objio_osd.c

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/*
 *  pNFS Objects layout implementation over open-osd initiator library
 *
 *  Copyright (C) 2009 Panasas Inc. [year of first publication]
 *  All rights reserved.
 *
 *  Benny Halevy <[email protected]>
 *  Boaz Harrosh <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  See the file COPYING included with this distribution for more details.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the Panasas company nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/module.h>
#include <scsi/osd_ore.h>

#include "objlayout.h"
#include "../internal.h"

#define NFSDBG_FACILITY         NFSDBG_PNFS_LD

struct objio_dev_ent {
    struct nfs4_deviceid_node id_node;
    struct ore_dev od;
};

static void
objio_free_deviceid_node(struct nfs4_deviceid_node *d)
{
    struct objio_dev_ent *de = container_of(d, struct objio_dev_ent, id_node);

    dprintk("%s: free od=%p\n", __func__, de->od.od);
    osduld_put_device(de->od.od);
    kfree(de);
}

static struct objio_dev_ent *_dev_list_find(const struct nfs_server *nfss,
    const struct nfs4_deviceid *d_id)
{
    struct nfs4_deviceid_node *d;
    struct objio_dev_ent *de;

    d = nfs4_find_get_deviceid(nfss->pnfs_curr_ld, nfss->nfs_client, d_id);
    if (!d)
        return NULL;

    de = container_of(d, struct objio_dev_ent, id_node);
    return de;
}

static struct objio_dev_ent *
_dev_list_add(const struct nfs_server *nfss,
    const struct nfs4_deviceid *d_id, struct osd_dev *od,
    gfp_t gfp_flags)
{
    struct nfs4_deviceid_node *d;
    struct objio_dev_ent *de = kzalloc(sizeof(*de), gfp_flags);
    struct objio_dev_ent *n;

    if (!de) {
        dprintk("%s: -ENOMEM od=%p\n", __func__, od);
        return NULL;
    }

    dprintk("%s: Adding od=%p\n", __func__, od);
    nfs4_init_deviceid_node(&de->id_node,
                nfss->pnfs_curr_ld,
                nfss->nfs_client,
                d_id);
    de->od.od = od;

    d = nfs4_insert_deviceid_node(&de->id_node);
    n = container_of(d, struct objio_dev_ent, id_node);
    if (n != de) {
        dprintk("%s: Race with other n->od=%p\n", __func__, n->od.od);
        objio_free_deviceid_node(&de->id_node);
        de = n;
    }

    return de;
}

struct objio_segment {
    struct pnfs_layout_segment lseg;

    struct ore_layout layout;
    struct ore_components oc;
};

static inline struct objio_segment *
OBJIO_LSEG(struct pnfs_layout_segment *lseg)
{
    return container_of(lseg, struct objio_segment, lseg);
}

struct objio_state {
    /* Generic layer */
    struct objlayout_io_res oir;

    bool sync;
    /*FIXME: Support for extra_bytes at ore_get_rw_state() */
    struct ore_io_state *ios;
};

/* Send and wait for a get_device_info of devices in the layout,
   then look them up with the osd_initiator library */
static int objio_devices_lookup(struct pnfs_layout_hdr *pnfslay,
    struct objio_segment *objio_seg, unsigned c, struct nfs4_deviceid *d_id,
    gfp_t gfp_flags)
{
    struct pnfs_osd_deviceaddr *deviceaddr;
    struct objio_dev_ent *ode;
    struct osd_dev *od;
    struct osd_dev_info odi;
    bool retry_flag = true;
    int err;

    ode = _dev_list_find(NFS_SERVER(pnfslay->plh_inode), d_id);
    if (ode) {
        objio_seg->oc.ods[c] = &ode->od; /* must use container_of */
        return 0;
    }

