Re: [PATCH 13/13] RFC: pnfs: filelayout: add driver's LAYOUTGET and GETDEVICEINFO infrastructure

Trond Myklebust
2010-09-10T20:33:44Z

On Thu, 2010-09-02 at 14:00 -0400, Fred Isaman wrote:
> From: The pNFS Team <linux-nfs@vger.kernel.org>
>
> Implement the driver's io_ops->alloc_lseg and free_lseg functions,
> which integrate into the deviceid cache and calls out to
> nfs4_proc_getdeviceinfo when necessary.
>
> Signed-off-by: TBD - melding/reorganization of several patches
> ---
> fs/nfs/Makefile | 2 +-
> fs/nfs/client.c | 1 +
> fs/nfs/nfs4filelayout.c | 203 ++++++++++++++++++++-
> fs/nfs/nfs4filelayout.h | 74 +++++++
> fs/nfs/nfs4filelayoutdev.c | 450 ++++++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 728 insertions(+), 2 deletions(-)
> create mode 100644 fs/nfs/nfs4filelayout.h
> create mode 100644 fs/nfs/nfs4filelayoutdev.c
>
> diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
> index 08a8889..4776ff9 100644
> --- a/fs/nfs/Makefile
> +++ b/fs/nfs/Makefile
> @@ -20,4 +20,4 @@ nfs-$(CONFIG_SYSCTL) += sysctl.o
> nfs-$(CONFIG_NFS_FSCACHE) += fscache.o fscache-index.o
>
> obj-$(CONFIG_PNFS_FILE_LAYOUT) += nfs_layout_nfsv41_files.o
> -nfs_layout_nfsv41_files-y := nfs4filelayout.o
> +nfs_layout_nfsv41_files-y := nfs4filelayout.o nfs4filelayoutdev.o
> diff --git a/fs/nfs/client.c b/fs/nfs/client.c
> index 6fc5c84..bac8ac2 100644
> --- a/fs/nfs/client.c
> +++ b/fs/nfs/client.c
> @@ -255,6 +255,7 @@ void nfs_put_client(struct nfs_client *clp)
> nfs_free_client(clp);
> }
> }
> +EXPORT_SYMBOL(nfs_put_client);
>
> #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
> /*
> diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
> index c685196..0104d09 100644
> --- a/fs/nfs/nfs4filelayout.c
> +++ b/fs/nfs/nfs4filelayout.c
> @@ -30,7 +30,9 @@
> */
>
> #include <linux/nfs_fs.h>
> -#include "pnfs.h"
> +
> +#include "internal.h"
> +#include "nfs4filelayout.h"
>
> #define NFSDBG_FACILITY NFSDBG_PNFS_LD
>
> @@ -41,18 +43,217 @@ MODULE_DESCRIPTION("The NFSv4 file layout driver");
> int
> filelayout_initialize_mountpoint(struct nfs_client *clp)
> {
> + int status = nfs4_alloc_init_deviceid_cache(clp,
> + nfs4_fl_free_deviceid_callback);
> + if (status) {
> + printk(KERN_WARNING "%s: deviceid cache could not be "
> + "initialized\n", __func__);
> + return status;
> + }
> + dprintk("%s: deviceid cache has been initialized successfully\n",
> + __func__);
> return 0;
> }
>
> +/* Uninitialize a mountpoint by destroying its device list */
> int
> filelayout_uninitialize_mountpoint(struct nfs_client *clp)
> {
> dprintk("--> %s\n", __func__);
>
> + if (clp->cl_devid_cache)
> + nfs4_put_deviceid_cache(clp);
> + return 0;
> +}
> +
> +/*
> + * 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 pnfs_layout_segment *lseg = &fl->generic_hdr;
> + struct nfs4_file_layout_dsaddr *dsaddr;
> + int status = -EINVAL;
> + struct nfs_server *nfss = PNFS_NFS_SERVER(lo);
> +
> + dprintk("--> %s\n", __func__);
> +
> + if (fl->pattern_offset > lgr->range.offset) {
> + dprintk("%s pattern_offset %lld to large\n",
> + __func__, fl->pattern_offset);
> + goto out;
> + }
> +
> + if (fl->stripe_unit % PAGE_SIZE) {
