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/mount.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
  80         bufp->f_type = VXFS_SUPER_MAGIC;
  81         bufp->f_bsize = dentry->d_sb->s_blocksize;
  82         bufp->f_blocks = fs32_to_cpu(infp, raw_sb->vs_dsize);
  83         bufp->f_bfree = fs32_to_cpu(infp, raw_sb->vs_free);
  84         bufp->f_bavail = 0;
  85         bufp->f_files = 0;
  86         bufp->f_ffree = fs32_to_cpu(infp, raw_sb->vs_ifree);
  87         bufp->f_namelen = VXFS_NAMELEN;
  88
  89         return 0;
  90 }
  91
  92 static int vxfs_remount(struct super_block *sb, int *flags, char *data)
  93 {
  94         sync_filesystem(sb);
  95         *flags |= SB_RDONLY;
  96         return 0;
  97 }
  98
  99 static struct inode *vxfs_alloc_inode(struct super_block *sb)
 100 {
 101         struct vxfs_inode_info *vi;
 102
 103         vi = alloc_inode_sb(sb, vxfs_inode_cachep, GFP_KERNEL);
 104         if (!vi)
 105                 return NULL;
 106         inode_init_once(&vi->vfs_inode);
 107         return &vi->vfs_inode;
 108 }
 109
 110 static void vxfs_free_inode(struct inode *inode)
 111 {
 112         kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
 113 }
 114
 115 static const struct super_operations vxfs_super_ops = {
 116         .alloc_inode            = vxfs_alloc_inode,
 117         .free_inode             = vxfs_free_inode,
 118         .evict_inode            = vxfs_evict_inode,
 119         .put_super              = vxfs_put_super,
 120         .statfs                 = vxfs_statfs,
 121         .remount_fs             = vxfs_remount,
 122 };
 123
 124 static int vxfs_try_sb_magic(struct super_block *sbp, int silent,
 125                 unsigned blk, __fs32 magic)
 126 {
 127         struct buffer_head *bp;
 128         struct vxfs_sb *rsbp;
 129         struct vxfs_sb_info *infp = VXFS_SBI(sbp);
 130         int rc = -ENOMEM;
 131
 132         bp = sb_bread(sbp, blk);
 133         do {
 134                 if (!bp || !buffer_mapped(bp)) {
 135                         if (!silent) {
 136                                 printk(KERN_WARNING
 137                                         "vxfs: unable to read disk superblock at %u\n",
 138                                         blk);
 139                         }
 140                         break;
 141                 }
 142
 143                 rc = -EINVAL;
 144                 rsbp = (struct vxfs_sb *)bp->b_data;
 145                 if (rsbp->vs_magic != magic) {
 146                         if (!silent)
 147                                 printk(KERN_NOTICE
 148                                         "vxfs: WRONG superblock magic %08x at %u\n",
 149                                         rsbp->vs_magic, blk);
 150                         break;
 151                 }
 152
 153                 rc = 0;
 154                 infp->vsi_raw = rsbp;
 155                 infp->vsi_bp = bp;
 156         } while (0);
 157
 158         if (rc) {
 159                 infp->vsi_raw = NULL;
 160                 infp->vsi_bp = NULL;
 161                 brelse(bp);
 162         }
 163
 164         return rc;
 165 }
 166
 167 /**
 168  * vxfs_read_super - read superblock into memory and initialize filesystem
 169  * @sbp:                VFS superblock (to fill)
 170  * @dp:                 fs private mount data
 171  * @silent:             do not complain loudly when sth is wrong
 172  *
 173  * Description:
 174  *   We are called on the first mount of a filesystem to read the
 175  *   superblock into memory and do some basic setup.
 176  *
 177  * Returns:
 178  *   The superblock on success, else %NULL.
 179  *
 180  * Locking:
 181  *   We are under @sbp->s_lock.
