[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit

Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/nfs/nfs4filelayout.c b/ap/os/linux/linux-3.4.x/fs/nfs/nfs4filelayout.c
new file mode 100644
index 0000000..4d64d5b
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/nfs/nfs4filelayout.c
@@ -0,0 +1,1108 @@
+/*
+ *  Module for the pnfs nfs4 file layout driver.
+ *  Defines all I/O and Policy interface operations, plus code
+ *  to register itself with the pNFS client.
+ *
+ *  Copyright (c) 2002
+ *  The Regents of the University of Michigan
+ *  All Rights Reserved
+ *
+ *  Dean Hildebrand <dhildebz@umich.edu>
+ *
+ *  Permission is granted to use, copy, create derivative works, and
+ *  redistribute this software and such derivative works for any purpose,
+ *  so long as the name of the University of Michigan is not used in
+ *  any advertising or publicity pertaining to the use or distribution
+ *  of this software without specific, written prior authorization. If
+ *  the above copyright notice or any other identification of the
+ *  University of Michigan is included in any copy of any portion of
+ *  this software, then the disclaimer below must also be included.
+ *
+ *  This software is provided as is, without representation or warranty
+ *  of any kind either express or implied, including without limitation
+ *  the implied warranties of merchantability, fitness for a particular
+ *  purpose, or noninfringement.  The Regents of the University of
+ *  Michigan shall not be liable for any damages, including special,
+ *  indirect, incidental, or consequential damages, with respect to any
+ *  claim arising out of or in connection with the use of the software,
+ *  even if it has been or is hereafter advised of the possibility of
+ *  such damages.
+ */
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/module.h>
+
+#include <linux/sunrpc/metrics.h>
+
+#include "internal.h"
+#include "delegation.h"
+#include "nfs4filelayout.h"
+
+#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
+MODULE_DESCRIPTION("The NFSv4 file layout driver");
+
+#define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
+
+static loff_t
+filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
+			    loff_t offset)
+{
+	u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
+	u64 stripe_no;
+	u32 rem;
+
+	offset -= flseg->pattern_offset;
+	stripe_no = div_u64(offset, stripe_width);
+	div_u64_rem(offset, flseg->stripe_unit, &rem);
+
+	return stripe_no * flseg->stripe_unit + rem;
+}
+
+/* This function is used by the layout driver to calculate the
+ * offset of the file on the dserver based on whether the
+ * layout type is STRIPE_DENSE or STRIPE_SPARSE
+ */
+static loff_t
+filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
+{
+	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
+
+	switch (flseg->stripe_type) {
+	case STRIPE_SPARSE:
+		return offset;
+
+	case STRIPE_DENSE:
+		return filelayout_get_dense_offset(flseg, offset);
+	}
+
+	BUG();
+}
+
+static int filelayout_async_handle_error(struct rpc_task *task,
+					 struct nfs4_state *state,
+					 struct nfs_client *clp,
+					 int *reset)
+{
+	struct nfs_server *mds_server = NFS_SERVER(state->inode);
+	struct nfs_client *mds_client = mds_server->nfs_client;
+
+	if (task->tk_status >= 0)
+		return 0;
+	*reset = 0;
+
+	switch (task->tk_status) {
+	/* MDS state errors */
+	case -NFS4ERR_DELEG_REVOKED:
+	case -NFS4ERR_ADMIN_REVOKED:
+	case -NFS4ERR_BAD_STATEID:
+		nfs_remove_bad_delegation(state->inode);
+	case -NFS4ERR_OPENMODE:
+		nfs4_schedule_stateid_recovery(mds_server, state);
+		goto wait_on_recovery;
+	case -NFS4ERR_EXPIRED:
+		nfs4_schedule_stateid_recovery(mds_server, state);
+		nfs4_schedule_lease_recovery(mds_client);
+		goto wait_on_recovery;
+	/* DS session errors */
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_BADSLOT:
+	case -NFS4ERR_BAD_HIGH_SLOT:
+	case -NFS4ERR_DEADSESSION:
+	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+	case -NFS4ERR_SEQ_FALSE_RETRY:
