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 MODULE_ALIAS("vxfs"); /* makes mount -t vxfs autoload the module */
  56
  57
  58 static void             vxfs_put_super(struct super_block *);
  59 static int              vxfs_statfs(struct dentry *, struct kstatfs *);
  60 static int              vxfs_remount(struct super_block *, int *, char *);
  61
  62 static const struct super_operations vxfs_super_ops = {
  63         .clear_inode =          vxfs_clear_inode,
  64         .put_super =            vxfs_put_super,
  65         .statfs =               vxfs_statfs,
  66         .remount_fs =           vxfs_remount,
  67 };
  68
  69 /**
  70  * vxfs_put_super - free superblock resources
  71  * @sbp:        VFS superblock.
  72  *
  73  * Description:
  74  *   vxfs_put_super frees all resources allocated for @sbp
  75  *   after the last instance of the filesystem is unmounted.
  76  */
  77
  78 static void
  79 vxfs_put_super(struct super_block *sbp)
  80 {
  81         struct vxfs_sb_info     *infp = VXFS_SBI(sbp);
  82
  83         lock_kernel();
  84
  85         vxfs_put_fake_inode(infp->vsi_fship);
  86         vxfs_put_fake_inode(infp->vsi_ilist);
  87         vxfs_put_fake_inode(infp->vsi_stilist);
  88
  89         brelse(infp->vsi_bp);
  90         kfree(infp);
  91
  92         unlock_kernel();
  93 }
  94
  95 /**
  96  * vxfs_statfs - get filesystem information
  97  * @dentry:     VFS dentry to locate superblock
  98  * @bufp:       output buffer
  99  *
 100  * Description:
 101  *   vxfs_statfs fills the statfs buffer @bufp with information
 102  *   about the filesystem described by @dentry.
 103  *
 104  * Returns:
 105  *   Zero.
 106  *
 107  * Locking:
 108  *   No locks held.
 109  *
 110  * Notes:
 111  *   This is everything but complete...
 112  */
 113 static int
 114 vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
 115 {
 116         struct vxfs_sb_info             *infp = VXFS_SBI(dentry->d_sb);
 117
 118         bufp->f_type = VXFS_SUPER_MAGIC;
 119         bufp->f_bsize = dentry->d_sb->s_blocksize;
 120         bufp->f_blocks = infp->vsi_raw->vs_dsize;
 121         bufp->f_bfree = infp->vsi_raw->vs_free;
 122         bufp->f_bavail = 0;
 123         bufp->f_files = 0;
 124         bufp->f_ffree = infp->vsi_raw->vs_ifree;
 125         bufp->f_namelen = VXFS_NAMELEN;
 126
 127         return 0;
 128 }
 129
 130 static int vxfs_remount(struct super_block *sb, int *flags, char *data)
 131 {
 132         *flags |= MS_RDONLY;
 133         return 0;
 134 }
 135
 136 /**
 137  * vxfs_read_super - read superblock into memory and initalize filesystem
 138  * @sbp:                VFS superblock (to fill)
 139  * @dp:                 fs private mount data
 140  * @silent:             do not complain loudly when sth is wrong
 141  *
 142  * Description:
 143  *   We are called on the first mount of a filesystem to read the
 144  *   superblock into memory and do some basic setup.
 145  *
 146  * Returns:
 147  *   The superblock on success, else %NULL.
 148  *
 149  * Locking:
 150  *   We are under the bkl and @sbp->s_lock.
