From bf294b41cefcb22fc3139e0f42c5b3f06728bd5e Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 21 Feb 2011 11:05:41 -0800 Subject: SUNRPC: Close a race in __rpc_wait_for_completion_task() Although they run as rpciod background tasks, under normal operation (i.e. no SIGKILL), functions like nfs_sillyrename(), nfs4_proc_unlck() and nfs4_do_close() want to be fully synchronous. This means that when we exit, we want all references to the rpc_task to be gone, and we want any dentry references etc. held by that task to be released. For this reason these functions call __rpc_wait_for_completion_task(), followed by rpc_put_task() in the expectation that the latter will be releasing the last reference to the rpc_task, and thus ensuring that the callback_ops->rpc_release() has been called synchronously. This patch fixes a race which exists due to the fact that rpciod calls rpc_complete_task() (in order to wake up the callers of __rpc_wait_for_completion_task()) and then subsequently calls rpc_put_task() without ensuring that these two steps are done atomically. In order to avoid adding new spin locks, the patch uses the existing waitqueue spin lock to order the rpc_task reference count releases between the waiting process and rpciod. The common case where nobody is waiting for completion is optimised for by checking if the RPC_TASK_ASYNC flag is cleared and/or if the rpc_task reference count is 1: in those cases we drop trying to grab the spin lock, and immediately free up the rpc_task. Those few processes that need to put the rpc_task from inside an asynchronous context and that do not care about ordering are given a new helper: rpc_put_task_async(). Signed-off-by: Trond Myklebust --- include/linux/sunrpc/sched.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h index 88513fd8e208..d81db8012c63 100644 --- a/include/linux/sunrpc/sched.h +++ b/include/linux/sunrpc/sched.h @@ -212,6 +212,7 @@ struct rpc_task *rpc_run_task(const struct rpc_task_setup *); struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req, const struct rpc_call_ops *ops); void rpc_put_task(struct rpc_task *); +void rpc_put_task_async(struct rpc_task *); void rpc_exit_task(struct rpc_task *); void rpc_exit(struct rpc_task *, int); void rpc_release_calldata(const struct rpc_call_ops *, void *); -- cgit v1.2.3 From 114f64b5f24abac33a42f4f1856eb3a9766d497e Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Wed, 9 Mar 2011 13:13:45 -0500 Subject: NFSv4: remove duplicate clientid in struct nfs_client Signed-off-by: Andy Adamson Signed-off-by: Trond Myklebust --- include/linux/nfs_fs_sb.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index b197563913bf..6beb33e834ba 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -71,8 +71,6 @@ struct nfs_client { #endif /* CONFIG_NFS_V4 */ #ifdef CONFIG_NFS_V4_1 - /* clientid returned from EXCHANGE_ID, used by session operations */ - u64 cl_ex_clid; /* The sequence id to use for the next CREATE_SESSION */ u32 cl_seqid; /* The flags used for obtaining the clientid during EXCHANGE_ID */ -- cgit v1.2.3 From 0400a6b0cb756f976bae32ae8db47bfa9853897c Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 9 Mar 2011 16:00:53 -0500 Subject: NFSv4/4.1: Fix nfs4_schedule_state_recovery abuses nfs4_schedule_state_recovery() should only be used when we need to force the state manager to check the lease. If we just want to start the state manager in order to handle a state recovery situation, we should be using nfs4_schedule_state_manager(). This patch fixes the abuses of nfs4_schedule_state_recovery() by replacing its use with a set of helper functions that do the right thing. Signed-off-by: Trond Myklebust --- include/linux/nfs_fs_sb.h | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index 6beb33e834ba..3e112de12d8d 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -68,9 +68,7 @@ struct nfs_client { unsigned char cl_id_uniquifier; u32 cl_cb_ident; /* v4.0 callback identifier */ const struct nfs4_minor_version_ops *cl_mvops; -#endif /* CONFIG_NFS_V4 */ -#ifdef CONFIG_NFS_V4_1 /* The sequence id to use for the next CREATE_SESSION */ u32 cl_seqid; /* The flags used for obtaining the clientid during EXCHANGE_ID */ @@ -78,7 +76,7 @@ struct nfs_client { struct nfs4_session *cl_session; /* sharred session */ struct list_head cl_layouts; struct pnfs_deviceid_cache *cl_devid_cache; /* pNFS deviceid cache */ -#endif /* CONFIG_NFS_V4_1 */ +#endif /* CONFIG_NFS_V4 */ #ifdef CONFIG_NFS_FSCACHE struct fscache_cookie *fscache; /* client index cache cookie */ @@ -183,7 +181,7 @@ struct nfs_server { /* maximum number of slots to use */ #define NFS4_MAX_SLOT_TABLE RPC_MAX_SLOT_TABLE -#if defined(CONFIG_NFS_V4_1) +#if defined(CONFIG_NFS_V4) /* Sessions */ #define SLOT_TABLE_SZ (NFS4_MAX_SLOT_TABLE/(8*sizeof(long))) @@ -223,5 +221,5 @@ struct nfs4_session { struct nfs_client *clp; }; -#endif /* CONFIG_NFS_V4_1 */ +#endif /* CONFIG_NFS_V4 */ #endif -- cgit v1.2.3