fs/freevxfs/vxfs_super.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2000-2001 Christoph Hellwig.
   4  * Copyright (c) 2016 Krzysztof Blaszkowski
   5  */
   6
   7 /*
   8  * Veritas filesystem driver - superblock related routines.
   9  */
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12
  13 #include <linux/blkdev.h>
  14 #include <linux/fs.h>
  15 #include <linux/buffer_head.h>
  16 #include <linux/kernel.h>
  17 #include <linux/slab.h>
  18 #include <linux/stat.h>
  19 #include <linux/vfs.h>
  20 #include <linux/fs_context.h>
  21
  22 #include "vxfs.h"
  23 #include "vxfs_extern.h"
  24 #include "vxfs_dir.h"
  25 #include "vxfs_inode.h"
  26
  27
  28 MODULE_AUTHOR("Christoph Hellwig, Krzysztof Blaszkowski");
  29 MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
  30 MODULE_LICENSE("Dual BSD/GPL");
  31
  32 static struct kmem_cache *vxfs_inode_cachep;
  33
  34 /**
  35  * vxfs_put_super - free superblock resources
  36  * @sbp:        VFS superblock.
  37  *
  38  * Description:
  39  *   vxfs_put_super frees all resources allocated for @sbp
  40  *   after the last instance of the filesystem is unmounted.
  41  */
  42
  43 static void
  44 vxfs_put_super(struct super_block *sbp)
  45 {
  46         struct vxfs_sb_info     *infp = VXFS_SBI(sbp);
  47
  48         iput(infp->vsi_fship);
  49         iput(infp->vsi_ilist);
  50         iput(infp->vsi_stilist);
  51
  52         brelse(infp->vsi_bp);
  53         kfree(infp);
  54 }
  55
  56 /**
  57  * vxfs_statfs - get filesystem information
  58  * @dentry:     VFS dentry to locate superblock
  59  * @bufp:       output buffer
  60  *
  61  * Description:
  62  *   vxfs_statfs fills the statfs buffer @bufp with information
  63  *   about the filesystem described by @dentry.
  64  *
  65  * Returns:
  66  *   Zero.
  67  *
  68  * Locking:
  69  *   No locks held.
  70  *
  71  * Notes:
  72  *   This is everything but complete...
  73  */
  74 static int
  75 vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
  76 {
  77         struct vxfs_sb_info             *infp = VXFS_SBI(dentry->d_sb);
  78         struct vxfs_sb *raw_sb = infp->vsi_raw;
  79         u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev);
  80
  81         bufp->f_type = VXFS_SUPER_MAGIC;
  82         bufp->f_bsize = dentry->d_sb->s_blocksize;
  83         bufp->f_blocks = fs32_to_cpu(infp, raw_sb->vs_dsize);
  84         bufp->f_bfree = fs32_to_cpu(infp, raw_sb->vs_free);
  85         bufp->f_bavail = 0;
  86         bufp->f_files = 0;
  87         bufp->f_ffree = fs32_to_cpu(infp, raw_sb->vs_ifree);
  88         bufp->f_fsid = u64_to_fsid(id);
  89         bufp->f_namelen = VXFS_NAMELEN;
  90
  91         return 0;
  92 }
  93
  94 static int vxfs_reconfigure(struct fs_context *fc)
  95 {
  96         sync_filesystem(fc->root->d_sb);
  97         fc->sb_flags |= SB_RDONLY;
  98         return 0;
  99 }
 100
 101 static struct inode *vxfs_alloc_inode(struct super_block *sb)
 102 {
 103         struct vxfs_inode_info *vi;
 104
 105         vi = alloc_inode_sb(sb, vxfs_inode_cachep, GFP_KERNEL);
 106         if (!vi)
 107                 return NULL;
 108         inode_init_once(&vi->vfs_inode);
 109         return &vi->vfs_inode;
 110 }
 111
 112 static void vxfs_free_inode(struct inode *inode)
 113 {
 114         kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
 115 }
 116
 117 static const struct super_operations vxfs_super_ops = {
 118         .alloc_inode            = vxfs_alloc_inode,
 119         .free_inode             = vxfs_free_inode,
 120         .evict_inode            = vxfs_evict_inode,
 121         .put_super              = vxfs_put_super,
 122         .statfs                 = vxfs_statfs,
 123 };
 124