> + dprintk("%s Stripe unit (%u) not page aligned\n",
> + __func__, fl->stripe_unit);
> + goto out;
> + }
> +
> + /* find and reference the deviceid */
> + dsaddr = nfs4_fl_find_get_deviceid(nfss->nfs_client, &fl->dev_id);
> + if (dsaddr == NULL) {
> + dsaddr = get_device_info(lo->inode, &fl->dev_id);
> + if (dsaddr == NULL)
> + goto out;
> + }
> +
> + nfs4_set_layout_deviceid(lseg, &dsaddr->deviceid);
> +
> + if (fl->first_stripe_index < 0 ||
> + fl->first_stripe_index >= dsaddr->stripe_count) {
> + dprintk("%s Bad first_stripe_index %d\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_put_layout_deviceid(lseg);
> + goto out;
> +}
> +
> +static void _filelayout_free_lseg(struct nfs4_filelayout_segment *fl);
> +static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl);
> +
> +static int
> +filelayout_decode_layout(struct pnfs_layout_hdr *flo,
> + struct nfs4_filelayout_segment *fl,
> + struct nfs4_layoutget_res *lgr)
> +{
> + uint32_t *p = (uint32_t *)lgr->layout.buf;
> + uint32_t nfl_util;
> + int i;
> +
> + dprintk("%s: set_layout_map Begin\n", __func__);
> +
> + memcpy(&fl->dev_id, p, sizeof(fl->dev_id));
> + p += XDR_QUADLEN(NFS4_PNFS_DEVICEID4_SIZE);
> + print_deviceid(&fl->dev_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);
> +
> + if (fl->num_fh * sizeof(struct nfs_fh) > 2*PAGE_SIZE) {
> + fl->fh_array = vmalloc(fl->num_fh * sizeof(struct nfs_fh));
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Please do this differently. vmalloc() use is frowned upon unless you
really need _contiguous_ memory. The 32-bit vmalloc address space is
limited, and easily exhausted.

In this case you could instead allocate an array of pointers to struct
nfs_fh.

> + if (fl->fh_array)
> + memset(fl->fh_array, 0,
> + fl->num_fh * sizeof(struct nfs_fh));
> + } else {
> + fl->fh_array = kzalloc(fl->num_fh * sizeof(struct nfs_fh),
> + GFP_KERNEL);
> + }
> + if (!fl->fh_array)
> + return -ENOMEM;
> +
> + for (i = 0; i < fl->num_fh; i++) {
> + /* fh */
> + fl->fh_array[i].size = be32_to_cpup(p++);
> + if (sizeof(struct nfs_fh) < fl->fh_array[i].size) {
> + printk(KERN_ERR "Too big fh %d received %d\n",
> + i, fl->fh_array[i].size);
> + /* Layout is now invalid, pretend it doesn't exist */
> + filelayout_free_fh_array(fl);
> + fl->num_fh = 0;
> + break;
> + }
> + memcpy(fl->fh_array[i].data, p, fl->fh_array[i].size);
> + p += XDR_QUADLEN(fl->fh_array[i].size);
> + dprintk("DEBUG: %s: fh len %d\n", __func__,
> + fl->fh_array[i].size);
> + }
> +
> return 0;
> }
>
> +static struct pnfs_layout_segment *
> +filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
> + struct nfs4_layoutget_res *lgr)
> +{
> + struct nfs4_filelayout_segment *fl;
> + int rc;
> +
> + dprintk("--> %s\n", __func__);
> + fl = kzalloc(sizeof(*fl), GFP_KERNEL);
> + if (!fl)
> + return NULL;
> +
> + rc = filelayout_decode_layout(layoutid, fl, lgr);
> + if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr)) {
> + _filelayout_free_lseg(fl);
> + return NULL;
> + }
> + return &fl->generic_hdr;
> +}
> +
> +static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
> +{
> + if (fl->num_fh * sizeof(struct nfs_fh) > 2*PAGE_SIZE)
> + vfree(fl->fh_array);

See above.

