From e9ab41b620e4b679ed069ab05cb85e67870b7c87 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 27 Sep 2012 15:44:19 -0400 Subject: [PATCH] NFSv4: Clean up the legacy idmapper upcall Replace the BUG_ON(idmap->idmap_key_cons != NULL) with a WARN_ON_ONCE(). Then get rid of the ACCESS_ONCE(idmap->idmap_key_cons). Then add helper functions for starting, finishing and aborting the legacy upcall. Signed-off-by: Trond Myklebust Cc: Bryan Schumaker --- fs/nfs/idmap.c | 65 +++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 44 insertions(+), 21 deletions(-) diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c index 79f6424..8222ad8 100644 --- a/fs/nfs/idmap.c +++ b/fs/nfs/idmap.c @@ -330,7 +330,6 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen, ret = nfs_idmap_request_key(&key_type_id_resolver_legacy, name, namelen, type, data, data_size, idmap); - idmap->idmap_key_cons = NULL; mutex_unlock(&idmap->idmap_mutex); } return ret; @@ -662,6 +661,34 @@ out: return ret; } +static bool +nfs_idmap_prepare_pipe_upcall(struct idmap *idmap, + struct key_construction *cons) +{ + if (idmap->idmap_key_cons != NULL) { + WARN_ON_ONCE(1); + return false; + } + idmap->idmap_key_cons = cons; + return true; +} + +static void +nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret) +{ + struct key_construction *cons = idmap->idmap_key_cons; + + idmap->idmap_key_cons = NULL; + complete_request_key(cons, ret); +} + +static void +nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret) +{ + if (idmap->idmap_key_cons != NULL) + nfs_idmap_complete_pipe_upcall_locked(idmap, ret); +} + static int nfs_idmap_legacy_upcall(struct key_construction *cons, const char *op, void *aux) @@ -686,21 +713,17 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons, if (ret < 0) goto out2; - if (idmap->idmap_key_cons != NULL) { - WARN_ON_ONCE(1); - ret = -EAGAIN; + ret = -EAGAIN; + if (!nfs_idmap_prepare_pipe_upcall(idmap, cons)) goto out2; - } - idmap->idmap_key_cons = cons; ret = rpc_queue_upcall(idmap->idmap_pipe, msg); - if (ret < 0) - goto out3; + if (ret < 0) { + nfs_idmap_abort_pipe_upcall(idmap, ret); + kfree(data); + } return ret; - -out3: - idmap->idmap_key_cons = NULL; out2: kfree(data); out1: @@ -741,14 +764,15 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) struct key_construction *cons; struct idmap_msg im; size_t namelen_in; - int ret; + int ret = -ENOKEY; /* If instantiation is successful, anyone waiting for key construction * 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 = idmap->idmap_key_cons; - idmap->idmap_key_cons = NULL; + if (cons == NULL) + goto out_noupcall; if (mlen != sizeof(im)) { ret = -ENOSPC; @@ -778,7 +802,8 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) } out: - complete_request_key(cons, ret); + nfs_idmap_complete_pipe_upcall_locked(idmap, ret); +out_noupcall: return ret; } @@ -789,12 +814,9 @@ idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg) struct idmap_legacy_upcalldata, pipe_msg); struct idmap *idmap = data->idmap; - struct key_construction *cons; - if (msg->errno) { - cons = idmap->idmap_key_cons; - idmap->idmap_key_cons = NULL; - complete_request_key(cons, msg->errno); - } + + if (msg->errno) + nfs_idmap_abort_pipe_upcall(idmap, msg->errno); /* Free memory allocated in nfs_idmap_legacy_upcall() */ kfree(data); } @@ -804,7 +826,8 @@ idmap_release_pipe(struct inode *inode) { struct rpc_inode *rpci = RPC_I(inode); struct idmap *idmap = (struct idmap *)rpci->private; - idmap->idmap_key_cons = NULL; + + nfs_idmap_abort_pipe_upcall(idmap, -EPIPE); } int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid) -- 2.7.4