Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * Device operations for the pnfs nfs4 file layout driver.
 *
 * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
 *
 * Tao Peng <bergwolf@primarydata.com>
 */
 
#include <linux/nfs_fs.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/sunrpc/addr.h>
 
#include "../internal.h"
#include "../nfs4session.h"
#include "flexfilelayout.h"
 
#define NFSDBG_FACILITY		NFSDBG_PNFS_LD
 
static unsigned int dataserver_timeo = NFS_DEF_TCP_TIMEO;
static unsigned int dataserver_retrans;
 
static bool ff_layout_has_available_ds(struct pnfs_layout_segment *lseg);
 
void nfs4_ff_layout_put_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
{
<------>if (!IS_ERR_OR_NULL(mirror_ds))
<------><------>nfs4_put_deviceid_node(&mirror_ds->id_node);
}
 
void nfs4_ff_layout_free_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
{
<------>nfs4_print_deviceid(&mirror_ds->id_node.deviceid);
<------>nfs4_pnfs_ds_put(mirror_ds->ds);
<------>kfree(mirror_ds->ds_versions);
<------>kfree_rcu(mirror_ds, id_node.rcu);
}
 
/* Decode opaque device data and construct new_ds using it */
struct nfs4_ff_layout_ds *
nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
<------><------><------>    gfp_t gfp_flags)
{
<------>struct xdr_stream stream;
<------>struct xdr_buf buf;
<------>struct page *scratch;
<------>struct list_head dsaddrs;
<------>struct nfs4_pnfs_ds_addr *da;
<------>struct nfs4_ff_layout_ds *new_ds = NULL;
<------>struct nfs4_ff_ds_version *ds_versions = NULL;
<------>u32 mp_count;
<------>u32 version_count;
<------>__be32 *p;
<------>int i, ret = -ENOMEM;
 
<------>/* set up xdr stream */
<------>scratch = alloc_page(gfp_flags);
<------>if (!scratch)
<------><------>goto out_err;
 
<------>new_ds = kzalloc(sizeof(struct nfs4_ff_layout_ds), gfp_flags);
<------>if (!new_ds)
<------><------>goto out_scratch;
 
<------>nfs4_init_deviceid_node(&new_ds->id_node,
<------><------><------><------>server,
<------><------><------><------>&pdev->dev_id);
<------>INIT_LIST_HEAD(&dsaddrs);
 
<------>xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
<------>xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 
<------>/* multipath count */
<------>p = xdr_inline_decode(&stream, 4);
<------>if (unlikely(!p))
<------><------>goto out_err_drain_dsaddrs;
<------>mp_count = be32_to_cpup(p);
<------>dprintk("%s: multipath ds count %d\n", __func__, mp_count);
 
<------>for (i = 0; i < mp_count; i++) {
<------><------>/* multipath ds */
<------><------>da = nfs4_decode_mp_ds_addr(server->nfs_client->cl_net,
<------><------><------><------><------>    &stream, gfp_flags);
<------><------>if (da)
<------><------><------>list_add_tail(&da->da_node, &dsaddrs);
<------>}
<------>if (list_empty(&dsaddrs)) {
<------><------>dprintk("%s: no suitable DS addresses found\n",
<------><------><------>__func__);
<------><------>ret = -ENOMEDIUM;
<------><------>goto out_err_drain_dsaddrs;
<------>}
 
<------>/* version count */
<------>p = xdr_inline_decode(&stream, 4);
<------>if (unlikely(!p))
<------><------>goto out_err_drain_dsaddrs;
<------>version_count = be32_to_cpup(p);
<------>dprintk("%s: version count %d\n", __func__, version_count);
 
<------>ds_versions = kcalloc(version_count,
<------><------><------>      sizeof(struct nfs4_ff_ds_version),
<------><------><------>      gfp_flags);
<------>if (!ds_versions)
<------><------>goto out_scratch;
 
