flexfilelayout.c 40.8 KB
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/*
 * Module for pnfs flexfile layout driver.
 *
 * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
 *
 * Tao Peng <bergwolf@primarydata.com>
 */

#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/module.h>

#include <linux/sunrpc/metrics.h>
#include <linux/nfs_idmap.h>

#include "flexfilelayout.h"
#include "../nfs4session.h"
#include "../internal.h"
#include "../delegation.h"
#include "../nfs4trace.h"
#include "../iostat.h"
#include "../nfs.h"

#define NFSDBG_FACILITY         NFSDBG_PNFS_LD

#define FF_LAYOUT_POLL_RETRY_MAX     (15*HZ)

static struct pnfs_layout_hdr *
ff_layout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
{
	struct nfs4_flexfile_layout *ffl;

	ffl = kzalloc(sizeof(*ffl), gfp_flags);
	if (ffl) {
		INIT_LIST_HEAD(&ffl->error_list);
		return &ffl->generic_hdr;
	} else
		return NULL;
}

static void
ff_layout_free_layout_hdr(struct pnfs_layout_hdr *lo)
{
	struct nfs4_ff_layout_ds_err *err, *n;

	list_for_each_entry_safe(err, n, &FF_LAYOUT_FROM_HDR(lo)->error_list,
				 list) {
		list_del(&err->list);
		kfree(err);
	}
	kfree(FF_LAYOUT_FROM_HDR(lo));
}

static int decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
	if (unlikely(p == NULL))
		return -ENOBUFS;
	memcpy(stateid, p, NFS4_STATEID_SIZE);
	dprintk("%s: stateid id= [%x%x%x%x]\n", __func__,
		p[0], p[1], p[2], p[3]);
	return 0;
}

static int decode_deviceid(struct xdr_stream *xdr, struct nfs4_deviceid *devid)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS4_DEVICEID4_SIZE);
	if (unlikely(!p))
		return -ENOBUFS;
	memcpy(devid, p, NFS4_DEVICEID4_SIZE);
	nfs4_print_deviceid(devid);
	return 0;
}

static int decode_nfs_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(!p))
		return -ENOBUFS;
	fh->size = be32_to_cpup(p++);
	if (fh->size > sizeof(struct nfs_fh)) {
		printk(KERN_ERR "NFS flexfiles: Too big fh received %d\n",
		       fh->size);
		return -EOVERFLOW;
	}
	/* fh.data */
	p = xdr_inline_decode(xdr, fh->size);
	if (unlikely(!p))
		return -ENOBUFS;
	memcpy(&fh->data, p, fh->size);
	dprintk("%s: fh len %d\n", __func__, fh->size);

	return 0;
}

/*
 * Currently only stringified uids and gids are accepted.
 * I.e., kerberos is not supported to the DSes, so no pricipals.
 *
 * That means that one common function will suffice, but when
 * principals are added, this should be split to accomodate
 * calls to both nfs_map_name_to_uid() and nfs_map_group_to_gid().
 */
static int
decode_name(struct xdr_stream *xdr, u32 *id)
{
	__be32 *p;
	int len;

	/* opaque_length(4)*/
	p = xdr_inline_decode(xdr, 4);
	if (unlikely(!p))
		return -ENOBUFS;
	len = be32_to_cpup(p++);
	if (len < 0)
		return -EINVAL;

	dprintk("%s: len %u\n", __func__, len);

	/* opaque body */
	p = xdr_inline_decode(xdr, len);
	if (unlikely(!p))
		return -ENOBUFS;

	if (!nfs_map_string_to_numeric((char *)p, len, id))
		return -EINVAL;

	return 0;
}

static void ff_layout_free_mirror_array(struct nfs4_ff_layout_segment *fls)
{
	int i;

	if (fls->mirror_array) {
		for (i = 0; i < fls->mirror_array_cnt; i++) {
			/* normally mirror_ds is freed in
			 * .free_deviceid_node but we still do it here
			 * for .alloc_lseg error path */
			if (fls->mirror_array[i]) {
				kfree(fls->mirror_array[i]->fh_versions);
				nfs4_ff_layout_put_deviceid(fls->mirror_array[i]->mirror_ds);
				kfree(fls->mirror_array[i]);
			}
		}
		kfree(fls->mirror_array);
		fls->mirror_array = NULL;
	}
}

static int ff_layout_check_layout(struct nfs4_layoutget_res *lgr)
{
	int ret = 0;

	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__);
		ret = -EINVAL;
	}

	dprintk("--> %s returns %d\n", __func__, ret);
	return ret;
}

static void _ff_layout_free_lseg(struct nfs4_ff_layout_segment *fls)
{
	if (fls) {
		ff_layout_free_mirror_array(fls);
		kfree(fls);
	}
}

static void ff_layout_sort_mirrors(struct nfs4_ff_layout_segment *fls)
{
	struct nfs4_ff_layout_mirror *tmp;
	int i, j;

	for (i = 0; i < fls->mirror_array_cnt - 1; i++) {
		for (j = i + 1; j < fls->mirror_array_cnt; j++)
			if (fls->mirror_array[i]->efficiency <
			    fls->mirror_array[j]->efficiency) {
				tmp = fls->mirror_array[i];
				fls->mirror_array[i] = fls->mirror_array[j];
				fls->mirror_array[j] = tmp;
			}
	}
}

static struct pnfs_layout_segment *
ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
		     struct nfs4_layoutget_res *lgr,
		     gfp_t gfp_flags)
{
	struct pnfs_layout_segment *ret;
	struct nfs4_ff_layout_segment *fls = NULL;
	struct xdr_stream stream;
	struct xdr_buf buf;
	struct page *scratch;
	u64 stripe_unit;
	u32 mirror_array_cnt;
	__be32 *p;
	int i, rc;

	dprintk("--> %s\n", __func__);
	scratch = alloc_page(gfp_flags);
	if (!scratch)
		return ERR_PTR(-ENOMEM);

