Messages in this thread Patch in this message | | | From | Chuck Lever <> | Subject | [PATCH 1/6] nfs: "open code" the NFS direct write rescheduler | Date | Fri, 19 May 2006 14:00:21 -0400 |
| |
In order to support direct asynchronous vectored writes, the write rescheduler in fs/nfs/direct.c must not depend on the I/O parameters in the controlling nfs_direct_req structure. Refactor the write rescheduler to use only the information in each nfs_write_data structure to redrive writes if the server rebooted before we can commit them.
Signed-off-by: Chuck Lever <cel@netapp.com> ---
fs/nfs/direct.c | 71 +++++++++++++++++++++++++++++++++++++++++++------------ 1 files changed, 56 insertions(+), 15 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 0980e43..0fde4bf 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -94,8 +94,19 @@ 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 int nfs_direct_dec_outstanding(struct nfs_direct_req *dreq) +{ + int result; + + spin_lock(&dreq->lock); + result = --dreq->outstanding; + spin_unlock(&dreq->lock); + + return (result == 0); +} /** * nfs_direct_IO - NFS address space operation for direct I/O @@ -428,14 +439,52 @@ static void nfs_direct_free_writedata(st #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) { + struct inode *inode = dreq->inode; struct list_head *pos; - list_splice_init(&dreq->rewrite_list, &dreq->list); - list_for_each(pos, &dreq->list) - dreq->outstanding++; + /* + * Prevent I/O completion while we're still rescheduling + */ + dreq->outstanding++; + dreq->count = 0; + list_for_each(pos, &dreq->rewrite_list) { + struct nfs_write_data *data = + list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages); + + spin_lock(&dreq->lock); + dreq->outstanding++; + spin_unlock(&dreq->lock); + + nfs_fattr_init(&data->fattr); + data->res.count = data->args.count; + memset(&data->verf, 0, sizeof(data->verf)); + + 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_HIGH; + data->task.tk_cookie = (unsigned long) inode; - nfs_direct_write_schedule(dreq, FLUSH_STABLE); + lock_kernel(); + rpc_execute(&data->task); + unlock_kernel(); + + dfprintk(VFS, "NFS: %5u rescheduled direct write call (req %s/%Ld, %zu 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); + } + + /* + * If we raced with the rescheduled I/O and lost, then + * all the I/O is already complete. + */ + if (nfs_direct_dec_outstanding(dreq)) + nfs_direct_write_complete(dreq, inode); } static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) @@ -605,8 +654,6 @@ static void nfs_direct_write_result(stru } } } - /* In case we have to resend */ - data->args.stable = NFS_FILE_SYNC; spin_unlock(&dreq->lock); } @@ -620,14 +667,8 @@ static void nfs_direct_write_release(voi struct nfs_write_data *data = calldata; struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req; - spin_lock(&dreq->lock); - if (--dreq->outstanding) { - spin_unlock(&dreq->lock); - return; - } - spin_unlock(&dreq->lock); - - nfs_direct_write_complete(dreq, data->inode); + if (nfs_direct_dec_outstanding(dreq)) + nfs_direct_write_complete(dreq, data->inode); } static const struct rpc_call_ops nfs_write_direct_ops = { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |