From fedb595c66e1fbd5acafe0d43b7e95c13c936d61 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 20 Jun 2006 12:55:45 -0400 Subject: NFS: "open code" the NFS direct write rescheduler An NFSv3/v4 client must reschedule on-the-wire writes if the writes are UNSTABLE, and the server reboots before the client can complete a subsequent COMMIT request. To support direct asynchronous scatter-gather writes, the write rescheduler in fs/nfs/direct.c must not depend on the I/O parameters in the controlling nfs_direct_req structure. iovecs can be somewhat arbitrarily complex, so there could be an unbounded amount of information to save for a rarely encountered requirement. Refactor the direct write rescheduler so it uses information from each nfs_write_data structure to reschedule writes, instead of caching that information in the controlling nfs_direct_req structure. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/direct.c | 51 +++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 43 insertions(+), 8 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index d78c61a41ec3..7101405713e1 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -94,8 +94,8 @@ struct nfs_direct_req { struct nfs_writeverf verf; /* unstable write verifier */ }; -static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync); static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode); +static const struct rpc_call_ops nfs_write_direct_ops; static inline void get_dreq(struct nfs_direct_req *dreq) { @@ -435,14 +435,51 @@ static void nfs_direct_free_writedata(struct nfs_direct_req *dreq) #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) { - struct list_head *pos; + struct inode *inode = dreq->inode; + struct list_head *p; + struct nfs_write_data *data; - list_splice_init(&dreq->rewrite_list, &dreq->list); - list_for_each(pos, &dreq->list) - get_dreq(dreq); dreq->count = 0; + get_dreq(dreq); + + list_for_each(p, &dreq->rewrite_list) { + data = list_entry(p, struct nfs_write_data, pages); + + get_dreq(dreq); + + /* + * Reset data->res. + */ + nfs_fattr_init(&data->fattr); + data->res.count = data->args.count; + memset(&data->verf, 0, sizeof(data->verf)); + + /* + * Reuse data->task; data->args should not have changed + * since the original request was sent. + */ + rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC, + &nfs_write_direct_ops, data); + NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE); + + data->task.tk_priority = RPC_PRIORITY_NORMAL; + data->task.tk_cookie = (unsigned long) inode; + + /* + * We're called via an RPC callback, so BKL is already held. + */ + rpc_execute(&data->task); + + dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n", + data->task.tk_pid, + inode->i_sb->s_id, + (long long)NFS_FILEID(inode), + data->args.count, + (unsigned long long)data->args.offset); + } - nfs_direct_write_schedule(dreq, FLUSH_STABLE); + if (put_dreq(dreq)) + nfs_direct_write_complete(dreq, inode); } static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) @@ -612,8 +649,6 @@ static void nfs_direct_write_result(struct rpc_task *task, void *calldata) } } } - /* In case we have to resend */ - data->args.stable = NFS_FILE_SYNC; spin_unlock(&dreq->lock); } -- cgit v1.2.2