linux-imx

/*

 * Ceph cache definitions.

 *

 *  Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.

 *  Written by Milosz Tanski (milosz@adfin.com)

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License version 2

 *  as published by the Free Software Foundation.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to:

 *  Free Software Foundation

 *  51 Franklin Street, Fifth Floor

 *  Boston, MA  02111-1301  USA

 *

 */

​

#include "super.h"

#include "cache.h"

​

struct ceph_aux_inode {

    u64     version;

    u64 mtime_sec;

    u64 mtime_nsec;

};

​

struct fscache_netfs ceph_cache_netfs = {

    .name       = "ceph",

    .version    = 0,

};

​

static DEFINE_MUTEX(ceph_fscache_lock);

static LIST_HEAD(ceph_fscache_list);

​

struct ceph_fscache_entry {

    struct list_head list;

    struct fscache_cookie *fscache;

    size_t uniq_len;

    /* The following members must be last */

    struct ceph_fsid fsid;

    char uniquifier[0];

};

​

static const struct fscache_cookie_def ceph_fscache_fsid_object_def = {

    .name       = "CEPH.fsid",

    .type       = FSCACHE_COOKIE_TYPE_INDEX,

};

​

int __init ceph_fscache_register(void)

{

    return fscache_register_netfs(&ceph_cache_netfs);

}

​

void ceph_fscache_unregister(void)

{

    fscache_unregister_netfs(&ceph_cache_netfs);

}

​

int ceph_fscache_register_fs(struct ceph_fs_client* fsc)

{

    const struct ceph_fsid *fsid = &fsc->client->fsid;

    const char *fscache_uniq = fsc->mount_options->fscache_uniq;

    size_t uniq_len = fscache_uniq ? strlen(fscache_uniq) : 0;

    struct ceph_fscache_entry *ent;

    int err = 0;

​

    mutex_lock(&ceph_fscache_lock);

    list_for_each_entry(ent, &ceph_fscache_list, list) {

        if (memcmp(&ent->fsid, fsid, sizeof(*fsid)))

            continue;

        if (ent->uniq_len != uniq_len)

            continue;

        if (uniq_len && memcmp(ent->uniquifier, fscache_uniq, uniq_len))

            continue;

​

        pr_err("fscache cookie already registered for fsid %pU\n", fsid);

        pr_err("  use fsc=%%s mount option to specify a uniquifier\n");

        err = -EBUSY;

        goto out_unlock;

    }

​

    ent = kzalloc(sizeof(*ent) + uniq_len, GFP_KERNEL);

    if (!ent) {

        err = -ENOMEM;

        goto out_unlock;

    }