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/smp_lock.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");
  53 MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
  54 MODULE_LICENSE("Dual BSD/GPL");
  55
  56 MODULE_ALIAS("vxfs"); /* makes mount -t vxfs autoload the module */
  57
  58
  59 static void             vxfs_put_super(struct super_block *);
  60 static int              vxfs_statfs(struct dentry *, struct kstatfs *);
  61 static int              vxfs_remount(struct super_block *, int *, char *);
  62
  63 static const struct super_operations vxfs_super_ops = {
  64         .evict_inode =          vxfs_evict_inode,
  65         .put_super =            vxfs_put_super,
  66         .statfs =               vxfs_statfs,
  67         .remount_fs =           vxfs_remount,
  68 };
  69
  70 /**
  71  * vxfs_put_super - free superblock resources
  72  * @sbp:        VFS superblock.
  73  *
  74  * Description:
  75  *   vxfs_put_super frees all resources allocated for @sbp
  76  *   after the last instance of the filesystem is unmounted.
  77  */
  78
  79 static void
  80 vxfs_put_super(struct super_block *sbp)
  81 {
  82         struct vxfs_sb_info     *infp = VXFS_SBI(sbp);
  83
  84         lock_kernel();
  85
  86         vxfs_put_fake_inode(infp->vsi_fship);
  87         vxfs_put_fake_inode(infp->vsi_ilist);
  88         vxfs_put_fake_inode(infp->vsi_stilist);
  89
  90         brelse(infp->vsi_bp);
  91         kfree(infp);
  92
  93         unlock_kernel();
  94 }
  95
  96 /**
  97  * vxfs_statfs - get filesystem information
  98  * @dentry:     VFS dentry to locate superblock
  99  * @bufp:       output buffer
 100  *
 101  * Description:
 102  *   vxfs_statfs fills the statfs buffer @bufp with information
 103  *   about the filesystem described by @dentry.
 104  *
 105  * Returns:
 106  *   Zero.
 107  *
 108  * Locking:
 109  *   No locks held.
 110  *
 111  * Notes:
 112  *   This is everything but complete...
 113  */
 114 static int
 115 vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
 116 {
 117         struct vxfs_sb_info             *infp = VXFS_SBI(dentry->d_sb);
 118
 119         bufp->f_type = VXFS_SUPER_MAGIC;
 120         bufp->f_bsize = dentry->d_sb->s_blocksize;
 121         bufp->f_blocks = infp->vsi_raw->vs_dsize;
 122         bufp->f_bfree = infp->vsi_raw->vs_free;
 123         bufp->f_bavail = 0;
 124         bufp->f_files = 0;
 125         bufp->f_ffree = infp->vsi_raw->vs_ifree;
 126         bufp->f_namelen = VXFS_NAMELEN;
 127
 128         return 0;
 129 }
 130
 131 static int vxfs_remount(struct super_block *sb, int *flags, char *data)
 132 {
 133         *flags |= MS_RDONLY;
 134         return 0;
 135 }
 136
 137 /**
 138  * vxfs_read_super - read superblock into memory and initialize filesystem
 139  * @sbp:                VFS superblock (to fill)
 140  * @dp:                 fs private mount data
 141  * @silent:             do not complain loudly when sth is wrong
 142  *
 143  * Description:
 144  *   We are called on the first mount of a filesystem to read the
 145  *   superblock into memory and do some basic setup.
 146  *
 147  * Returns:
 148  *   The superblock on success, else %NULL.
 149  *
 150  * Locking:
 151  *   We are under the bkl and @sbp->s_lock.
