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| author |   Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-09-28 12:03:09 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-09-28 12:27:11 -0400 |
| commit | 0e24d849c4ea777c59955b241fd3af14a1b84af5 (patch) | |
| tree | 040025f1f7439395233591cdece544708e8ec333 /fs/nfs/idmap.c | |
| parent | NFS4: avoid underflow when converting error to pointer. (diff) | |
| download | linux-dev-0e24d849c4ea777c59955b241fd3af14a1b84af5.tar.xz linux-dev-0e24d849c4ea777c59955b241fd3af14a1b84af5.zip | |
NFSv4: Remove BUG_ON() and ACCESS_ONCE() calls in the idmapper
The use of ACCESS_ONCE() is wrong, since the various routines that set/clear
idmap->idmap_key_cons should be strictly ordered w.r.t. each other, and
the idmap->idmap_mutex ensures that only one thread at a time may be in
an upcall situation.
Also replace the BUG_ON()s with WARN_ON_ONCE() where appropriate.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/idmap.c')
| -rw-r--r-- | fs/nfs/idmap.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c index a850079467d8..79f6424aa081 100644 --- a/fs/nfs/idmap.c +++ b/fs/nfs/idmap.c @@ -465,8 +465,6 @@ nfs_idmap_new(struct nfs_client *clp) struct rpc_pipe *pipe; int error; - BUG_ON(clp->cl_idmap != NULL); - idmap = kzalloc(sizeof(*idmap), GFP_KERNEL); if (idmap == NULL) return -ENOMEM; @@ -510,7 +508,6 @@ static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event, switch (event) { case RPC_PIPEFS_MOUNT: - BUG_ON(clp->cl_rpcclient->cl_dentry == NULL); err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry, clp->cl_idmap, clp->cl_idmap->idmap_pipe); @@ -689,7 +686,11 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons, if (ret < 0) goto out2; - BUG_ON(idmap->idmap_key_cons != NULL); + if (idmap->idmap_key_cons != NULL) { + WARN_ON_ONCE(1); + ret = -EAGAIN; + goto out2; + } idmap->idmap_key_cons = cons; ret = rpc_queue_upcall(idmap->idmap_pipe, msg); @@ -746,7 +747,7 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) * will have been woken up and someone else may now have used * idmap_key_cons - so after this point we may no longer touch it. */ - cons = ACCESS_ONCE(idmap->idmap_key_cons); + cons = idmap->idmap_key_cons; idmap->idmap_key_cons = NULL; if (mlen != sizeof(im)) { @@ -790,7 +791,7 @@ idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg) struct idmap *idmap = data->idmap; struct key_construction *cons; if (msg->errno) { - cons = ACCESS_ONCE(idmap->idmap_key_cons); + cons = idmap->idmap_key_cons; idmap->idmap_key_cons = NULL; complete_request_key(cons, msg->errno); } |