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
 113         bufp->f_type = VXFS_SUPER_MAGIC;
 114         bufp->f_bsize = dentry->d_sb->s_blocksize;
 115         bufp->f_blocks = infp->vsi_raw->vs_dsize;
 116         bufp->f_bfree = infp->vsi_raw->vs_free;
 117         bufp->f_bavail = 0;
 118         bufp->f_files = 0;
 119         bufp->f_ffree = infp->vsi_raw->vs_ifree;
 120         bufp->f_namelen = VXFS_NAMELEN;
 121
 122         return 0;
 123 }
 124
 125 static int vxfs_remount(struct super_block *sb, int *flags, char *data)
 126 {
 127         *flags |= MS_RDONLY;
 128         return 0;
 129 }
 130
 131 /**
 132  * vxfs_read_super - read superblock into memory and initialize filesystem
 133  * @sbp:                VFS superblock (to fill)
 134  * @dp:                 fs private mount data
 135  * @silent:             do not complain loudly when sth is wrong
 136  *
 137  * Description:
 138  *   We are called on the first mount of a filesystem to read the
 139  *   superblock into memory and do some basic setup.
 140  *
 141  * Returns:
 142  *   The superblock on success, else %NULL.
 143  *
 144  * Locking:
 145  *   We are under @sbp->s_lock.
 146  */
 147 static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
 148 {
 149         struct vxfs_sb_info     *infp;
 150         struct vxfs_sb          *rsbp;
 151         struct buffer_head      *bp = NULL;
 152         u_long                  bsize;
 153         struct inode *root;
 154         int ret = -EINVAL;
 155
 156         sbp->s_flags |= MS_RDONLY;
 157
 158         infp = kzalloc(sizeof(*infp), GFP_KERNEL);
 159         if (!infp) {
 160                 printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
 161                 return -ENOMEM;
 162         }
 163
 164         bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
 165         if (!bsize) {
 166                 printk(KERN_WARNING "vxfs: unable to set blocksize\n");
 167                 goto out;
 168         }
 169
 170         bp = sb_bread(sbp, 1);
 171         if (!bp || !buffer_mapped(bp)) {
 172                 if (!silent) {
 173                         printk(KERN_WARNING
 174                                 "vxfs: unable to read disk superblock\n");
 175                 }
 176                 goto out;
 177         }
 178
 179         rsbp = (struct vxfs_sb *)bp->b_data;
 180         if (rsbp->vs_magic != VXFS_SUPER_MAGIC) {
 181                 if (!silent)
 182                         printk(KERN_NOTICE "vxfs: WRONG superblock magic\n");
 183                 goto out;
 184         }
 185
 186         if ((rsbp->vs_version < 2 || rsbp->vs_version > 4) && !silent) {
 187                 printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n",
 188                        rsbp->vs_version);
 189                 goto out;
 190         }
 191
 192 #ifdef DIAGNOSTIC
 193         printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", rsbp->vs_version);
 194         printk(KERN_DEBUG "vxfs: blocksize: %d\n", rsbp->vs_bsize);
 195 #endif
 196
 197         sbp->s_magic = rsbp->vs_magic;
 198         sbp->s_fs_info = infp;
 199
 200         infp->vsi_raw = rsbp;
 201         infp->vsi_bp = bp;
 202         infp->vsi_oltext = rsbp->vs_oltext[0];
 203         infp->vsi_oltsize = rsbp->vs_oltsize;
 204
 205         if (!sb_set_blocksize(sbp, rsbp->vs_bsize)) {
 206                 printk(KERN_WARNING "vxfs: unable to set final block size\n");
 207                 goto out;
 208         }
 209
 210         if (vxfs_read_olt(sbp, bsize)) {
 211                 printk(KERN_WARNING "vxfs: unable to read olt\n");
 212                 goto out;
 213         }
 214
 215         if (vxfs_read_fshead(sbp)) {
 216                 printk(KERN_WARNING "vxfs: unable to read fshead\n");
 217                 goto out;
 218         }
 219
 220         sbp->s_op = &vxfs_super_ops;
 221         root = vxfs_iget(sbp, VXFS_ROOT_INO);
 222         if (IS_ERR(root)) {
 223                 ret = PTR_ERR(root);
 224                 goto out;
 225         }
 226         sbp->s_root = d_make_root(root);
 227         if (!sbp->s_root) {
 228                 printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
 229                 goto out_free_ilist;
 230         }
 231
 232         return 0;
 233
 234 out_free_ilist:
 235         vxfs_put_fake_inode(infp->vsi_fship);
 236         vxfs_put_fake_inode(infp->vsi_ilist);
 237         vxfs_put_fake_inode(infp->vsi_stilist);
 238 out:
 239         brelse(bp);
 240         kfree(infp);
 241         return ret;
 242 }
 243
 244 /*
 245  * The usual module blurb.
 246  */
 247 static struct dentry *vxfs_mount(struct file_system_type *fs_type,
 248         int flags, const char *dev_name, void *data)
 249 {
 250         return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
 251 }
 252
 253 static struct file_system_type vxfs_fs_type = {
 254         .owner          = THIS_MODULE,
 255         .name           = "vxfs",
 256         .mount          = vxfs_mount,
 257         .kill_sb        = kill_block_super,
 258         .fs_flags       = FS_REQUIRES_DEV,
 259 };
 260 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
 261 MODULE_ALIAS("vxfs");
 262
 263 static int __init
 264 vxfs_init(void)
 265 {
 266         int rv;
 267
 268         vxfs_inode_cachep = kmem_cache_create("vxfs_inode",
 269                         sizeof(struct vxfs_inode_info), 0,
 270                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
 271         if (!vxfs_inode_cachep)
 272                 return -ENOMEM;
 273         rv = register_filesystem(&vxfs_fs_type);
 274         if (rv < 0)
 275                 kmem_cache_destroy(vxfs_inode_cachep);
 276         return rv;
 277 }
 278
 279 static void __exit
 280 vxfs_cleanup(void)
 281 {
 282         unregister_filesystem(&vxfs_fs_type);
 283         /*
 284          * Make sure all delayed rcu free inodes are flushed before we
 285          * destroy cache.
 286          */
 287         rcu_barrier();
 288         kmem_cache_destroy(vxfs_inode_cachep);
 289 }
 290
 291 module_init(vxfs_init);
 292 module_exit(vxfs_cleanup);