 182  */
 183 static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
 184 {
 185         struct vxfs_sb_info     *infp;
 186         struct vxfs_sb          *rsbp;
 187         u_long                  bsize;
 188         struct inode *root;
 189         int ret = -EINVAL;
 190         u32 j;
 191
 192         sbp->s_flags |= SB_RDONLY;
 193
 194         infp = kzalloc(sizeof(*infp), GFP_KERNEL);
 195         if (!infp) {
 196                 printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
 197                 return -ENOMEM;
 198         }
 199
 200         bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
 201         if (!bsize) {
 202                 printk(KERN_WARNING "vxfs: unable to set blocksize\n");
 203                 goto out;
 204         }
 205
 206         sbp->s_op = &vxfs_super_ops;
 207         sbp->s_fs_info = infp;
 208         sbp->s_time_min = 0;
 209         sbp->s_time_max = U32_MAX;
 210
 211         if (!vxfs_try_sb_magic(sbp, silent, 1,
 212                         (__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
 213                 /* Unixware, x86 */
 214                 infp->byte_order = VXFS_BO_LE;
 215         } else if (!vxfs_try_sb_magic(sbp, silent, 8,
 216                         (__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
 217                 /* HP-UX, parisc */
 218                 infp->byte_order = VXFS_BO_BE;
 219         } else {
 220                 if (!silent)
 221                         printk(KERN_NOTICE "vxfs: can't find superblock.\n");
 222                 goto out;
 223         }
 224
 225         rsbp = infp->vsi_raw;
 226         j = fs32_to_cpu(infp, rsbp->vs_version);
 227         if ((j < 2 || j > 4) && !silent) {
 228                 printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n", j);
 229                 goto out;
 230         }
 231
 232 #ifdef DIAGNOSTIC
 233         printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
 234         printk(KERN_DEBUG "vxfs: blocksize: %d\n",
 235                 fs32_to_cpu(infp, rsbp->vs_bsize));
 236 #endif
 237
 238         sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
 239
 240         infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
 241         infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
 242
 243         j = fs32_to_cpu(infp, rsbp->vs_bsize);
 244         if (!sb_set_blocksize(sbp, j)) {
 245                 printk(KERN_WARNING "vxfs: unable to set final block size\n");
 246                 goto out;
 247         }
 248
 249         if (vxfs_read_olt(sbp, bsize)) {
 250                 printk(KERN_WARNING "vxfs: unable to read olt\n");
 251                 goto out;
 252         }
 253
 254         if (vxfs_read_fshead(sbp)) {
 255                 printk(KERN_WARNING "vxfs: unable to read fshead\n");
 256                 goto out;
 257         }
 258
 259         root = vxfs_iget(sbp, VXFS_ROOT_INO);
 260         if (IS_ERR(root)) {
 261                 ret = PTR_ERR(root);
 262                 goto out;
 263         }
 264         sbp->s_root = d_make_root(root);
 265         if (!sbp->s_root) {
 266                 printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
 267                 goto out_free_ilist;
 268         }
 269
 270         return 0;
 271
 272 out_free_ilist:
 273         iput(infp->vsi_fship);
 274         iput(infp->vsi_ilist);
 275         iput(infp->vsi_stilist);
 276 out:
 277         brelse(infp->vsi_bp);
 278         kfree(infp);
 279         return ret;
 280 }
 281
 282 /*
 283  * The usual module blurb.
 284  */
 285 static struct dentry *vxfs_mount(struct file_system_type *fs_type,
 286         int flags, const char *dev_name, void *data)
 287 {
 288         return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
 289 }
 290
 291 static struct file_system_type vxfs_fs_type = {
 292         .owner          = THIS_MODULE,
 293         .name           = "vxfs",
 294         .mount          = vxfs_mount,
 295         .kill_sb        = kill_block_super,
 296         .fs_flags       = FS_REQUIRES_DEV,
 297 };
 298 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
 299 MODULE_ALIAS("vxfs");
 300
 301 static int __init
 302 vxfs_init(void)
 303 {
 304         int rv;
 305
 306         vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
 307                         sizeof(struct vxfs_inode_info), 0,
 308                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 309                         offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
 310                         sizeof_field(struct vxfs_inode_info,
 311                                 vii_immed.vi_immed),
 312                         NULL);
 313         if (!vxfs_inode_cachep)
 314                 return -ENOMEM;
 315         rv = register_filesystem(&vxfs_fs_type);
 316         if (rv < 0)
 317                 kmem_cache_destroy(vxfs_inode_cachep);
 318         return rv;
 319 }
 320
 321 static void __exit
 322 vxfs_cleanup(void)
 323 {
 324         unregister_filesystem(&vxfs_fs_type);
 325         /*
 326          * Make sure all delayed rcu free inodes are flushed before we
 327          * destroy cache.
 328          */
 329         rcu_barrier();
 330         kmem_cache_destroy(vxfs_inode_cachep);
 331 }
 332
 333 module_init(vxfs_init);
 334 module_exit(vxfs_cleanup);