fs/efs/super.c

   1 /*
   2  * super.c
   3  *
   4  * Copyright (c) 1999 Al Smith
   5  *
   6  * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 <<<<<<< HEAD:fs/efs/super.c
  12 #include <linux/efs_fs.h>
  13 #include <linux/efs_vh.h>
  14 #include <linux/efs_fs_sb.h>
  15 =======
  16 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:fs/efs/super.c
  17 #include <linux/exportfs.h>
  18 #include <linux/slab.h>
  19 #include <linux/buffer_head.h>
  20 #include <linux/vfs.h>
  21
  22 <<<<<<< HEAD:fs/efs/super.c
  23 =======
  24 #include "efs.h"
  25 #include <linux/efs_vh.h>
  26 #include <linux/efs_fs_sb.h>
  27
  28 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:fs/efs/super.c
  29 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf);
  30 static int efs_fill_super(struct super_block *s, void *d, int silent);
  31
  32 static int efs_get_sb(struct file_system_type *fs_type,
  33         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
  34 {
  35         return get_sb_bdev(fs_type, flags, dev_name, data, efs_fill_super, mnt);
  36 }
  37
  38 static struct file_system_type efs_fs_type = {
  39         .owner          = THIS_MODULE,
  40         .name           = "efs",
  41         .get_sb         = efs_get_sb,
  42         .kill_sb        = kill_block_super,
  43         .fs_flags       = FS_REQUIRES_DEV,
  44 };
  45
  46 static struct pt_types sgi_pt_types[] = {
  47         {0x00,          "SGI vh"},
  48         {0x01,          "SGI trkrepl"},
  49         {0x02,          "SGI secrepl"},
  50         {0x03,          "SGI raw"},
  51         {0x04,          "SGI bsd"},
  52         {SGI_SYSV,      "SGI sysv"},
  53         {0x06,          "SGI vol"},
  54         {SGI_EFS,       "SGI efs"},
  55         {0x08,          "SGI lv"},
  56         {0x09,          "SGI rlv"},
  57         {0x0A,          "SGI xfs"},
  58         {0x0B,          "SGI xfslog"},
  59         {0x0C,          "SGI xlv"},
  60         {0x82,          "Linux swap"},
  61         {0x83,          "Linux native"},
  62         {0,             NULL}
  63 };
  64
  65
  66 static struct kmem_cache * efs_inode_cachep;
  67
  68 static struct inode *efs_alloc_inode(struct super_block *sb)
  69 {
  70         struct efs_inode_info *ei;
  71         ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL);
  72         if (!ei)
  73                 return NULL;
  74         return &ei->vfs_inode;
  75 }
  76
  77 static void efs_destroy_inode(struct inode *inode)
  78 {
  79         kmem_cache_free(efs_inode_cachep, INODE_INFO(inode));
  80 }
  81
  82 static void init_once(struct kmem_cache *cachep, void *foo)
  83 {
  84         struct efs_inode_info *ei = (struct efs_inode_info *) foo;
  85
  86         inode_init_once(&ei->vfs_inode);
  87 }
  88
  89 static int init_inodecache(void)
  90 {
  91         efs_inode_cachep = kmem_cache_create("efs_inode_cache",
  92                                 sizeof(struct efs_inode_info),
  93                                 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
  94                                 init_once);
  95         if (efs_inode_cachep == NULL)
  96                 return -ENOMEM;
  97         return 0;
  98 }
  99
 100 static void destroy_inodecache(void)
 101 {
 102         kmem_cache_destroy(efs_inode_cachep);
 103 }
 104
 105 static void efs_put_super(struct super_block *s)
 106 {
 107         kfree(s->s_fs_info);
 108         s->s_fs_info = NULL;
 109 }
 110
 111 static int efs_remount(struct super_block *sb, int *flags, char *data)
 112 {
 113         *flags |= MS_RDONLY;
 114         return 0;
 115 }
 116
 117 static const struct super_operations efs_superblock_operations = {
 118         .alloc_inode    = efs_alloc_inode,
 119         .destroy_inode  = efs_destroy_inode,
 120         .put_super      = efs_put_super,
 121         .statfs         = efs_statfs,
 122         .remount_fs     = efs_remount,
 123 };
 124
 125 static const struct export_operations efs_export_ops = {
 126         .fh_to_dentry   = efs_fh_to_dentry,
 127         .fh_to_parent   = efs_fh_to_parent,
 128         .get_parent     = efs_get_parent,
 129 };
 130
 131 static int __init init_efs_fs(void) {
 132         int err;
 133         printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n");
 134         err = init_inodecache();
 135         if (err)
 136                 goto out1;
 137         err = register_filesystem(&efs_fs_type);
 138         if (err)
 139                 goto out;
 140         return 0;
 141 out:
 142         destroy_inodecache();
 143 out1:
 144         return err;
 145 }
 146
 147 static void __exit exit_efs_fs(void) {
 148         unregister_filesystem(&efs_fs_type);
 149         destroy_inodecache();
 150 }
 151
 152 module_init(init_efs_fs)
 153 module_exit(exit_efs_fs)
 154
 155 static efs_block_t efs_validate_vh(struct volume_header *vh) {
 156         int             i;
 157         __be32          cs, *ui;
 158         int             csum;