> + else
> + 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 void
> +filelayout_free_lseg(struct pnfs_layout_segment *lseg)
> +{
> + dprintk("--> %s\n", __func__);
> + nfs4_put_layout_deviceid(lseg);
> + _filelayout_free_lseg(FILELAYOUT_LSEG(lseg));
> +}
> +
> struct layoutdriver_io_operations filelayout_io_operations = {
> + .alloc_lseg = filelayout_alloc_lseg,
> + .free_lseg = filelayout_free_lseg,
> .initialize_mountpoint = filelayout_initialize_mountpoint,
> .uninitialize_mountpoint = filelayout_uninitialize_mountpoint,
> };
> diff --git a/fs/nfs/nfs4filelayout.h b/fs/nfs/nfs4filelayout.h
> new file mode 100644
> index 0000000..2467b5f
> --- /dev/null
> +++ b/fs/nfs/nfs4filelayout.h
> @@ -0,0 +1,74 @@
> +/*
> + * NFSv4 file layout driver data structures.
> + *
> + * Copyright (c) 2002 The Regents of the University of Michigan.
> + * All rights reserved.
> + *
> + * Dean Hildebrand <dhildebz@umich.edu>
> + */
> +
> +#ifndef FS_NFS_NFS4FILELAYOUT_H
> +#define FS_NFS_NFS4FILELAYOUT_H
> +
> +#include "pnfs.h"
> +
> +/*
> + * Field testing shows we need to support upto 4096 stripe indices.
> + * We store each index as a u8 (u32 on the wire) to keep the memory footprint
> + * reasonable. This in turn means we support a maximum of 256
> + * RFC 5661 multipath_list4 structures.
> + */
> +#define NFS4_PNFS_MAX_STRIPE_CNT 4096
> +#define NFS4_PNFS_MAX_MULTI_CNT 256 /* 256 fit into a u8 stripe_index */
> +
> +enum stripetype4 {
> + STRIPE_SPARSE = 1,
> + STRIPE_DENSE = 2
> +};
> +
> +/* Individual ip address */
> +struct nfs4_pnfs_ds {
> + struct list_head ds_node; /* nfs4_pnfs_dev_hlist dev_dslist */
> + u32 ds_ip_addr;
> + u32 ds_port;
> + struct nfs_client *ds_clp;
> + atomic_t ds_count;
> +};
> +
> +struct nfs4_file_layout_dsaddr {
> + struct nfs4_deviceid deviceid;
> + u32 stripe_count;
> + u8 *stripe_indices;
> + u32 ds_num;
> + struct nfs4_pnfs_ds *ds_list[1];
> +};
> +
> +struct nfs4_filelayout_segment {
> + struct pnfs_layout_segment generic_hdr;
> + u32 stripe_type;
> + u32 commit_through_mds;
> + u32 stripe_unit;
> + u32 first_stripe_index;
> + u64 pattern_offset;
> + struct pnfs_deviceid dev_id;
> + unsigned int num_fh;
> + struct nfs_fh *fh_array;
> +};
> +
> +static inline struct nfs4_filelayout_segment *
> +FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg)
> +{
> + return container_of(lseg,
> + struct nfs4_filelayout_segment,
> + generic_hdr);
> +}
> +
> +extern void nfs4_fl_free_deviceid_callback(struct nfs4_deviceid *);
> +extern void print_ds(struct nfs4_pnfs_ds *ds);
> +extern void print_deviceid(struct pnfs_deviceid *dev_id);
> +extern struct nfs4_file_layout_dsaddr *
> +nfs4_fl_find_get_deviceid(struct nfs_client *, struct pnfs_deviceid *dev_id);
> +struct nfs4_file_layout_dsaddr *
> +get_device_info(struct inode *inode, struct pnfs_deviceid *dev_id);
> +
> +#endif /* FS_NFS_NFS4FILELAYOUT_H */
> diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
> new file mode 100644
> index 0000000..833ff9a
> --- /dev/null
> +++ b/fs/nfs/nfs4filelayoutdev.c
> @@ -0,0 +1,450 @@
> +/*
> + * Device operations for the pnfs nfs4 file layout driver.