+	case -NFS4ERR_SEQ_MISORDERED:
+		dprintk("%s ERROR %d, Reset session. Exchangeid "
+			"flags 0x%x\n", __func__, task->tk_status,
+			clp->cl_exchange_flags);
+		nfs4_schedule_session_recovery(clp->cl_session);
+		break;
+	case -NFS4ERR_DELAY:
+	case -NFS4ERR_GRACE:
+		rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
+		break;
+	case -NFS4ERR_RETRY_UNCACHED_REP:
+		break;
+	default:
+		dprintk("%s DS error. Retry through MDS %d\n", __func__,
+			task->tk_status);
+		*reset = 1;
+		break;
+	}
+out:
+	task->tk_status = 0;
+	return -EAGAIN;
+wait_on_recovery:
+	rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
+	if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
+		rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
+	goto out;
+}
+
+/* NFS_PROTO call done callback routines */
+
+static int filelayout_read_done_cb(struct rpc_task *task,
+				struct nfs_read_data *data)
+{
+	int reset = 0;
+
+	dprintk("%s DS read\n", __func__);
+
+	if (filelayout_async_handle_error(task, data->args.context->state,
+					  data->ds_clp, &reset) == -EAGAIN) {
+		dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
+			__func__, data->ds_clp, data->ds_clp->cl_session);
+		if (reset) {
+			pnfs_set_lo_fail(data->lseg);
+			nfs4_reset_read(task, data);
+		}
+		rpc_restart_call_prepare(task);
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+/*
+ * We reference the rpc_cred of the first WRITE that triggers the need for
+ * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
+ * rfc5661 is not clear about which credential should be used.
+ */
+static void
+filelayout_set_layoutcommit(struct nfs_write_data *wdata)
+{
+	if (FILELAYOUT_LSEG(wdata->lseg)->commit_through_mds ||
+	    wdata->res.verf->committed == NFS_FILE_SYNC)
+		return;
+
+	pnfs_set_layoutcommit(wdata);
+	dprintk("%s ionde %lu pls_end_pos %lu\n", __func__, wdata->inode->i_ino,
+		(unsigned long) NFS_I(wdata->inode)->layout->plh_lwb);
+}
+
+/*
+ * 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;
+
+	rdata->read_done_cb = filelayout_read_done_cb;
+
+	if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
+				&rdata->args.seq_args, &rdata->res.seq_res,
+				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_count_stats(struct rpc_task *task, void *data)
+{
+	struct nfs_read_data *rdata = (struct nfs_read_data *)data;
+
+	rpc_count_iostats(task, NFS_SERVER(rdata->inode)->client->cl_metrics);
+}
+
+static void filelayout_read_release(void *data)
+{
+	struct nfs_read_data *rdata = (struct nfs_read_data *)data;
+
+	put_lseg(rdata->lseg);
+	rdata->mds_ops->rpc_release(data);
+}
+
+static int filelayout_write_done_cb(struct rpc_task *task,
+				struct nfs_write_data *data)
+{
+	int reset = 0;
+
+	if (filelayout_async_handle_error(task, data->args.context->state,
+					  data->ds_clp, &reset) == -EAGAIN) {
+		dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
+			__func__, data->ds_clp, data->ds_clp->cl_session);
+		if (reset) {
+			pnfs_set_lo_fail(data->lseg);
+			nfs4_reset_write(task, data);
+		}
+		rpc_restart_call_prepare(task);
+		return -EAGAIN;
+	}
+
+	filelayout_set_layoutcommit(data);
+	return 0;
+}
+
+/* Fake up some data that will cause nfs_commit_release to retry the writes. */
+static void prepare_to_resend_writes(struct nfs_write_data *data)
+{
+	struct nfs_page *first = nfs_list_entry(data->pages.next);
+
+	data->task.tk_status = 0;
+	memcpy(data->verf.verifier, first->wb_verf.verifier,
+	       sizeof(first->wb_verf.verifier));
+	data->verf.verifier[0]++; /* ensure verifier mismatch */
+}
+
+static int filelayout_commit_done_cb(struct rpc_task *task,
+				     struct nfs_write_data *data)
+{
+	int reset = 0;
+
+	if (filelayout_async_handle_error(task, data->args.context->state,
+					  data->ds_clp, &reset) == -EAGAIN) {
+		dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
+			__func__, data->ds_clp, data->ds_clp->cl_session);
+		if (reset) {
+			prepare_to_resend_writes(data);
+			pnfs_set_lo_fail(data->lseg);
+		} else
+			rpc_restart_call_prepare(task);
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+static void filelayout_write_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs_write_data *wdata = (struct nfs_write_data *)data;
+
+	if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
+				&wdata->args.seq_args, &wdata->res.seq_res,
+				task))
+		return;
+
+	rpc_call_start(task);
+}
+
+static void filelayout_write_call_done(struct rpc_task *task, void *data)
+{
+	struct nfs_write_data *wdata = (struct nfs_write_data *)data;
+
+	/* Note this may cause RPC to be resent */
+	wdata->mds_ops->rpc_call_done(task, data);
+}
+
+static void filelayout_write_count_stats(struct rpc_task *task, void *data)
+{
+	struct nfs_write_data *wdata = (struct nfs_write_data *)data;
+
+	rpc_count_iostats(task, NFS_SERVER(wdata->inode)->client->cl_metrics);
+}
+
+static void filelayout_write_release(void *data)
+{
+	struct nfs_write_data *wdata = (struct nfs_write_data *)data;
+
+	put_lseg(wdata->lseg);
+	wdata->mds_ops->rpc_release(data);
+}
+
+static void filelayout_commit_release(void *data)
+{
+	struct nfs_write_data *wdata = (struct nfs_write_data *)data;
+
+	nfs_commit_release_pages(wdata);
+	if (atomic_dec_and_test(&NFS_I(wdata->inode)->commits_outstanding))
+		nfs_commit_clear_lock(NFS_I(wdata->inode));
+	put_lseg(wdata->lseg);
+	nfs_commitdata_release(wdata);
+}
+
+static const struct rpc_call_ops filelayout_read_call_ops = {
+	.rpc_call_prepare = filelayout_read_prepare,
+	.rpc_call_done = filelayout_read_call_done,
+	.rpc_count_stats = filelayout_read_count_stats,
+	.rpc_release = filelayout_read_release,
+};
+
+static const struct rpc_call_ops filelayout_write_call_ops = {
+	.rpc_call_prepare = filelayout_write_prepare,
+	.rpc_call_done = filelayout_write_call_done,
+	.rpc_count_stats = filelayout_write_count_stats,
+	.rpc_release = filelayout_write_release,
+};
+
+static const struct rpc_call_ops filelayout_commit_call_ops = {
+	.rpc_call_prepare = filelayout_write_prepare,
+	.rpc_call_done = filelayout_write_call_done,
+	.rpc_count_stats = filelayout_write_count_stats,
+	.rpc_release = filelayout_commit_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);
+
+	if (test_bit(NFS_DEVICEID_INVALID, &FILELAYOUT_DEVID_NODE(lseg)->flags))
+		return PNFS_NOT_ATTEMPTED;
+
+	/* 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) {
+		/* Either layout fh index faulty, or ds connect failed */
+		set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
+		set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
+		return PNFS_NOT_ATTEMPTED;
+	}
+	dprintk("%s USE DS: %s\n", __func__, ds->ds_remotestr);
+
+	/* 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;
+}
+
+/* Perform async writes. */
+static enum pnfs_try_status
+filelayout_write_pagelist(struct nfs_write_data *data, int sync)
+{
+	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;
+
+	if (test_bit(NFS_DEVICEID_INVALID, &FILELAYOUT_DEVID_NODE(lseg)->flags))
+		return PNFS_NOT_ATTEMPTED;
+
+	/* 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 "NFS: %s: prepare_ds failed, use MDS\n",
+			__func__);
+		set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
+		set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
+		return PNFS_NOT_ATTEMPTED;
+	}
+	dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s\n", __func__,
+		data->inode->i_ino, sync, (size_t) data->args.count, offset,
+		ds->ds_remotestr);
+
+	data->write_done_cb = filelayout_write_done_cb;
+	data->ds_clp = ds->ds_clp;
+	fh = nfs4_fl_select_ds_fh(lseg, j);
+	if (fh)
+		data->args.fh = fh;
+	/*
+	 * Get the file offset on the dserver. Set the write offset to
+	 * this offset and save the original offset.
+	 */
+	data->args.offset = filelayout_get_dserver_offset(lseg, offset);
+
+	/* Perform an asynchronous write */
+	status = nfs_initiate_write(data, ds->ds_clp->cl_rpcclient,
+				    &filelayout_write_call_ops, sync);
+	BUG_ON(status != 0);
+	return PNFS_ATTEMPTED;
+}
+
+/*
+ * filelayout_check_layout()
+ *
+ * Make sure layout segment parameters are sane WRT the device.
+ * At this point no generic layer initialization of the lseg has occurred,
+ * and nothing has been added to the layout_hdr cache.
+ *
+ */
+static int
+filelayout_check_layout(struct pnfs_layout_hdr *lo,
+			struct nfs4_filelayout_segment *fl,
+			struct nfs4_layoutget_res *lgr,
+			struct nfs4_deviceid *id,
+			gfp_t gfp_flags)
+{
+	struct nfs4_deviceid_node *d;
+	struct nfs4_file_layout_dsaddr *dsaddr;
+	int status = -EINVAL;
+	struct nfs_server *nfss = NFS_SERVER(lo->plh_inode);
+
+	dprintk("--> %s\n", __func__);
+
+	/* FIXME: remove this check when layout segment support is added */
+	if (lgr->range.offset != 0 ||
+	    lgr->range.length != NFS4_MAX_UINT64) {
+		dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
+			__func__);
+		goto out;
+	}
+
+	if (fl->pattern_offset > lgr->range.offset) {
+		dprintk("%s pattern_offset %lld too large\n",
+				__func__, fl->pattern_offset);
+		goto out;
+	}
+
+	if (!fl->stripe_unit || fl->stripe_unit % PAGE_SIZE) {
+		dprintk("%s Invalid stripe unit (%u)\n",
+			__func__, fl->stripe_unit);
+		goto out;
+	}
+
+	/* find and reference the deviceid */
+	d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
+				   NFS_SERVER(lo->plh_inode)->nfs_client, id);
+	if (d == NULL) {
+		dsaddr = get_device_info(lo->plh_inode, id, gfp_flags);
+		if (dsaddr == NULL)
+			goto out;
+	} else
+		dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
+	/* Found deviceid is being reaped */
+	if (test_bit(NFS_DEVICEID_INVALID, &dsaddr->id_node.flags))
+			goto out_put;
+
+	fl->dsaddr = dsaddr;
+
+	if (fl->first_stripe_index >= dsaddr->stripe_count) {
+		dprintk("%s Bad first_stripe_index %u\n",
+				__func__, fl->first_stripe_index);
+		goto out_put;
+	}
+
+	if ((fl->stripe_type == STRIPE_SPARSE &&
+	    fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
+	    (fl->stripe_type == STRIPE_DENSE &&
+	    fl->num_fh != dsaddr->stripe_count)) {
+		dprintk("%s num_fh %u not valid for given packing\n",
+			__func__, fl->num_fh);
+		goto out_put;
+	}
+
+	if (fl->stripe_unit % nfss->rsize || fl->stripe_unit % nfss->wsize) {
+		dprintk("%s Stripe unit (%u) not aligned with rsize %u "
+			"wsize %u\n", __func__, fl->stripe_unit, nfss->rsize,
+			nfss->wsize);
+	}
+
+	status = 0;
+out:
+	dprintk("--> %s returns %d\n", __func__, status);
+	return status;
+out_put:
+	nfs4_fl_put_deviceid(dsaddr);
+	goto out;
+}
+
+static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
+{
+	int i;
+
+	for (i = 0; i < fl->num_fh; i++) {
+		if (!fl->fh_array[i])
+			break;
+		kfree(fl->fh_array[i]);
+	}
+	kfree(fl->fh_array);
+	fl->fh_array = NULL;
+}
+
+static void
+_filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
+{
+	filelayout_free_fh_array(fl);
+	kfree(fl);
+}
+
+static int
+filelayout_decode_layout(struct pnfs_layout_hdr *flo,
+			 struct nfs4_filelayout_segment *fl,
+			 struct nfs4_layoutget_res *lgr,
+			 struct nfs4_deviceid *id,
+			 gfp_t gfp_flags)
+{
+	struct xdr_stream stream;
+	struct xdr_buf buf;
+	struct page *scratch;
+	__be32 *p;
+	uint32_t nfl_util;
+	int i;
+
+	dprintk("%s: set_layout_map Begin\n", __func__);
+
+	scratch = alloc_page(gfp_flags);
+	if (!scratch)
+		return -ENOMEM;
+
+	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
+	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+	/* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
+	 * num_fh (4) */
+	p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
+	if (unlikely(!p))
+		goto out_err;
+
+	memcpy(id, p, sizeof(*id));
+	p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
+	nfs4_print_deviceid(id);
+
+	nfl_util = be32_to_cpup(p++);
+	if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
+		fl->commit_through_mds = 1;
+	if (nfl_util & NFL4_UFLG_DENSE)
+		fl->stripe_type = STRIPE_DENSE;
+	else
+		fl->stripe_type = STRIPE_SPARSE;
+	fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
+
+	fl->first_stripe_index = be32_to_cpup(p++);
+	p = xdr_decode_hyper(p, &fl->pattern_offset);
+	fl->num_fh = be32_to_cpup(p++);
+
+	dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
+		__func__, nfl_util, fl->num_fh, fl->first_stripe_index,
+		fl->pattern_offset);
+
+	/* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
+	 * Futher checking is done in filelayout_check_layout */
+	if (fl->num_fh >
+	    max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
+		goto out_err;
+
+	if (fl->num_fh > 0) {
+		fl->fh_array = kzalloc(fl->num_fh * sizeof(struct nfs_fh *),
+				       gfp_flags);
+		if (!fl->fh_array)
+			goto out_err;
+	}
+
+	for (i = 0; i < fl->num_fh; i++) {
+		/* Do we want to use a mempool here? */
+		fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
+		if (!fl->fh_array[i])
+			goto out_err_free;
+
+		p = xdr_inline_decode(&stream, 4);
+		if (unlikely(!p))
+			goto out_err_free;
+		fl->fh_array[i]->size = be32_to_cpup(p++);
+		if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
+			printk(KERN_ERR "NFS: Too big fh %d received %d\n",
+			       i, fl->fh_array[i]->size);
+			goto out_err_free;
+		}
+
+		p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
+		if (unlikely(!p))
+			goto out_err_free;
+		memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
+		dprintk("DEBUG: %s: fh len %d\n", __func__,
+			fl->fh_array[i]->size);
+	}
+
+	__free_page(scratch);
+	return 0;
+
+out_err_free:
+	filelayout_free_fh_array(fl);
+out_err:
+	__free_page(scratch);
+	return -EIO;
+}
+
+static void
+filelayout_free_lseg(struct pnfs_layout_segment *lseg)
+{
+	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
+
+	dprintk("--> %s\n", __func__);
+	nfs4_fl_put_deviceid(fl->dsaddr);
+	kfree(fl->commit_buckets);
+	_filelayout_free_lseg(fl);
+}
+
+static struct pnfs_layout_segment *
+filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
+		      struct nfs4_layoutget_res *lgr,
+		      gfp_t gfp_flags)
+{
+	struct nfs4_filelayout_segment *fl;
+	int rc;
+	struct nfs4_deviceid id;
+
+	dprintk("--> %s\n", __func__);
+	fl = kzalloc(sizeof(*fl), gfp_flags);
+	if (!fl)
+		return NULL;
+
+	rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
+	if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
+		_filelayout_free_lseg(fl);
+		return NULL;
+	}
+
+	/* This assumes there is only one IOMODE_RW lseg.  What
+	 * we really want to do is have a layout_hdr level
+	 * dictionary of <multipath_list4, fh> keys, each
+	 * associated with a struct list_head, populated by calls
+	 * to filelayout_write_pagelist().
+	 * */
+	if ((!fl->commit_through_mds) && (lgr->range.iomode == IOMODE_RW)) {
+		int i;
+		int size = (fl->stripe_type == STRIPE_SPARSE) ?