 159         efs_block_t     sblock = 0; /* shuts up gcc */
 160         struct pt_types *pt_entry;
 161         int             pt_type, slice = -1;
 162
 163         if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {
 164                 /*
 165                  * assume that we're dealing with a partition and allow
 166                  * read_super() to try and detect a valid superblock
 167                  * on the next block.
 168                  */
 169                 return 0;
 170         }
 171
 172         ui = ((__be32 *) (vh + 1)) - 1;
 173         for(csum = 0; ui >= ((__be32 *) vh);) {
 174                 cs = *ui--;
 175                 csum += be32_to_cpu(cs);
 176         }
 177         if (csum) {
 178                 printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n");
 179                 return 0;
 180         }
 181
 182 #ifdef DEBUG
 183         printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile);
 184
 185         for(i = 0; i < NVDIR; i++) {
 186                 int     j;
 187                 char    name[VDNAMESIZE+1];
 188
 189                 for(j = 0; j < VDNAMESIZE; j++) {
 190                         name[j] = vh->vh_vd[i].vd_name[j];
 191                 }
 192                 name[j] = (char) 0;
 193
 194                 if (name[0]) {
 195                         printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n",
 196                                 name,
 197                                 (int) be32_to_cpu(vh->vh_vd[i].vd_lbn),
 198                                 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes));
 199                 }
 200         }
 201 #endif
 202
 203         for(i = 0; i < NPARTAB; i++) {
 204                 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);
 205                 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) {
 206                         if (pt_type == pt_entry->pt_type) break;
 207                 }
 208 #ifdef DEBUG
 209                 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) {
 210                         printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n",
 211                                 i,
 212                                 (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn),
 213                                 (int) be32_to_cpu(vh->vh_pt[i].pt_nblks),
 214                                 pt_type,
 215                                 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown");
 216                 }
 217 #endif
 218                 if (IS_EFS(pt_type)) {
 219                         sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
 220                         slice = i;
 221                 }
 222         }
 223
 224         if (slice == -1) {
 225                 printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n");
 226 #ifdef DEBUG
 227         } else {
 228                 printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n",
 229                         slice,
 230                         (pt_entry->pt_name) ? pt_entry->pt_name : "unknown",
 231                         sblock);
 232 #endif
 233         }
 234         return sblock;
 235 }
 236
 237 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) {
 238
 239         if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic)))
 240                 return -1;
 241
 242         sb->fs_magic     = be32_to_cpu(super->fs_magic);
 243         sb->total_blocks = be32_to_cpu(super->fs_size);
 244         sb->first_block  = be32_to_cpu(super->fs_firstcg);
 245         sb->group_size   = be32_to_cpu(super->fs_cgfsize);
 246         sb->data_free    = be32_to_cpu(super->fs_tfree);
 247         sb->inode_free   = be32_to_cpu(super->fs_tinode);
 248         sb->inode_blocks = be16_to_cpu(super->fs_cgisize);
 249         sb->total_groups = be16_to_cpu(super->fs_ncg);
 250
 251         return 0;
 252 }
 253
 254 static int efs_fill_super(struct super_block *s, void *d, int silent)
 255 {
 256         struct efs_sb_info *sb;
 257         struct buffer_head *bh;
 258         struct inode *root;
 259         int ret = -EINVAL;
 260
 261         sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL);
 262         if (!sb)
 263                 return -ENOMEM;
 264         s->s_fs_info = sb;
 265
 266         s->s_magic              = EFS_SUPER_MAGIC;
 267         if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {
 268                 printk(KERN_ERR "EFS: device does not support %d byte blocks\n",
 269                         EFS_BLOCKSIZE);
 270                 goto out_no_fs_ul;
 271         }
 272
 273         /* read the vh (volume header) block */
 274         bh = sb_bread(s, 0);
 275
 276         if (!bh) {
 277                 printk(KERN_ERR "EFS: cannot read volume header\n");
 278                 goto out_no_fs_ul;
 279         }
 280
 281         /*
 282          * if this returns zero then we didn't find any partition table.
