NFSv4.1: filelayout read
Attempt a pNFS file layout read by setting up the nfs_read_data struct and
calling nfs_initiate_read with the data server rpc client and the
filelayout rpc call ops.
Error handling is implemented in a subsequent patch.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Tested-by: Guo Mingyang <guomingyang@nrchpc.ac.cn>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index ed83370..3608411 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -101,6 +101,87 @@
}
/*
+ * Call ops for the async read/write cases
+ * In the case of dense layouts, the offset needs to be reset to its
+ * original value.
+ */
+static void filelayout_read_prepare(struct rpc_task *task, void *data)
+{
+ struct nfs_read_data *rdata = (struct nfs_read_data *)data;
+
+ if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
+ &rdata->args.seq_args, &rdata->res.seq_res,
+ 0, task))
+ return;
+
+ rpc_call_start(task);
+}
+
+static void filelayout_read_call_done(struct rpc_task *task, void *data)
+{
+ struct nfs_read_data *rdata = (struct nfs_read_data *)data;
+
+ dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
+
+ /* Note this may cause RPC to be resent */
+ rdata->mds_ops->rpc_call_done(task, data);
+}
+
+static void filelayout_read_release(void *data)
+{
+ struct nfs_read_data *rdata = (struct nfs_read_data *)data;
+
+ rdata->mds_ops->rpc_release(data);
+}
+
+struct rpc_call_ops filelayout_read_call_ops = {
+ .rpc_call_prepare = filelayout_read_prepare,
+ .rpc_call_done = filelayout_read_call_done,
+ .rpc_release = filelayout_read_release,
+};
+
+static enum pnfs_try_status
+filelayout_read_pagelist(struct nfs_read_data *data)
+{
+ struct pnfs_layout_segment *lseg = data->lseg;
+ struct nfs4_pnfs_ds *ds;
+ loff_t offset = data->args.offset;
+ u32 j, idx;
+ struct nfs_fh *fh;
+ int status;
+
+ dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
+ __func__, data->inode->i_ino,
+ data->args.pgbase, (size_t)data->args.count, offset);
+
+ /* Retrieve the correct rpc_client for the byte range */
+ j = nfs4_fl_calc_j_index(lseg, offset);
+ idx = nfs4_fl_calc_ds_index(lseg, j);
+ ds = nfs4_fl_prepare_ds(lseg, idx);
+ if (!ds) {
+ printk(KERN_ERR "%s: prepare_ds failed, use MDS\n", __func__);
+ return PNFS_NOT_ATTEMPTED;
+ }
+ dprintk("%s USE DS:ip %x %hu\n", __func__,
+ ntohl(ds->ds_ip_addr), ntohs(ds->ds_port));
+
+ /* No multipath support. Use first DS */
+ data->ds_clp = ds->ds_clp;
+ fh = nfs4_fl_select_ds_fh(lseg, j);
+ if (fh)
+ data->args.fh = fh;
+
+ data->args.offset = filelayout_get_dserver_offset(lseg, offset);
+ data->mds_offset = offset;
+
+ /* Perform an asynchronous read to ds */
+ status = nfs_initiate_read(data, ds->ds_clp->cl_rpcclient,
+ &filelayout_read_call_ops);
+ BUG_ON(status != 0);
+ return PNFS_ATTEMPTED;
+}
+
+/*
* filelayout_check_layout()
*
* Make sure layout segment parameters are sane WRT the device.
@@ -320,6 +401,7 @@
.alloc_lseg = filelayout_alloc_lseg,
.free_lseg = filelayout_free_lseg,
.pg_test = filelayout_pg_test,
+ .read_pagelist = filelayout_read_pagelist,
};
static int __init nfs4filelayout_init(void)