    err = objlayout_get_deviceinfo(pnfslay, d_id, &deviceaddr, gfp_flags);
    if (unlikely(err)) {
        dprintk("%s: objlayout_get_deviceinfo dev(%llx:%llx) =>%d\n",
            __func__, _DEVID_LO(d_id), _DEVID_HI(d_id), err);
        return err;
    }

    odi.systemid_len = deviceaddr->oda_systemid.len;
    if (odi.systemid_len > sizeof(odi.systemid)) {
        dprintk("%s: odi.systemid_len > sizeof(systemid=%zd)\n",
            __func__, sizeof(odi.systemid));
        err = -EINVAL;
        goto out;
    } else if (odi.systemid_len)
        memcpy(odi.systemid, deviceaddr->oda_systemid.data,
               odi.systemid_len);
    odi.osdname_len  = deviceaddr->oda_osdname.len;
    odi.osdname  = (u8 *)deviceaddr->oda_osdname.data;

    if (!odi.osdname_len && !odi.systemid_len) {
        dprintk("%s: !odi.osdname_len && !odi.systemid_len\n",
            __func__);
        err = -ENODEV;
        goto out;
    }

retry_lookup:
    od = osduld_info_lookup(&odi);
    if (unlikely(IS_ERR(od))) {
        err = PTR_ERR(od);
        dprintk("%s: osduld_info_lookup => %d\n", __func__, err);
        if (err == -ENODEV && retry_flag) {
            err = objlayout_autologin(deviceaddr);
            if (likely(!err)) {
                retry_flag = false;
                goto retry_lookup;
            }
        }
        goto out;
    }

    ode = _dev_list_add(NFS_SERVER(pnfslay->plh_inode), d_id, od,
                gfp_flags);
    objio_seg->oc.ods[c] = &ode->od; /* must use container_of */
    dprintk("Adding new dev_id(%llx:%llx)\n",
        _DEVID_LO(d_id), _DEVID_HI(d_id));
out:
    objlayout_put_deviceinfo(deviceaddr);
    return err;
}

static void copy_single_comp(struct ore_components *oc, unsigned c,
                 struct pnfs_osd_object_cred *src_comp)
{
    struct ore_comp *ocomp = &oc->comps[c];

    WARN_ON(src_comp->oc_cap_key.cred_len > 0); /* libosd is NO_SEC only */
    WARN_ON(src_comp->oc_cap.cred_len > sizeof(ocomp->cred));

    ocomp->obj.partition = src_comp->oc_object_id.oid_partition_id;
    ocomp->obj.id = src_comp->oc_object_id.oid_object_id;

    memcpy(ocomp->cred, src_comp->oc_cap.cred, sizeof(ocomp->cred));
}

static int __alloc_objio_seg(unsigned numdevs, gfp_t gfp_flags,
               struct objio_segment **pseg)
{
/*  This is the in memory structure of the objio_segment
 *
 *  struct __alloc_objio_segment {
 *      struct objio_segment olseg;
 *      struct ore_dev *ods[numdevs];
 *      struct ore_comp comps[numdevs];
 *  } *aolseg;
 *  NOTE: The code as above compiles and runs perfectly. It is elegant,
 *  type safe and compact. At some Past time Linus has decided he does not
 *  like variable length arrays, For the sake of this principal we uglify
 *  the code as below.
 */
    struct objio_segment *lseg;
    size_t lseg_size = sizeof(*lseg) +
            numdevs * sizeof(lseg->oc.ods[0]) +
            numdevs * sizeof(*lseg->oc.comps);

    lseg = kzalloc(lseg_size, gfp_flags);
    if (unlikely(!lseg)) {
        dprintk("%s: Faild allocation numdevs=%d size=%zd\n", __func__,
            numdevs, lseg_size);
        return -ENOMEM;
    }

    lseg->oc.numdevs = numdevs;
    lseg->oc.single_comp = EC_MULTPLE_COMPS;
    lseg->oc.ods = (void *)(lseg + 1);
    lseg->oc.comps = (void *)(lseg->oc.ods + numdevs);