+			fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
+
+		fl->commit_buckets = kcalloc(size, sizeof(struct nfs4_fl_commit_bucket), gfp_flags);
+		if (!fl->commit_buckets) {
+			filelayout_free_lseg(&fl->generic_hdr);
+			return NULL;
+		}
+		fl->number_of_buckets = size;
+		for (i = 0; i < size; i++) {
+			INIT_LIST_HEAD(&fl->commit_buckets[i].written);
+			INIT_LIST_HEAD(&fl->commit_buckets[i].committing);
+		}
+	}
+	return &fl->generic_hdr;
+}
+
+/*
+ * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
+ *
+ * return true  : coalesce page
+ * return false : don't coalesce page
+ */
+static bool
+filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
+		   struct nfs_page *req)
+{
+	u64 p_stripe, r_stripe;
+	u32 stripe_unit;
+
+	if (!pnfs_generic_pg_test(pgio, prev, req) ||
+	    !nfs_generic_pg_test(pgio, prev, req))
+		return false;
+
+	p_stripe = (u64)prev->wb_index << PAGE_CACHE_SHIFT;
+	r_stripe = (u64)req->wb_index << PAGE_CACHE_SHIFT;
+	stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
+
+	do_div(p_stripe, stripe_unit);
+	do_div(r_stripe, stripe_unit);
+
+	return (p_stripe == r_stripe);
+}
+
+static void
+filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
+			struct nfs_page *req)
+{
+	BUG_ON(pgio->pg_lseg != NULL);
+
+	pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+					   req->wb_context,
+					   0,
+					   NFS4_MAX_UINT64,
+					   IOMODE_READ,
+					   GFP_KERNEL);
+	/* If no lseg, fall back to read through mds */
+	if (pgio->pg_lseg == NULL)
+		nfs_pageio_reset_read_mds(pgio);
+}
+
+static void
+filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
+			 struct nfs_page *req)
+{
+	BUG_ON(pgio->pg_lseg != NULL);
+
+	pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+					   req->wb_context,
+					   0,
+					   NFS4_MAX_UINT64,
+					   IOMODE_RW,
+					   GFP_NOFS);
+	/* If no lseg, fall back to write through mds */
+	if (pgio->pg_lseg == NULL)
+		nfs_pageio_reset_write_mds(pgio);
+}
+
+static const struct nfs_pageio_ops filelayout_pg_read_ops = {
+	.pg_init = filelayout_pg_init_read,
+	.pg_test = filelayout_pg_test,
+	.pg_doio = pnfs_generic_pg_readpages,
+};
+
+static const struct nfs_pageio_ops filelayout_pg_write_ops = {
+	.pg_init = filelayout_pg_init_write,
+	.pg_test = filelayout_pg_test,
+	.pg_doio = pnfs_generic_pg_writepages,
+};
+
+static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
+{
+	if (fl->stripe_type == STRIPE_SPARSE)
+		return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
+	else
+		return j;
+}
+
+/* The generic layer is about to remove the req from the commit list.
+ * If this will make the bucket empty, it will need to put the lseg reference.
+ */
+static void
+filelayout_clear_request_commit(struct nfs_page *req)
+{
+	struct pnfs_layout_segment *freeme = NULL;
+	struct inode *inode = req->wb_context->dentry->d_inode;
+
+	spin_lock(&inode->i_lock);
+	if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
+		goto out;
+	if (list_is_singular(&req->wb_list)) {
+		struct pnfs_layout_segment *lseg;
+
+		/* From here we can find the bucket, but for the moment,
+		 * since there is only one relevant lseg...
+		 */
+		list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
+			if (lseg->pls_range.iomode == IOMODE_RW) {
+				freeme = lseg;
+				break;
+			}
+		}
+	}
+out:
+	nfs_request_remove_commit_list(req);
+	spin_unlock(&inode->i_lock);
+	put_lseg(freeme);
+}
+
+static struct list_head *
+filelayout_choose_commit_list(struct nfs_page *req,
+			      struct pnfs_layout_segment *lseg)
+{
+	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
+	u32 i, j;
+	struct list_head *list;
+
+	if (fl->commit_through_mds)
+		return &NFS_I(req->wb_context->dentry->d_inode)->commit_list;
+
+	/* Note that we are calling nfs4_fl_calc_j_index on each page
+	 * that ends up being committed to a data server.  An attractive
+	 * alternative is to add a field to nfs_write_data and nfs_page
+	 * to store the value calculated in filelayout_write_pagelist
+	 * and just use that here.