<------>for (i = 0; i < version_count; i++) {
<------><------>/* 20 = version(4) + minor_version(4) + rsize(4) + wsize(4) +
<------><------> * tightly_coupled(4) */
<------><------>p = xdr_inline_decode(&stream, 20);
<------><------>if (unlikely(!p))
<------><------><------>goto out_err_drain_dsaddrs;
<------><------>ds_versions[i].version = be32_to_cpup(p++);
<------><------>ds_versions[i].minor_version = be32_to_cpup(p++);
<------><------>ds_versions[i].rsize = nfs_block_size(be32_to_cpup(p++), NULL);
<------><------>ds_versions[i].wsize = nfs_block_size(be32_to_cpup(p++), NULL);
<------><------>ds_versions[i].tightly_coupled = be32_to_cpup(p);
 
<------><------>if (ds_versions[i].rsize > NFS_MAX_FILE_IO_SIZE)
<------><------><------>ds_versions[i].rsize = NFS_MAX_FILE_IO_SIZE;
<------><------>if (ds_versions[i].wsize > NFS_MAX_FILE_IO_SIZE)
<------><------><------>ds_versions[i].wsize = NFS_MAX_FILE_IO_SIZE;
 
<------><------>/*
<------><------> * check for valid major/minor combination.
<------><------> * currently we support dataserver which talk:
<------><------> *   v3, v4.0, v4.1, v4.2
<------><------> */
<------><------>if (!((ds_versions[i].version == 3 && ds_versions[i].minor_version == 0) ||
<------><------><------>(ds_versions[i].version == 4 && ds_versions[i].minor_version < 3))) {
<------><------><------>dprintk("%s: [%d] unsupported ds version %d-%d\n", __func__,
<------><------><------><------>i, ds_versions[i].version,
<------><------><------><------>ds_versions[i].minor_version);
<------><------><------>ret = -EPROTONOSUPPORT;
<------><------><------>goto out_err_drain_dsaddrs;
<------><------>}
 
<------><------>dprintk("%s: [%d] vers %u minor_ver %u rsize %u wsize %u coupled %d\n",
<------><------><------>__func__, i, ds_versions[i].version,
<------><------><------>ds_versions[i].minor_version,
<------><------><------>ds_versions[i].rsize,
<------><------><------>ds_versions[i].wsize,
<------><------><------>ds_versions[i].tightly_coupled);
<------>}
 
<------>new_ds->ds_versions = ds_versions;
<------>new_ds->ds_versions_cnt = version_count;
 
<------>new_ds->ds = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
<------>if (!new_ds->ds)
<------><------>goto out_err_drain_dsaddrs;
 
<------>/* If DS was already in cache, free ds addrs */
<------>while (!list_empty(&dsaddrs)) {
<------><------>da = list_first_entry(&dsaddrs,
<------><------><------><------>      struct nfs4_pnfs_ds_addr,
<------><------><------><------>      da_node);
<------><------>list_del_init(&da->da_node);
<------><------>kfree(da->da_remotestr);
<------><------>kfree(da);
<------>}
 
<------>__free_page(scratch);
<------>return new_ds;
 
out_err_drain_dsaddrs:
<------>while (!list_empty(&dsaddrs)) {
<------><------>da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
<------><------><------><------>      da_node);
<------><------>list_del_init(&da->da_node);
<------><------>kfree(da->da_remotestr);
<------><------>kfree(da);
<------>}
 
<------>kfree(ds_versions);
out_scratch:
<------>__free_page(scratch);
out_err:
<------>kfree(new_ds);
 
<------>dprintk("%s ERROR: returning %d\n", __func__, ret);
<------>return NULL;
}
 
static void extend_ds_error(struct nfs4_ff_layout_ds_err *err,
<------><------><------>    u64 offset, u64 length)
{
<------>u64 end;
 
<------>end = max_t(u64, pnfs_end_offset(err->offset, err->length),
<------><------>    pnfs_end_offset(offset, length));
<------>err->offset = min_t(u64, err->offset, offset);
<------>err->length = end - err->offset;
}
 
static int
ff_ds_error_match(const struct nfs4_ff_layout_ds_err *e1,
<------><------>const struct nfs4_ff_layout_ds_err *e2)
{
<------>int ret;
 