    *pseg = lseg;
    return 0;
}

int objio_alloc_lseg(struct pnfs_layout_segment **outp,
    struct pnfs_layout_hdr *pnfslay,
    struct pnfs_layout_range *range,
    struct xdr_stream *xdr,
    gfp_t gfp_flags)
{
    struct objio_segment *objio_seg;
    struct pnfs_osd_xdr_decode_layout_iter iter;
    struct pnfs_osd_layout layout;
    struct pnfs_osd_object_cred src_comp;
    unsigned cur_comp;
    int err;

    err = pnfs_osd_xdr_decode_layout_map(&layout, &iter, xdr);
    if (unlikely(err))
        return err;

    err = __alloc_objio_seg(layout.olo_num_comps, gfp_flags, &objio_seg);
    if (unlikely(err))
        return err;

    objio_seg->layout.stripe_unit = layout.olo_map.odm_stripe_unit;
    objio_seg->layout.group_width = layout.olo_map.odm_group_width;
    objio_seg->layout.group_depth = layout.olo_map.odm_group_depth;
    objio_seg->layout.mirrors_p1 = layout.olo_map.odm_mirror_cnt + 1;
    objio_seg->layout.raid_algorithm = layout.olo_map.odm_raid_algorithm;

    err = ore_verify_layout(layout.olo_map.odm_num_comps,
                      &objio_seg->layout);
    if (unlikely(err))
        goto err;

    objio_seg->oc.first_dev = layout.olo_comps_index;
    cur_comp = 0;
    while (pnfs_osd_xdr_decode_layout_comp(&src_comp, &iter, xdr, &err)) {
        copy_single_comp(&objio_seg->oc, cur_comp, &src_comp);
        err = objio_devices_lookup(pnfslay, objio_seg, cur_comp,
                       &src_comp.oc_object_id.oid_device_id,
                       gfp_flags);
        if (err)
            goto err;
        ++cur_comp;
    }
    /* pnfs_osd_xdr_decode_layout_comp returns false on error */
    if (unlikely(err))
        goto err;

    *outp = &objio_seg->lseg;
    return 0;

err:
    kfree(objio_seg);
    dprintk("%s: Error: return %d\n", __func__, err);
    *outp = NULL;
    return err;
}

void objio_free_lseg(struct pnfs_layout_segment *lseg)
{
    int i;
    struct objio_segment *objio_seg = OBJIO_LSEG(lseg);

    for (i = 0; i < objio_seg->oc.numdevs; i++) {
        struct ore_dev *od = objio_seg->oc.ods[i];
        struct objio_dev_ent *ode;

        if (!od)
            break;
        ode = container_of(od, typeof(*ode), od);
        nfs4_put_deviceid_node(&ode->id_node);
    }
    kfree(objio_seg);
}

static int
objio_alloc_io_state(struct pnfs_layout_hdr *pnfs_layout_type, bool is_reading,
    struct pnfs_layout_segment *lseg, struct page **pages, unsigned pgbase,
    loff_t offset, size_t count, void *rpcdata, gfp_t gfp_flags,
    struct objio_state **outp)
{
    struct objio_segment *objio_seg = OBJIO_LSEG(lseg);
    struct ore_io_state *ios;
    int ret;
    struct __alloc_objio_state {
        struct objio_state objios;
        struct pnfs_osd_ioerr ioerrs[objio_seg->oc.numdevs];
    } *aos;

    aos = kzalloc(sizeof(*aos), gfp_flags);
    if (unlikely(!aos))
        return -ENOMEM;

    objlayout_init_ioerrs(&aos->objios.oir, objio_seg->oc.numdevs,
            aos->ioerrs, rpcdata, pnfs_layout_type);

    ret = ore_get_rw_state(&objio_seg->layout, &objio_seg->oc, is_reading,
                   offset, count, &ios);
    if (unlikely(ret)) {
        kfree(aos);
        return ret;
    }