	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages,
			      lgr->layoutp->len);
	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);

	/* stripe unit and mirror_array_cnt */
	rc = -EIO;
	p = xdr_inline_decode(&stream, 8 + 4);
	if (!p)
		goto out_err_free;

	p = xdr_decode_hyper(p, &stripe_unit);
	mirror_array_cnt = be32_to_cpup(p++);
	dprintk("%s: stripe_unit=%llu mirror_array_cnt=%u\n", __func__,
		stripe_unit, mirror_array_cnt);

	if (mirror_array_cnt > NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT ||
	    mirror_array_cnt == 0)
		goto out_err_free;

	rc = -ENOMEM;
	fls = kzalloc(sizeof(*fls), gfp_flags);
	if (!fls)
		goto out_err_free;

	fls->mirror_array_cnt = mirror_array_cnt;
	fls->stripe_unit = stripe_unit;
	fls->mirror_array = kcalloc(fls->mirror_array_cnt,
				    sizeof(fls->mirror_array[0]), gfp_flags);
	if (fls->mirror_array == NULL)
		goto out_err_free;

	for (i = 0; i < fls->mirror_array_cnt; i++) {
		struct nfs4_deviceid devid;
		struct nfs4_deviceid_node *idnode;
		u32 ds_count;
		u32 fh_count;
		int j;

		rc = -EIO;
		p = xdr_inline_decode(&stream, 4);
		if (!p)
			goto out_err_free;
		ds_count = be32_to_cpup(p);

		/* FIXME: allow for striping? */
		if (ds_count != 1)
			goto out_err_free;

		fls->mirror_array[i] =
			kzalloc(sizeof(struct nfs4_ff_layout_mirror),
				gfp_flags);
		if (fls->mirror_array[i] == NULL) {
			rc = -ENOMEM;
			goto out_err_free;
		}

		spin_lock_init(&fls->mirror_array[i]->lock);
		fls->mirror_array[i]->ds_count = ds_count;

		/* deviceid */
		rc = decode_deviceid(&stream, &devid);
		if (rc)
			goto out_err_free;

		idnode = nfs4_find_get_deviceid(NFS_SERVER(lh->plh_inode),
						&devid, lh->plh_lc_cred,
						gfp_flags);
		/*
		 * upon success, mirror_ds is allocated by previous
		 * getdeviceinfo, or newly by .alloc_deviceid_node
		 * nfs4_find_get_deviceid failure is indeed getdeviceinfo falure
		 */
		if (idnode)
			fls->mirror_array[i]->mirror_ds =
				FF_LAYOUT_MIRROR_DS(idnode);
		else
			goto out_err_free;

		/* efficiency */
		rc = -EIO;
		p = xdr_inline_decode(&stream, 4);
		if (!p)
			goto out_err_free;
		fls->mirror_array[i]->efficiency = be32_to_cpup(p);

		/* stateid */
		rc = decode_stateid(&stream, &fls->mirror_array[i]->stateid);
		if (rc)
			goto out_err_free;

		/* fh */
		p = xdr_inline_decode(&stream, 4);
		if (!p)
			goto out_err_free;
		fh_count = be32_to_cpup(p);

		fls->mirror_array[i]->fh_versions =
			kzalloc(fh_count * sizeof(struct nfs_fh),
				gfp_flags);
		if (fls->mirror_array[i]->fh_versions == NULL) {
			rc = -ENOMEM;
			goto out_err_free;
		}

		for (j = 0; j < fh_count; j++) {
			rc = decode_nfs_fh(&stream,
					   &fls->mirror_array[i]->fh_versions[j]);
			if (rc)
				goto out_err_free;
		}

		fls->mirror_array[i]->fh_versions_cnt = fh_count;

		/* user */
		rc = decode_name(&stream, &fls->mirror_array[i]->uid);
		if (rc)
			goto out_err_free;

		/* group */
		rc = decode_name(&stream, &fls->mirror_array[i]->gid);
		if (rc)
			goto out_err_free;

		dprintk("%s: uid %d gid %d\n", __func__,
			fls->mirror_array[i]->uid,
			fls->mirror_array[i]->gid);
	}

	ff_layout_sort_mirrors(fls);
	rc = ff_layout_check_layout(lgr);
	if (rc)
		goto out_err_free;

	ret = &fls->generic_hdr;
	dprintk("<-- %s (success)\n", __func__);
out_free_page:
	__free_page(scratch);
	return ret;
out_err_free:
	_ff_layout_free_lseg(fls);
	ret = ERR_PTR(rc);
	dprintk("<-- %s (%d)\n", __func__, rc);
	goto out_free_page;
}

static bool ff_layout_has_rw_segments(struct pnfs_layout_hdr *layout)
{
	struct pnfs_layout_segment *lseg;

	list_for_each_entry(lseg, &layout->plh_segs, pls_list)
		if (lseg->pls_range.iomode == IOMODE_RW)
			return true;

	return false;
}

static void
ff_layout_free_lseg(struct pnfs_layout_segment *lseg)
{
	struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
	int i;

	dprintk("--> %s\n", __func__);

	for (i = 0; i < fls->mirror_array_cnt; i++) {
		if (fls->mirror_array[i]) {
			nfs4_ff_layout_put_deviceid(fls->mirror_array[i]->mirror_ds);
			fls->mirror_array[i]->mirror_ds = NULL;
			if (fls->mirror_array[i]->cred) {
				put_rpccred(fls->mirror_array[i]->cred);
				fls->mirror_array[i]->cred = NULL;
			}
		}
	}