 151  */
 152 static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
 153 {
 154         struct vxfs_sb_info     *infp;
 155         struct vxfs_sb          *rsbp;
 156         struct buffer_head      *bp = NULL;
 157         u_long                  bsize;
 158         struct inode *root;
 159         int ret = -EINVAL;
 160
 161         sbp->s_flags |= MS_RDONLY;
 162
 163         infp = kzalloc(sizeof(*infp), GFP_KERNEL);
 164         if (!infp) {
 165                 printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
 166                 return -ENOMEM;
 167         }
 168
 169         bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
 170         if (!bsize) {
 171                 printk(KERN_WARNING "vxfs: unable to set blocksize\n");
 172                 goto out;
 173         }
 174
 175         bp = sb_bread(sbp, 1);
 176         if (!bp || !buffer_mapped(bp)) {
 177                 if (!silent) {
 178                         printk(KERN_WARNING
 179                                 "vxfs: unable to read disk superblock\n");
 180                 }
 181                 goto out;
 182         }
 183
 184         rsbp = (struct vxfs_sb *)bp->b_data;
 185         if (rsbp->vs_magic != VXFS_SUPER_MAGIC) {
 186                 if (!silent)
 187                         printk(KERN_NOTICE "vxfs: WRONG superblock magic\n");
 188                 goto out;
 189         }
 190
 191         if ((rsbp->vs_version < 2 || rsbp->vs_version > 4) && !silent) {
 192                 printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n",
 193                        rsbp->vs_version);
 194                 goto out;
 195         }
 196
 197 #ifdef DIAGNOSTIC
 198         printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", rsbp->vs_version);
 199         printk(KERN_DEBUG "vxfs: blocksize: %d\n", rsbp->vs_bsize);
 200 #endif
 201
 202         sbp->s_magic = rsbp->vs_magic;
 203         sbp->s_fs_info = infp;
 204
 205         infp->vsi_raw = rsbp;
 206         infp->vsi_bp = bp;
 207         infp->vsi_oltext = rsbp->vs_oltext[0];
 208         infp->vsi_oltsize = rsbp->vs_oltsize;
 209
 210         if (!sb_set_blocksize(sbp, rsbp->vs_bsize)) {
 211                 printk(KERN_WARNING "vxfs: unable to set final block size\n");
 212                 goto out;
 213         }
 214
 215         if (vxfs_read_olt(sbp, bsize)) {
 216                 printk(KERN_WARNING "vxfs: unable to read olt\n");
 217                 goto out;
 218         }
 219
 220         if (vxfs_read_fshead(sbp)) {
 221                 printk(KERN_WARNING "vxfs: unable to read fshead\n");
 222                 goto out;
 223         }
 224
 225         sbp->s_op = &vxfs_super_ops;
 226         root = vxfs_iget(sbp, VXFS_ROOT_INO);
 227         if (IS_ERR(root)) {
 228                 ret = PTR_ERR(root);
 229                 goto out;
 230         }
 231         sbp->s_root = d_alloc_root(root);
 232         if (!sbp->s_root) {
 233                 iput(root);
 234                 printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
 235                 goto out_free_ilist;
 236         }
 237
 238         return 0;
 239
 240 out_free_ilist:
 241         vxfs_put_fake_inode(infp->vsi_fship);
 242         vxfs_put_fake_inode(infp->vsi_ilist);
 243         vxfs_put_fake_inode(infp->vsi_stilist);
 244 out:
 245         brelse(bp);
 246         kfree(infp);
 247         return ret;
 248 }
 249
 250 /*
 251  * The usual module blurb.
 252  */
 253 static int vxfs_get_sb(struct file_system_type *fs_type,
 254         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 255 {
 256         return get_sb_bdev(fs_type, flags, dev_name, data, vxfs_fill_super,
 257                            mnt);
 258 }
 259
 260 static struct file_system_type vxfs_fs_type = {
 261         .owner          = THIS_MODULE,
 262         .name           = "vxfs",
 263         .get_sb         = vxfs_get_sb,
 264         .kill_sb        = kill_block_super,
 265         .fs_flags       = FS_REQUIRES_DEV,
 266 };
 267
 268 static int __init
 269 vxfs_init(void)
 270 {
 271         int rv;
 272
 273         vxfs_inode_cachep = kmem_cache_create("vxfs_inode",
 274                         sizeof(struct vxfs_inode_info), 0,
 275                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
 276         if (!vxfs_inode_cachep)
 277                 return -ENOMEM;
 278         rv = register_filesystem(&vxfs_fs_type);
 279         if (rv < 0)
 280                 kmem_cache_destroy(vxfs_inode_cachep);
 281         return rv;
 282 }
 283
 284 static void __exit
 285 vxfs_cleanup(void)
 286 {
 287         unregister_filesystem(&vxfs_fs_type);
 288         kmem_cache_destroy(vxfs_inode_cachep);
 289 }
 290
 291 module_init(vxfs_init);
 292 module_exit(vxfs_cleanup);