> + *
> + * Copyright (c) 2002
> + * The Regents of the University of Michigan
> + * All Rights Reserved
> + *
> + * Dean Hildebrand <dhildebz@umich.edu>
> + * Garth Goodson <Garth.Goodson@netapp.com>
> + *
> + * 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 "internal.h"
> +#include "nfs4filelayout.h"
> +
> +#define NFSDBG_FACILITY NFSDBG_PNFS_LD
> +
> +/*
> + * Data server cache
> + *
> + * Data servers can be mapped to different device ids.
> + * nfs4_pnfs_ds reference counting
> + * - set to 1 on allocation
> + * - incremented when a device id maps a data server already in the cache.
> + * - decremented when deviceid is removed from the cache.
> + */
> +DEFINE_SPINLOCK(nfs4_ds_cache_lock);
> +static LIST_HEAD(nfs4_data_server_cache);
> +
> +/* Debug routines */
> +void
> +print_ds(struct nfs4_pnfs_ds *ds)
> +{
> + if (ds == NULL) {
> + dprintk("%s NULL device\n", __func__);
> + return;
> + }
> + dprintk(" ip_addr %x port %hu\n"
> + " ref count %d\n"
> + " client %p\n"
> + " cl_exchange_flags %x\n",
> + ntohl(ds->ds_ip_addr), ntohs(ds->ds_port),
> + atomic_read(&ds->ds_count), ds->ds_clp,
> + ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
> +}
> +
> +void
> +print_ds_list(struct nfs4_file_layout_dsaddr *dsaddr)
> +{
> + int i;
> +
> + dprintk("%s dsaddr->ds_num %d\n", __func__,
> + dsaddr->ds_num);

Can we just do 1 test of ifdebug() at the beginning of this function
instead of doing the same test for each and every printk()?

> + for (i = 0; i < dsaddr->ds_num; i++)
> + print_ds(dsaddr->ds_list[i]);
> +}
> +
> +void print_deviceid(struct pnfs_deviceid *id)
> +{
> + u32 *p = (u32 *)id;
> +
> + dprintk("%s: device id= [%x%x%x%x]\n", __func__,
> + p[0], p[1], p[2], p[3]);
> +}
> +
> +/* nfs4_ds_cache_lock is held */
> +static struct nfs4_pnfs_ds *
> +_data_server_lookup_locked(u32 ip_addr, u32 port)
> +{
> + struct nfs4_pnfs_ds *ds;
> +
> + dprintk("_data_server_lookup: ip_addr=%x port=%hu\n",
> + ntohl(ip_addr), ntohs(port));
> +
> + list_for_each_entry(ds, &nfs4_data_server_cache, ds_node) {
> + if (ds->ds_ip_addr == ip_addr &&
> + ds->ds_port == port) {
> + return ds;
> + }
> + }
> + return NULL;
> +}
> +
> +static void
> +destroy_ds(struct nfs4_pnfs_ds *ds)
> +{
> + dprintk("--> %s\n", __func__);
> + print_ds(ds);
> +
> + if (ds->ds_clp)
> + nfs_put_client(ds->ds_clp);
> + kfree(ds);
> +}
> +
> +static void
> +nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
> +{
> + struct nfs4_pnfs_ds *ds;
> + int i;
> +
> + print_deviceid(&dsaddr->deviceid.de_id);
> +
> + for (i = 0; i < dsaddr->ds_num; i++) {
> + ds = dsaddr->ds_list[i];
> + if (ds != NULL) {
> + if (atomic_dec_and_lock(&ds->ds_count,
> + &nfs4_ds_cache_lock)) {
> + list_del_init(&ds->ds_node);
> + spin_unlock(&nfs4_ds_cache_lock);
> + destroy_ds(ds);
> + }
> + }
> + }
