/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * 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 version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2012, Whamcloud, Inc.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/osd/osd_oi.c
 *
 * Object Index.
 *
 * Author: Nikita Danilov <nikita@clusterfs.com>
 */

/*
 * oi uses two mechanisms to implement fid->cookie mapping:
 *
 *     - persistent index, where cookie is a record and fid is a key, and
 *
 *     - algorithmic mapping for "igif" fids.
 *
 */

#define DEBUG_SUBSYSTEM S_MDS

#include <linux/module.h>

/* LUSTRE_VERSION_CODE */
#include <lustre_ver.h>
/*
 * struct OBD_{ALLOC,FREE}*()
 * OBD_FAIL_CHECK
 */
#include <obd.h>
#include <obd_support.h>

/* fid_cpu_to_be() */
#include <lustre_fid.h>

#include "osd_oi.h"
/* osd_lookup(), struct osd_thread_info */
#include "osd_internal.h"
#include "osd_igif.h"
#include "dt_object.h"

#define OSD_OI_FID_NR         (1UL << OSD_OI_FID_OID_BITS)
#define OSD_OI_FID_NR_MAX     (1UL << OSD_OI_FID_OID_BITS_MAX)

static unsigned int osd_oi_count = OSD_OI_FID_NR;
CFS_MODULE_PARM(osd_oi_count, "i", int, 0444,
                "Number of Object Index containers to be created, "
                "it's only valid for new filesystem.");

/** to serialize concurrent OI index initialization */
static cfs_mutex_t oi_init_lock;

static struct dt_index_features oi_feat = {
        .dif_flags       = DT_IND_UPDATE,
        .dif_recsize_min = sizeof(struct osd_inode_id),
        .dif_recsize_max = sizeof(struct osd_inode_id),
        .dif_ptrsize     = 4
};

#define OSD_OI_NAME_BASE        "oi.16"

static void osd_oi_table_put(struct osd_thread_info *info,
                             struct osd_oi **oi_table, unsigned oi_count)
{
        struct iam_container *bag;
        int                   i;

        for (i = 0; i < oi_count; i++) {
                LASSERT(oi_table[i] != NULL);
                LASSERT(oi_table[i]->oi_inode != NULL);

                bag = &(oi_table[i]->oi_dir.od_container);
                if (bag->ic_object == oi_table[i]->oi_inode)
                        iam_container_fini(bag);
                iput(oi_table[i]->oi_inode);
                oi_table[i]->oi_inode = NULL;
                OBD_FREE_PTR(oi_table[i]);
        }
}

static int osd_oi_index_create_one(struct osd_thread_info *info,
                                   struct osd_device *osd, const char *name,
                                   struct dt_index_features *feat)
{
        const struct lu_env             *env = info->oti_env;
        struct osd_inode_id             *id  = &info->oti_id;
        struct buffer_head              *bh;
        struct inode                    *inode;
        struct ldiskfs_dir_entry_2      *de;
        struct dentry                   *dentry;
        struct inode                    *dir;
        handle_t                        *jh;
        int                              rc;

        dentry = osd_child_dentry_by_inode(env, osd_sb(osd)->s_root->d_inode,
                                           name, strlen(name));
        dir = osd_sb(osd)->s_root->d_inode;
        bh = osd_ldiskfs_find_entry(dir, dentry, &de, NULL);
        if (bh) {
                brelse(bh);

                id->oii_ino = le32_to_cpu(de->inode);
                id->oii_gen = OSD_OII_NOGEN;

                inode = osd_iget(info, osd, id);
                if (!IS_ERR(inode)) {
                        iput(inode);
                        RETURN(-EEXIST);
                }
                RETURN(PTR_ERR(inode));
        }

        jh = ldiskfs_journal_start_sb(osd_sb(osd), 100);
        LASSERT(!IS_ERR(jh));

        inode = ldiskfs_create_inode(jh, osd_sb(osd)->s_root->d_inode,
                                     (S_IFREG | S_IRUGO | S_IWUSR));
        LASSERT(!IS_ERR(inode));