 125 static int vxfs_try_sb_magic(struct super_block *sbp, struct fs_context *fc,
 126                 unsigned blk, __fs32 magic)
 127 {
 128         struct buffer_head *bp;
 129         struct vxfs_sb *rsbp;
 130         struct vxfs_sb_info *infp = VXFS_SBI(sbp);
 131         int silent = fc->sb_flags & SB_SILENT;
 132         int rc = -ENOMEM;
 133
 134         bp = sb_bread(sbp, blk);
 135         do {
 136                 if (!bp || !buffer_mapped(bp)) {
 137                         if (!silent) {
 138                                 warnf(fc,
 139                                       "vxfs: unable to read disk superblock at %u",
 140                                       blk);
 141                         }
 142                         break;
 143                 }
 144
 145                 rc = -EINVAL;
 146                 rsbp = (struct vxfs_sb *)bp->b_data;
 147                 if (rsbp->vs_magic != magic) {
 148                         if (!silent)
 149                                 infof(fc,
 150                                       "vxfs: WRONG superblock magic %08x at %u",
 151                                       rsbp->vs_magic, blk);
 152                         break;
 153                 }
 154
 155                 rc = 0;
 156                 infp->vsi_raw = rsbp;
 157                 infp->vsi_bp = bp;
 158         } while (0);
 159
 160         if (rc) {
 161                 infp->vsi_raw = NULL;
 162                 infp->vsi_bp = NULL;
 163                 brelse(bp);
 164         }
 165
 166         return rc;
 167 }
 168
 169 /**
 170  * vxfs_fill_super - read superblock into memory and initialize filesystem
 171  * @sbp:                VFS superblock (to fill)
 172  * @fc:                 filesytem context
 173  *
 174  * Description:
 175  *   We are called on the first mount of a filesystem to read the
 176  *   superblock into memory and do some basic setup.
 177  *
 178  * Returns:
 179  *   The superblock on success, else %NULL.
 180  *
 181  * Locking:
 182  *   We are under @sbp->s_lock.
 183  */
 184 static int vxfs_fill_super(struct super_block *sbp, struct fs_context *fc)
 185 {
 186         struct vxfs_sb_info     *infp;
 187         struct vxfs_sb          *rsbp;
 188         u_long                  bsize;
 189         struct inode *root;
 190         int ret = -EINVAL;
 191         int silent = fc->sb_flags & SB_SILENT;
 192         u32 j;
 193
 194         sbp->s_flags |= SB_RDONLY;
 195
 196         infp = kzalloc(sizeof(*infp), GFP_KERNEL);
 197         if (!infp) {
 198                 warnf(fc, "vxfs: unable to allocate incore superblock");
 199                 return -ENOMEM;
 200         }
 201
 202         bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
 203         if (!bsize) {
 204                 warnf(fc, "vxfs: unable to set blocksize");
 205                 goto out;
 206         }
 207
 208         sbp->s_op = &vxfs_super_ops;
 209         sbp->s_fs_info = infp;
 210         sbp->s_time_min = 0;
 211         sbp->s_time_max = U32_MAX;
 212
 213         if (!vxfs_try_sb_magic(sbp, fc, 1,
 214                         (__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
 215                 /* Unixware, x86 */
 216                 infp->byte_order = VXFS_BO_LE;
 217         } else if (!vxfs_try_sb_magic(sbp, fc, 8,
 218                         (__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
 219                 /* HP-UX, parisc */
 220                 infp->byte_order = VXFS_BO_BE;
 221         } else {
 222                 if (!silent)
 223                         infof(fc, "vxfs: can't find superblock.");
 224                 goto out;
 225         }
 226
 227         rsbp = infp->vsi_raw;
 228         j = fs32_to_cpu(infp, rsbp->vs_version);
 229         if ((j < 2 || j > 4) && !silent) {
