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 |= MS_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_i_callback(struct rcu_head *head)
 135 {
 136         struct inode *inode = container_of(head, struct inode, i_rcu);
 137
 138         kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
 139 }
 140
 141 static void vxfs_destroy_inode(struct inode *inode)
 142 {
 143         call_rcu(&inode->i_rcu, vxfs_i_callback);
 144 }
 145
 146 static const struct super_operations vxfs_super_ops = {
 147         .alloc_inode            = vxfs_alloc_inode,
 148         .destroy_inode          = vxfs_destroy_inode,
 149         .evict_inode            = vxfs_evict_inode,
 150         .put_super              = vxfs_put_super,
 151         .statfs                 = vxfs_statfs,
 152         .remount_fs             = vxfs_remount,
 153 };
 154
 155 static int vxfs_try_sb_magic(struct super_block *sbp, int silent,
 156                 unsigned blk, __fs32 magic)
 157 {
 158         struct buffer_head *bp;
 159         struct vxfs_sb *rsbp;
 160         struct vxfs_sb_info *infp = VXFS_SBI(sbp);
 161         int rc = -ENOMEM;
 162
 163         bp = sb_bread(sbp, blk);
 164         do {
 165                 if (!bp || !buffer_mapped(bp)) {
 166                         if (!silent) {
 167                                 printk(KERN_WARNING
 168                                         "vxfs: unable to read disk superblock at %u\n",
 169                                         blk);
 170                         }
 171                         break;
 172                 }
 173
 174                 rc = -EINVAL;
 175                 rsbp = (struct vxfs_sb *)bp->b_data;
 176                 if (rsbp->vs_magic != magic) {
 177                         if (!silent)
 178                                 printk(KERN_NOTICE
 179                                         "vxfs: WRONG superblock magic %08x at %u\n",
 180                                         rsbp->vs_magic, blk);
 181                         break;
 182                 }
 183
 184                 rc = 0;
 185                 infp->vsi_raw = rsbp;
 186                 infp->vsi_bp = bp;
 187         } while (0);
 188
 189         if (rc) {
 190                 infp->vsi_raw = NULL;
 191                 infp->vsi_bp = NULL;
 192                 brelse(bp);
 193         }
 194
 195         return rc;
 196 }
 197
 198 /**
 199  * vxfs_read_super - read superblock into memory and initialize filesystem
 200  * @sbp:                VFS superblock (to fill)
 201  * @dp:                 fs private mount data
 202  * @silent:             do not complain loudly when sth is wrong
 203  *
 204  * Description:
 205  *   We are called on the first mount of a filesystem to read the
 206  *   superblock into memory and do some basic setup.
 207  *
 208  * Returns:
 209  *   The superblock on success, else %NULL.
 210  *
 211  * Locking:
 212  *   We are under @sbp->s_lock.
 213  */
 214 static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
 215 {
 216         struct vxfs_sb_info     *infp;
 217         struct vxfs_sb          *rsbp;
 218         u_long                  bsize;
 219         struct inode *root;
 220         int ret = -EINVAL;
 221         u32 j;
 222
 223         sbp->s_flags |= MS_RDONLY;
 224
 225         infp = kzalloc(sizeof(*infp), GFP_KERNEL);
 226         if (!infp) {
 227                 printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
 228                 return -ENOMEM;
 229         }
 230
 231         bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
 232         if (!bsize) {
 233                 printk(KERN_WARNING "vxfs: unable to set blocksize\n");
 234                 goto out;
 235         }
 236
 237         sbp->s_op = &vxfs_super_ops;
 238         sbp->s_fs_info = infp;
 239
 240         if (!vxfs_try_sb_magic(sbp, silent, 1,
 241                         (__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
 242                 /* Unixware, x86 */
 243                 infp->byte_order = VXFS_BO_LE;
 244         } else if (!vxfs_try_sb_magic(sbp, silent, 8,
 245                         (__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
 246                 /* HP-UX, parisc */
 247                 infp->byte_order = VXFS_BO_BE;
 248         } else {
 249                 if (!silent)
 250                         printk(KERN_NOTICE "vxfs: can't find superblock.\n");
 251                 goto out;
 252         }
 253
 254         rsbp = infp->vsi_raw;
 255         j = fs32_to_cpu(infp, rsbp->vs_version);
 256         if ((j < 2 || j > 4) && !silent) {
 257                 printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n", j);
 258                 goto out;
 259         }
 260
 261 #ifdef DIAGNOSTIC
 262         printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
 263         printk(KERN_DEBUG "vxfs: blocksize: %d\n",
 264                 fs32_to_cpu(infp, rsbp->vs_bsize));
 265 #endif
 266
 267         sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
 268
 269         infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
 270         infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
 271
 272         j = fs32_to_cpu(infp, rsbp->vs_bsize);
 273         if (!sb_set_blocksize(sbp, j)) {
 274                 printk(KERN_WARNING "vxfs: unable to set final block size\n");
 275                 goto out;
 276         }
 277
 278         if (vxfs_read_olt(sbp, bsize)) {
 279                 printk(KERN_WARNING "vxfs: unable to read olt\n");
 280                 goto out;
 281         }
 282
 283         if (vxfs_read_fshead(sbp)) {
 284                 printk(KERN_WARNING "vxfs: unable to read fshead\n");
 285                 goto out;
 286         }
 287
 288         root = vxfs_iget(sbp, VXFS_ROOT_INO);
 289         if (IS_ERR(root)) {
 290                 ret = PTR_ERR(root);
 291                 goto out;
 292         }
 293         sbp->s_root = d_make_root(root);
 294         if (!sbp->s_root) {
 295                 printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
 296                 goto out_free_ilist;
 297         }
 298
 299         return 0;
 300
 301 out_free_ilist:
 302         iput(infp->vsi_fship);
 303         iput(infp->vsi_ilist);
 304         iput(infp->vsi_stilist);
 305 out:
 306         brelse(infp->vsi_bp);
 307         kfree(infp);
 308         return ret;
 309 }
 310
 311 /*
 312  * The usual module blurb.
 313  */
 314 static struct dentry *vxfs_mount(struct file_system_type *fs_type,
 315         int flags, const char *dev_name, void *data)
 316 {
 317         return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
 318 }
 319
 320 static struct file_system_type vxfs_fs_type = {
 321         .owner          = THIS_MODULE,
 322         .name           = "vxfs",
 323         .mount          = vxfs_mount,
 324         .kill_sb        = kill_block_super,
 325         .fs_flags       = FS_REQUIRES_DEV,
 326 };
 327 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
 328 MODULE_ALIAS("vxfs");
 329
 330 static int __init
 331 vxfs_init(void)
 332 {
 333         int rv;
 334
 335         vxfs_inode_cachep = kmem_cache_create("vxfs_inode",
 336                         sizeof(struct vxfs_inode_info), 0,
 337                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
 338         if (!vxfs_inode_cachep)
 339                 return -ENOMEM;
 340         rv = register_filesystem(&vxfs_fs_type);
 341         if (rv < 0)
 342                 kmem_cache_destroy(vxfs_inode_cachep);
 343         return rv;
 344 }
 345
 346 static void __exit
 347 vxfs_cleanup(void)
 348 {
 349         unregister_filesystem(&vxfs_fs_type);
 350         /*
 351          * Make sure all delayed rcu free inodes are flushed before we
 352          * destroy cache.
 353          */
 354         rcu_barrier();
 355         kmem_cache_destroy(vxfs_inode_cachep);
 356 }
 357
 358 module_init(vxfs_init);
 359 module_exit(vxfs_cleanup);