LXR linux/fs/freevxfs/vxfs

   1/*
   2 * Copyright (c) 2000-2001 Christoph Hellwig.
   3 * Copyright (c) 2016 Krzysztof Blaszkowski
   4 * All rights reserved.
   5 *
   6 * Redistribution and use in source and binary forms, with or without
   7 * modification, are permitted provided that the following conditions
   8 * are met:
   9 * 1. Redistributions of source code must retain the above copyright
  10 *    notice, this list of conditions, and the following disclaimer,
  11 *    without modification.
  12 * 2. The name of the author may not be used to endorse or promote products
  13 *    derived from this software without specific prior written permission.
  14 *
  15 * Alternatively, this software may be distributed under the terms of the
  16 * GNU General Public License ("GPL").
  17 *
  18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28 * SUCH DAMAGE.
  29 */
  30
  31/*
  32 * Veritas filesystem driver - superblock related routines.
  33 */
  34#include <linux/init.h>
  35#include <linux/module.h>
  36
  37#include <linux/blkdev.h>
  38#include <linux/fs.h>
  39#include <linux/buffer_head.h>
  40#include <linux/kernel.h>
  41#include <linux/slab.h>
  42#include <linux/stat.h>
  43#include <linux/vfs.h>
  44#include <linux/mount.h>
  45
  46#include "vxfs.h"
  47#include "vxfs_extern.h"
  48#include "vxfs_dir.h"
  49#include "vxfs_inode.h"
  50
  51
  52MODULE_AUTHOR("Christoph Hellwig, Krzysztof Blaszkowski");
  53MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
  54MODULE_LICENSE("Dual BSD/GPL");
  55
  56static struct kmem_cache *vxfs_inode_cachep;
  57
  58/**
  59 * vxfs_put_super - free superblock resources
  60 * @sbp:        VFS superblock.
  61 *
  62 * Description:
  63 *   vxfs_put_super frees all resources allocated for @sbp
  64 *   after the last instance of the filesystem is unmounted.
  65 */
  66
  67static void
  68vxfs_put_super(struct super_block *sbp)
  69{
  70        struct vxfs_sb_info     *infp = VXFS_SBI(sbp);
  71
  72        iput(infp->vsi_fship);
  73        iput(infp->vsi_ilist);
  74        iput(infp->vsi_stilist);
  75
  76        brelse(infp->vsi_bp);
  77        kfree(infp);
  78}
  79
  80/**
  81 * vxfs_statfs - get filesystem information
  82 * @dentry:     VFS dentry to locate superblock
  83 * @bufp:       output buffer
  84 *
  85 * Description:
  86 *   vxfs_statfs fills the statfs buffer @bufp with information
  87 *   about the filesystem described by @dentry.
  88 *
  89 * Returns:
  90 *   Zero.
  91 *
  92 * Locking:
  93 *   No locks held.
  94 *
  95 * Notes:
  96 *   This is everything but complete...