    ios->pages = pages;
    ios->pgbase = pgbase;
    ios->private = aos;
    BUG_ON(ios->nr_pages > (pgbase + count + PAGE_SIZE - 1) >> PAGE_SHIFT);

    aos->objios.sync = 0;
    aos->objios.ios = ios;
    *outp = &aos->objios;
    return 0;
}

void objio_free_result(struct objlayout_io_res *oir)
{
    struct objio_state *objios = container_of(oir, struct objio_state, oir);

    ore_put_io_state(objios->ios);
    kfree(objios);
}

static enum pnfs_osd_errno osd_pri_2_pnfs_err(enum osd_err_priority oep)
{
    switch (oep) {
    case OSD_ERR_PRI_NO_ERROR:
        return (enum pnfs_osd_errno)0;

    case OSD_ERR_PRI_CLEAR_PAGES:
        BUG_ON(1);
        return 0;

    case OSD_ERR_PRI_RESOURCE:
        return PNFS_OSD_ERR_RESOURCE;
    case OSD_ERR_PRI_BAD_CRED:
        return PNFS_OSD_ERR_BAD_CRED;
    case OSD_ERR_PRI_NO_ACCESS:
        return PNFS_OSD_ERR_NO_ACCESS;
    case OSD_ERR_PRI_UNREACHABLE:
        return PNFS_OSD_ERR_UNREACHABLE;
    case OSD_ERR_PRI_NOT_FOUND:
        return PNFS_OSD_ERR_NOT_FOUND;
    case OSD_ERR_PRI_NO_SPACE:
        return PNFS_OSD_ERR_NO_SPACE;
    default:
        WARN_ON(1);
        /* fallthrough */
    case OSD_ERR_PRI_EIO:
        return PNFS_OSD_ERR_EIO;
    }
}

static void __on_dev_error(struct ore_io_state *ios,
    struct ore_dev *od, unsigned dev_index, enum osd_err_priority oep,
    u64 dev_offset, u64  dev_len)
{
    struct objio_state *objios = ios->private;
    struct pnfs_osd_objid pooid;
    struct objio_dev_ent *ode = container_of(od, typeof(*ode), od);
    /* FIXME: what to do with more-then-one-group layouts. We need to
     * translate from ore_io_state index to oc->comps index
     */
    unsigned comp = dev_index;

    pooid.oid_device_id = ode->id_node.deviceid;
    pooid.oid_partition_id = ios->oc->comps[comp].obj.partition;
    pooid.oid_object_id = ios->oc->comps[comp].obj.id;

    objlayout_io_set_result(&objios->oir, comp,
                &pooid, osd_pri_2_pnfs_err(oep),
                dev_offset, dev_len, !ios->reading);
}

/*
 * read
 */
static void _read_done(struct ore_io_state *ios, void *private)
{
    struct objio_state *objios = private;
    ssize_t status;
    int ret = ore_check_io(ios, &__on_dev_error);

    /* FIXME: _io_free(ios) can we dealocate the libosd resources; */

    if (likely(!ret))
        status = ios->length;
    else
        status = ret;

    objlayout_read_done(&objios->oir, status, objios->sync);
}

int objio_read_pagelist(struct nfs_read_data *rdata)
{
    struct nfs_pgio_header *hdr = rdata->header;
    struct objio_state *objios;
    int ret;

    ret = objio_alloc_io_state(NFS_I(hdr->inode)->layout, true,
            hdr->lseg, rdata->args.pages, rdata->args.pgbase,
            rdata->args.offset, rdata->args.count, rdata,
            GFP_KERNEL, &objios);
    if (unlikely(ret))
        return ret;

    objios->ios->done = _read_done;
    dprintk("%s: offset=0x%llx length=0x%x\n", __func__,
        rdata->args.offset, rdata->args.count);
    ret = ore_read(objios->ios);
    if (unlikely(ret))
        objio_free_result(&objios->oir);
    return ret;
}

