usr/src/cmd/mdb/common/modules/lofs/lofs.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <sys/types.h>
  30 #include <sys/vfs.h>
  31 #include <sys/fs/lofs_node.h>
  32 #include <sys/fs/lofs_info.h>
  33
  34 #include <mdb/mdb_modapi.h>
  35
  36 typedef struct lnode_walk {
  37         struct lobucket *lw_table;      /* Snapshot of hash table */
  38         uint_t lw_tabsz;                /* Size of hash table */
  39         uint_t lw_tabi;                 /* Current table index */
  40         lnode_t *lw_lnode;              /* Current buffer */
  41 } lnode_walk_t;
  42
  43 int
  44 lnode_walk_init(mdb_walk_state_t *wsp)
  45 {
  46         lnode_walk_t *lwp;
  47
  48         int lofsfstype;
  49         struct vfs vfs;
  50         struct loinfo loinfo;
  51
  52         if (mdb_readvar(&lofsfstype, "lofsfstype") == -1) {
  53                 mdb_warn("failed to read 'lofsfstype' symbol\n");
  54                 return (WALK_ERR);
  55         }
  56
  57         if (wsp->walk_addr == NULL) {
  58                 uintptr_t rootvfsp, vfsp;
  59                 uint_t htsize;
  60
  61                 lwp = mdb_alloc(sizeof (lnode_walk_t), UM_SLEEP);
  62
  63 retry:
  64                 lwp->lw_tabsz = 0;
  65                 if (mdb_readvar(&rootvfsp, "rootvfs") == -1) {
  66                         mdb_warn("failed to read 'rootvfs' symbol\n");
  67                         mdb_free(lwp, sizeof (lnode_walk_t));
  68                         return (WALK_ERR);
  69                 }
  70
  71                 vfsp = rootvfsp;
  72                 do {
  73                         (void) mdb_vread(&vfs, sizeof (vfs), vfsp);
  74                         if (lofsfstype != vfs.vfs_fstype) {
  75                                 vfsp = (uintptr_t)vfs.vfs_next;
  76                                 continue;
  77                         }
  78                         (void) mdb_vread(&loinfo, sizeof (struct loinfo),
  79                             (uintptr_t)vfs.vfs_data);
  80                         lwp->lw_tabsz += loinfo.li_htsize;
  81                         vfsp = (uintptr_t)vfs.vfs_next;
  82                 } while (vfsp != rootvfsp);
  83
  84                 if (lwp->lw_tabsz == 0) {
  85                         /*
  86                          * No lofs filesystems mounted.
  87                          */
  88                         mdb_free(lwp, sizeof (lnode_walk_t));
  89                         return (WALK_DONE);
  90                 }
  91                 lwp->lw_table = mdb_alloc(lwp->lw_tabsz *
  92                     sizeof (struct lobucket), UM_SLEEP);
  93                 htsize = 0;
  94
  95                 vfsp = rootvfsp;
  96                 do {
  97                         (void) mdb_vread(&vfs, sizeof (vfs), vfsp);
  98                         if (lofsfstype != vfs.vfs_fstype) {
  99                                 vfsp = (uintptr_t)vfs.vfs_next;
 100                                 continue;
 101                         }
 102                         (void) mdb_vread(&loinfo, sizeof (struct loinfo),
 103                             (uintptr_t)vfs.vfs_data);
 104                         if (htsize + loinfo.li_htsize > lwp->lw_tabsz) {
 105                                 /*
 106                                  * Something must have resized.
 107                                  */
 108                                 mdb_free(lwp->lw_table,
 109                                     lwp->lw_tabsz * sizeof (struct lobucket));
 110                                 goto retry;
 111                         }
 112                         (void) mdb_vread(lwp->lw_table + htsize,
 113                             loinfo.li_htsize * sizeof (struct lobucket),
 114                             (uintptr_t)loinfo.li_hashtable);
 115                         htsize += loinfo.li_htsize;
 116                         vfsp = (uintptr_t)vfs.vfs_next;
 117                 } while (vfsp != rootvfsp);
 118         } else {
 119                 if (mdb_vread(&vfs, sizeof (vfs_t), wsp->walk_addr) == -1) {
 120                         mdb_warn("failed to read from '%p'\n", wsp->walk_addr);
 121                         return (WALK_ERR);
 122                 }
 123                 if (lofsfstype != vfs.vfs_fstype) {
 124                         mdb_warn("%p does not point to a lofs mount vfs\n",
 125                             wsp->walk_addr);
 126                         return (WALK_ERR);
 127                 }
 128                 if (mdb_vread(&loinfo, sizeof (loinfo),
 129                     (uintptr_t)vfs.vfs_data) == -1) {
 130                         mdb_warn("failed to read struct loinfo from '%p'\n",
 131                             vfs.vfs_data);
 132                         return (WALK_ERR);
 133                 }
 134
 135                 lwp = mdb_alloc(sizeof (lnode_walk_t), UM_SLEEP);
 136                 lwp->lw_tabsz = loinfo.li_htsize;
 137                 lwp->lw_table = mdb_alloc(lwp->lw_tabsz *
 138                     sizeof (struct lobucket), UM_SLEEP);
 139                 (void) mdb_vread(lwp->lw_table,
 140                     lwp->lw_tabsz * sizeof (struct lobucket),
 141                     (uintptr_t)loinfo.li_hashtable);
 142         }
 143         lwp->lw_tabi = 0;
 144         lwp->lw_lnode = mdb_alloc(sizeof (lnode_t), UM_SLEEP);
 145
 146         wsp->walk_addr = (uintptr_t)lwp->lw_table[0].lh_chain;
 147         wsp->walk_data = lwp;
 148
 149         return (WALK_NEXT);
 150 }
 151
 152 int
 153 lnode_walk_step(mdb_walk_state_t *wsp)
 154 {
 155         lnode_walk_t *lwp = wsp->walk_data;
 156         uintptr_t addr;
 157
 158         /*
 159          * If the next lnode_t address we want is NULL, advance to the next
 160          * hash bucket.  When we reach lw_tabsz, we're done.