<------>if (e1->opnum != e2->opnum)
<------><------>return e1->opnum < e2->opnum ? -1 : 1;
<------>if (e1->status != e2->status)
<------><------>return e1->status < e2->status ? -1 : 1;
<------>ret = memcmp(e1->stateid.data, e2->stateid.data,
<------><------><------>sizeof(e1->stateid.data));
<------>if (ret != 0)
<------><------>return ret;
<------>ret = memcmp(&e1->deviceid, &e2->deviceid, sizeof(e1->deviceid));
<------>if (ret != 0)
<------><------>return ret;
<------>if (pnfs_end_offset(e1->offset, e1->length) < e2->offset)
<------><------>return -1;
<------>if (e1->offset > pnfs_end_offset(e2->offset, e2->length))
<------><------>return 1;
<------>/* If ranges overlap or are contiguous, they are the same */
<------>return 0;
}
 
static void
ff_layout_add_ds_error_locked(struct nfs4_flexfile_layout *flo,
<------><------><------>      struct nfs4_ff_layout_ds_err *dserr)
{
<------>struct nfs4_ff_layout_ds_err *err, *tmp;
<------>struct list_head *head = &flo->error_list;
<------>int match;
 
<------>/* Do insertion sort w/ merges */
<------>list_for_each_entry_safe(err, tmp, &flo->error_list, list) {
<------><------>match = ff_ds_error_match(err, dserr);
<------><------>if (match < 0)
<------><------><------>continue;
<------><------>if (match > 0) {
<------><------><------>/* Add entry "dserr" _before_ entry "err" */
<------><------><------>head = &err->list;
<------><------><------>break;
<------><------>}
<------><------>/* Entries match, so merge "err" into "dserr" */
<------><------>extend_ds_error(dserr, err->offset, err->length);
<------><------>list_replace(&err->list, &dserr->list);
<------><------>kfree(err);
<------><------>return;
<------>}
 
<------>list_add_tail(&dserr->list, head);
}
 
int ff_layout_track_ds_error(struct nfs4_flexfile_layout *flo,
<------><------><------>     struct nfs4_ff_layout_mirror *mirror, u64 offset,
<------><------><------>     u64 length, int status, enum nfs_opnum4 opnum,
<------><------><------>     gfp_t gfp_flags)
{
<------>struct nfs4_ff_layout_ds_err *dserr;
 
<------>if (status == 0)
<------><------>return 0;
 
<------>if (IS_ERR_OR_NULL(mirror->mirror_ds))
<------><------>return -EINVAL;
 
<------>dserr = kmalloc(sizeof(*dserr), gfp_flags);
<------>if (!dserr)
<------><------>return -ENOMEM;
 
<------>INIT_LIST_HEAD(&dserr->list);
<------>dserr->offset = offset;
<------>dserr->length = length;
<------>dserr->status = status;
<------>dserr->opnum = opnum;
<------>nfs4_stateid_copy(&dserr->stateid, &mirror->stateid);
<------>memcpy(&dserr->deviceid, &mirror->mirror_ds->id_node.deviceid,
<------>       NFS4_DEVICEID4_SIZE);
 
<------>spin_lock(&flo->generic_hdr.plh_inode->i_lock);
<------>ff_layout_add_ds_error_locked(flo, dserr);
<------>spin_unlock(&flo->generic_hdr.plh_inode->i_lock);
<------>return 0;
}
 
static const struct cred *
ff_layout_get_mirror_cred(struct nfs4_ff_layout_mirror *mirror, u32 iomode)
{
<------>const struct cred *cred, __rcu **pcred;
 
<------>if (iomode == IOMODE_READ)
<------><------>pcred = &mirror->ro_cred;
<------>else
<------><------>pcred = &mirror->rw_cred;
 
<------>rcu_read_lock();
<------>do {
<------><------>cred = rcu_dereference(*pcred);
<------><------>if (!cred)
<------><------><------>break;
 
<------><------>cred = get_cred_rcu(cred);
<------>} while(!cred);
<------>rcu_read_unlock();
<------>return cred;
}
 
struct nfs_fh *
nfs4_ff_layout_select_ds_fh(struct nfs4_ff_layout_mirror *mirror)
{
<------>/* FIXME: For now assume there is only 1 version available for the DS */
<------>return &mirror->fh_versions[0];
}
 
void
nfs4_ff_layout_select_ds_stateid(const struct nfs4_ff_layout_mirror *mirror,
<------><------>nfs4_stateid *stateid)
{
<------>if (nfs4_ff_layout_ds_version(mirror) == 4)
<------><------>nfs4_stateid_copy(stateid, &mirror->stateid);
}
 
static bool
ff_layout_init_mirror_ds(struct pnfs_layout_hdr *lo,
<------><------><------> struct nfs4_ff_layout_mirror *mirror)
{
<------>if (mirror == NULL)
<------><------>goto outerr;
<------>if (mirror->mirror_ds == NULL) {
<------><------>struct nfs4_deviceid_node *node;
<------><------>struct nfs4_ff_layout_ds *mirror_ds = ERR_PTR(-ENODEV);
 