 230                 infof(fc, "vxfs: unsupported VxFS version (%d)", j);
 231                 goto out;
 232         }
 233
 234 #ifdef DIAGNOSTIC
 235         printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
 236         printk(KERN_DEBUG "vxfs: blocksize: %d\n",
 237                 fs32_to_cpu(infp, rsbp->vs_bsize));
 238 #endif
 239
 240         sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
 241
 242         infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
 243         infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
 244
 245         j = fs32_to_cpu(infp, rsbp->vs_bsize);
 246         if (!sb_set_blocksize(sbp, j)) {
 247                 warnf(fc, "vxfs: unable to set final block size");
 248                 goto out;
 249         }
 250
 251         if (vxfs_read_olt(sbp, bsize)) {
 252                 warnf(fc, "vxfs: unable to read olt");
 253                 goto out;
 254         }
 255
 256         if (vxfs_read_fshead(sbp)) {
 257                 warnf(fc, "vxfs: unable to read fshead");
 258                 goto out;
 259         }
 260
 261         root = vxfs_iget(sbp, VXFS_ROOT_INO);
 262         if (IS_ERR(root)) {
 263                 ret = PTR_ERR(root);
 264                 goto out;
 265         }
 266         sbp->s_root = d_make_root(root);
 267         if (!sbp->s_root) {
 268                 warnf(fc, "vxfs: unable to get root dentry.");
 269                 goto out_free_ilist;
 270         }
 271
 272         return 0;
 273
 274 out_free_ilist:
 275         iput(infp->vsi_fship);
 276         iput(infp->vsi_ilist);
 277         iput(infp->vsi_stilist);
 278 out:
 279         brelse(infp->vsi_bp);
 280         kfree(infp);
 281         return ret;
 282 }
 283
 284 /*
 285  * The usual module blurb.
 286  */
 287 static int vxfs_get_tree(struct fs_context *fc)
 288 {
 289         return get_tree_bdev(fc, vxfs_fill_super);
 290 }
 291
 292 static const struct fs_context_operations vxfs_context_ops = {
 293         .get_tree       = vxfs_get_tree,
 294         .reconfigure    = vxfs_reconfigure,
 295 };
 296
 297 static int vxfs_init_fs_context(struct fs_context *fc)
 298 {
 299         fc->ops = &vxfs_context_ops;
 300
 301         return 0;
 302 }
 303
 304 static struct file_system_type vxfs_fs_type = {
 305         .owner          = THIS_MODULE,
 306         .name           = "vxfs",
 307         .kill_sb        = kill_block_super,
 308         .fs_flags       = FS_REQUIRES_DEV,
 309         .init_fs_context = vxfs_init_fs_context,
 310 };
 311 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
 312 MODULE_ALIAS("vxfs");
 313
 314 static int __init
 315 vxfs_init(void)
 316 {
 317         int rv;
 318
 319         vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
 320                         sizeof(struct vxfs_inode_info), 0,
 321                         SLAB_RECLAIM_ACCOUNT,
 322                         offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
 323                         sizeof_field(struct vxfs_inode_info,
 324                                 vii_immed.vi_immed),
 325                         NULL);
 326         if (!vxfs_inode_cachep)
 327                 return -ENOMEM;
 328         rv = register_filesystem(&vxfs_fs_type);
 329         if (rv < 0)
 330                 kmem_cache_destroy(vxfs_inode_cachep);
 331         return rv;
 332 }
 333
 334 static void __exit
 335 vxfs_cleanup(void)
 336 {
 337         unregister_filesystem(&vxfs_fs_type);
 338         /*
 339          * Make sure all delayed rcu free inodes are flushed before we
 340          * destroy cache.
 341          */
 342         rcu_barrier();
 343         kmem_cache_destroy(vxfs_inode_cachep);
 344 }
 345
 346 module_init(vxfs_init);
 347 module_exit(vxfs_cleanup);