        if (feat->dif_flags & DT_IND_VARKEY)
                rc = iam_lvar_create(inode, feat->dif_keysize_max,
                                     feat->dif_ptrsize, feat->dif_recsize_max,
                                     jh);
        else
                rc = iam_lfix_create(inode, feat->dif_keysize_max,
                                     feat->dif_ptrsize, feat->dif_recsize_max,
                                     jh);

        dentry = osd_child_dentry_by_inode(env, osd_sb(osd)->s_root->d_inode,
                                           name, strlen(name));
        rc = osd_ldiskfs_add_entry(jh, dentry, inode, NULL);
        LASSERT(rc == 0);

        ldiskfs_journal_stop(jh);
        iput(inode);

        return rc;
}

static struct inode *osd_oi_index_open(struct osd_thread_info *info,
                                       struct osd_device *osd,
                                       const char *name,
                                       struct dt_index_features *f,
                                       bool create)
{
        struct dentry *dentry;
        struct inode  *inode;
        int            rc;

        dentry = ll_lookup_one_len(name, osd_sb(osd)->s_root, strlen(name));
        if (IS_ERR(dentry))
                return (void *) dentry;

        if (dentry->d_inode) {
                LASSERT(!is_bad_inode(dentry->d_inode));
                inode = dentry->d_inode;
                atomic_inc(&inode->i_count);
                dput(dentry);
                return inode;
        }

        /* create */
        dput(dentry);
        shrink_dcache_parent(osd_sb(osd)->s_root);
        if (!create)
                return ERR_PTR(-ENOENT);

        rc = osd_oi_index_create_one(info, osd, name, f);
        if (rc)
                RETURN(ERR_PTR(rc));

        dentry = ll_lookup_one_len(name, osd_sb(osd)->s_root, strlen(name));
        if (IS_ERR(dentry))
                return (void *) dentry;

        if (dentry->d_inode) {
                LASSERT(!is_bad_inode(dentry->d_inode));
                inode = dentry->d_inode;
                atomic_inc(&inode->i_count);
                dput(dentry);
                return inode;
        }

        return ERR_PTR(-ENOENT);
}

/**
 * Open an OI(Ojbect Index) container.
 *
 * \param       name    Name of OI container
 * \param       objp    Pointer of returned OI
 *
 * \retval      0       success
 * \retval      -ve     failure
 */
static int osd_oi_open(struct osd_thread_info *info, struct osd_device *osd,
                       char *name, struct osd_oi **oi_slot, bool create)
{
        struct osd_directory *dir;
        struct iam_container *bag;
        struct inode         *inode;
        struct osd_oi        *oi;
        int                   rc;

        ENTRY;

        oi_feat.dif_keysize_min = sizeof(struct lu_fid);
        oi_feat.dif_keysize_max = sizeof(struct lu_fid);

        inode = osd_oi_index_open(info, osd, name, &oi_feat, create);
        if (IS_ERR(inode))
                RETURN(PTR_ERR(inode));

        OBD_ALLOC_PTR(oi);
        if (oi == NULL)
                GOTO(out_inode, rc = -ENOMEM);

        oi->oi_inode = inode;
        dir = &oi->oi_dir;

        bag = &dir->od_container;
        rc = iam_container_init(bag, &dir->od_descr, inode);
        if (rc < 0)
                GOTO(out_free, rc);

        rc = iam_container_setup(bag);
        if (rc < 0)
                GOTO(out_container, rc);

        *oi_slot = oi;
        RETURN(0);

out_container:
        iam_container_fini(bag);
out_free:
        OBD_FREE_PTR(oi);
out_inode:
        iput(inode);
        return rc;
}