/*
 * write
 */
static void _write_done(struct ore_io_state *ios, void *private)
{
    struct objio_state *objios = private;
    ssize_t status;
    int ret = ore_check_io(ios, &__on_dev_error);

    /* FIXME: _io_free(ios) can we dealocate the libosd resources; */

    if (likely(!ret)) {
        /* FIXME: should be based on the OSD's persistence model
         * See OSD2r05 Section 4.13 Data persistence model */
        objios->oir.committed = NFS_FILE_SYNC;
        status = ios->length;
    } else {
        status = ret;
    }

    objlayout_write_done(&objios->oir, status, objios->sync);
}

static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
{
    struct objio_state *objios = priv;
    struct nfs_write_data *wdata = objios->oir.rpcdata;
    struct address_space *mapping = wdata->header->inode->i_mapping;
    pgoff_t index = offset / PAGE_SIZE;
    struct page *page;
    loff_t i_size = i_size_read(wdata->header->inode);

    if (offset >= i_size) {
        *uptodate = true;
        dprintk("%s: g_zero_page index=0x%lx\n", __func__, index);
        return ZERO_PAGE(0);
    }

    page = find_get_page(mapping, index);
    if (!page) {
        page = find_or_create_page(mapping, index, GFP_NOFS);
        if (unlikely(!page)) {
            dprintk("%s: grab_cache_page Failed index=0x%lx\n",
                __func__, index);
            return NULL;
        }
        unlock_page(page);
    }
    if (PageDirty(page) || PageWriteback(page))
        *uptodate = true;
    else
        *uptodate = PageUptodate(page);
    dprintk("%s: index=0x%lx uptodate=%d\n", __func__, index, *uptodate);
    return page;
}

static void __r4w_put_page(void *priv, struct page *page)
{
    dprintk("%s: index=0x%lx\n", __func__,
        (page == ZERO_PAGE(0)) ? -1UL : page->index);
    if (ZERO_PAGE(0) != page)
        page_cache_release(page);
    return;
}

static const struct _ore_r4w_op _r4w_op = {
    .get_page = &__r4w_get_page,
    .put_page = &__r4w_put_page,
};

int objio_write_pagelist(struct nfs_write_data *wdata, int how)
{
    struct nfs_pgio_header *hdr = wdata->header;
    struct objio_state *objios;
    int ret;

    ret = objio_alloc_io_state(NFS_I(hdr->inode)->layout, false,
            hdr->lseg, wdata->args.pages, wdata->args.pgbase,
            wdata->args.offset, wdata->args.count, wdata, GFP_NOFS,
            &objios);
    if (unlikely(ret))
        return ret;

    objios->sync = 0 != (how & FLUSH_SYNC);
    objios->ios->r4w = &_r4w_op;

    if (!objios->sync)
        objios->ios->done = _write_done;

    dprintk("%s: offset=0x%llx length=0x%x\n", __func__,
        wdata->args.offset, wdata->args.count);
    ret = ore_write(objios->ios);
    if (unlikely(ret)) {
        objio_free_result(&objios->oir);
        return ret;
    }

    if (objios->sync)
        _write_done(objios->ios, objios);

    return 0;
}

static bool objio_pg_test(struct nfs_pageio_descriptor *pgio,
              struct nfs_page *prev, struct nfs_page *req)
{
    if (!pnfs_generic_pg_test(pgio, prev, req))
        return false;

    return pgio->pg_count + req->wb_bytes <=
            (unsigned long)pgio->pg_layout_private;
}

static void objio_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
{
    pnfs_generic_pg_init_read(pgio, req);
    if (unlikely(pgio->pg_lseg == NULL))
        return; /* Not pNFS */

    pgio->pg_layout_private = (void *)
                OBJIO_LSEG(pgio->pg_lseg)->layout.max_io_length;
}

static bool aligned_on_raid_stripe(u64 offset, struct ore_layout *layout,
                   unsigned long *stripe_end)
{
    u32 stripe_off;
    unsigned stripe_size;

    if (layout->raid_algorithm == PNFS_OSD_RAID_0)
        return true;

    stripe_size = layout->stripe_unit *
                (layout->group_width - layout->parity);

    div_u64_rem(offset, stripe_size, &stripe_off);
    if (!stripe_off)
        return true;