	if (lseg->pls_range.iomode == IOMODE_RW) {
		struct nfs4_flexfile_layout *ffl;
		struct inode *inode;

		ffl = FF_LAYOUT_FROM_HDR(lseg->pls_layout);
		inode = ffl->generic_hdr.plh_inode;
		spin_lock(&inode->i_lock);
		if (!ff_layout_has_rw_segments(lseg->pls_layout)) {
			ffl->commit_info.nbuckets = 0;
			kfree(ffl->commit_info.buckets);
			ffl->commit_info.buckets = NULL;
		}
		spin_unlock(&inode->i_lock);
	}
	_ff_layout_free_lseg(fls);
}

/* Return 1 until we have multiple lsegs support */
static int
ff_layout_get_lseg_count(struct nfs4_ff_layout_segment *fls)
{
	return 1;
}

static int
ff_layout_alloc_commit_info(struct pnfs_layout_segment *lseg,
			    struct nfs_commit_info *cinfo,
			    gfp_t gfp_flags)
{
	struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
	struct pnfs_commit_bucket *buckets;
	int size;

	if (cinfo->ds->nbuckets != 0) {
		/* This assumes there is only one RW lseg per file.
		 * To support multiple lseg per file, we need to
		 * change struct pnfs_commit_bucket to allow dynamic
		 * increasing nbuckets.
		 */
		return 0;
	}

	size = ff_layout_get_lseg_count(fls) * FF_LAYOUT_MIRROR_COUNT(lseg);

	buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
			  gfp_flags);
	if (!buckets)
		return -ENOMEM;
	else {
		int i;

		spin_lock(cinfo->lock);
		if (cinfo->ds->nbuckets != 0)
			kfree(buckets);
		else {
			cinfo->ds->buckets = buckets;
			cinfo->ds->nbuckets = size;
			for (i = 0; i < size; i++) {
				INIT_LIST_HEAD(&buckets[i].written);
				INIT_LIST_HEAD(&buckets[i].committing);
				/* mark direct verifier as unset */
				buckets[i].direct_verf.committed =
					NFS_INVALID_STABLE_HOW;
			}
		}
		spin_unlock(cinfo->lock);
		return 0;
	}
}

static struct nfs4_pnfs_ds *
ff_layout_choose_best_ds_for_read(struct nfs_pageio_descriptor *pgio,
				  int *best_idx)
{
	struct nfs4_ff_layout_segment *fls;
	struct nfs4_pnfs_ds *ds;
	int idx;

	fls = FF_LAYOUT_LSEG(pgio->pg_lseg);
	/* mirrors are sorted by efficiency */
	for (idx = 0; idx < fls->mirror_array_cnt; idx++) {
		ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, idx, false);
		if (ds) {
			*best_idx = idx;
			return ds;
		}
	}

	return NULL;
}

static void
ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
			struct nfs_page *req)
{
	struct nfs_pgio_mirror *pgm;
	struct nfs4_ff_layout_mirror *mirror;
	struct nfs4_pnfs_ds *ds;
	int ds_idx;

	/* Use full layout for now */
	if (!pgio->pg_lseg)
		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)
		goto out_mds;

	ds = ff_layout_choose_best_ds_for_read(pgio, &ds_idx);
	if (!ds)
		goto out_mds;
	mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);

	pgio->pg_mirror_idx = ds_idx;

	/* read always uses only one mirror - idx 0 for pgio layer */
	pgm = &pgio->pg_mirrors[0];
	pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;

	return;
out_mds:
	pnfs_put_lseg(pgio->pg_lseg);
	pgio->pg_lseg = NULL;
	nfs_pageio_reset_read_mds(pgio);
}

static void
ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
			struct nfs_page *req)
{
	struct nfs4_ff_layout_mirror *mirror;
	struct nfs_pgio_mirror *pgm;
	struct nfs_commit_info cinfo;
	struct nfs4_pnfs_ds *ds;
	int i;
	int status;

	if (!pgio->pg_lseg)
		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)
		goto out_mds;

	nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
	status = ff_layout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
	if (status < 0)
		goto out_mds;

	/* Use a direct mapping of ds_idx to pgio mirror_idx */
	if (WARN_ON_ONCE(pgio->pg_mirror_count !=
	    FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg)))
		goto out_mds;

	for (i = 0; i < pgio->pg_mirror_count; i++) {
		ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, i, true);
		if (!ds)
			goto out_mds;
		pgm = &pgio->pg_mirrors[i];
		mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
		pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
	}

	return;

out_mds:
	pnfs_put_lseg(pgio->pg_lseg);
	pgio->pg_lseg = NULL;
	nfs_pageio_reset_write_mds(pgio);
}

static unsigned int
ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
				    struct nfs_page *req)
{
	if (!pgio->pg_lseg)
		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
						   req->wb_context,
						   0,
						   NFS4_MAX_UINT64,
						   IOMODE_RW,
						   GFP_NOFS);
	if (pgio->pg_lseg)
		return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);