<------><------>node = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode),
<------><------><------><------>&mirror->devid, lo->plh_lc_cred,
<------><------><------><------>GFP_KERNEL);
<------><------>if (node)
<------><------><------>mirror_ds = FF_LAYOUT_MIRROR_DS(node);
 
<------><------>/* check for race with another call to this function */
<------><------>if (cmpxchg(&mirror->mirror_ds, NULL, mirror_ds) &&
<------><------>    mirror_ds != ERR_PTR(-ENODEV))
<------><------><------>nfs4_put_deviceid_node(node);
<------>}
 
<------>if (IS_ERR(mirror->mirror_ds))
<------><------>goto outerr;
 
<------>return true;
outerr:
<------>return false;
}
 
/**
 * nfs4_ff_layout_prepare_ds - prepare a DS connection for an RPC call
 * @lseg: the layout segment we're operating on
 * @mirror: layout mirror describing the DS to use
 * @fail_return: return layout on connect failure?
 *
 * Try to prepare a DS connection to accept an RPC call. This involves
 * selecting a mirror to use and connecting the client to it if it's not
 * already connected.
 *
 * Since we only need a single functioning mirror to satisfy a read, we don't
 * want to return the layout if there is one. For writes though, any down
 * mirror should result in a LAYOUTRETURN. @fail_return is how we distinguish
 * between the two cases.
 *
 * Returns a pointer to a connected DS object on success or NULL on failure.
 */
struct nfs4_pnfs_ds *
nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg,
<------><------><------>  struct nfs4_ff_layout_mirror *mirror,
<------><------><------>  bool fail_return)
{
<------>struct nfs4_pnfs_ds *ds = NULL;
<------>struct inode *ino = lseg->pls_layout->plh_inode;
<------>struct nfs_server *s = NFS_SERVER(ino);
<------>unsigned int max_payload;
<------>int status;
 
<------>if (!ff_layout_init_mirror_ds(lseg->pls_layout, mirror))
<------><------>goto noconnect;
 
<------>ds = mirror->mirror_ds->ds;
<------>if (READ_ONCE(ds->ds_clp))
<------><------>goto out;
<------>/* matching smp_wmb() in _nfs4_pnfs_v3/4_ds_connect */
<------>smp_rmb();
 
<------>/* FIXME: For now we assume the server sent only one version of NFS
<------> * to use for the DS.
<------> */
<------>status = nfs4_pnfs_ds_connect(s, ds, &mirror->mirror_ds->id_node,
<------><------><------>     dataserver_timeo, dataserver_retrans,
<------><------><------>     mirror->mirror_ds->ds_versions[0].version,
<------><------><------>     mirror->mirror_ds->ds_versions[0].minor_version);
 
<------>/* connect success, check rsize/wsize limit */
<------>if (!status) {
<------><------>max_payload =
<------><------><------>nfs_block_size(rpc_max_payload(ds->ds_clp->cl_rpcclient),
<------><------><------><------>       NULL);
<------><------>if (mirror->mirror_ds->ds_versions[0].rsize > max_payload)
<------><------><------>mirror->mirror_ds->ds_versions[0].rsize = max_payload;
<------><------>if (mirror->mirror_ds->ds_versions[0].wsize > max_payload)
<------><------><------>mirror->mirror_ds->ds_versions[0].wsize = max_payload;
<------><------>goto out;
<------>}
noconnect:
<------>ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
<------><------><------><------> mirror, lseg->pls_range.offset,
<------><------><------><------> lseg->pls_range.length, NFS4ERR_NXIO,
<------><------><------><------> OP_ILLEGAL, GFP_NOIO);
<------>ff_layout_send_layouterror(lseg);
<------>if (fail_return || !ff_layout_has_available_ds(lseg))
<------><------>pnfs_error_mark_layout_for_return(ino, lseg);
<------>ds = NULL;
out:
<------>return ds;
}
 
const struct cred *
ff_layout_get_ds_cred(struct nfs4_ff_layout_mirror *mirror,
<------><------>      const struct pnfs_layout_range *range,
<------><------>      const struct cred *mdscred)
{
<------>const struct cred *cred;
 