 152  */
 153 static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
 154 {
 155         struct vxfs_sb_info     *infp;
 156         struct vxfs_sb          *rsbp;
 157         struct buffer_head      *bp = NULL;
 158         u_long                  bsize;
 159         struct inode *root;
 160         int ret = -EINVAL;
 161
 162         sbp->s_flags |= MS_RDONLY;
 163
 164         infp = kzalloc(sizeof(*infp), GFP_KERNEL);
 165         if (!infp) {
 166                 printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
 167                 return -ENOMEM;
 168         }
 169
 170         bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
 171         if (!bsize) {
 172                 printk(KERN_WARNING "vxfs: unable to set blocksize\n");
 173                 goto out;
 174         }
 175
 176         bp = sb_bread(sbp, 1);
 177         if (!bp || !buffer_mapped(bp)) {
 178                 if (!silent) {
 179                         printk(KERN_WARNING
 180                                 "vxfs: unable to read disk superblock\n");
 181                 }
 182                 goto out;
 183         }
 184
 185         rsbp = (struct vxfs_sb *)bp->b_data;
 186         if (rsbp->vs_magic != VXFS_SUPER_MAGIC) {
 187                 if (!silent)
 188                         printk(KERN_NOTICE "vxfs: WRONG superblock magic\n");
 189                 goto out;
 190         }
 191
 192         if ((rsbp->vs_version < 2 || rsbp->vs_version > 4) && !silent) {
 193                 printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n",
 194                        rsbp->vs_version);
 195                 goto out;
 196         }
 197
 198 #ifdef DIAGNOSTIC
 199         printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", rsbp->vs_version);
 200         printk(KERN_DEBUG "vxfs: blocksize: %d\n", rsbp->vs_bsize);
 201 #endif
 202
 203         sbp->s_magic = rsbp->vs_magic;
 204         sbp->s_fs_info = infp;
 205
 206         infp->vsi_raw = rsbp;
 207         infp->vsi_bp = bp;
 208         infp->vsi_oltext = rsbp->vs_oltext[0];
 209         infp->vsi_oltsize = rsbp->vs_oltsize;
 210
 211         if (!sb_set_blocksize(sbp, rsbp->vs_bsize)) {
 212                 printk(KERN_WARNING "vxfs: unable to set final block size\n");
 213                 goto out;
 214         }
 215
 216         if (vxfs_read_olt(sbp, bsize)) {
 217                 printk(KERN_WARNING "vxfs: unable to read olt\n");
 218                 goto out;
 219         }
 220
 221         if (vxfs_read_fshead(sbp)) {
 222                 printk(KERN_WARNING "vxfs: unable to read fshead\n");
 223                 goto out;
 224         }
 225
 226         sbp->s_op = &vxfs_super_ops;
 227         root = vxfs_iget(sbp, VXFS_ROOT_INO);
 228         if (IS_ERR(root)) {
 229                 ret = PTR_ERR(root);
 230                 goto out;
 231         }
 232         sbp->s_root = d_alloc_root(root);
 233         if (!sbp->s_root) {
 234                 iput(root);
 235                 printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
 236                 goto out_free_ilist;
 237         }
 238
 239         return 0;
 240
 241 out_free_ilist:
 242         vxfs_put_fake_inode(infp->vsi_fship);
 243         vxfs_put_fake_inode(infp->vsi_ilist);
 244         vxfs_put_fake_inode(infp->vsi_stilist);
 245 out:
 246         brelse(bp);
 247         kfree(infp);
 248         return ret;
 249 }
 250
 251 /*
 252  * The usual module blurb.
 253  */
 254 static int vxfs_get_sb(struct file_system_type *fs_type,
 255         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 256 {
 257         return get_sb_bdev(fs_type, flags, dev_name, data, vxfs_fill_super,
 258                            mnt);
 259 }
 260
 261 static struct file_system_type vxfs_fs_type = {
 262         .owner          = THIS_MODULE,
 263         .name           = "vxfs",
 264         .get_sb         = vxfs_get_sb,
 265         .kill_sb        = kill_block_super,
 266         .fs_flags       = FS_REQUIRES_DEV,
 267 };
 268
 269 static int __init
 270 vxfs_init(void)
 271 {
 272         int rv;
 273
 274         vxfs_inode_cachep = kmem_cache_create("vxfs_inode",
 275                         sizeof(struct vxfs_inode_info), 0,
 276                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
 277         if (!vxfs_inode_cachep)
 278                 return -ENOMEM;
 279         rv = register_filesystem(&vxfs_fs_type);
 280         if (rv < 0)
 281                 kmem_cache_destroy(vxfs_inode_cachep);
 282         return rv;
 283 }
 284
 285 static void __exit
 286 vxfs_cleanup(void)
 287 {
 288         unregister_filesystem(&vxfs_fs_type);
 289         kmem_cache_destroy(vxfs_inode_cachep);
 290 }
 291
 292 module_init(vxfs_init);
 293 module_exit(vxfs_cleanup);