/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/vfs.h>
#include <sys/fs/lofs_node.h>
#include <sys/fs/lofs_info.h>

#include <mdb/mdb_modapi.h>

typedef struct lnode_walk {
        struct lobucket *lw_table;      /* Snapshot of hash table */
        uint_t lw_tabsz;                /* Size of hash table */
        uint_t lw_tabi;                 /* Current table index */
        lnode_t *lw_lnode;              /* Current buffer */
} lnode_walk_t;

int
lnode_walk_init(mdb_walk_state_t *wsp)
{
        lnode_walk_t *lwp;

        int lofsfstype;
        struct vfs vfs;
        struct loinfo loinfo;

        if (mdb_readvar(&lofsfstype, "lofsfstype") == -1) {
                mdb_warn("failed to read 'lofsfstype' symbol\n");
                return (WALK_ERR);
        }

        if (wsp->walk_addr == 0) {
                uintptr_t rootvfsp, vfsp;
                uint_t htsize;

                lwp = mdb_alloc(sizeof (lnode_walk_t), UM_SLEEP);

retry:
                lwp->lw_tabsz = 0;
                if (mdb_readvar(&rootvfsp, "rootvfs") == -1) {
                        mdb_warn("failed to read 'rootvfs' symbol\n");
                        mdb_free(lwp, sizeof (lnode_walk_t));
                        return (WALK_ERR);
                }

                vfsp = rootvfsp;
                do {
                        (void) mdb_vread(&vfs, sizeof (vfs), vfsp);
                        if (lofsfstype != vfs.vfs_fstype) {
                                vfsp = (uintptr_t)vfs.vfs_next;
                                continue;
                        }
                        (void) mdb_vread(&loinfo, sizeof (struct loinfo),
                            (uintptr_t)vfs.vfs_data);
                        lwp->lw_tabsz += loinfo.li_htsize;
                        vfsp = (uintptr_t)vfs.vfs_next;
                } while (vfsp != rootvfsp);

                if (lwp->lw_tabsz == 0) {
                        /*
                         * No lofs filesystems mounted.
                         */
                        mdb_free(lwp, sizeof (lnode_walk_t));
                        return (WALK_DONE);
                }
                lwp->lw_table = mdb_alloc(lwp->lw_tabsz *
                    sizeof (struct lobucket), UM_SLEEP);
                htsize = 0;

                vfsp = rootvfsp;
                do {
                        (void) mdb_vread(&vfs, sizeof (vfs), vfsp);
                        if (lofsfstype != vfs.vfs_fstype) {
                                vfsp = (uintptr_t)vfs.vfs_next;
                                continue;
                        }
                        (void) mdb_vread(&loinfo, sizeof (struct loinfo),
                            (uintptr_t)vfs.vfs_data);
                        if (htsize + loinfo.li_htsize > lwp->lw_tabsz) {
                                /*
                                 * Something must have resized.
                                 */
                                mdb_free(lwp->lw_table,
                                    lwp->lw_tabsz * sizeof (struct lobucket));
                                goto retry;
                        }
                        (void) mdb_vread(lwp->lw_table + htsize,
                            loinfo.li_htsize * sizeof (struct lobucket),
                            (uintptr_t)loinfo.li_hashtable);
                        htsize += loinfo.li_htsize;
                        vfsp = (uintptr_t)vfs.vfs_next;
                } while (vfsp != rootvfsp);
        } else {
                if (mdb_vread(&vfs, sizeof (vfs_t), wsp->walk_addr) == -1) {
                        mdb_warn("failed to read from '%p'\n", wsp->walk_addr);
                        return (WALK_ERR);
                }
                if (lofsfstype != vfs.vfs_fstype) {
                        mdb_warn("%p does not point to a lofs mount vfs\n",
                            wsp->walk_addr);
                        return (WALK_ERR);
                }
                if (mdb_vread(&loinfo, sizeof (loinfo),
                    (uintptr_t)vfs.vfs_data) == -1) {
                        mdb_warn("failed to read struct loinfo from '%p'\n",
                            vfs.vfs_data);
                        return (WALK_ERR);
                }

