fs/freevxfs/vxfs_super.c

   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
  52 MODULE_AUTHOR("Christoph Hellwig, Krzysztof Blaszkowski");
  53 MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
  54 MODULE_LICENSE("Dual BSD/GPL");
  55
  56 static 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
  67 static void
  68 vxfs_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  */
  98 static int
  99 vxfs_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
 116 static 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
 123 static 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
 134 static void vxfs_free_inode(struct inode *inode)
 135 {
 136         kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
 137 }
 138
 139 static 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
 148 static 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  */
 207 static 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
 296 out_free_ilist:
 297         iput(infp->vsi_fship);
 298         iput(infp->vsi_ilist);
 299         iput(infp->vsi_stilist);
 300 out:
 301         brelse(infp->vsi_bp);
 302         kfree(infp);
 303         return ret;
 304 }
 305
 306 /*
 307  * The usual module blurb.
 308  */
 309 static 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
 315 static 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 };
 322 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
 323 MODULE_ALIAS("vxfs");
 324
 325 static int __init
 326 vxfs_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
 345 static void __exit
 346 vxfs_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
 357 module_init(vxfs_init);
 358 module_exit(vxfs_cleanup);