  97 */
  98static int
  99vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
 100{
 101        struct vxfs_sb_info             *infp = VXFS_SBI(dentry->d_sb);
 102        struct vxfs_sb *raw_sb = infp->vsi_raw;
 103
 104        bufp->f_type = VXFS_SUPER_MAGIC;
 105        bufp->f_bsize = dentry->d_sb->s_blocksize;
 106        bufp->f_blocks = fs32_to_cpu(infp, raw_sb->vs_dsize);
 107        bufp->f_bfree = fs32_to_cpu(infp, raw_sb->vs_free);
 108        bufp->f_bavail = 0;
 109        bufp->f_files = 0;
 110        bufp->f_ffree = fs32_to_cpu(infp, raw_sb->vs_ifree);
 111        bufp->f_namelen = VXFS_NAMELEN;
 112
 113        return 0;
 114}
 115
 116static int vxfs_remount(struct super_block *sb, int *flags, char *data)
 117{
 118        sync_filesystem(sb);
 119        *flags |= SB_RDONLY;
 120        return 0;
 121}
 122
 123static struct inode *vxfs_alloc_inode(struct super_block *sb)
 124{
 125        struct vxfs_inode_info *vi;
 126
 127        vi = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL);
 128        if (!vi)
 129                return NULL;
 130        inode_init_once(&vi->vfs_inode);
 131        return &vi->vfs_inode;
 132}
 133
 134static void vxfs_i_callback(struct rcu_head *head)
 135{
 136        struct inode *inode = container_of(head, struct inode, i_rcu);
 137
 138        kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
 139}
 140
 141static void vxfs_destroy_inode(struct inode *inode)
 142{
 143        call_rcu(&inode->i_rcu, vxfs_i_callback);
 144}
 145
 146static const struct super_operations vxfs_super_ops = {
 147        .alloc_inode            = vxfs_alloc_inode,
 148        .destroy_inode          = vxfs_destroy_inode,
 149        .evict_inode            = vxfs_evict_inode,
 150        .put_super              = vxfs_put_super,
 151        .statfs                 = vxfs_statfs,
 152        .remount_fs             = vxfs_remount,
 153};
 154
 155static int vxfs_try_sb_magic(struct super_block *sbp, int silent,
 156                unsigned blk, __fs32 magic)
 157{
 158        struct buffer_head *bp;
 159        struct vxfs_sb *rsbp;
 160        struct vxfs_sb_info *infp = VXFS_SBI(sbp);
 161        int rc = -ENOMEM;
 162
 163        bp = sb_bread(sbp, blk);
 164        do {
 165                if (!bp || !buffer_mapped(bp)) {
 166                        if (!silent) {
 167                                printk(KERN_WARNING
 168                                        "vxfs: unable to read disk superblock at %u\n",
 169                                        blk);
 170                        }
 171                        break;
 172                }
 173
 174                rc = -EINVAL;
 175                rsbp = (struct vxfs_sb *)bp->b_data;
 176                if (rsbp->vs_magic != magic) {
 177                        if (!silent)
 178                                printk(KERN_NOTICE
 179                                        "vxfs: WRONG superblock magic %08x at %u\n",
 180                                        rsbp->vs_magic, blk);
 181                        break;
 182                }
 183
 184                rc = 0;
 185                infp->vsi_raw = rsbp;
 186                infp->vsi_bp = bp;
 187        } while (0);
 188
 189        if (rc) {
 190                infp->vsi_raw = NULL;
 191                infp->vsi_bp = NULL;
 192                brelse(bp);
 193        }
 194
 195        return rc;
 196}
 197
 198/**
 199 * vxfs_read_super - read superblock into memory and initialize filesystem
 200 * @sbp:                VFS superblock (to fill)
 201 * @dp:                 fs private mount data
 202 * @silent:             do not complain loudly when sth is wrong
 203 *
 204 * Description:
 205 *   We are called on the first mount of a filesystem to read the
 206 *   superblock into memory and do some basic setup.
 207 *
 208 * Returns:
 209 *   The superblock on success, else %NULL.
 210 *
 211 * Locking:
 212 *   We are under @sbp->s_lock.