<------>if (mirror && !mirror->mirror_ds->ds_versions[0].tightly_coupled) {
<------><------>cred = ff_layout_get_mirror_cred(mirror, range->iomode);
<------><------>if (!cred)
<------><------><------>cred = get_cred(mdscred);
<------>} else {
<------><------>cred = get_cred(mdscred);
<------>}
<------>return cred;
}
 
/**
 * nfs4_ff_find_or_create_ds_client - Find or create a DS rpc client
 * @mirror: pointer to the mirror
 * @ds_clp: nfs_client for the DS
 * @inode: pointer to inode
 *
 * Find or create a DS rpc client with th MDS server rpc client auth flavor
 * in the nfs_client cl_ds_clients list.
 */
struct rpc_clnt *
nfs4_ff_find_or_create_ds_client(struct nfs4_ff_layout_mirror *mirror,
<------><------><------><------> struct nfs_client *ds_clp, struct inode *inode)
{
<------>switch (mirror->mirror_ds->ds_versions[0].version) {
<------>case 3:
<------><------>/* For NFSv3 DS, flavor is set when creating DS connections */
<------><------>return ds_clp->cl_rpcclient;
<------>case 4:
<------><------>return nfs4_find_or_create_ds_client(ds_clp, inode);
<------>default:
<------><------>BUG();
<------>}
}
 
void ff_layout_free_ds_ioerr(struct list_head *head)
{
<------>struct nfs4_ff_layout_ds_err *err;
 
<------>while (!list_empty(head)) {
<------><------>err = list_first_entry(head,
<------><------><------><------>struct nfs4_ff_layout_ds_err,
<------><------><------><------>list);
<------><------>list_del(&err->list);
<------><------>kfree(err);
<------>}
}
 
/* called with inode i_lock held */
int ff_layout_encode_ds_ioerr(struct xdr_stream *xdr, const struct list_head *head)
{
<------>struct nfs4_ff_layout_ds_err *err;
<------>__be32 *p;
 
<------>list_for_each_entry(err, head, list) {
<------><------>/* offset(8) + length(8) + stateid(NFS4_STATEID_SIZE)
<------><------> * + array length + deviceid(NFS4_DEVICEID4_SIZE)
<------><------> * + status(4) + opnum(4)
<------><------> */
<------><------>p = xdr_reserve_space(xdr,
<------><------><------><------>28 + NFS4_STATEID_SIZE + NFS4_DEVICEID4_SIZE);
<------><------>if (unlikely(!p))
<------><------><------>return -ENOBUFS;
<------><------>p = xdr_encode_hyper(p, err->offset);
<------><------>p = xdr_encode_hyper(p, err->length);
<------><------>p = xdr_encode_opaque_fixed(p, &err->stateid,
<------><------><------><------><------>    NFS4_STATEID_SIZE);
<------><------>/* Encode 1 error */
<------><------>*p++ = cpu_to_be32(1);
<------><------>p = xdr_encode_opaque_fixed(p, &err->deviceid,
<------><------><------><------><------>    NFS4_DEVICEID4_SIZE);
<------><------>*p++ = cpu_to_be32(err->status);
<------><------>*p++ = cpu_to_be32(err->opnum);
<------><------>dprintk("%s: offset %llu length %llu status %d op %d\n",
<------><------><------>__func__, err->offset, err->length, err->status,
<------><------><------>err->opnum);
<------>}
 
<------>return 0;
}
 
static
unsigned int do_layout_fetch_ds_ioerr(struct pnfs_layout_hdr *lo,
<------><------><------><------>      const struct pnfs_layout_range *range,
<------><------><------><------>      struct list_head *head,
<------><------><------><------>      unsigned int maxnum)
{
<------>struct nfs4_flexfile_layout *flo = FF_LAYOUT_FROM_HDR(lo);
<------>struct inode *inode = lo->plh_inode;
<------>struct nfs4_ff_layout_ds_err *err, *n;
<------>unsigned int ret = 0;
 