 161          */
 162         while (wsp->walk_addr == NULL) {
 163                 if (++lwp->lw_tabi < lwp->lw_tabsz)
 164                         wsp->walk_addr =
 165                             (uintptr_t)lwp->lw_table[lwp->lw_tabi].lh_chain;
 166                 else
 167                         return (WALK_DONE);
 168         }
 169
 170         /*
 171          * When we have an lnode_t address, read the lnode and invoke the
 172          * walk callback.  Keep the next lnode_t address in wsp->walk_addr.
 173          */
 174         addr = wsp->walk_addr;
 175         (void) mdb_vread(lwp->lw_lnode, sizeof (lnode_t), addr);
 176         wsp->walk_addr = (uintptr_t)lwp->lw_lnode->lo_next;
 177
 178         return (wsp->walk_callback(addr, lwp->lw_lnode, wsp->walk_cbdata));
 179 }
 180
 181 void
 182 lnode_walk_fini(mdb_walk_state_t *wsp)
 183 {
 184         lnode_walk_t *lwp = wsp->walk_data;
 185
 186         mdb_free(lwp->lw_table, lwp->lw_tabsz * sizeof (struct lobucket));
 187         mdb_free(lwp->lw_lnode, sizeof (lnode_t));
 188         mdb_free(lwp, sizeof (lnode_walk_t));
 189 }
 190
 191 /*ARGSUSED*/
 192 static int
 193 lnode_format(uintptr_t addr, const void *data, void *private)
 194 {
 195         const lnode_t *lop = data;
 196
 197         mdb_printf("%?p %?p %?p\n",
 198             addr, lop->lo_vnode, lop->lo_vp);
 199
 200         return (DCMD_OK);
 201 }
 202
 203 /*ARGSUSED*/
 204 int
 205 lnode(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
 206 {
 207         if (argc != 0)
 208                 return (DCMD_USAGE);
 209
 210         if (DCMD_HDRSPEC(flags)) {
 211                 mdb_printf("%<u>%?s %?s %?s%</u>\n",
 212                     "LNODE", "VNODE", "REALVP");
 213         }
 214
 215         if (flags & DCMD_ADDRSPEC) {
 216                 lnode_t lo;
 217
 218                 (void) mdb_vread(&lo, sizeof (lo), addr);
 219                 return (lnode_format(addr, &lo, NULL));
 220         }
 221
 222         if (mdb_walk("lnode", lnode_format, NULL) == -1)
 223                 return (DCMD_ERR);
 224
 225         return (DCMD_OK);
 226 }
 227
 228 /*ARGSUSED*/
 229 int
 230 lnode2dev(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
 231 {
 232         lnode_t lo;
 233         vnode_t vno;
 234         vfs_t vfs;
 235
 236         if (argc != 0)
 237                 return (DCMD_ERR);
 238
 239         (void) mdb_vread(&lo, sizeof (lo), addr);
 240         (void) mdb_vread(&vno, sizeof (vno), (uintptr_t)lo.lo_vnode);
 241         (void) mdb_vread(&vfs, sizeof (vfs), (uintptr_t)vno.v_vfsp);
 242
 243         mdb_printf("lnode %p vfs_dev %0?lx\n", addr, vfs.vfs_dev);
 244         return (DCMD_OK);
 245 }
 246
 247 static const mdb_dcmd_t dcmds[] = {
 248         { "lnode", NULL, "print lnode structure(s)", lnode },
 249         { "lnode2dev", ":", "print vfs_dev given lnode", lnode2dev },
 250         { NULL }
 251 };
 252
 253 static const mdb_walker_t walkers[] = {
 254         { "lnode", "hash of lnode structures",
 255                 lnode_walk_init, lnode_walk_step, lnode_walk_fini },
 256         { NULL }
 257 };
 258
 259 static const mdb_modinfo_t modinfo = {
 260         MDB_API_VERSION, dcmds, walkers
 261 };
 262
 263 const mdb_modinfo_t *
 264 _mdb_init(void)
 265 {
 266         return (&modinfo);
 267 }