diff options
Diffstat (limited to 'fs/nfsd')
| -rw-r--r-- | fs/nfsd/filecache.c | 32 | ||||
| -rw-r--r-- | fs/nfsd/filecache.h | 3 | ||||
| -rw-r--r-- | fs/nfsd/localio.c | 70 |
3 files changed, 83 insertions, 22 deletions
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index ab85e6a2454f..e108b6c705b4 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -378,15 +378,41 @@ nfsd_file_put(struct nfsd_file *nf) * the reference of the nfsd_file. */ struct net * -nfsd_file_put_local(struct nfsd_file *nf) +nfsd_file_put_local(struct nfsd_file __rcu **pnf) { - struct net *net = nf->nf_net; + struct nfsd_file *nf; + struct net *net = NULL; - nfsd_file_put(nf); + nf = unrcu_pointer(xchg(pnf, NULL)); + if (nf) { + net = nf->nf_net; + nfsd_file_put(nf); + } return net; } /** + * nfsd_file_get_local - get nfsd_file reference and reference to net + * @nf: nfsd_file of which to put the reference + * + * Get reference to both the nfsd_file and nf->nf_net. + */ +struct nfsd_file * +nfsd_file_get_local(struct nfsd_file *nf) +{ + struct net *net = nf->nf_net; + + if (nfsd_net_try_get(net)) { + nf = nfsd_file_get(nf); + if (!nf) + nfsd_net_put(net); + } else { + nf = NULL; + } + return nf; +} + +/** * nfsd_file_file - get the backing file of an nfsd_file * @nf: nfsd_file of which to access the backing file. * diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h index 5865f9c72712..722b26c71e45 100644 --- a/fs/nfsd/filecache.h +++ b/fs/nfsd/filecache.h @@ -62,7 +62,8 @@ void nfsd_file_cache_shutdown(void); int nfsd_file_cache_start_net(struct net *net); void nfsd_file_cache_shutdown_net(struct net *net); void nfsd_file_put(struct nfsd_file *nf); -struct net *nfsd_file_put_local(struct nfsd_file *nf); +struct net *nfsd_file_put_local(struct nfsd_file __rcu **nf); +struct nfsd_file *nfsd_file_get_local(struct nfsd_file *nf); struct nfsd_file *nfsd_file_get(struct nfsd_file *nf); struct file *nfsd_file_file(struct nfsd_file *nf); void nfsd_file_close_inode_sync(struct inode *inode); diff --git a/fs/nfsd/localio.c b/fs/nfsd/localio.c index 238647fa379e..80d9ff6608a7 100644 --- a/fs/nfsd/localio.c +++ b/fs/nfsd/localio.c @@ -24,21 +24,6 @@ #include "filecache.h" #include "cache.h" -static const struct nfsd_localio_operations nfsd_localio_ops = { - .nfsd_net_try_get = nfsd_net_try_get, - .nfsd_net_put = nfsd_net_put, - .nfsd_open_local_fh = nfsd_open_local_fh, - .nfsd_file_put_local = nfsd_file_put_local, - .nfsd_file_get = nfsd_file_get, - .nfsd_file_put = nfsd_file_put, - .nfsd_file_file = nfsd_file_file, -}; - -void nfsd_localio_ops_init(void) -{ - nfs_to = &nfsd_localio_ops; -} - /** * nfsd_open_local_fh - lookup a local filehandle @nfs_fh and map to nfsd_file * @@ -47,6 +32,7 @@ void nfsd_localio_ops_init(void) * @rpc_clnt: rpc_clnt that the client established * @cred: cred that the client established * @nfs_fh: filehandle to lookup + * @nfp: place to find the nfsd_file, or store it if it was non-NULL * @fmode: fmode_t to use for open * * This function maps a local fh to a path on a local filesystem. @@ -57,10 +43,11 @@ void nfsd_localio_ops_init(void) * set. Caller (NFS client) is responsible for calling nfsd_net_put and * nfsd_file_put (via nfs_to_nfsd_file_put_local). */ -struct nfsd_file * +static struct nfsd_file * nfsd_open_local_fh(struct net *net, struct auth_domain *dom, struct rpc_clnt *rpc_clnt, const struct cred *cred, - const struct nfs_fh *nfs_fh, const fmode_t fmode) + const struct nfs_fh *nfs_fh, struct nfsd_file __rcu **pnf, + const fmode_t fmode) { int mayflags = NFSD_MAY_LOCALIO; struct svc_cred rq_cred; @@ -71,6 +58,15 @@ nfsd_open_local_fh(struct net *net, struct auth_domain *dom, if (nfs_fh->size > NFS4_FHSIZE) return ERR_PTR(-EINVAL); + if (!nfsd_net_try_get(net)) + return ERR_PTR(-ENXIO); + + rcu_read_lock(); + localio = nfsd_file_get(rcu_dereference(*pnf)); + rcu_read_unlock(); + if (localio) + return localio; + /* nfs_fh -> svc_fh */ fh_init(&fh, NFS4_FHSIZE); fh.fh_handle.fh_size = nfs_fh->size; @@ -92,9 +88,47 @@ nfsd_open_local_fh(struct net *net, struct auth_domain *dom, if (rq_cred.cr_group_info) put_group_info(rq_cred.cr_group_info); + if (!IS_ERR(localio)) { + struct nfsd_file *new; + if (!nfsd_net_try_get(net)) { + nfsd_file_put(localio); + nfsd_net_put(net); + return ERR_PTR(-ENXIO); + } + nfsd_file_get(localio); + again: + new = unrcu_pointer(cmpxchg(pnf, NULL, RCU_INITIALIZER(localio))); + if (new) { + /* Some other thread installed an nfsd_file */ + if (nfsd_file_get(new) == NULL) + goto again; + /* + * Drop the ref we were going to install and the + * one we were going to return. + */ + nfsd_file_put(localio); + nfsd_file_put(localio); + localio = new; + } + } else + nfsd_net_put(net); + return localio; } -EXPORT_SYMBOL_GPL(nfsd_open_local_fh); + +static const struct nfsd_localio_operations nfsd_localio_ops = { + .nfsd_net_try_get = nfsd_net_try_get, + .nfsd_net_put = nfsd_net_put, + .nfsd_open_local_fh = nfsd_open_local_fh, + .nfsd_file_put_local = nfsd_file_put_local, + .nfsd_file_get_local = nfsd_file_get_local, + .nfsd_file_file = nfsd_file_file, +}; + +void nfsd_localio_ops_init(void) +{ + nfs_to = &nfsd_localio_ops; +} /* * UUID_IS_LOCAL XDR functions |