<------>spin_lock(&inode->i_lock);
<------>list_for_each_entry_safe(err, n, &flo->error_list, list) {
<------><------>if (!pnfs_is_range_intersecting(err->offset,
<------><------><------><------>pnfs_end_offset(err->offset, err->length),
<------><------><------><------>range->offset,
<------><------><------><------>pnfs_end_offset(range->offset, range->length)))
<------><------><------>continue;
<------><------>if (!maxnum)
<------><------><------>break;
<------><------>list_move(&err->list, head);
<------><------>maxnum--;
<------><------>ret++;
<------>}
<------>spin_unlock(&inode->i_lock);
<------>return ret;
}
 
unsigned int ff_layout_fetch_ds_ioerr(struct pnfs_layout_hdr *lo,
<------><------><------><------>      const struct pnfs_layout_range *range,
<------><------><------><------>      struct list_head *head,
<------><------><------><------>      unsigned int maxnum)
{
<------>unsigned int ret;
 
<------>ret = do_layout_fetch_ds_ioerr(lo, range, head, maxnum);
<------>/* If we're over the max, discard all remaining entries */
<------>if (ret == maxnum) {
<------><------>LIST_HEAD(discard);
<------><------>do_layout_fetch_ds_ioerr(lo, range, &discard, -1);
<------><------>ff_layout_free_ds_ioerr(&discard);
<------>}
<------>return ret;
}
 
static bool ff_read_layout_has_available_ds(struct pnfs_layout_segment *lseg)
{
<------>struct nfs4_ff_layout_mirror *mirror;
<------>struct nfs4_deviceid_node *devid;
<------>u32 idx;
 
<------>for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
<------><------>mirror = FF_LAYOUT_COMP(lseg, idx);
<------><------>if (mirror) {
<------><------><------>if (!mirror->mirror_ds)
<------><------><------><------>return true;
<------><------><------>if (IS_ERR(mirror->mirror_ds))
<------><------><------><------>continue;
<------><------><------>devid = &mirror->mirror_ds->id_node;
<------><------><------>if (!nfs4_test_deviceid_unavailable(devid))
<------><------><------><------>return true;
<------><------>}
<------>}
 
<------>return false;
}
 
static bool ff_rw_layout_has_available_ds(struct pnfs_layout_segment *lseg)
{
<------>struct nfs4_ff_layout_mirror *mirror;
<------>struct nfs4_deviceid_node *devid;
<------>u32 idx;
 
<------>for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
<------><------>mirror = FF_LAYOUT_COMP(lseg, idx);
<------><------>if (!mirror || IS_ERR(mirror->mirror_ds))
<------><------><------>return false;
<------><------>if (!mirror->mirror_ds)
<------><------><------>continue;
<------><------>devid = &mirror->mirror_ds->id_node;
<------><------>if (nfs4_test_deviceid_unavailable(devid))
<------><------><------>return false;
<------>}
 
<------>return FF_LAYOUT_MIRROR_COUNT(lseg) != 0;
}
 
static bool ff_layout_has_available_ds(struct pnfs_layout_segment *lseg)
{
<------>if (lseg->pls_range.iomode == IOMODE_READ)
<------><------>return  ff_read_layout_has_available_ds(lseg);
<------>/* Note: RW layout needs all mirrors available */
<------>return ff_rw_layout_has_available_ds(lseg);
}
 
bool ff_layout_avoid_mds_available_ds(struct pnfs_layout_segment *lseg)
{
<------>return ff_layout_no_fallback_to_mds(lseg) ||
<------>       ff_layout_has_available_ds(lseg);
}
 
bool ff_layout_avoid_read_on_rw(struct pnfs_layout_segment *lseg)
{
<------>return lseg->pls_range.iomode == IOMODE_RW &&
<------>       ff_layout_no_read_on_rw(lseg);
}
 
module_param(dataserver_retrans, uint, 0644);
MODULE_PARM_DESC(dataserver_retrans, "The  number of times the NFSv4.1 client "
<------><------><------>"retries a request before it attempts further "
<------><------><------>" recovery  action.");
module_param(dataserver_timeo, uint, 0644);
MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
<------><------><------>"NFSv4.1  client  waits for a response from a "
<------><------><------>" data server before it retries an NFS request.");