID_CUR_BITS 7
#define HASH_JOBID_MAX_BITS 12
int jobid_cache_init(void)
{
int rc = 0;
ENTRY;
if (jobid_hash)
return 0;
spin_lock_init(&jobid_hash_lock);
jobid_hash = cfs_hash_create("JOBID_HASH", HASH_JOBID_CUR_BITS,
HASH_JOBID_MAX_BITS, HASH_JOBID_BKT_BITS,
0, CFS_HASH_MIN_THETA, CFS_HASH_MAX_THETA,
&jobid_hash_ops, CFS_HASH_DEFAULT);
if (!jobid_hash) {
rc = -ENOMEM;
} else {
rc = rhashtable_init(&session_jobids, &jobid_params);
if (rc) {
cfs_hash_putref(jobid_hash);
jobid_hash = NULL;
}
}
RETURN(rc);
}
EXPORT_SYMBOL(jobid_cache_init);
void jobid_cache_fini(void)
{
struct cfs_hash *tmp_hash;
ENTRY;
spin_lock(&jobid_hash_lock);
tmp_hash = jobid_hash;
jobid_hash = NULL;
spin_unlock(&jobid_hash_lock);
cancel_delayed_work_sync(&jobid_prune_work);
cancel_delayed_work_sync(&jobid_pidmap_gc_work);
if (tmp_hash != NULL) {
cfs_hash_cond_del(tmp_hash, jobid_should_free_item, NULL);
cfs_hash_putref(tmp_hash);
rhashtable_free_and_destroy(&session_jobids, jobid_free, NULL);
}
EXIT;
}
EXPORT_SYMBOL(jobid_cache_fini);
/*
* Hash operations for pid<->jobid
*/
static unsigned int
jobid_hashfn(struct cfs_hash *hs, const void *key, const unsigned int bits)
{
return cfs_hash_djb2_hash(key, sizeof(pid_t), bits);
}
static void *jobid_key(struct hlist_node *hnode)
{
struct jobid_pid_map *pidmap;
pidmap = hlist_entry(hnode, struct jobid_pid_map, jp_hash);
return &pidmap->jp_pid;
}
static int jobid_keycmp(const void *key, struct hlist_node *hnode)
{
const pid_t *pid_key1;
const pid_t *pid_key2;
LASSERT(key != NULL);
pid_key1 = (pid_t *)key;
pid_key2 = (pid_t *)jobid_key(hnode);
return *pid_key1 == *pid_key2;
}
static void *jobid_object(struct hlist_node *hnode)
{
return hlist_entry(hnode, struct jobid_pid_map, jp_hash);
}
static void jobid_get(struct cfs_hash *hs, struct hlist_node *hnode)
{
struct jobid_pid_map *pidmap;
pidmap = hlist_entry(hnode, struct jobid_pid_map, jp_hash);
kref_get(&pidmap->jp_refcount);
}
static void jobid_put_locked_free(struct kref *kref)
{
struct jobid_pid_map *pidmap = container_of(kref, struct jobid_pid_map,
jp_refcount);
CDEBUG(D_INFO, "Freeing: %d->%s\n", pidmap->jp_pid, pidmap->jp_jobid);
OBD_FREE_PTR(pidmap);
}
static void jobid_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
{
struct jobid_pid_map *pidmap;
if (hnode == NULL)
return;
pidmap = hlist_entry(hnode, struct jobid_pid_map, jp_hash);
LASSERT(kref_read(&pidmap->jp_refcount) > 0);
kref_put(&pidmap->jp_refcount, jobid_put_locked_free);
}
static struct cfs_hash_ops jobid_hash_ops = {
.hs_hash = jobid_hashfn,
.hs_keycmp = jobid_keycmp,
.hs_key = jobid_key,
.hs_object = jobid_object,
.hs_get = jobid_get,
.hs_put = jobid_put_locked,
.hs_put_locked = jobid_put_locked,
};
/**
* Generate the job identifier string for this process for tracking purposes.
*
* Fill in @jobid string based on the value of obd_jobid_var:
* JOBSTATS_DISABLE: none
* JOBSTATS_NODELOCAL: content of obd_jobid_name (jobid_interpret_string())
* JOBSTATS_PROCNAME_UID: process name/UID
* JOBSTATS_SESSION per-session value set by
* /sys/fs/lustre/jobid_this_session
* anything else: look up obd_jobid_var in the processes environment
*
* Return -ve error number, 0 on success.
*/
int lustre_get_jobid(char *jobid, size_t joblen)
{
int len = min_t(int, joblen, LUSTRE_JOBID_SIZE);
int rc = 0;
ENTRY;
if (unlikely(joblen < 2)) {
if (joblen == 1)
jobid[0] = '\0';
RETURN(-EINVAL);
}
if (strcmp(obd_jobid_var, JOBSTATS_DISABLE) == 0) {
/* Jobstats isn't enabled */
memset(jobid, 0, joblen);
RETURN(0);
}
if (strcmp(obd_jobid_var, JOBSTATS_NODELOCAL) == 0) {
/* Whole node dedicated to single job */
rc = jobid_interpret_string(obd_jobid_name, jobid, len);
} else if (strcmp(obd_jobid_var, JOBSTATS_PROCNAME_UID) == 0) {
rc = jobid_interpret_string("%e.%u", jobid, len);
} else if (strcmp(obd_jobid_var, JOBSTATS_SESSION) == 0 ||
jobid_name_is_valid(current->comm)) {
/*
* per-process jobid wanted, either from environment or from
* per-session setting.
* If obd_jobid_name contains "%j" or if getting the per-process
* jobid directly fails, fall back to using obd_jobid_name.
*/
rc = -EAGAIN;
if (!strnstr(obd_jobid_name, "%j", joblen))
rc = jobid_get_from_cache(jobid, len);
/* fall back to jobid_name if jobid_var not available */
if (rc < 0) {
int rc2 = jobid_interpret_string(obd_jobid_name,
jobid, len);
if (!rc2)
rc = 0;
}
}
RETURN(rc);
}
EXPORT_SYMBOL(lustre_get_jobid);
/*
* lustre_jobid_clear
*
* Search cache for JobID given by @find_jobid.
* If any entries in the hash table match the value, they are removed
*/
void lustre_jobid_clear(const char *find_jobid)
{
char jobid[LUSTRE_JOBID_SIZE];
char *end;
if (jobid_hash == NULL)
return;
strscpy(jobid, find_jobid, sizeof(jobid));
/* trim \n off the end of the incoming jobid */
end = strchr(jobid, '\n');
if (end && *end == '\n')
*end = '\0';
CDEBUG(D_INFO, "Clearing Jobid: %s\n", jobid);
cfs_hash_cond_del(jobid_hash, jobid_should_free_item, jobid);
CDEBUG(D_INFO, "%d items remain in jobID table\n",
atomic_read(&jobid_hash->hs_count));
}