 283          * this isn't (yet) an error - just assume for the moment that
 284          * the device is valid and go on to search for a superblock.
 285          */
 286         sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data);
 287         brelse(bh);
 288
 289         if (sb->fs_start == -1) {
 290                 goto out_no_fs_ul;
 291         }
 292
 293         bh = sb_bread(s, sb->fs_start + EFS_SUPER);
 294         if (!bh) {
 295                 printk(KERN_ERR "EFS: cannot read superblock\n");
 296                 goto out_no_fs_ul;
 297         }
 298
 299         if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) {
 300 #ifdef DEBUG
 301                 printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER);
 302 #endif
 303                 brelse(bh);
 304                 goto out_no_fs_ul;
 305         }
 306         brelse(bh);
 307
 308         if (!(s->s_flags & MS_RDONLY)) {
 309 #ifdef DEBUG
 310                 printk(KERN_INFO "EFS: forcing read-only mode\n");
 311 #endif
 312                 s->s_flags |= MS_RDONLY;
 313         }
 314         s->s_op   = &efs_superblock_operations;
 315         s->s_export_op = &efs_export_ops;
 316         root = efs_iget(s, EFS_ROOTINODE);
 317         if (IS_ERR(root)) {
 318                 printk(KERN_ERR "EFS: get root inode failed\n");
 319                 ret = PTR_ERR(root);
 320                 goto out_no_fs;
 321         }
 322
 323         s->s_root = d_alloc_root(root);
 324         if (!(s->s_root)) {
 325                 printk(KERN_ERR "EFS: get root dentry failed\n");
 326                 iput(root);
 327                 ret = -ENOMEM;
 328                 goto out_no_fs;
 329         }
 330
 331         return 0;
 332
 333 out_no_fs_ul:
 334 out_no_fs:
 335         s->s_fs_info = NULL;
 336         kfree(sb);
 337         return ret;
 338 }
 339
 340 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) {
 341         struct efs_sb_info *sb = SUPER_INFO(dentry->d_sb);
 342
 343         buf->f_type    = EFS_SUPER_MAGIC;       /* efs magic number */
 344         buf->f_bsize   = EFS_BLOCKSIZE;         /* blocksize */
 345         buf->f_blocks  = sb->total_groups *     /* total data blocks */
 346                         (sb->group_size - sb->inode_blocks);
 347         buf->f_bfree   = sb->data_free;         /* free data blocks */
 348         buf->f_bavail  = sb->data_free;         /* free blocks for non-root */
 349         buf->f_files   = sb->total_groups *     /* total inodes */
 350                         sb->inode_blocks *
 351                         (EFS_BLOCKSIZE / sizeof(struct efs_dinode));
 352         buf->f_ffree   = sb->inode_free;        /* free inodes */
 353         buf->f_fsid.val[0] = (sb->fs_magic >> 16) & 0xffff; /* fs ID */
 354         buf->f_fsid.val[1] =  sb->fs_magic        & 0xffff; /* fs ID */
 355         buf->f_namelen = EFS_MAXNAMELEN;        /* max filename length */
 356
 357         return 0;
 358 }
 359