	/* no lseg means that pnfs is not in use, so no mirroring here */
	pnfs_put_lseg(pgio->pg_lseg);
	pgio->pg_lseg = NULL;
	nfs_pageio_reset_write_mds(pgio);
	return 1;
}

static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
	.pg_init = ff_layout_pg_init_read,
	.pg_test = pnfs_generic_pg_test,
	.pg_doio = pnfs_generic_pg_readpages,
	.pg_cleanup = pnfs_generic_pg_cleanup,
};

static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
	.pg_init = ff_layout_pg_init_write,
	.pg_test = pnfs_generic_pg_test,
	.pg_doio = pnfs_generic_pg_writepages,
	.pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
	.pg_cleanup = pnfs_generic_pg_cleanup,
};

static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
{
	struct rpc_task *task = &hdr->task;

	pnfs_layoutcommit_inode(hdr->inode, false);

	if (retry_pnfs) {
		dprintk("%s Reset task %5u for i/o through pNFS "
			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
			hdr->task.tk_pid,
			hdr->inode->i_sb->s_id,
			(unsigned long long)NFS_FILEID(hdr->inode),
			hdr->args.count,
			(unsigned long long)hdr->args.offset);

		if (!hdr->dreq) {
			struct nfs_open_context *ctx;

			ctx = nfs_list_entry(hdr->pages.next)->wb_context;
			set_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags);
			hdr->completion_ops->error_cleanup(&hdr->pages);
		} else {
			nfs_direct_set_resched_writes(hdr->dreq);
			/* fake unstable write to let common nfs resend pages */
			hdr->verf.committed = NFS_UNSTABLE;
			hdr->good_bytes = 0;
		}
		return;
	}

	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
		dprintk("%s Reset task %5u for i/o through MDS "
			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
			hdr->task.tk_pid,
			hdr->inode->i_sb->s_id,
			(unsigned long long)NFS_FILEID(hdr->inode),
			hdr->args.count,
			(unsigned long long)hdr->args.offset);

		task->tk_status = pnfs_write_done_resend_to_mds(hdr);
	}
}

static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
{
	struct rpc_task *task = &hdr->task;

	pnfs_layoutcommit_inode(hdr->inode, false);

	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
		dprintk("%s Reset task %5u for i/o through MDS "
			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
			hdr->task.tk_pid,
			hdr->inode->i_sb->s_id,
			(unsigned long long)NFS_FILEID(hdr->inode),
			hdr->args.count,
			(unsigned long long)hdr->args.offset);

		task->tk_status = pnfs_read_done_resend_to_mds(hdr);
	}
}

static int ff_layout_async_handle_error_v4(struct rpc_task *task,
					   struct nfs4_state *state,
					   struct nfs_client *clp,
					   struct pnfs_layout_segment *lseg,
					   int idx)
{
	struct pnfs_layout_hdr *lo = lseg->pls_layout;
	struct inode *inode = lo->plh_inode;
	struct nfs_server *mds_server = NFS_SERVER(inode);

	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
	struct nfs_client *mds_client = mds_server->nfs_client;
	struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;

	if (task->tk_status >= 0)
		return 0;

	switch (task->tk_status) {
	/* MDS state errors */
	case -NFS4ERR_DELEG_REVOKED:
	case -NFS4ERR_ADMIN_REVOKED:
	case -NFS4ERR_BAD_STATEID:
		if (state == NULL)
			break;
		nfs_remove_bad_delegation(state->inode);
	case -NFS4ERR_OPENMODE:
		if (state == NULL)
			break;
		if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
			goto out_bad_stateid;
		goto wait_on_recovery;
	case -NFS4ERR_EXPIRED:
		if (state != NULL) {
			if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
				goto out_bad_stateid;
		}
		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, task->tk_status);
		break;
	case -NFS4ERR_DELAY:
	case -NFS4ERR_GRACE:
		rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
		break;
	case -NFS4ERR_RETRY_UNCACHED_REP:
		break;
	/* Invalidate Layout errors */
	case -NFS4ERR_PNFS_NO_LAYOUT:
	case -ESTALE:           /* mapped NFS4ERR_STALE */
	case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
	case -EISDIR:           /* mapped NFS4ERR_ISDIR */
	case -NFS4ERR_FHEXPIRED:
	case -NFS4ERR_WRONG_TYPE:
		dprintk("%s Invalid layout error %d\n", __func__,
			task->tk_status);
		/*
		 * Destroy layout so new i/o will get a new layout.
		 * Layout will not be destroyed until all current lseg
		 * references are put. Mark layout as invalid to resend failed
		 * i/o and all i/o waiting on the slot table to the MDS until
		 * layout is destroyed and a new valid layout is obtained.
		 */
		pnfs_destroy_layout(NFS_I(inode));
		rpc_wake_up(&tbl->slot_tbl_waitq);
		goto reset;
	/* RPC connection errors */
	case -ECONNREFUSED:
	case -EHOSTDOWN:
	case -EHOSTUNREACH:
	case -ENETUNREACH:
	case -EIO:
	case -ETIMEDOUT:
	case -EPIPE:
		dprintk("%s DS connection error %d\n", __func__,
			task->tk_status);
		nfs4_mark_deviceid_unavailable(devid);
		rpc_wake_up(&tbl->slot_tbl_waitq);
		/* fall through */
	default:
		if (ff_layout_has_available_ds(lseg))
			return -NFS4ERR_RESET_TO_PNFS;
reset:
		dprintk("%s Retry through MDS. Error %d\n", __func__,
			task->tk_status);
		return -NFS4ERR_RESET_TO_MDS;
	}
out:
	task->tk_status = 0;
	return -EAGAIN;
out_bad_stateid:
	task->tk_status = -EIO;
	return 0;
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;
}

/* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
static int ff_layout_async_handle_error_v3(struct rpc_task *task,
					   struct pnfs_layout_segment *lseg,
					   int idx)
{
	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);

	if (task->tk_status >= 0)
		return 0;

	if (task->tk_status != -EJUKEBOX) {
		dprintk("%s DS connection error %d\n", __func__,
			task->tk_status);
		nfs4_mark_deviceid_unavailable(devid);
		if (ff_layout_has_available_ds(lseg))
			return -NFS4ERR_RESET_TO_PNFS;
		else
			return -NFS4ERR_RESET_TO_MDS;
	}

	if (task->tk_status == -EJUKEBOX)
		nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
	task->tk_status = 0;
	rpc_restart_call(task);
	rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
	return -EAGAIN;
}

static int ff_layout_async_handle_error(struct rpc_task *task,
					struct nfs4_state *state,
					struct nfs_client *clp,
					struct pnfs_layout_segment *lseg,
					int idx)
{
	int vers = clp->cl_nfs_mod->rpc_vers->number;

	switch (vers) {
	case 3:
		return ff_layout_async_handle_error_v3(task, lseg, idx);
	case 4:
		return ff_layout_async_handle_error_v4(task, state, clp,
						       lseg, idx);
	default:
		/* should never happen */
		WARN_ON_ONCE(1);
		return 0;
	}
}

static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
					int idx, u64 offset, u64 length,
					u32 status, int opnum)
{
	struct nfs4_ff_layout_mirror *mirror;
	int err;

	mirror = FF_LAYOUT_COMP(lseg, idx);
	err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
				       mirror, offset, length, status, opnum,
				       GFP_NOIO);
	dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
}

/* NFS_PROTO call done callback routines */

static int ff_layout_read_done_cb(struct rpc_task *task,
				struct nfs_pgio_header *hdr)
{
	struct inode *inode;
	int err;

	trace_nfs4_pnfs_read(hdr, task->tk_status);
	if (task->tk_status == -ETIMEDOUT && !hdr->res.op_status)
		hdr->res.op_status = NFS4ERR_NXIO;
	if (task->tk_status < 0 && hdr->res.op_status)
		ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
					    hdr->args.offset, hdr->args.count,
					    hdr->res.op_status, OP_READ);
	err = ff_layout_async_handle_error(task, hdr->args.context->state,
					   hdr->ds_clp, hdr->lseg,
					   hdr->pgio_mirror_idx);

	switch (err) {
	case -NFS4ERR_RESET_TO_PNFS:
		set_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
			&hdr->lseg->pls_layout->plh_flags);
		pnfs_read_resend_pnfs(hdr);
		return task->tk_status;
	case -NFS4ERR_RESET_TO_MDS:
		inode = hdr->lseg->pls_layout->plh_inode;
		pnfs_error_mark_layout_for_return(inode, hdr->lseg);
		ff_layout_reset_read(hdr);
		return task->tk_status;
	case -EAGAIN:
		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.
 *
 * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
 * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
 * we always send layoutcommit after DS writes.
 */
static void
ff_layout_set_layoutcommit(struct nfs_pgio_header *hdr)
{
	pnfs_set_layoutcommit(hdr);
	dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
		(unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
}

static bool
ff_layout_reset_to_mds(struct pnfs_layout_segment *lseg, int idx)
{
	/* No mirroring for now */
	struct nfs4_deviceid_node *node = FF_LAYOUT_DEVID_NODE(lseg, idx);

	return ff_layout_test_devid_unavailable(node);
}

static int ff_layout_read_prepare_common(struct rpc_task *task,
					 struct nfs_pgio_header *hdr)
{
	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
		rpc_exit(task, -EIO);
		return -EIO;
	}
	if (ff_layout_reset_to_mds(hdr->lseg, hdr->pgio_mirror_idx)) {
		dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
		if (ff_layout_has_available_ds(hdr->lseg))
			pnfs_read_resend_pnfs(hdr);
		else
			ff_layout_reset_read(hdr);
		rpc_exit(task, 0);
		return -EAGAIN;
	}
	hdr->pgio_done_cb = ff_layout_read_done_cb;

	return 0;
}

/*
 * 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 ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
{
	struct nfs_pgio_header *hdr = data;

	if (ff_layout_read_prepare_common(task, hdr))
		return;

	rpc_call_start(task);
}

static int ff_layout_setup_sequence(struct nfs_client *ds_clp,
				    struct nfs4_sequence_args *args,
				    struct nfs4_sequence_res *res,
				    struct rpc_task *task)
{
	if (ds_clp->cl_session)
		return nfs41_setup_sequence(ds_clp->cl_session,
					   args,
					   res,
					   task);
	return nfs40_setup_sequence(ds_clp->cl_slot_tbl,
				   args,
				   res,
				   task);
}

static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
{
	struct nfs_pgio_header *hdr = data;

	if (ff_layout_read_prepare_common(task, hdr))
		return;

	if (ff_layout_setup_sequence(hdr->ds_clp,
				     &hdr->args.seq_args,
				     &hdr->res.seq_res,
				     task))
		return;

	if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
			hdr->args.lock_context, FMODE_READ) == -EIO)
		rpc_exit(task, -EIO); /* lost lock, terminate I/O */
}

static void ff_layout_read_call_done(struct rpc_task *task, void *data)
{
	struct nfs_pgio_header *hdr = data;

	dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);

	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
	    task->tk_status == 0) {
		nfs4_sequence_done(task, &hdr->res.seq_res);
		return;
	}