 213 */
 214static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
 215{
 216        struct vxfs_sb_info     *infp;
 217        struct vxfs_sb          *rsbp;
 218        u_long                  bsize;
 219        struct inode *root;
 220        int ret = -EINVAL;
 221        u32 j;
 222
 223        sbp->s_flags |= SB_RDONLY;
 224
 225        infp = kzalloc(sizeof(*infp), GFP_KERNEL);
 226        if (!infp) {
 227                printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
 228                return -ENOMEM;
 229        }
 230
 231        bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
 232        if (!bsize) {
 233                printk(KERN_WARNING "vxfs: unable to set blocksize\n");
 234                goto out;
 235        }
 236
 237        sbp->s_op = &vxfs_super_ops;
 238        sbp->s_fs_info = infp;
 239        sbp->s_time_min = 0;
 240        sbp->s_time_max = U32_MAX;
 241
 242        if (!vxfs_try_sb_magic(sbp, silent, 1,
 243                        (__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
 244                /* Unixware, x86 */
 245                infp->byte_order = VXFS_BO_LE;
 246        } else if (!vxfs_try_sb_magic(sbp, silent, 8,
 247                        (__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
 248                /* HP-UX, parisc */
 249                infp->byte_order = VXFS_BO_BE;
 250        } else {
 251                if (!silent)
 252                        printk(KERN_NOTICE "vxfs: can't find superblock.\n");
 253                goto out;
 254        }
 255
 256        rsbp = infp->vsi_raw;
 257        j = fs32_to_cpu(infp, rsbp->vs_version);
 258        if ((j < 2 || j > 4) && !silent) {
 259                printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n", j);
 260                goto out;
 261        }
 262
 263#ifdef DIAGNOSTIC
 264        printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
 265        printk(KERN_DEBUG "vxfs: blocksize: %d\n",
 266                fs32_to_cpu(infp, rsbp->vs_bsize));
 267#endif
 268
 269        sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
 270
 271        infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
 272        infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
 273
 274        j = fs32_to_cpu(infp, rsbp->vs_bsize);
 275        if (!sb_set_blocksize(sbp, j)) {
 276                printk(KERN_WARNING "vxfs: unable to set final block size\n");
 277                goto out;
 278        }
 279
 280        if (vxfs_read_olt(sbp, bsize)) {
 281                printk(KERN_WARNING "vxfs: unable to read olt\n");
 282                goto out;
 283        }
 284
 285        if (vxfs_read_fshead(sbp)) {
 286                printk(KERN_WARNING "vxfs: unable to read fshead\n");
 287                goto out;
 288        }
 289
 290        root = vxfs_iget(sbp, VXFS_ROOT_INO);
 291        if (IS_ERR(root)) {
 292                ret = PTR_ERR(root);
 293                goto out;
 294        }
 295        sbp->s_root = d_make_root(root);
 296        if (!sbp->s_root) {
 297                printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
 298                goto out_free_ilist;
 299        }
 300
 301        return 0;
 302        
 303out_free_ilist:
 304        iput(infp->vsi_fship);
 305        iput(infp->vsi_ilist);
 306        iput(infp->vsi_stilist);
 307out:
 308        brelse(infp->vsi_bp);
 309        kfree(infp);
 310        return ret;
 311}
 312
 313/*
 314 * The usual module blurb.
 315 */
 316static struct dentry *vxfs_mount(struct file_system_type *fs_type,
 317        int flags, const char *dev_name, void *data)
 318{
 319        return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
 320}
 321
 322static struct file_system_type vxfs_fs_type = {
 323        .owner          = THIS_MODULE,
 324        .name           = "vxfs",
 325        .mount          = vxfs_mount,
 326        .kill_sb        = kill_block_super,
 327        .fs_flags       = FS_REQUIRES_DEV,
 328};
 329MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
 330MODULE_ALIAS("vxfs");
 331
 332static int __init
 333vxfs_init(void)
 334{
 335        int rv;
 336
 337        vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
 338                        sizeof(struct vxfs_inode_info), 0,
 339                        SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 340                        offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
 341                        sizeof_field(struct vxfs_inode_info,
 342                                vii_immed.vi_immed),
 343                        NULL);
 344        if (!vxfs_inode_cachep)
 345                return -ENOMEM;
 346        rv = register_filesystem(&vxfs_fs_type);
 347        if (rv < 0)
 348                kmem_cache_destroy(vxfs_inode_cachep);
 349        return rv;
 350}
 351
 352static void __exit
 353vxfs_cleanup(void)
 354{
 355        unregister_filesystem(&vxfs_fs_type);
 356        /*
 357         * Make sure all delayed rcu free inodes are flushed before we
 358         * destroy cache.
 359         */
 360        rcu_barrier();
 361        kmem_cache_destroy(vxfs_inode_cachep);
 362}
 363
 364module_init(vxfs_init);
 365module_exit(vxfs_cleanup);
 366