Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc

[cris-mirror.git] / fs / nfs / nfs4filelayoutdev.c

/*
 *  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 <linux/vmalloc.h>

#include "internal.h"
#include "nfs4filelayout.h"

#define NFSDBG_FACILITY         NFSDBG_PNFS_LD

/*
 * Device ID RCU cache. A device ID is unique per client ID and layout type.
 */
#define NFS4_FL_DEVICE_ID_HASH_BITS     5
#define NFS4_FL_DEVICE_ID_HASH_SIZE     (1 << NFS4_FL_DEVICE_ID_HASH_BITS)
#define NFS4_FL_DEVICE_ID_HASH_MASK     (NFS4_FL_DEVICE_ID_HASH_SIZE - 1)

static inline u32
nfs4_fl_deviceid_hash(struct nfs4_deviceid *id)
{
        unsigned char *cptr = (unsigned char *)id->data;
        unsigned int nbytes = NFS4_DEVICEID4_SIZE;
        u32 x = 0;

        while (nbytes--) {
                x *= 37;
                x += *cptr++;
        }
        return x & NFS4_FL_DEVICE_ID_HASH_MASK;
}

static struct hlist_head filelayout_deviceid_cache[NFS4_FL_DEVICE_ID_HASH_SIZE];
static DEFINE_SPINLOCK(filelayout_deviceid_lock);

/*
 * 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) {
                printk("%s NULL device\n", __func__);
                return;
        }
        printk("        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;

        ifdebug(FACILITY) {
                printk("%s dsaddr->ds_num %d\n", __func__,
                       dsaddr->ds_num);
                for (i = 0; i < dsaddr->ds_num; i++)
                        print_ds(dsaddr->ds_list[i]);
        }
}

void print_deviceid(struct nfs4_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;
}

/*
 * Create an rpc connection to the nfs4_pnfs_ds data server
 * Currently only support IPv4
 */
static int
nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds)
{
        struct nfs_client *clp;
        struct sockaddr_in sin;
        int status = 0;

        dprintk("--> %s ip:port %x:%hu au_flavor %d\n", __func__,
                ntohl(ds->ds_ip_addr), ntohs(ds->ds_port),
                mds_srv->nfs_client->cl_rpcclient->cl_auth->au_flavor);

        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = ds->ds_ip_addr;
        sin.sin_port = ds->ds_port;

        clp = nfs4_set_ds_client(mds_srv->nfs_client, (struct sockaddr *)&sin,
                                 sizeof(sin), IPPROTO_TCP);
        if (IS_ERR(clp)) {
                status = PTR_ERR(clp);
                goto out;
        }

        if ((clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) != 0) {
                if (!is_ds_client(clp)) {
                        status = -ENODEV;
                        goto out_put;
                }
                ds->ds_clp = clp;
                dprintk("%s [existing] ip=%x, port=%hu\n", __func__,
                        ntohl(ds->ds_ip_addr), ntohs(ds->ds_port));
                goto out;
        }

        /*
         * Do not set NFS_CS_CHECK_LEASE_TIME instead set the DS lease to
         * be equal to the MDS lease. Renewal is scheduled in create_session.
         */
        spin_lock(&mds_srv->nfs_client->cl_lock);
        clp->cl_lease_time = mds_srv->nfs_client->cl_lease_time;
        spin_unlock(&mds_srv->nfs_client->cl_lock);
        clp->cl_last_renewal = jiffies;

        /* New nfs_client */
        status = nfs4_init_ds_session(clp);
        if (status)
                goto out_put;

        ds->ds_clp = clp;
        dprintk("%s [new] ip=%x, port=%hu\n", __func__, ntohl(ds->ds_ip_addr),
                ntohs(ds->ds_port));
out:
        return status;
out_put:
        nfs_put_client(clp);
        goto out;
}

static void
destroy_ds(struct nfs4_pnfs_ds *ds)
{
        dprintk("--> %s\n", __func__);
        ifdebug(FACILITY)
                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);

        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);
}

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(struct xdr_stream *streamp, 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 *p;

        /* r_netid */
        p = xdr_inline_decode(streamp, 4);
        if (unlikely(!p))
                goto out_err;
        nlen = be32_to_cpup(p++);

        p = xdr_inline_decode(streamp, nlen);
        if (unlikely(!p))
                goto out_err;

        /* Check that netid is "tcp" */
        if (nlen != 3 ||  memcmp((char *)p, "tcp", 3)) {
                dprintk("%s: ERROR: non ipv4 TCP r_netid\n", __func__);
                goto out_err;
        }

        /* r_addr */
        p = xdr_inline_decode(streamp, 4);
        if (unlikely(!p))
                goto out_err;
        rlen = be32_to_cpup(p);

        p = xdr_inline_decode(streamp, rlen);
        if (unlikely(!p))
                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);
        if (!buf) {
                dprintk("%s: Not enough memory\n", __func__);
                goto out_err;
        }
        buf[rlen] = '\0';
        memcpy(buf, p, rlen);