/**
 * Open OI(Object Index) table.
 * If \a oi_count is zero, which means caller doesn't know how many OIs there
 * will be, this function can either return 0 for new filesystem, or number
 * of OIs on existed filesystem.
 *
 * If \a oi_count is non-zero, which means caller does know number of OIs on
 * filesystem, this function should return the exactly same number on
 * success, or error code in failure.
 *
 * \param     oi_count  Number of expected OI containers
 * \param     create    Create OIs if doesn't exist
 *
 * \retval    +ve       number of opened OI containers
 * \retval      0       no OI containers found
 * \retval    -ve       failure
 */
static int
osd_oi_table_open(struct osd_thread_info *info, struct osd_device *osd,
                  struct osd_oi **oi_table, unsigned oi_count, bool create)
{
        struct dt_device *dev = &osd->od_dt_dev;
        int               count = 0;
        int               rc = 0;
        int               i;

        /* NB: oi_count != 0 means that we have already created/known all OIs
         * and have known exact number of OIs. */
        LASSERT(oi_count <= OSD_OI_FID_NR_MAX);

        for (i = 0; i < (oi_count != 0 ? oi_count : OSD_OI_FID_NR_MAX); i++) {
                char name[12];

                sprintf(name, "%s.%d", OSD_OI_NAME_BASE, i);
                rc = osd_oi_open(info, osd, name, &oi_table[i], create);
                if (rc == 0) {
                        count++;
                        continue;
                }

                if (rc == -ENOENT && oi_count == 0)
                        return count;

                CERROR("%s: can't open %s: rc = %d\n",
                       dev->dd_lu_dev.ld_obd->obd_name, name, rc);
                if (oi_count > 0) {
                        CERROR("%s: expect to open total %d OI files.\n",
                               dev->dd_lu_dev.ld_obd->obd_name, oi_count);
                }
                break;
        }

        if (rc < 0) {
                osd_oi_table_put(info, oi_table, count);
                return rc;
        }

        return count;
}

int osd_oi_init(struct osd_thread_info *info, struct osd_device *osd)
{
        struct dt_device *dev = &osd->od_dt_dev;
        struct osd_oi   **oi;
        int               rc;

        OBD_ALLOC(oi, sizeof(*oi) * OSD_OI_FID_NR_MAX);
        if (oi == NULL)
                return -ENOMEM;

        cfs_mutex_lock(&oi_init_lock);
        /* try to open existing multiple OIs first */
        rc = osd_oi_table_open(info, osd, oi, 0, false);
        if (rc != 0)
                goto out;

        /* if previous failed then try found single OI from old filesystem */
        rc = osd_oi_open(info, osd, OSD_OI_NAME_BASE, &oi[0], false);
        if (rc == 0) { /* found single OI from old filesystem */
                rc = 1;
                goto out;
        } else if (rc != -ENOENT) {
                CERROR("%s: can't open %s: rc = %d\n",
                       dev->dd_lu_dev.ld_obd->obd_name, OSD_OI_NAME_BASE, rc);
                goto out;
        }

        /* No OIs exist, new filesystem, create OI objects */
        rc = osd_oi_table_open(info, osd, oi, osd_oi_count, true);
        LASSERT(ergo(rc >= 0, rc == osd_oi_count));
out:
        if (rc < 0) {
                OBD_FREE(oi, sizeof(*oi) * OSD_OI_FID_NR_MAX);
        } else {
                LASSERT((rc & (rc - 1)) == 0);
                osd->od_oi_table = oi;
                osd->od_oi_count = rc;
                rc = 0;
        }

        cfs_mutex_unlock(&oi_init_lock);
        return rc;
}

void osd_oi_fini(struct osd_thread_info *info, struct osd_device *osd)
{
        osd_oi_table_put(info, osd->od_oi_table, osd->od_oi_count);

        OBD_FREE(osd->od_oi_table,
                 sizeof(*(osd->od_oi_table)) * OSD_OI_FID_NR_MAX);
        osd->od_oi_table = NULL;
}

static inline int fid_is_fs_root(const struct lu_fid *fid)
{
        /* Map root inode to special local object FID */
        return (unlikely(fid_seq(fid) == FID_SEQ_LOCAL_FILE &&
                         fid_oid(fid) == OSD_FS_ROOT_OID));
}

static int osd_oi_iam_lookup(struct osd_thread_info *oti,
                             struct osd_oi *oi, struct dt_rec *rec,
                             const struct dt_key *key)
{
        struct iam_container  *bag;
        struct iam_iterator   *it = &oti->oti_idx_it;
        struct iam_rec        *iam_rec;
        struct iam_path_descr *ipd;
        int                    rc;
        ENTRY;

