ipc: convert to idr_alloc()

Convert to the much saner new idr interface.

The new interface doesn't directly translate to the way idr_pre_get()
was used around ipc_addid() as preloading disables preemption.  From
my cursory reading, it seems like we should be able to do all
allocation from ipc_addid(), so I moved it there.  Can you please
check whether this would be okay?  If this is wrong and ipc_addid()
should be allowed to be called from non-sleepable context, I'd suggest
allocating id itself in the outer functions and later install the
pointer using idr_replace().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Tejun Heo 2013-02-27 17:04:53 -08:00 committed by Linus Torvalds
parent 6b207ba3eb
commit 54924ea33f

View File

@ -252,7 +252,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
{
kuid_t euid;
kgid_t egid;
int id, err;
int id;
int next_id = ids->next_id;
if (size > IPCMNI)
@ -261,17 +261,21 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
if (ids->in_use >= size)
return -ENOSPC;
idr_preload(GFP_KERNEL);
spin_lock_init(&new->lock);
new->deleted = 0;
rcu_read_lock();
spin_lock(&new->lock);
err = idr_get_new_above(&ids->ipcs_idr, new,
(next_id < 0) ? 0 : ipcid_to_idx(next_id), &id);
if (err) {
id = idr_alloc(&ids->ipcs_idr, new,
(next_id < 0) ? 0 : ipcid_to_idx(next_id), 0,
GFP_NOWAIT);
idr_preload_end();
if (id < 0) {
spin_unlock(&new->lock);
rcu_read_unlock();
return err;
return id;
}
ids->in_use++;
@ -307,19 +311,10 @@ static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
struct ipc_ops *ops, struct ipc_params *params)
{
int err;
retry:
err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
if (!err)
return -ENOMEM;
down_write(&ids->rw_mutex);
err = ops->getnew(ns, params);
up_write(&ids->rw_mutex);
if (err == -EAGAIN)
goto retry;
return err;
}
@ -376,8 +371,6 @@ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
struct kern_ipc_perm *ipcp;
int flg = params->flg;
int err;
retry:
err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
/*
* Take the lock as a writer since we are potentially going to add
@ -389,8 +382,6 @@ retry:
/* key not used */
if (!(flg & IPC_CREAT))
err = -ENOENT;
else if (!err)
err = -ENOMEM;
else
err = ops->getnew(ns, params);
} else {
@ -413,9 +404,6 @@ retry:
}
up_write(&ids->rw_mutex);
if (err == -EAGAIN)
goto retry;
return err;
}