    *stripe_end = stripe_size - stripe_off;
    return false;
}

static void objio_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
{
    unsigned long stripe_end = 0;
    u64 wb_size;

    if (pgio->pg_dreq == NULL)
        wb_size = i_size_read(pgio->pg_inode) - req_offset(req);
    else
        wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);

    pnfs_generic_pg_init_write(pgio, req, wb_size);
    if (unlikely(pgio->pg_lseg == NULL))
        return; /* Not pNFS */

    if (req->wb_offset ||
        !aligned_on_raid_stripe(req->wb_index * PAGE_SIZE,
                   &OBJIO_LSEG(pgio->pg_lseg)->layout,
                   &stripe_end)) {
        pgio->pg_layout_private = (void *)stripe_end;
    } else {
        pgio->pg_layout_private = (void *)
                OBJIO_LSEG(pgio->pg_lseg)->layout.max_io_length;
    }
}

static const struct nfs_pageio_ops objio_pg_read_ops = {
    .pg_init = objio_init_read,
    .pg_test = objio_pg_test,
    .pg_doio = pnfs_generic_pg_readpages,
};

static const struct nfs_pageio_ops objio_pg_write_ops = {
    .pg_init = objio_init_write,
    .pg_test = objio_pg_test,
    .pg_doio = pnfs_generic_pg_writepages,
};

static struct pnfs_layoutdriver_type objlayout_type = {
    .id = LAYOUT_OSD2_OBJECTS,
    .name = "LAYOUT_OSD2_OBJECTS",
    .flags                   = PNFS_LAYOUTRET_ON_SETATTR |
                   PNFS_LAYOUTRET_ON_ERROR,

    .alloc_layout_hdr        = objlayout_alloc_layout_hdr,
    .free_layout_hdr         = objlayout_free_layout_hdr,

    .alloc_lseg              = objlayout_alloc_lseg,
    .free_lseg               = objlayout_free_lseg,

    .read_pagelist           = objlayout_read_pagelist,
    .write_pagelist          = objlayout_write_pagelist,
    .pg_read_ops             = &objio_pg_read_ops,
    .pg_write_ops            = &objio_pg_write_ops,

    .free_deviceid_node  = objio_free_deviceid_node,

    .encode_layoutcommit     = objlayout_encode_layoutcommit,
    .encode_layoutreturn     = objlayout_encode_layoutreturn,
};

MODULE_DESCRIPTION("pNFS Layout Driver for OSD2 objects");
MODULE_AUTHOR("Benny Halevy <[email protected]>");
MODULE_LICENSE("GPL");

static int __init
objlayout_init(void)
{
    int ret = pnfs_register_layoutdriver(&objlayout_type);

    if (ret)
        printk(KERN_INFO
            "NFS: %s: Registering OSD pNFS Layout Driver failed: error=%d\n",
            __func__, ret);
    else
        printk(KERN_INFO "NFS: %s: Registered OSD pNFS Layout Driver\n",
            __func__);
    return ret;
}

static void __exit
objlayout_exit(void)
{
    pnfs_unregister_layoutdriver(&objlayout_type);
    printk(KERN_INFO "NFS: %s: Unregistered OSD pNFS Layout Driver\n",
           __func__);
}

MODULE_ALIAS("nfs-layouttype4-2");

module_init(objlayout_init);
module_exit(objlayout_exit);