        /* replace the port dots with dashes for the in4_pton() delimiter*/
        for (i = 0; i < 2; i++) {
                char *res = strrchr(buf, '.');
                if (!res) {
                        dprintk("%s: Failed finding expected dots in port\n",
                                __func__);
                        goto out_free;
                }
                *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;
        u32 cnt, num;
        u8 *indexp;
        __be32 *p;
        u8 *stripe_indices;
        u8 max_stripe_index;
        struct nfs4_file_layout_dsaddr *dsaddr = NULL;
        struct xdr_stream stream;
        struct xdr_buf buf = {
                .pages = pdev->pages,
                .page_len = pdev->pglen,
                .buflen = pdev->pglen,
                .len = pdev->pglen,
        };
        struct page *scratch;

        /* set up xdr stream */
        scratch = alloc_page(GFP_KERNEL);
        if (!scratch)
                goto out_err;

        xdr_init_decode(&stream, &buf, NULL);
        xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);

        /* Get the stripe count (number of stripe index) */
        p = xdr_inline_decode(&stream, 4);
        if (unlikely(!p))
                goto out_err_free_scratch;

        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_free_scratch;
        }

        /* read stripe indices */
        stripe_indices = kcalloc(cnt, sizeof(u8), GFP_KERNEL);
        if (!stripe_indices)
                goto out_err_free_scratch;

        p = xdr_inline_decode(&stream, cnt << 2);
        if (unlikely(!p))
                goto out_err_free_stripe_indices;

        indexp = &stripe_indices[0];
        max_stripe_index = 0;
        for (i = 0; i < cnt; i++) {
                *indexp = be32_to_cpup(p++);
                max_stripe_index = max(max_stripe_index, *indexp);
                indexp++;
        }

        /* Check the multipath list count */
        p = xdr_inline_decode(&stream, 4);
        if (unlikely(!p))
                goto out_err_free_stripe_indices;

        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_free_stripe_indices;
        }

        /* validate stripe indices are all < num */
        if (max_stripe_index >= num) {
                printk(KERN_WARNING "%s: stripe index %u >= num ds %u\n",
                        __func__, max_stripe_index, num);
                goto out_err_free_stripe_indices;
        }

        dsaddr = kzalloc(sizeof(*dsaddr) +
                        (sizeof(struct nfs4_pnfs_ds *) * (num - 1)),
                        GFP_KERNEL);
        if (!dsaddr)
                goto out_err_free_stripe_indices;

        dsaddr->stripe_count = cnt;
        dsaddr->stripe_indices = stripe_indices;
        stripe_indices = NULL;
        dsaddr->ds_num = num;

        memcpy(&dsaddr->deviceid, &pdev->dev_id, sizeof(pdev->dev_id));

        for (i = 0; i < dsaddr->ds_num; i++) {
                int j;
                u32 mp_count;

                p = xdr_inline_decode(&stream, 4);
                if (unlikely(!p))
                        goto out_err_free_deviceid;

                mp_count = be32_to_cpup(p); /* multipath count */
                if (mp_count > 1) {
                        printk(KERN_WARNING
                               "%s: Multipath count %d not supported, "
                               "skipping all greater than 1\n", __func__,
                                mp_count);
                }
                for (j = 0; j < mp_count; j++) {
                        if (j == 0) {
                                dsaddr->ds_list[i] = decode_and_add_ds(&stream,
                                        ino);
                                if (dsaddr->ds_list[i] == NULL)
                                        goto out_err_free_deviceid;
                        } else {
                                u32 len;
                                /* skip extra multipath */

                                /* read len, skip */
                                p = xdr_inline_decode(&stream, 4);
                                if (unlikely(!p))
                                        goto out_err_free_deviceid;
                                len = be32_to_cpup(p);

                                p = xdr_inline_decode(&stream, len);
                                if (unlikely(!p))
                                        goto out_err_free_deviceid;

                                /* read len, skip */
                                p = xdr_inline_decode(&stream, 4);
                                if (unlikely(!p))
                                        goto out_err_free_deviceid;
                                len = be32_to_cpup(p);

                                p = xdr_inline_decode(&stream, len);
                                if (unlikely(!p))
                                        goto out_err_free_deviceid;
                        }
                }
        }

        __free_page(scratch);
        return dsaddr;

out_err_free_deviceid:
        nfs4_fl_free_deviceid(dsaddr);
        /* stripe_indicies was part of dsaddr */
        goto out_err_free_scratch;
out_err_free_stripe_indices:
        kfree(stripe_indices);
out_err_free_scratch:
        __free_page(scratch);
out_err:
        dprintk("%s ERROR: returning NULL\n", __func__);
        return NULL;
}

