fs/freevxfs/vxfs_super.c

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