> + kfree(dsaddr->stripe_indices);
> + kfree(dsaddr);
> +}
> +
> +void
> +nfs4_fl_free_deviceid_callback(struct nfs4_deviceid *device)
> +{
> + struct nfs4_file_layout_dsaddr *dsaddr =
> + container_of(device, struct nfs4_file_layout_dsaddr, deviceid);
> +
> + nfs4_fl_free_deviceid(dsaddr);
> +}
> +
> +static struct nfs4_pnfs_ds *
> +nfs4_pnfs_ds_add(struct inode *inode, u32 ip_addr, u32 port)
> +{
> + struct nfs4_pnfs_ds *tmp_ds, *ds;
> +
> + ds = kzalloc(sizeof(*tmp_ds), GFP_KERNEL);
> + if (!ds)
> + goto out;
> +
> + spin_lock(&nfs4_ds_cache_lock);
> + tmp_ds = _data_server_lookup_locked(ip_addr, port);
> + if (tmp_ds == NULL) {
> + ds->ds_ip_addr = ip_addr;
> + ds->ds_port = port;
> + atomic_set(&ds->ds_count, 1);
> + INIT_LIST_HEAD(&ds->ds_node);
> + ds->ds_clp = NULL;
> + list_add(&ds->ds_node, &nfs4_data_server_cache);
> + dprintk("%s add new data server ip 0x%x\n", __func__,
> + ds->ds_ip_addr);
> + } else {
> + kfree(ds);
> + atomic_inc(&tmp_ds->ds_count);
> + dprintk("%s data server found ip 0x%x, inc'ed ds_count to %d\n",
> + __func__, tmp_ds->ds_ip_addr,
> + atomic_read(&tmp_ds->ds_count));
> + ds = tmp_ds;
> + }
> + spin_unlock(&nfs4_ds_cache_lock);
> +out:
> + return ds;
> +}
> +
> +/*
> + * Currently only support ipv4, and one multi-path address.
> + */
> +static struct nfs4_pnfs_ds *
> +decode_and_add_ds(__be32 **pp, struct inode *inode)
> +{
> + struct nfs4_pnfs_ds *ds = NULL;
> + char *buf;
> + const char *ipend, *pstr;
> + u32 ip_addr, port;
> + int nlen, rlen, i;
> + int tmp[2];
> + __be32 *r_netid, *r_addr, *p = *pp;
> +
> + /* r_netid */
> + nlen = be32_to_cpup(p++);
> + r_netid = p;
> + p += XDR_QUADLEN(nlen);
> +
> + /* r_addr */
> + rlen = be32_to_cpup(p++);
> + r_addr = p;
> + p += XDR_QUADLEN(rlen);
> + *pp = p;
> +
> + /* Check that netid is "tcp" */
> + if (nlen != 3 || memcmp((char *)r_netid, "tcp", 3)) {
> + dprintk("%s: ERROR: non ipv4 TCP r_netid\n", __func__);
> + goto out_err;
> + }
> +
> + /* ipv6 length plus port is legal */
> + if (rlen > INET6_ADDRSTRLEN + 8) {
> + dprintk("%s Invalid address, length %d\n", __func__,
> + rlen);
> + goto out_err;
> + }
> + buf = kmalloc(rlen + 1, GFP_KERNEL);
> + buf[rlen] = '\0';
> + memcpy(buf, r_addr, rlen);
> +
> + /* replace the port dots with dashes for the in4_pton() delimiter*/
> + for (i = 0; i < 2; i++) {
> + char *res = strrchr(buf, '.');
> + *res = '-';
> + }
> +
> + /* Currently only support ipv4 address */
> + if (in4_pton(buf, rlen, (u8 *)&ip_addr, '-', &ipend) == 0) {
> + dprintk("%s: Only ipv4 addresses supported\n", __func__);
> + goto out_free;
> + }
> +
> + /* port */
> + pstr = ipend;
> + sscanf(pstr, "-%d-%d", &tmp[0], &tmp[1]);
> + port = htons((tmp[0] << 8) | (tmp[1]));
> +
> + ds = nfs4_pnfs_ds_add(inode, ip_addr, port);
> + dprintk("%s Decoded address and port %s\n", __func__, buf);