+	 */
+	j = nfs4_fl_calc_j_index(lseg,
+				 (loff_t)req->wb_index << PAGE_CACHE_SHIFT);
+	i = select_bucket_index(fl, j);
+	list = &fl->commit_buckets[i].written;
+	if (list_empty(list)) {
+		/* Non-empty buckets hold a reference on the lseg.  That ref
+		 * is normally transferred to the COMMIT call and released
+		 * there.  It could also be released if the last req is pulled
+		 * off due to a rewrite, in which case it will be done in
+		 * filelayout_remove_commit_req
+		 */
+		get_lseg(lseg);
+	}
+	set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
+	return list;
+}
+
+static void
+filelayout_mark_request_commit(struct nfs_page *req,
+		struct pnfs_layout_segment *lseg)
+{
+	struct list_head *list;
+
+	list = filelayout_choose_commit_list(req, lseg);
+	nfs_request_add_commit_list(req, list);
+}
+
+static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
+{
+	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
+
+	if (flseg->stripe_type == STRIPE_SPARSE)
+		return i;
+	else
+		return nfs4_fl_calc_ds_index(lseg, i);
+}
+
+static struct nfs_fh *
+select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
+{
+	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
+
+	if (flseg->stripe_type == STRIPE_SPARSE) {
+		if (flseg->num_fh == 1)
+			i = 0;
+		else if (flseg->num_fh == 0)
+			/* Use the MDS OPEN fh set in nfs_read_rpcsetup */
+			return NULL;
+	}
+	return flseg->fh_array[i];
+}
+
+static int filelayout_initiate_commit(struct nfs_write_data *data, int how)
+{
+	struct pnfs_layout_segment *lseg = data->lseg;
+	struct nfs4_pnfs_ds *ds;
+	u32 idx;
+	struct nfs_fh *fh;
+
+	idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
+	ds = nfs4_fl_prepare_ds(lseg, idx);
+	if (!ds) {
+		printk(KERN_ERR "NFS: %s: prepare_ds failed, use MDS\n",
+			__func__);
+		set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
+		set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
+		prepare_to_resend_writes(data);
+		filelayout_commit_release(data);
+		return -EAGAIN;
+	}
+	dprintk("%s ino %lu, how %d\n", __func__, data->inode->i_ino, how);
+	data->write_done_cb = filelayout_commit_done_cb;
+	data->ds_clp = ds->ds_clp;
+	fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
+	if (fh)
+		data->args.fh = fh;
+	return nfs_initiate_commit(data, ds->ds_clp->cl_rpcclient,
+				   &filelayout_commit_call_ops, how);
+}
+
+/*
+ * This is only useful while we are using whole file layouts.
+ */
+static struct pnfs_layout_segment *
+find_only_write_lseg_locked(struct inode *inode)
+{
+	struct pnfs_layout_segment *lseg;
+
+	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list)
+		if (lseg->pls_range.iomode == IOMODE_RW)
+			return lseg;
+	return NULL;
+}
+
+static struct pnfs_layout_segment *find_only_write_lseg(struct inode *inode)
+{
+	struct pnfs_layout_segment *rv;
+
+	spin_lock(&inode->i_lock);
+	rv = find_only_write_lseg_locked(inode);
+	if (rv)
+		get_lseg(rv);
+	spin_unlock(&inode->i_lock);
+	return rv;
+}
+
+static int
+filelayout_scan_ds_commit_list(struct nfs4_fl_commit_bucket *bucket, int max,
+		spinlock_t *lock)
+{
+	struct list_head *src = &bucket->written;
+	struct list_head *dst = &bucket->committing;
+	struct nfs_page *req, *tmp;
+	int ret = 0;
+
+	list_for_each_entry_safe(req, tmp, src, wb_list) {
+		if (!nfs_lock_request(req))
+			continue;
+		if (cond_resched_lock(lock))
+			list_safe_reset_next(req, tmp, wb_list);
+		nfs_request_remove_commit_list(req);
+		clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
+		nfs_list_add_request(req, dst);
+		ret++;
+		if (ret == max)
+			break;
+	}
+	return ret;
+}
+
+/* Move reqs from written to committing lists, returning count of number moved.
+ * Note called with i_lock held.