/*
 * Decode the opaque device specified in 'dev' and add it to the cache of
 * available devices.
 */
static struct nfs4_file_layout_dsaddr *
decode_and_add_device(struct inode *inode, struct pnfs_device *dev)
{
        struct nfs4_file_layout_dsaddr *d, *new;
        long hash;

        new = decode_device(inode, dev);
        if (!new) {
                printk(KERN_WARNING "%s: Could not decode or add device\n",
                        __func__);
                return NULL;
        }

        spin_lock(&filelayout_deviceid_lock);
        d = nfs4_fl_find_get_deviceid(&new->deviceid);
        if (d) {
                spin_unlock(&filelayout_deviceid_lock);
                nfs4_fl_free_deviceid(new);
                return d;
        }

        INIT_HLIST_NODE(&new->node);
        atomic_set(&new->ref, 1);
        hash = nfs4_fl_deviceid_hash(&new->deviceid);
        hlist_add_head_rcu(&new->node, &filelayout_deviceid_cache[hash]);
        spin_unlock(&filelayout_deviceid_lock);

        return new;
}

/*
 * 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 nfs4_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;
        }

        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;

        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:
        for (i = 0; i < max_pages; i++)
                __free_page(pages[i]);
        kfree(pages);
        kfree(pdev);
        dprintk("<-- %s dsaddr %p\n", __func__, dsaddr);
        return dsaddr;
}

void
nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
{
        if (atomic_dec_and_lock(&dsaddr->ref, &filelayout_deviceid_lock)) {
                hlist_del_rcu(&dsaddr->node);
                spin_unlock(&filelayout_deviceid_lock);

                synchronize_rcu();
                nfs4_fl_free_deviceid(dsaddr);
        }
}

struct nfs4_file_layout_dsaddr *
nfs4_fl_find_get_deviceid(struct nfs4_deviceid *id)
{
        struct nfs4_file_layout_dsaddr *d;
        struct hlist_node *n;
        long hash = nfs4_fl_deviceid_hash(id);


        rcu_read_lock();
        hlist_for_each_entry_rcu(d, n, &filelayout_deviceid_cache[hash], node) {
                if (!memcmp(&d->deviceid, id, sizeof(*id))) {
                        if (!atomic_inc_not_zero(&d->ref))
                                goto fail;
                        rcu_read_unlock();
                        return d;
                }
        }
fail:
        rcu_read_unlock();
        return NULL;
}

/*
 * Want res = (offset - layout->pattern_offset)/ layout->stripe_unit
 * Then: ((res + fsi) % dsaddr->stripe_count)
 */
u32
nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset)
{
        struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
        u64 tmp;

        tmp = offset - flseg->pattern_offset;
        do_div(tmp, flseg->stripe_unit);
        tmp += flseg->first_stripe_index;
        return do_div(tmp, flseg->dsaddr->stripe_count);
}

u32
nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j)
{
        return FILELAYOUT_LSEG(lseg)->dsaddr->stripe_indices[j];
}

struct nfs_fh *
nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)
{
        struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
        u32 i;

        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;
                else
                        i = nfs4_fl_calc_ds_index(lseg, j);
        } else
                i = j;
        return flseg->fh_array[i];
}

static void
filelayout_mark_devid_negative(struct nfs4_file_layout_dsaddr *dsaddr,
                               int err, u32 ds_addr)
{
        u32 *p = (u32 *)&dsaddr->deviceid;

        printk(KERN_ERR "NFS: data server %x connection error %d."
                " Deviceid [%x%x%x%x] marked out of use.\n",
                ds_addr, err, p[0], p[1], p[2], p[3]);

        spin_lock(&filelayout_deviceid_lock);
        dsaddr->flags |= NFS4_DEVICE_ID_NEG_ENTRY;
        spin_unlock(&filelayout_deviceid_lock);
}

struct nfs4_pnfs_ds *
nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx)
{
        struct nfs4_file_layout_dsaddr *dsaddr = FILELAYOUT_LSEG(lseg)->dsaddr;
        struct nfs4_pnfs_ds *ds = dsaddr->ds_list[ds_idx];

        if (ds == NULL) {
                printk(KERN_ERR "%s: No data server for offset index %d\n",
                        __func__, ds_idx);
                return NULL;
        }

        if (!ds->ds_clp) {
                struct nfs_server *s = NFS_SERVER(lseg->pls_layout->plh_inode);
                int err;

                if (dsaddr->flags & NFS4_DEVICE_ID_NEG_ENTRY) {
                        /* Already tried to connect, don't try again */
                        dprintk("%s Deviceid marked out of use\n", __func__);
                        return NULL;
                }
                err = nfs4_ds_connect(s, ds);
                if (err) {
                        filelayout_mark_devid_negative(dsaddr, err,
                                                       ntohl(ds->ds_ip_addr));
                        return NULL;
                }
        }
        return ds;
}