From cee54fc944422c44e476736c045a9e8053cb0644 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 18 Oct 2005 14:20:12 -0700 Subject: NFSv4: Add functions to order RPC calls NFSv4 file state-changing functions such as OPEN, CLOSE, LOCK,... are all labelled with "sequence identifiers" in order to prevent the server from reordering RPC requests, as this could cause its file state to become out of sync with the client. Currently the NFS client code enforces this ordering locally using semaphores to restrict access to structures until the RPC call is done. This, of course, only works with synchronous RPC calls, since the user process must first grab the semaphore. By dropping semaphores, and instead teaching the RPC engine to hold the RPC calls until they are ready to be sent, we can extend this process to work nicely with asynchronous RPC calls too. This patch adds a new list called "rpc_sequence" that defines the order of the RPC calls to be sent. We add one such list for each state_owner. When an RPC call is ready to be sent, it checks if it is top of the rpc_sequence list. If so, it proceeds. If not, it goes back to sleep, and loops until it hits top of the list. Once the RPC call has completed, it can then bump the sequence id counter, and remove itself from the rpc_sequence list, and then wake up the next sleeper. Note that the state_owner sequence ids and lock_owner sequence ids are all indexed to the same rpc_sequence list, so OPEN, LOCK,... requests are all ordered w.r.t. each other. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 42 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 38 insertions(+), 4 deletions(-) (limited to 'fs/nfs/nfs4_fs.h') diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index ec1a22d7b87..6ac6708484f 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -92,6 +92,35 @@ struct nfs4_client { unsigned char cl_id_uniquifier; }; +/* + * struct rpc_sequence ensures that RPC calls are sent in the exact + * order that they appear on the list. + */ +struct rpc_sequence { + struct rpc_wait_queue wait; /* RPC call delay queue */ + spinlock_t lock; /* Protects the list */ + struct list_head list; /* Defines sequence of RPC calls */ +}; + +#define NFS_SEQID_CONFIRMED 1 +struct nfs_seqid_counter { + struct rpc_sequence *sequence; + int flags; + u32 counter; +}; + +struct nfs_seqid { + struct list_head list; + struct nfs_seqid_counter *sequence; + struct rpc_task *task; +}; + +static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status) +{ + if (seqid_mutating_err(-status)) + seqid->flags |= NFS_SEQID_CONFIRMED; +} + /* * NFS4 state_owners and lock_owners are simply labels for ordered * sequences of RPC calls. Their sole purpose is to provide once-only @@ -106,12 +135,13 @@ struct nfs4_state_owner { struct nfs4_client *so_client; u32 so_id; /* 32-bit identifier, unique */ struct semaphore so_sema; - u32 so_seqid; /* protected by so_sema */ atomic_t so_count; struct rpc_cred *so_cred; /* Associated cred */ struct list_head so_states; struct list_head so_delegations; + struct nfs_seqid_counter so_seqid; + struct rpc_sequence so_sequence; }; /* @@ -132,7 +162,7 @@ struct nfs4_lock_state { fl_owner_t ls_owner; /* POSIX lock owner */ #define NFS_LOCK_INITIALIZED 1 int ls_flags; - u32 ls_seqid; + struct nfs_seqid_counter ls_seqid; u32 ls_id; nfs4_stateid ls_stateid; atomic_t ls_count; @@ -224,12 +254,16 @@ extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state extern void nfs4_put_open_state(struct nfs4_state *); extern void nfs4_close_state(struct nfs4_state *, mode_t); extern struct nfs4_state *nfs4_find_state(struct inode *, struct rpc_cred *, mode_t mode); -extern void nfs4_increment_seqid(int status, struct nfs4_state_owner *sp); extern void nfs4_schedule_state_recovery(struct nfs4_client *); extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl); -extern void nfs4_increment_lock_seqid(int status, struct nfs4_lock_state *ls); extern void nfs4_copy_stateid(nfs4_stateid *, struct nfs4_state *, fl_owner_t); +extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter); +extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task); +extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid); +extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid); +extern void nfs_free_seqid(struct nfs_seqid *seqid); + extern const nfs4_stateid zero_stateid; /* nfs4xdr.c */ -- cgit v1.2.3-18-g5258 From e6dfa553cffcb9740f932311dff42f81d6ac63bb Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 18 Oct 2005 14:20:13 -0700 Subject: NFSv4: Remove obsolete state_owner and lock_owner semaphores OPEN, CLOSE, etc no longer need these semaphores to ensure ordering of requests. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'fs/nfs/nfs4_fs.h') diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 6ac6708484f..d4fcb5d0ce6 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -125,16 +125,11 @@ static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status * NFS4 state_owners and lock_owners are simply labels for ordered * sequences of RPC calls. Their sole purpose is to provide once-only * semantics by allowing the server to identify replayed requests. - * - * The ->so_sema is held during all state_owner seqid-mutating operations: - * OPEN, OPEN_DOWNGRADE, and CLOSE. Its purpose is to properly serialize - * so_seqid. */ struct nfs4_state_owner { struct list_head so_list; /* per-clientid list of state_owners */ struct nfs4_client *so_client; u32 so_id; /* 32-bit identifier, unique */ - struct semaphore so_sema; atomic_t so_count; struct rpc_cred *so_cred; /* Associated cred */ @@ -183,7 +178,6 @@ struct nfs4_state { struct inode *inode; /* Pointer to the inode */ unsigned long flags; /* Do we hold any locks? */ - struct semaphore lock_sema; /* Serializes file locking operations */ spinlock_t state_lock; /* Protects the lock_states list */ nfs4_stateid stateid; -- cgit v1.2.3-18-g5258 From faf5f49c2d9c0af2847837c232a432cc146e203b Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 18 Oct 2005 14:20:15 -0700 Subject: NFSv4: Make NFS clean up byte range locks asynchronously Currently we fail to do so if the process was signalled. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/nfs/nfs4_fs.h') diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index d4fcb5d0ce6..2215cdee43a 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -249,6 +249,7 @@ extern void nfs4_put_open_state(struct nfs4_state *); extern void nfs4_close_state(struct nfs4_state *, mode_t); extern struct nfs4_state *nfs4_find_state(struct inode *, struct rpc_cred *, mode_t mode); extern void nfs4_schedule_state_recovery(struct nfs4_client *); +extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp); extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl); extern void nfs4_copy_stateid(nfs4_stateid *, struct nfs4_state *, fl_owner_t); -- cgit v1.2.3-18-g5258 From 02a913a73b52071e93f4b76db3e86138d19efffd Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 18 Oct 2005 14:20:17 -0700 Subject: NFSv4: Eliminate nfsv4 open race... Make NFSv4 return the fully initialized file pointer with the stateid that it created in the lookup w/intent. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/nfs/nfs4_fs.h') diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 2215cdee43a..8a378819905 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -215,8 +215,8 @@ extern int nfs4_proc_setclientid_confirm(struct nfs4_client *); extern int nfs4_proc_async_renew(struct nfs4_client *); extern int nfs4_proc_renew(struct nfs4_client *); extern int nfs4_do_close(struct inode *inode, struct nfs4_state *state, mode_t mode); -extern struct inode *nfs4_atomic_open(struct inode *, struct dentry *, struct nameidata *); -extern int nfs4_open_revalidate(struct inode *, struct dentry *, int); +extern struct dentry *nfs4_atomic_open(struct inode *, struct dentry *, struct nameidata *); +extern int nfs4_open_revalidate(struct inode *, struct dentry *, int, struct nameidata *); extern struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops; extern struct nfs4_state_recovery_ops nfs4_network_partition_recovery_ops; -- cgit v1.2.3-18-g5258 From 7f709a48fa798cfa0f2f777c8752e12995054f78 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 18 Oct 2005 23:19:39 -0700 Subject: NFSv4: Fix an oopsable condition in nfs_free_seqid Storing a pointer to the struct rpc_task in the nfs_seqid is broken since the nfs_seqid may be freed well after the task has been destroyed. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/nfs/nfs4_fs.h') diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 8a378819905..45bff1d1a51 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -112,7 +112,6 @@ struct nfs_seqid_counter { struct nfs_seqid { struct list_head list; struct nfs_seqid_counter *sequence; - struct rpc_task *task; }; static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status) -- cgit v1.2.3-18-g5258 From 4e51336a00bdcb42960acca52c23e90e9f4e6959 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 20 Oct 2005 14:22:41 -0700 Subject: NFSv4: Final tweak to sequence id Sacrifice queueing fairness for performance. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs/nfs4_fs.h') diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 45bff1d1a51..5c0dd26d098 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -110,8 +110,8 @@ struct nfs_seqid_counter { }; struct nfs_seqid { - struct list_head list; struct nfs_seqid_counter *sequence; + struct list_head list; }; static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status) -- cgit v1.2.3-18-g5258 From ec073428281b401f1142cb84b277a5b00c7994c9 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 20 Oct 2005 14:22:47 -0700 Subject: NFSv4: Fix up locking for nfs4_state_owner Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/nfs/nfs4_fs.h') diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 5c0dd26d098..78a53f5a9f1 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -126,6 +126,7 @@ static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status * semantics by allowing the server to identify replayed requests. */ struct nfs4_state_owner { + spinlock_t so_lock; struct list_head so_list; /* per-clientid list of state_owners */ struct nfs4_client *so_client; u32 so_id; /* 32-bit identifier, unique */ -- cgit v1.2.3-18-g5258