                lwp = mdb_alloc(sizeof (lnode_walk_t), UM_SLEEP);
                lwp->lw_tabsz = loinfo.li_htsize;
                lwp->lw_table = mdb_alloc(lwp->lw_tabsz *
                    sizeof (struct lobucket), UM_SLEEP);
                (void) mdb_vread(lwp->lw_table,
                    lwp->lw_tabsz * sizeof (struct lobucket),
                    (uintptr_t)loinfo.li_hashtable);
        }
        lwp->lw_tabi = 0;
        lwp->lw_lnode = mdb_alloc(sizeof (lnode_t), UM_SLEEP);

        wsp->walk_addr = (uintptr_t)lwp->lw_table[0].lh_chain;
        wsp->walk_data = lwp;

        return (WALK_NEXT);
}

int
lnode_walk_step(mdb_walk_state_t *wsp)
{
        lnode_walk_t *lwp = wsp->walk_data;
        uintptr_t addr;

        /*
         * If the next lnode_t address we want is NULL, advance to the next
         * hash bucket.  When we reach lw_tabsz, we're done.
         */
        while (wsp->walk_addr == 0) {
                if (++lwp->lw_tabi < lwp->lw_tabsz)
                        wsp->walk_addr =
                            (uintptr_t)lwp->lw_table[lwp->lw_tabi].lh_chain;
                else
                        return (WALK_DONE);
        }

        /*
         * When we have an lnode_t address, read the lnode and invoke the
         * walk callback.  Keep the next lnode_t address in wsp->walk_addr.
         */
        addr = wsp->walk_addr;
        (void) mdb_vread(lwp->lw_lnode, sizeof (lnode_t), addr);
        wsp->walk_addr = (uintptr_t)lwp->lw_lnode->lo_next;

        return (wsp->walk_callback(addr, lwp->lw_lnode, wsp->walk_cbdata));
}

void
lnode_walk_fini(mdb_walk_state_t *wsp)
{
        lnode_walk_t *lwp = wsp->walk_data;

        mdb_free(lwp->lw_table, lwp->lw_tabsz * sizeof (struct lobucket));
        mdb_free(lwp->lw_lnode, sizeof (lnode_t));
        mdb_free(lwp, sizeof (lnode_walk_t));
}

/*ARGSUSED*/
static int
lnode_format(uintptr_t addr, const void *data, void *private)
{
        const lnode_t *lop = data;

        mdb_printf("%?p %?p %?p\n",
            addr, lop->lo_vnode, lop->lo_vp);

        return (DCMD_OK);
}

/*ARGSUSED*/
int
lnode(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
        if (argc != 0)
                return (DCMD_USAGE);

        if (DCMD_HDRSPEC(flags)) {
                mdb_printf("%<u>%?s %?s %?s%</u>\n",
                    "LNODE", "VNODE", "REALVP");
        }

        if (flags & DCMD_ADDRSPEC) {
                lnode_t lo;

                (void) mdb_vread(&lo, sizeof (lo), addr);
                return (lnode_format(addr, &lo, NULL));
        }

        if (mdb_walk("lnode", lnode_format, NULL) == -1)
                return (DCMD_ERR);

        return (DCMD_OK);
}

/*ARGSUSED*/
int
lnode2dev(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
        lnode_t lo;
        vnode_t vno;
        vfs_t vfs;

        if (argc != 0)
                return (DCMD_ERR);

        (void) mdb_vread(&lo, sizeof (lo), addr);
        (void) mdb_vread(&vno, sizeof (vno), (uintptr_t)lo.lo_vnode);
        (void) mdb_vread(&vfs, sizeof (vfs), (uintptr_t)vno.v_vfsp);

        mdb_printf("lnode %p vfs_dev %0?lx\n", addr, vfs.vfs_dev);
        return (DCMD_OK);
}

static const mdb_dcmd_t dcmds[] = {
        { "lnode", NULL, "print lnode structure(s)", lnode },
        { "lnode2dev", ":", "print vfs_dev given lnode", lnode2dev },
        { NULL }
};

static const mdb_walker_t walkers[] = {
        { "lnode", "hash of lnode structures",
                lnode_walk_init, lnode_walk_step, lnode_walk_fini },
        { NULL }
};

static const mdb_modinfo_t modinfo = {
        MDB_API_VERSION, dcmds, walkers
};

const mdb_modinfo_t *
_mdb_init(void)
{
        return (&modinfo);
}