	/* Note this may cause RPC to be resent */
	hdr->mds_ops->rpc_call_done(task, hdr);
}

static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
{
	struct nfs_pgio_header *hdr = data;

	rpc_count_iostats_metrics(task,
	    &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
}

static int ff_layout_write_done_cb(struct rpc_task *task,
				struct nfs_pgio_header *hdr)
{
	struct inode *inode;
	int err;

	trace_nfs4_pnfs_write(hdr, task->tk_status);
	if (task->tk_status == -ETIMEDOUT && !hdr->res.op_status)
		hdr->res.op_status = NFS4ERR_NXIO;
	if (task->tk_status < 0 && hdr->res.op_status)
		ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
					    hdr->args.offset, hdr->args.count,
					    hdr->res.op_status, OP_WRITE);
	err = ff_layout_async_handle_error(task, hdr->args.context->state,
					   hdr->ds_clp, hdr->lseg,
					   hdr->pgio_mirror_idx);

	switch (err) {
	case -NFS4ERR_RESET_TO_PNFS:
	case -NFS4ERR_RESET_TO_MDS:
		inode = hdr->lseg->pls_layout->plh_inode;
		pnfs_error_mark_layout_for_return(inode, hdr->lseg);
		if (err == -NFS4ERR_RESET_TO_PNFS) {
			pnfs_set_retry_layoutget(hdr->lseg->pls_layout);
			ff_layout_reset_write(hdr, true);
		} else {
			pnfs_clear_retry_layoutget(hdr->lseg->pls_layout);
			ff_layout_reset_write(hdr, false);
		}
		return task->tk_status;
	case -EAGAIN:
		rpc_restart_call_prepare(task);
		return -EAGAIN;
	}

	if (hdr->res.verf->committed == NFS_FILE_SYNC ||
	    hdr->res.verf->committed == NFS_DATA_SYNC)
		ff_layout_set_layoutcommit(hdr);

	return 0;
}

static int ff_layout_commit_done_cb(struct rpc_task *task,
				     struct nfs_commit_data *data)
{
	struct inode *inode;
	int err;

	trace_nfs4_pnfs_commit_ds(data, task->tk_status);
	if (task->tk_status == -ETIMEDOUT && !data->res.op_status)
		data->res.op_status = NFS4ERR_NXIO;
	if (task->tk_status < 0 && data->res.op_status)
		ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
					    data->args.offset, data->args.count,
					    data->res.op_status, OP_COMMIT);
	err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
					   data->lseg, data->ds_commit_index);

	switch (err) {
	case -NFS4ERR_RESET_TO_PNFS:
	case -NFS4ERR_RESET_TO_MDS:
		inode = data->lseg->pls_layout->plh_inode;
		pnfs_error_mark_layout_for_return(inode, data->lseg);
		if (err == -NFS4ERR_RESET_TO_PNFS)
			pnfs_set_retry_layoutget(data->lseg->pls_layout);
		else
			pnfs_clear_retry_layoutget(data->lseg->pls_layout);
		pnfs_generic_prepare_to_resend_writes(data);
		return -EAGAIN;
	case -EAGAIN:
		rpc_restart_call_prepare(task);
		return -EAGAIN;
	}

	if (data->verf.committed == NFS_UNSTABLE)
		pnfs_commit_set_layoutcommit(data);

	return 0;
}

static int ff_layout_write_prepare_common(struct rpc_task *task,
					  struct nfs_pgio_header *hdr)
{
	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
		rpc_exit(task, -EIO);
		return -EIO;
	}

	if (ff_layout_reset_to_mds(hdr->lseg, hdr->pgio_mirror_idx)) {
		bool retry_pnfs;

		retry_pnfs = ff_layout_has_available_ds(hdr->lseg);
		dprintk("%s task %u reset io to %s\n", __func__,
			task->tk_pid, retry_pnfs ? "pNFS" : "MDS");
		ff_layout_reset_write(hdr, retry_pnfs);
		rpc_exit(task, 0);
		return -EAGAIN;
	}

	return 0;
}

static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
{
	struct nfs_pgio_header *hdr = data;

	if (ff_layout_write_prepare_common(task, hdr))
		return;

	rpc_call_start(task);
}

static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
{
	struct nfs_pgio_header *hdr = data;

	if (ff_layout_write_prepare_common(task, hdr))
		return;

	if (ff_layout_setup_sequence(hdr->ds_clp,
				     &hdr->args.seq_args,
				     &hdr->res.seq_res,
				     task))
		return;

	if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
			hdr->args.lock_context, FMODE_WRITE) == -EIO)
		rpc_exit(task, -EIO); /* lost lock, terminate I/O */
}

static void ff_layout_write_call_done(struct rpc_task *task, void *data)
{
	struct nfs_pgio_header *hdr = data;

	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
	    task->tk_status == 0) {
		nfs4_sequence_done(task, &hdr->res.seq_res);
		return;
	}

	/* Note this may cause RPC to be resent */
	hdr->mds_ops->rpc_call_done(task, hdr);
}

static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
{
	struct nfs_pgio_header *hdr = data;

	rpc_count_iostats_metrics(task,
	    &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
}

static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
{
	rpc_call_start(task);
}

static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
{
	struct nfs_commit_data *wdata = data;

	ff_layout_setup_sequence(wdata->ds_clp,
				 &wdata->args.seq_args,
				 &wdata->res.seq_res,
				 task);
}

static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
{
	struct nfs_commit_data *cdata = data;

	rpc_count_iostats_metrics(task,
	    &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
}

static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
	.rpc_call_prepare = ff_layout_read_prepare_v3,
	.rpc_call_done = ff_layout_read_call_done,
	.rpc_count_stats = ff_layout_read_count_stats,
	.rpc_release = pnfs_generic_rw_release,
};

static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
	.rpc_call_prepare = ff_layout_read_prepare_v4,
	.rpc_call_done = ff_layout_read_call_done,
	.rpc_count_stats = ff_layout_read_count_stats,
	.rpc_release = pnfs_generic_rw_release,
};

static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
	.rpc_call_prepare = ff_layout_write_prepare_v3,
	.rpc_call_done = ff_layout_write_call_done,
	.rpc_count_stats = ff_layout_write_count_stats,
	.rpc_release = pnfs_generic_rw_release,
};

static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
	.rpc_call_prepare = ff_layout_write_prepare_v4,
	.rpc_call_done = ff_layout_write_call_done,
	.rpc_count_stats = ff_layout_write_count_stats,
	.rpc_release = pnfs_generic_rw_release,
};

static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
	.rpc_call_prepare = ff_layout_commit_prepare_v3,
	.rpc_call_done = pnfs_generic_write_commit_done,
	.rpc_count_stats = ff_layout_commit_count_stats,
	.rpc_release = pnfs_generic_commit_release,
};

static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
	.rpc_call_prepare = ff_layout_commit_prepare_v4,
	.rpc_call_done = pnfs_generic_write_commit_done,
	.rpc_count_stats = ff_layout_commit_count_stats,
	.rpc_release = pnfs_generic_commit_release,
};

static enum pnfs_try_status
ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
{
	struct pnfs_layout_segment *lseg = hdr->lseg;
	struct nfs4_pnfs_ds *ds;
	struct rpc_clnt *ds_clnt;
	struct rpc_cred *ds_cred;
	loff_t offset = hdr->args.offset;
	u32 idx = hdr->pgio_mirror_idx;
	int vers;
	struct nfs_fh *fh;

	dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
		__func__, hdr->inode->i_ino,
		hdr->args.pgbase, (size_t)hdr->args.count, offset);

	ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
	if (!ds)
		goto out_failed;

	ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
						   hdr->inode);
	if (IS_ERR(ds_clnt))
		goto out_failed;

	ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
	if (IS_ERR(ds_cred))
		goto out_failed;

	vers = nfs4_ff_layout_ds_version(lseg, idx);

	dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
		ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers);

	atomic_inc(&ds->ds_clp->cl_count);
	hdr->ds_clp = ds->ds_clp;
	fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
	if (fh)
		hdr->args.fh = fh;

	/*
	 * Note that if we ever decide to split across DSes,
	 * then we may need to handle dense-like offsets.
	 */
	hdr->args.offset = offset;
	hdr->mds_offset = offset;

	/* Perform an asynchronous read to ds */
	nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
			  vers == 3 ? &ff_layout_read_call_ops_v3 :
				      &ff_layout_read_call_ops_v4,
			  0, RPC_TASK_SOFTCONN);

	return PNFS_ATTEMPTED;

out_failed:
	if (ff_layout_has_available_ds(lseg))
		return PNFS_TRY_AGAIN;
	return PNFS_NOT_ATTEMPTED;
}

/* Perform async writes. */
static enum pnfs_try_status
ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
{
	struct pnfs_layout_segment *lseg = hdr->lseg;
	struct nfs4_pnfs_ds *ds;
	struct rpc_clnt *ds_clnt;
	struct rpc_cred *ds_cred;
	loff_t offset = hdr->args.offset;
	int vers;
	struct nfs_fh *fh;
	int idx = hdr->pgio_mirror_idx;

	ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
	if (!ds)
		return PNFS_NOT_ATTEMPTED;

	ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
						   hdr->inode);
	if (IS_ERR(ds_clnt))
		return PNFS_NOT_ATTEMPTED;

	ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
	if (IS_ERR(ds_cred))
		return PNFS_NOT_ATTEMPTED;

	vers = nfs4_ff_layout_ds_version(lseg, idx);

	dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d vers %d\n",
		__func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
		offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count),
		vers);

	hdr->pgio_done_cb = ff_layout_write_done_cb;
	atomic_inc(&ds->ds_clp->cl_count);
	hdr->ds_clp = ds->ds_clp;
	hdr->ds_commit_idx = idx;
	fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
	if (fh)
		hdr->args.fh = fh;

	/*
	 * Note that if we ever decide to split across DSes,
	 * then we may need to handle dense-like offsets.
	 */
	hdr->args.offset = offset;

	/* Perform an asynchronous write */
	nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
			  vers == 3 ? &ff_layout_write_call_ops_v3 :
				      &ff_layout_write_call_ops_v4,
			  sync, RPC_TASK_SOFTCONN);
	return PNFS_ATTEMPTED;
}

static void
ff_layout_mark_request_commit(struct nfs_page *req,
			      struct pnfs_layout_segment *lseg,
			      struct nfs_commit_info *cinfo,
			      u32 ds_commit_idx)
{
	struct list_head *list;
	struct pnfs_commit_bucket *buckets;

	spin_lock(cinfo->lock);
	buckets = cinfo->ds->buckets;
	list = &buckets[ds_commit_idx].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
		 * pnfs_common_clear_request_commit
		 */
		WARN_ON_ONCE(buckets[ds_commit_idx].wlseg != NULL);
		buckets[ds_commit_idx].wlseg = pnfs_get_lseg(lseg);
	}
	set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
	cinfo->ds->nwritten++;

	/* nfs_request_add_commit_list(). We need to add req to list without
	 * dropping cinfo lock.
	 */
	set_bit(PG_CLEAN, &(req)->wb_flags);
	nfs_list_add_request(req, list);
	cinfo->mds->ncommit++;
	spin_unlock(cinfo->lock);
1367 1368
	if (!cinfo->dreq)
		nfs_mark_page_unstable(req->wb_page);
1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569
}

static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
{
	return i;
}

static struct nfs_fh *
select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
{
	struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);

