diff options
| -rw-r--r-- | fs/nfs/callback.c | 112 | ||||
| -rw-r--r-- | fs/nfs/callback.h | 7 |
2 files changed, 115 insertions, 4 deletions
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c index 4b1313eda6f..47092889806 100644 --- a/fs/nfs/callback.c +++ b/fs/nfs/callback.c @@ -17,6 +17,9 @@ #include <linux/freezer.h> #include <linux/kthread.h> #include <linux/sunrpc/svcauth_gss.h> +#if defined(CONFIG_NFS_V4_1) +#include <linux/sunrpc/bc_xprt.h> +#endif #include <net/inet_sock.h> @@ -28,6 +31,7 @@ struct nfs_callback_data { unsigned int users; + struct svc_serv *serv; struct svc_rqst *rqst; struct task_struct *task; }; @@ -131,6 +135,99 @@ out_err: return ERR_PTR(ret); } +#if defined(CONFIG_NFS_V4_1) +/* + * The callback service for NFSv4.1 callbacks + */ +static int +nfs41_callback_svc(void *vrqstp) +{ + struct svc_rqst *rqstp = vrqstp; + struct svc_serv *serv = rqstp->rq_server; + struct rpc_rqst *req; + int error; + DEFINE_WAIT(wq); + + set_freezable(); + + /* + * FIXME: do we really need to run this under the BKL? If so, please + * add a comment about what it's intended to protect. + */ + lock_kernel(); + while (!kthread_should_stop()) { + prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE); + spin_lock_bh(&serv->sv_cb_lock); + if (!list_empty(&serv->sv_cb_list)) { + req = list_first_entry(&serv->sv_cb_list, + struct rpc_rqst, rq_bc_list); + list_del(&req->rq_bc_list); + spin_unlock_bh(&serv->sv_cb_lock); + dprintk("Invoking bc_svc_process()\n"); + error = bc_svc_process(serv, req, rqstp); + dprintk("bc_svc_process() returned w/ error code= %d\n", + error); + } else { + spin_unlock_bh(&serv->sv_cb_lock); + schedule(); + } + finish_wait(&serv->sv_cb_waitq, &wq); + } + unlock_kernel(); + nfs_callback_info.task = NULL; + svc_exit_thread(rqstp); + return 0; +} + +/* + * Bring up the NFSv4.1 callback service + */ +struct svc_rqst * +nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt) +{ + /* + * Save the svc_serv in the transport so that it can + * be referenced when the session backchannel is initialized + */ + xprt->bc_serv = serv; + + INIT_LIST_HEAD(&serv->sv_cb_list); + spin_lock_init(&serv->sv_cb_lock); + init_waitqueue_head(&serv->sv_cb_waitq); + return svc_prepare_thread(serv, &serv->sv_pools[0]); +} + +static inline int nfs_minorversion_callback_svc_setup(u32 minorversion, + struct svc_serv *serv, struct rpc_xprt *xprt, + struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) +{ + if (minorversion) { + *rqstpp = nfs41_callback_up(serv, xprt); + *callback_svc = nfs41_callback_svc; + } + return minorversion; +} + +static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, + struct nfs_callback_data *cb_info) +{ + if (minorversion) + xprt->bc_serv = cb_info->serv; +} +#else +static inline int nfs_minorversion_callback_svc_setup(u32 minorversion, + struct svc_serv *serv, struct rpc_xprt *xprt, + struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp)) +{ + return 0; +} + +static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt, + struct nfs_callback_data *cb_info) +{ +} +#endif /* CONFIG_NFS_V4_1 */ + /* * Bring up the callback thread if it is not already up. */ @@ -141,21 +238,25 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt) int (*callback_svc)(void *vrqstp); char svc_name[12]; int ret = 0; + int minorversion_setup; mutex_lock(&nfs_callback_mutex); - if (nfs_callback_info.users++ || nfs_callback_info.task != NULL) + if (nfs_callback_info.users++ || nfs_callback_info.task != NULL) { + nfs_callback_bc_serv(minorversion, xprt, &nfs_callback_info); goto out; + } serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL); if (!serv) { ret = -ENOMEM; goto out_err; } - if (!minorversion) { + minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion, + serv, xprt, &rqstp, &callback_svc); + if (!minorversion_setup) { + /* v4.0 callback setup */ rqstp = nfs4_callback_up(serv); callback_svc = nfs4_callback_svc; - } else { - BUG(); /* for now */ } if (IS_ERR(rqstp)) { @@ -166,6 +267,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt) svc_sock_update_bufs(serv); sprintf(svc_name, "nfsv4.%u-svc", minorversion); + nfs_callback_info.serv = serv; nfs_callback_info.rqst = rqstp; nfs_callback_info.task = kthread_run(callback_svc, nfs_callback_info.rqst, @@ -173,6 +275,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt) if (IS_ERR(nfs_callback_info.task)) { ret = PTR_ERR(nfs_callback_info.task); svc_exit_thread(nfs_callback_info.rqst); + nfs_callback_info.serv = NULL; nfs_callback_info.rqst = NULL; nfs_callback_info.task = NULL; goto out_err; @@ -205,6 +308,7 @@ void nfs_callback_down(void) if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) { kthread_stop(nfs_callback_info.task); svc_exit_thread(nfs_callback_info.rqst); + nfs_callback_info.serv = NULL; nfs_callback_info.rqst = NULL; nfs_callback_info.task = NULL; } diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h index 9b907f408b8..29123b5604f 100644 --- a/fs/nfs/callback.h +++ b/fs/nfs/callback.h @@ -70,6 +70,13 @@ extern void nfs_callback_down(void); #define nfs_callback_down() do {} while(0) #endif +/* + * nfs41: Callbacks are expected to not cause substantial latency, + * so we limit their concurrency to 1 by setting up the maximum number + * of slots for the backchannel. + */ +#define NFS41_BC_MIN_CALLBACKS 1 + extern unsigned int nfs_callback_set_tcpport; extern unsigned short nfs_callback_tcpport; extern unsigned short nfs_callback_tcpport6; |