+ */
+static int filelayout_scan_commit_lists(struct inode *inode, int max,
+		spinlock_t *lock)
+{
+	struct pnfs_layout_segment *lseg;
+	struct nfs4_filelayout_segment *fl;
+	int i, rv = 0, cnt;
+
+	lseg = find_only_write_lseg_locked(inode);
+	if (!lseg)
+		goto out_done;
+	fl = FILELAYOUT_LSEG(lseg);
+	if (fl->commit_through_mds)
+		goto out_done;
+	for (i = 0; i < fl->number_of_buckets && max != 0; i++) {
+		cnt = filelayout_scan_ds_commit_list(&fl->commit_buckets[i],
+				max, lock);
+		max -= cnt;
+		rv += cnt;
+	}
+out_done:
+	return rv;
+}
+
+static unsigned int
+alloc_ds_commits(struct inode *inode, struct list_head *list)
+{
+	struct pnfs_layout_segment *lseg;
+	struct nfs4_filelayout_segment *fl;
+	struct nfs_write_data *data;
+	int i, j;
+	unsigned int nreq = 0;
+
+	/* Won't need this when non-whole file layout segments are supported
+	 * instead we will use a pnfs_layout_hdr structure */
+	lseg = find_only_write_lseg(inode);
+	if (!lseg)
+		return 0;
+	fl = FILELAYOUT_LSEG(lseg);
+	for (i = 0; i < fl->number_of_buckets; i++) {
+		if (list_empty(&fl->commit_buckets[i].committing))
+			continue;
+		data = nfs_commitdata_alloc();
+		if (!data)
+			break;
+		data->ds_commit_index = i;
+		data->lseg = lseg;
+		list_add(&data->pages, list);
+		nreq++;
+	}
+
+	/* Clean up on error */
+	for (j = i; j < fl->number_of_buckets; j++) {
+		if (list_empty(&fl->commit_buckets[i].committing))
+			continue;
+		nfs_retry_commit(&fl->commit_buckets[i].committing, lseg);
+		put_lseg(lseg);  /* associated with emptying bucket */
+	}
+	put_lseg(lseg);
+	/* Caller will clean up entries put on list */
+	return nreq;
+}
+
+/* This follows nfs_commit_list pretty closely */
+static int
+filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
+			   int how)
+{
+	struct nfs_write_data	*data, *tmp;
+	LIST_HEAD(list);
+	unsigned int nreq = 0;
+
+	if (!list_empty(mds_pages)) {
+		data = nfs_commitdata_alloc();
+		if (data != NULL) {
+			data->lseg = NULL;
+			list_add(&data->pages, &list);
+			nreq++;
+		} else
+			nfs_retry_commit(mds_pages, NULL);
+	}
+
+	nreq += alloc_ds_commits(inode, &list);
+
+	if (nreq == 0) {
+		nfs_commit_clear_lock(NFS_I(inode));
+		goto out;
+	}
+
+	atomic_add(nreq, &NFS_I(inode)->commits_outstanding);
+
+	list_for_each_entry_safe(data, tmp, &list, pages) {
+		list_del_init(&data->pages);
+		if (!data->lseg) {
+			nfs_init_commit(data, mds_pages, NULL);
+			nfs_initiate_commit(data, NFS_CLIENT(inode),
+					    data->mds_ops, how);
+		} else {
+			nfs_init_commit(data, &FILELAYOUT_LSEG(data->lseg)->commit_buckets[data->ds_commit_index].committing, data->lseg);
+			filelayout_initiate_commit(data, how);
+		}
+	}
+out:
+	return PNFS_ATTEMPTED;
+}
+
+static void
+filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
+{
+	nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
+}
+
+static struct pnfs_layoutdriver_type filelayout_type = {
+	.id			= LAYOUT_NFSV4_1_FILES,
+	.name			= "LAYOUT_NFSV4_1_FILES",
+	.owner			= THIS_MODULE,
+	.alloc_lseg		= filelayout_alloc_lseg,
+	.free_lseg		= filelayout_free_lseg,
+	.pg_read_ops		= &filelayout_pg_read_ops,
+	.pg_write_ops		= &filelayout_pg_write_ops,
+	.mark_request_commit	= filelayout_mark_request_commit,
+	.clear_request_commit	= filelayout_clear_request_commit,
+	.scan_commit_lists	= filelayout_scan_commit_lists,
+	.commit_pagelist	= filelayout_commit_pagelist,
+	.read_pagelist		= filelayout_read_pagelist,
+	.write_pagelist		= filelayout_write_pagelist,
+	.free_deviceid_node	= filelayout_free_deveiceid_node,
+};
+
+static int __init nfs4filelayout_init(void)
+{
+	printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
+	       __func__);
+	return pnfs_register_layoutdriver(&filelayout_type);
+}
+
+static void __exit nfs4filelayout_exit(void)
+{
+	printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
+	       __func__);
+	pnfs_unregister_layoutdriver(&filelayout_type);
+}
+
+MODULE_ALIAS("nfs-layouttype4-1");
+
+module_init(nfs4filelayout_init);
+module_exit(nfs4filelayout_exit);