        LASSERT(oi);
        LASSERT(oi->oi_inode);

        bag = &oi->oi_dir.od_container;
        ipd = osd_idx_ipd_get(oti->oti_env, bag);
        if (IS_ERR(ipd))
                RETURN(-ENOMEM);

        /* got ipd now we can start iterator. */
        iam_it_init(it, bag, 0, ipd);

        rc = iam_it_get(it, (struct iam_key *)key);
        if (rc >= 0) {
                if (S_ISDIR(oi->oi_inode->i_mode))
                        iam_rec = (struct iam_rec *)oti->oti_ldp;
                else
                        iam_rec = (struct iam_rec *)rec;

                iam_reccpy(&it->ii_path.ip_leaf, (struct iam_rec *)iam_rec);
                if (S_ISDIR(oi->oi_inode->i_mode))
                        osd_fid_unpack((struct lu_fid *)rec,
                                       (struct osd_fid_pack *)iam_rec);
        }
        iam_it_put(it);
        iam_it_fini(it);
        osd_ipd_put(oti->oti_env, bag, ipd);

        LINVRNT(osd_invariant(obj));

        RETURN(rc);
}

int osd_oi_lookup(struct osd_thread_info *info, struct osd_device *osd,
                  const struct lu_fid *fid, struct osd_inode_id *id)
{
        struct lu_fid       *oi_fid = &info->oti_fid;
        const struct dt_key *key;
        int                  rc = 0;

        if (fid_is_idif(fid) || fid_seq(fid) == FID_SEQ_LLOG) {
                /* old OSD obj id */
                rc = osd_compat_objid_lookup(info, osd, fid, id);
        } else if (fid_is_igif(fid)) {
                lu_igif_to_id(fid, id);
                rc = 0;
        } else if (fid_is_fs_root(fid)) {
                struct inode *inode = osd_sb(osd)->s_root->d_inode;

                id->oii_ino = inode->i_ino;
                id->oii_gen = inode->i_generation;
        } else {
                if (unlikely(fid_seq(fid) == FID_SEQ_LOCAL_FILE)) {
                        rc = osd_compat_spec_lookup(info, osd, fid, id);
                        if (rc == 0 || rc != -ERESTART)
                                goto out;
                }

                fid_cpu_to_be(oi_fid, fid);
                key = (struct dt_key *)oi_fid;

                rc = osd_oi_iam_lookup(info, osd_fid2oi(osd, fid),
                                       (struct dt_rec *)id, key);

                if (rc > 0) {
                        id->oii_ino = be32_to_cpu(id->oii_ino);
                        id->oii_gen = be32_to_cpu(id->oii_gen);
                        rc = 0;
                } else if (rc == 0) {
                        rc = -ENOENT;
                }
        }

out:
        return rc;
}

static int osd_oi_iam_insert(struct osd_thread_info *oti, struct osd_oi *oi,
                             const struct dt_rec *rec, const struct dt_key *key,
                             struct thandle *th, int ignore_quota)
{
        struct iam_container  *bag;
        struct iam_rec        *iam_rec = (struct iam_rec *)oti->oti_ldp;
        struct iam_path_descr *ipd;
        struct osd_thandle    *oh;
        int                    rc;
#ifdef HAVE_QUOTA_SUPPORT
        cfs_cap_t              save    = cfs_curproc_cap_pack();
#endif
        ENTRY;