	/* FIXME: Assume that there is only one NFS version available
	 * for the DS.
	 */
	return &flseg->mirror_array[i]->fh_versions[0];
}

static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
{
	struct pnfs_layout_segment *lseg = data->lseg;
	struct nfs4_pnfs_ds *ds;
	struct rpc_clnt *ds_clnt;
	struct rpc_cred *ds_cred;
	u32 idx;
	int vers;
	struct nfs_fh *fh;

	idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
	ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
	if (!ds)
		goto out_err;

	ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
						   data->inode);
	if (IS_ERR(ds_clnt))
		goto out_err;

	ds_cred = ff_layout_get_ds_cred(lseg, idx, data->cred);
	if (IS_ERR(ds_cred))
		goto out_err;

	vers = nfs4_ff_layout_ds_version(lseg, idx);

	dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
		data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count),
		vers);
	data->commit_done_cb = ff_layout_commit_done_cb;
	data->cred = ds_cred;
	atomic_inc(&ds->ds_clp->cl_count);
	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(ds_clnt, data, ds->ds_clp->rpc_ops,
				   vers == 3 ? &ff_layout_commit_call_ops_v3 :
					       &ff_layout_commit_call_ops_v4,
				   how, RPC_TASK_SOFTCONN);
out_err:
	pnfs_generic_prepare_to_resend_writes(data);
	pnfs_generic_commit_release(data);
	return -EAGAIN;
}

static int
ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
			   int how, struct nfs_commit_info *cinfo)
{
	return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
					    ff_layout_initiate_commit);
}

static struct pnfs_ds_commit_info *
ff_layout_get_ds_info(struct inode *inode)
{
	struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;

	if (layout == NULL)
		return NULL;

	return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
}

static void
ff_layout_free_deveiceid_node(struct nfs4_deviceid_node *d)
{
	nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
						  id_node));
}

static int ff_layout_encode_ioerr(struct nfs4_flexfile_layout *flo,
				  struct xdr_stream *xdr,
				  const struct nfs4_layoutreturn_args *args)
{
	struct pnfs_layout_hdr *hdr = &flo->generic_hdr;
	__be32 *start;
	int count = 0, ret = 0;

	start = xdr_reserve_space(xdr, 4);
	if (unlikely(!start))
		return -E2BIG;

	/* This assume we always return _ALL_ layouts */
	spin_lock(&hdr->plh_inode->i_lock);
	ret = ff_layout_encode_ds_ioerr(flo, xdr, &count, &args->range);
	spin_unlock(&hdr->plh_inode->i_lock);

	*start = cpu_to_be32(count);

	return ret;
}

/* report nothing for now */
static void ff_layout_encode_iostats(struct nfs4_flexfile_layout *flo,
				     struct xdr_stream *xdr,
				     const struct nfs4_layoutreturn_args *args)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, 4);
	if (likely(p))
		*p = cpu_to_be32(0);
}

static struct nfs4_deviceid_node *
ff_layout_alloc_deviceid_node(struct nfs_server *server,
			      struct pnfs_device *pdev, gfp_t gfp_flags)
{
	struct nfs4_ff_layout_ds *dsaddr;

	dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
	if (!dsaddr)
		return NULL;
	return &dsaddr->id_node;
}

static void
ff_layout_encode_layoutreturn(struct pnfs_layout_hdr *lo,
			      struct xdr_stream *xdr,
			      const struct nfs4_layoutreturn_args *args)
{
	struct nfs4_flexfile_layout *flo = FF_LAYOUT_FROM_HDR(lo);
	__be32 *start;

	dprintk("%s: Begin\n", __func__);
	start = xdr_reserve_space(xdr, 4);
	BUG_ON(!start);

	if (ff_layout_encode_ioerr(flo, xdr, args))
		goto out;

	ff_layout_encode_iostats(flo, xdr, args);
out:
	*start = cpu_to_be32((xdr->p - start - 1) * 4);
	dprintk("%s: Return\n", __func__);
}

static struct pnfs_layoutdriver_type flexfilelayout_type = {
	.id			= LAYOUT_FLEX_FILES,
	.name			= "LAYOUT_FLEX_FILES",
	.owner			= THIS_MODULE,
	.alloc_layout_hdr	= ff_layout_alloc_layout_hdr,
	.free_layout_hdr	= ff_layout_free_layout_hdr,
	.alloc_lseg		= ff_layout_alloc_lseg,
	.free_lseg		= ff_layout_free_lseg,
	.pg_read_ops		= &ff_layout_pg_read_ops,
	.pg_write_ops		= &ff_layout_pg_write_ops,
	.get_ds_info		= ff_layout_get_ds_info,
	.free_deviceid_node	= ff_layout_free_deveiceid_node,
	.mark_request_commit	= ff_layout_mark_request_commit,
	.clear_request_commit	= pnfs_generic_clear_request_commit,
	.scan_commit_lists	= pnfs_generic_scan_commit_lists,
	.recover_commit_reqs	= pnfs_generic_recover_commit_reqs,
	.commit_pagelist	= ff_layout_commit_pagelist,
	.read_pagelist		= ff_layout_read_pagelist,
	.write_pagelist		= ff_layout_write_pagelist,
	.alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
	.encode_layoutreturn    = ff_layout_encode_layoutreturn,
};

static int __init nfs4flexfilelayout_init(void)
{
	printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
	       __func__);
	return pnfs_register_layoutdriver(&flexfilelayout_type);
}

static void __exit nfs4flexfilelayout_exit(void)
{
	printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
	       __func__);
	pnfs_unregister_layoutdriver(&flexfilelayout_type);
}

MODULE_ALIAS("nfs-layouttype4-4");

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");

module_init(nfs4flexfilelayout_init);
module_exit(nfs4flexfilelayout_exit);