In pid_alloc function, idr_preload function is used along with idr_alloc_cyclic. idr_alloc_cyclic is used instead of idr_alloc because we might want to reuse the unassigned integers. The rest of the code is same as the previous alloc_pid, which puts the pid allocated onto the task list. After the flag out_free, ids are removed from the idr entry using idr_remove function. Inside free_pid() deleting from rcu hash list is same as before. The only change is instead of removing entry from pidmap, allocated number is now deleted from the idr entry.
Signed-off-by: Gargi Sharma <[email protected]> --- kernel/pid.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/kernel/pid.c b/kernel/pid.c index fd1cde1..5060266 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -287,8 +287,14 @@ void free_pid(struct pid *pid) } spin_unlock_irqrestore(&pidmap_lock, flags); - for (i = 0; i <= pid->level; i++) - free_pidmap(pid->numbers + i); + for (i = 0; i <= pid->level; i++) { + struct upid *upid = pid->numbers + i; + struct pid_namespace *ns = upid->ns; + + mutex_lock(&ns->idr_mutex_lock); + idr_remove(ns->idr, upid->nr); + mutex_unlock(&ns->idr_mutex_lock); + } call_rcu(&pid->rcu, delayed_put_pid); } @@ -309,7 +315,15 @@ struct pid *alloc_pid(struct pid_namespace *ns) tmp = ns; pid->level = ns->level; for (i = ns->level; i >= 0; i--) { - nr = alloc_pidmap(tmp); + idr_preload(GFP_KERNEL); + + mutex_lock(&ns->idr_mutex_lock); + nr = idr_alloc_cyclic(tmp->idr, ns, RESERVED_PIDS, + pid_max, GFP_KERNEL); + + mutex_unlock(&ns->idr_mutex_lock); + idr_preload_end(); + if (nr < 0) { retval = nr; goto out_free; @@ -350,8 +364,10 @@ struct pid *alloc_pid(struct pid_namespace *ns) put_pid_ns(ns); out_free: - while (++i <= ns->level) - free_pidmap(pid->numbers + i); + while (++i <= ns->level) { + idr_remove(ns->idr, (pid->numbers + i)->nr); + mutex_unlock(&ns->idr_mutex_lock); + } kmem_cache_free(ns->pid_cachep, pid); return ERR_PTR(retval); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