> +out_free:
> + kfree(buf);
> +out_err:
> + return ds;
> +}
> +
> +
> +
> +/*Decode opaque device data and return the result */
> +static struct nfs4_file_layout_dsaddr*
> +decode_device(struct inode *ino, struct pnfs_device *pdev)
> +{
> + int i, dummy;
> + u32 cnt, num;
> + u8 *indexp;
> + __be32 *p = (__be32 *)pdev->area, *indicesp;
> + struct nfs4_file_layout_dsaddr *dsaddr;
> +
> + /* Get the stripe count (number of stripe index) */
> + cnt = be32_to_cpup(p++);
> + dprintk("%s stripe count %d\n", __func__, cnt);
> + if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
> + printk(KERN_WARNING "%s: stripe count %d greater than "
> + "supported maximum %d\n", __func__,
> + cnt, NFS4_PNFS_MAX_STRIPE_CNT);
> + goto out_err;
> + }
> +
> + /* Check the multipath list count */
> + indicesp = p;
> + p += XDR_QUADLEN(cnt << 2);
> + num = be32_to_cpup(p++);
> + dprintk("%s ds_num %u\n", __func__, num);
> + if (num > NFS4_PNFS_MAX_MULTI_CNT) {
> + printk(KERN_WARNING "%s: multipath count %d greater than "
> + "supported maximum %d\n", __func__,
> + num, NFS4_PNFS_MAX_MULTI_CNT);
> + goto out_err;
> + }
> + dsaddr = kzalloc(sizeof(*dsaddr) +
> + (sizeof(struct nfs4_pnfs_ds *) * (num - 1)),
> + GFP_KERNEL);
> + if (!dsaddr)
> + goto out_err;
> +
> + dsaddr->stripe_indices = kzalloc(sizeof(u8) * cnt, GFP_KERNEL);
> + if (!dsaddr->stripe_indices)
> + goto out_err_free;
> +
> + dsaddr->stripe_count = cnt;
> + dsaddr->ds_num = num;
> +
> + memcpy(&dsaddr->deviceid.de_id, &pdev->dev_id, sizeof(pdev->dev_id));
> +
> + /* Go back an read stripe indices */
> + p = indicesp;
> + indexp = &dsaddr->stripe_indices[0];
> + for (i = 0; i < dsaddr->stripe_count; i++) {
> + *indexp = be32_to_cpup(p++);
> + if (*indexp >= num)
> + goto out_err_free;
> + indexp++;
> + }
> + /* Skip already read multipath list count */
> + p++;
> +
> + for (i = 0; i < dsaddr->ds_num; i++) {
> + int j;
> +
> + dummy = be32_to_cpup(p++); /* multipath count */
> + if (dummy > 1) {
> + printk(KERN_WARNING
> + "%s: Multipath count %d not supported, "
> + "skipping all greater than 1\n", __func__,
> + dummy);
> + }
> + for (j = 0; j < dummy; j++) {
> + if (j == 0) {
> + dsaddr->ds_list[i] = decode_and_add_ds(&p, ino);
> + if (dsaddr->ds_list[i] == NULL)
> + goto out_err_free;
> + } else {
> + u32 len;
> + /* skip extra multipath */
> + len = be32_to_cpup(p++);
> + p += XDR_QUADLEN(len);
> + len = be32_to_cpup(p++);
> + p += XDR_QUADLEN(len);
> + continue;
> + }
> + }
> + }
> + nfs4_init_deviceid_node(&dsaddr->deviceid);
> +
> + return dsaddr;
> +
> +out_err_free:
> + nfs4_fl_free_deviceid(dsaddr);
> +out_err:
> + dprintk("%s ERROR: returning NULL\n", __func__);
> + return NULL;
> +}
> +
> +/*
> + * Decode the opaque device specified in 'dev'
> + * and add it to the list of available devices.
