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_free_inode(struct inode *inode)
 135{
 136        kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
 137}
 138
 139static const struct super_operations vxfs_super_ops = {
 140        .alloc_inode            = vxfs_alloc_inode,
 141        .free_inode             = vxfs_free_inode,
 142        .evict_inode            = vxfs_evict_inode,
 143        .put_super              = vxfs_put_super,
 144        .statfs                 = vxfs_statfs,
 145        .remount_fs             = vxfs_remount,
 146};
 147
 148static int vxfs_try_sb_magic(struct super_block *sbp, int silent,
 149                unsigned blk, __fs32 magic)
 150{
 151        struct buffer_head *bp;
 152        struct vxfs_sb *rsbp;
 153        struct vxfs_sb_info *infp = VXFS_SBI(sbp);
 154        int rc = -ENOMEM;
 155
 156        bp = sb_bread(sbp, blk);
 157        do {
 158                if (!bp || !buffer_mapped(bp)) {
 159                        if (!silent) {
 160                                printk(KERN_WARNING
 161                                        "vxfs: unable to read disk superblock at %u\n",
 162                                        blk);
 163                        }
 164                        break;
 165                }
 166
 167                rc = -EINVAL;
 168                rsbp = (struct vxfs_sb *)bp->b_data;
 169                if (rsbp->vs_magic != magic) {
 170                        if (!silent)
 171                                printk(KERN_NOTICE
 172                                        "vxfs: WRONG superblock magic %08x at %u\n",
 173                                        rsbp->vs_magic, blk);
 174                        break;
 175                }
 176
 177                rc = 0;
 178                infp->vsi_raw = rsbp;
 179                infp->vsi_bp = bp;
 180        } while (0);
 181
 182        if (rc) {
 183                infp->vsi_raw = NULL;
 184                infp->vsi_bp = NULL;
 185                brelse(bp);
 186        }
 187
 188        return rc;
 189}
 190
 191/**
 192 * vxfs_read_super - read superblock into memory and initialize filesystem
 193 * @sbp:                VFS superblock (to fill)
 194 * @dp:                 fs private mount data
 195 * @silent:             do not complain loudly when sth is wrong
 196 *
 197 * Description:
 198 *   We are called on the first mount of a filesystem to read the
 199 *   superblock into memory and do some basic setup.
 200 *
 201 * Returns:
 202 *   The superblock on success, else %NULL.
 203 *
 204 * Locking:
 205 *   We are under @sbp->s_lock.
 206 */
 207static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
 208{
 209        struct vxfs_sb_info     *infp;
 210        struct vxfs_sb          *rsbp;
 211        u_long                  bsize;
 212        struct inode *root;
 213        int ret = -EINVAL;
 214        u32 j;
 215
 216        sbp->s_flags |= SB_RDONLY;
 217
 218        infp = kzalloc(sizeof(*infp), GFP_KERNEL);
 219        if (!infp) {
 220                printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
 221                return -ENOMEM;
 222        }
 223
 224        bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
 225        if (!bsize) {
 226                printk(KERN_WARNING "vxfs: unable to set blocksize\n");
 227                goto out;
 228        }
 229
 230        sbp->s_op = &vxfs_super_ops;
 231        sbp->s_fs_info = infp;
 232        sbp->s_time_min = 0;
 233        sbp->s_time_max = U32_MAX;
 234
 235        if (!vxfs_try_sb_magic(sbp, silent, 1,
 236                        (__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
 237                /* Unixware, x86 */
 238                infp->byte_order = VXFS_BO_LE;
 239        } else if (!vxfs_try_sb_magic(sbp, silent, 8,
 240                        (__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
 241                /* HP-UX, parisc */
 242                infp->byte_order = VXFS_BO_BE;
 243        } else {
 244                if (!silent)
 245                        printk(KERN_NOTICE "vxfs: can't find superblock.\n");
 246                goto out;
 247        }
 248
 249        rsbp = infp->vsi_raw;
 250        j = fs32_to_cpu(infp, rsbp->vs_version);
 251        if ((j < 2 || j > 4) && !silent) {
 252                printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n", j);
 253                goto out;
 254        }
 255
 256#ifdef DIAGNOSTIC
 257        printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
 258        printk(KERN_DEBUG "vxfs: blocksize: %d\n",
 259                fs32_to_cpu(infp, rsbp->vs_bsize));
 260#endif
 261
 262        sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
 263
 264        infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
 265        infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
 266
 267        j = fs32_to_cpu(infp, rsbp->vs_bsize);
 268        if (!sb_set_blocksize(sbp, j)) {
 269                printk(KERN_WARNING "vxfs: unable to set final block size\n");
 270                goto out;
 271        }
 272
 273        if (vxfs_read_olt(sbp, bsize)) {
 274                printk(KERN_WARNING "vxfs: unable to read olt\n");
 275                goto out;
 276        }
 277
 278        if (vxfs_read_fshead(sbp)) {
 279                printk(KERN_WARNING "vxfs: unable to read fshead\n");
 280                goto out;
 281        }
 282
 283        root = vxfs_iget(sbp, VXFS_ROOT_INO);
 284        if (IS_ERR(root)) {
 285                ret = PTR_ERR(root);
 286                goto out;
 287        }
 288        sbp->s_root = d_make_root(root);
 289        if (!sbp->s_root) {
 290                printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
 291                goto out_free_ilist;
 292        }
 293
 294        return 0;
 295        
 296out_free_ilist:
 297        iput(infp->vsi_fship);
 298        iput(infp->vsi_ilist);
 299        iput(infp->vsi_stilist);
 300out:
 301        brelse(infp->vsi_bp);
 302        kfree(infp);
 303        return ret;
 304}
 305
 306/*
 307 * The usual module blurb.
 308 */
 309static struct dentry *vxfs_mount(struct file_system_type *fs_type,
 310        int flags, const char *dev_name, void *data)
 311{
 312        return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
 313}
 314
 315static struct file_system_type vxfs_fs_type = {
 316        .owner          = THIS_MODULE,
 317        .name           = "vxfs",
 318        .mount          = vxfs_mount,
 319        .kill_sb        = kill_block_super,
 320        .fs_flags       = FS_REQUIRES_DEV,
 321};
 322MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
 323MODULE_ALIAS("vxfs");
 324
 325static int __init
 326vxfs_init(void)
 327{
 328        int rv;
 329
 330        vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
 331                        sizeof(struct vxfs_inode_info), 0,
 332                        SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 333                        offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
 334                        sizeof_field(struct vxfs_inode_info,
 335                                vii_immed.vi_immed),
 336                        NULL);
 337        if (!vxfs_inode_cachep)
 338                return -ENOMEM;
 339        rv = register_filesystem(&vxfs_fs_type);
 340        if (rv < 0)
 341                kmem_cache_destroy(vxfs_inode_cachep);
 342        return rv;
 343}
 344
 345static void __exit
 346vxfs_cleanup(void)
 347{
 348        unregister_filesystem(&vxfs_fs_type);
 349        /*
 350         * Make sure all delayed rcu free inodes are flushed before we
 351         * destroy cache.
 352         */
 353        rcu_barrier();
 354        kmem_cache_destroy(vxfs_inode_cachep);
 355}
 356
 357module_init(vxfs_init);
 358module_exit(vxfs_cleanup);
 359