        LASSERT(oi);
        LASSERT(oi->oi_inode);

        bag = &oi->oi_dir.od_container;
        ipd = osd_idx_ipd_get(oti->oti_env, bag);
        if (unlikely(ipd == NULL))
                RETURN(-ENOMEM);

        oh = container_of0(th, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle != NULL);
        LASSERT(oh->ot_handle->h_transaction != NULL);
#ifdef HAVE_QUOTA_SUPPORT
        if (ignore_quota)
                cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
        else
                cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
#endif
        if (S_ISDIR(oi->oi_inode->i_mode))
                osd_fid_pack((struct osd_fid_pack *)iam_rec, rec,
                             &oti->oti_fid);
        else
                iam_rec = (struct iam_rec *) rec;
        rc = iam_insert(oh->ot_handle, bag, (const struct iam_key *)key,
                        iam_rec, ipd);
#ifdef HAVE_QUOTA_SUPPORT
        cfs_curproc_cap_unpack(save);
#endif
        osd_ipd_put(oti->oti_env, bag, ipd);
        LINVRNT(osd_invariant(obj));
        RETURN(rc);
}

int osd_oi_insert(struct osd_thread_info *info, struct osd_device *osd,
                  const struct lu_fid *fid, const struct osd_inode_id *id0,
                  struct thandle *th, int ignore_quota)
{
        struct lu_fid       *oi_fid = &info->oti_fid;
        struct osd_inode_id *id;
        const struct dt_key *key;

        if (fid_is_igif(fid))
                return 0;

        if (fid_is_idif(fid) || fid_seq(fid) == FID_SEQ_LLOG)
                return osd_compat_objid_insert(info, osd, fid, id0, th);

        /* notice we don't return immediately, but continue to get into OI */
        if (unlikely(fid_seq(fid) == FID_SEQ_LOCAL_FILE))
                osd_compat_spec_insert(info, osd, fid, id0, th);

        fid_cpu_to_be(oi_fid, fid);
        key = (struct dt_key *)oi_fid;

        id  = &info->oti_id;
        id->oii_ino = cpu_to_be32(id0->oii_ino);
        id->oii_gen = cpu_to_be32(id0->oii_gen);

        return osd_oi_iam_insert(info, osd_fid2oi(osd, fid),
                                 (struct dt_rec *)id, key, th, ignore_quota);
}

static int osd_oi_iam_delete(struct osd_thread_info *oti, struct osd_oi *oi,
                             const struct dt_key *key, struct thandle *handle)
{
        struct iam_container  *bag;
        struct iam_path_descr *ipd;
        struct osd_thandle    *oh;
        int                    rc;
        ENTRY;

        LASSERT(oi);

        bag = &oi->oi_dir.od_container;
        ipd = osd_idx_ipd_get(oti->oti_env, bag);
        if (unlikely(ipd == NULL))
                RETURN(-ENOMEM);

        oh = container_of0(handle, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle != NULL);
        LASSERT(oh->ot_handle->h_transaction != NULL);

        rc = iam_delete(oh->ot_handle, bag, (const struct iam_key *)key, ipd);
        osd_ipd_put(oti->oti_env, bag, ipd);
        LINVRNT(osd_invariant(obj));
        RETURN(rc);
}

int osd_oi_delete(struct osd_thread_info *info,
                  struct osd_device *osd, const struct lu_fid *fid,
                  struct thandle *th)
{
        struct lu_fid       *oi_fid = &info->oti_fid;
        const struct dt_key *key;

        if (!fid_is_norm(fid))
                return 0;

        LASSERT(fid_seq(fid) != FID_SEQ_LOCAL_FILE);

        if (fid_is_idif(fid) || fid_seq(fid) == FID_SEQ_LLOG)
                return osd_compat_objid_delete(info, osd, fid, th);

        fid_cpu_to_be(oi_fid, fid);
        key = (struct dt_key *)oi_fid;

        return osd_oi_iam_delete(info, osd_fid2oi(osd, fid), key, th);
}

int osd_oi_mod_init()
{
        if (osd_oi_count == 0 || osd_oi_count > OSD_OI_FID_NR_MAX)
                osd_oi_count = OSD_OI_FID_NR;

        if ((osd_oi_count & (osd_oi_count - 1)) != 0) {
                LCONSOLE_WARN("Round up oi_count %d to power2 %d\n",
                              osd_oi_count, size_roundup_power2(osd_oi_count));
                osd_oi_count = size_roundup_power2(osd_oi_count);
        }

        cfs_mutex_init(&oi_init_lock);
        return 0;
}