> + * If the deviceid is already cached, nfs4_add_deviceid will return
> + * a pointer to the cached struct and throw away the new.
> + */
> +static struct nfs4_file_layout_dsaddr*
> +decode_and_add_device(struct inode *inode, struct pnfs_device *dev)
> +{
> + struct nfs4_file_layout_dsaddr *dsaddr;
> + struct nfs4_deviceid *d;
> +
> + dsaddr = decode_device(inode, dev);
> + if (!dsaddr) {
> + printk(KERN_WARNING "%s: Could not decode or add device\n",
> + __func__);
> + return NULL;
> + }
> +
> + d = nfs4_add_deviceid(NFS_SERVER(inode)->nfs_client->cl_devid_cache,
> + &dsaddr->deviceid);
> +
> + return container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
> +}
> +
> +/*
> + * Retrieve the information for dev_id, add it to the list
> + * of available devices, and return it.
> + */
> +struct nfs4_file_layout_dsaddr *
> +get_device_info(struct inode *inode, struct pnfs_deviceid *dev_id)
> +{
> + struct pnfs_device *pdev = NULL;
> + u32 max_resp_sz;
> + int max_pages;
> + struct page **pages = NULL;
> + struct nfs4_file_layout_dsaddr *dsaddr = NULL;
> + int rc, i;
> + struct nfs_server *server = NFS_SERVER(inode);
> +
> + /*
> + * Use the session max response size as the basis for setting
> + * GETDEVICEINFO's maxcount
> + */
> + max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
> + max_pages = max_resp_sz >> PAGE_SHIFT;
> + dprintk("%s inode %p max_resp_sz %u max_pages %d\n",
> + __func__, inode, max_resp_sz, max_pages);
> +
> + pdev = kzalloc(sizeof(struct pnfs_device), GFP_KERNEL);
> + if (pdev == NULL)
> + return NULL;
> +
> + pages = kzalloc(max_pages * sizeof(struct page *), GFP_KERNEL);
> + if (pages == NULL) {
> + kfree(pdev);
> + return NULL;
> + }
> + for (i = 0; i < max_pages; i++) {
> + pages[i] = alloc_page(GFP_KERNEL);
> + if (!pages[i])
> + goto out_free;
> + }
> +
> + /* set pdev->area */
> + pdev->area = vmap(pages, max_pages, VM_MAP, PAGE_KERNEL);
> + if (!pdev->area)
> + goto out_free;
> +
> + memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
> + pdev->layout_type = LAYOUT_NFSV4_1_FILES;
> + pdev->pages = pages;
> + pdev->pgbase = 0;
> + pdev->pglen = PAGE_SIZE * max_pages;
> + pdev->mincount = 0;
> + /* TODO: Update types when CB_NOTIFY_DEVICEID is available */
> + pdev->dev_notify_types = 0;
> +
> + rc = nfs4_proc_getdeviceinfo(server, pdev);
> + dprintk("%s getdevice info returns %d\n", __func__, rc);
> + if (rc)
> + goto out_free;
> +
> + /*
> + * Found new device, need to decode it and then add it to the
> + * list of known devices for this mountpoint.
> + */
> + dsaddr = decode_and_add_device(inode, pdev);
> +out_free:
> + if (pdev->area != NULL)
> + vunmap(pdev->area);
> + for (i = 0; i < max_pages; i++)
> + __free_page(pages[i]);
> + kfree(pages);
> + kfree(pdev);
> + dprintk("<-- %s dsaddr %p\n", __func__, dsaddr);
> + return dsaddr;
> +}
> +
> +struct nfs4_file_layout_dsaddr *
> +nfs4_fl_find_get_deviceid(struct nfs_client *clp, struct pnfs_deviceid *id)
> +{
> + struct nfs4_deviceid *d;
> +
> + d = nfs4_find_get_deviceid(clp->cl_devid_cache, id);
> + return (d == NULL) ? NULL :
> + container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
> +}