root/fs/jffs2/super.c

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DEFINITIONS

This source file includes following definitions.
  1. jffs2_alloc_inode
  2. jffs2_free_inode
  3. jffs2_i_init_once
  4. jffs2_compr_name
  5. jffs2_show_options
  6. jffs2_sync_fs
  7. jffs2_nfs_get_inode
  8. jffs2_fh_to_dentry
  9. jffs2_fh_to_parent
  10. jffs2_get_parent
  11. jffs2_parse_param
  12. jffs2_reconfigure
  13. jffs2_fill_super
  14. jffs2_get_tree
  15. jffs2_free_fc
  16. jffs2_init_fs_context
  17. jffs2_put_super
  18. jffs2_kill_sb
  19. init_jffs2_fs
  20. exit_jffs2_fs

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright © 2001-2007 Red Hat, Inc.
   5  *
   6  * Created by David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  */
  11 
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13 
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/init.h>
  18 #include <linux/list.h>
  19 #include <linux/fs.h>
  20 #include <linux/err.h>
  21 #include <linux/mount.h>
  22 #include <linux/fs_context.h>
  23 #include <linux/fs_parser.h>
  24 #include <linux/jffs2.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/mtd/super.h>
  27 #include <linux/ctype.h>
  28 #include <linux/namei.h>
  29 #include <linux/seq_file.h>
  30 #include <linux/exportfs.h>
  31 #include "compr.h"
  32 #include "nodelist.h"
  33 
  34 static void jffs2_put_super(struct super_block *);
  35 
  36 static struct kmem_cache *jffs2_inode_cachep;
  37 
  38 static struct inode *jffs2_alloc_inode(struct super_block *sb)
  39 {
  40         struct jffs2_inode_info *f;
  41 
  42         f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
  43         if (!f)
  44                 return NULL;
  45         return &f->vfs_inode;
  46 }
  47 
  48 static void jffs2_free_inode(struct inode *inode)
  49 {
  50         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
  51 
  52         kfree(f->target);
  53         kmem_cache_free(jffs2_inode_cachep, f);
  54 }
  55 
  56 static void jffs2_i_init_once(void *foo)
  57 {
  58         struct jffs2_inode_info *f = foo;
  59 
  60         mutex_init(&f->sem);
  61         inode_init_once(&f->vfs_inode);
  62 }
  63 
  64 static const char *jffs2_compr_name(unsigned int compr)
  65 {
  66         switch (compr) {
  67         case JFFS2_COMPR_MODE_NONE:
  68                 return "none";
  69 #ifdef CONFIG_JFFS2_LZO
  70         case JFFS2_COMPR_MODE_FORCELZO:
  71                 return "lzo";
  72 #endif
  73 #ifdef CONFIG_JFFS2_ZLIB
  74         case JFFS2_COMPR_MODE_FORCEZLIB:
  75                 return "zlib";
  76 #endif
  77         default:
  78                 /* should never happen; programmer error */
  79                 WARN_ON(1);
  80                 return "";
  81         }
  82 }
  83 
  84 static int jffs2_show_options(struct seq_file *s, struct dentry *root)
  85 {
  86         struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
  87         struct jffs2_mount_opts *opts = &c->mount_opts;
  88 
  89         if (opts->override_compr)
  90                 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
  91         if (opts->rp_size)
  92                 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
  93 
  94         return 0;
  95 }
  96 
  97 static int jffs2_sync_fs(struct super_block *sb, int wait)
  98 {
  99         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 100 
 101 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 102         if (jffs2_is_writebuffered(c))
 103                 cancel_delayed_work_sync(&c->wbuf_dwork);
 104 #endif
 105 
 106         mutex_lock(&c->alloc_sem);
 107         jffs2_flush_wbuf_pad(c);
 108         mutex_unlock(&c->alloc_sem);
 109         return 0;
 110 }
 111 
 112 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
 113                                          uint32_t generation)
 114 {
 115         /* We don't care about i_generation. We'll destroy the flash
 116            before we start re-using inode numbers anyway. And even
 117            if that wasn't true, we'd have other problems...*/
 118         return jffs2_iget(sb, ino);
 119 }
 120 
 121 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 122                                          int fh_len, int fh_type)
 123 {
 124         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 125                                     jffs2_nfs_get_inode);
 126 }
 127 
 128 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
 129                                          int fh_len, int fh_type)
 130 {
 131         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 132                                     jffs2_nfs_get_inode);
 133 }
 134 
 135 static struct dentry *jffs2_get_parent(struct dentry *child)
 136 {
 137         struct jffs2_inode_info *f;
 138         uint32_t pino;
 139 
 140         BUG_ON(!d_is_dir(child));
 141 
 142         f = JFFS2_INODE_INFO(d_inode(child));
 143 
 144         pino = f->inocache->pino_nlink;
 145 
 146         JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
 147                     f->inocache->ino, pino);
 148 
 149         return d_obtain_alias(jffs2_iget(child->d_sb, pino));
 150 }
 151 
 152 static const struct export_operations jffs2_export_ops = {
 153         .get_parent = jffs2_get_parent,
 154         .fh_to_dentry = jffs2_fh_to_dentry,
 155         .fh_to_parent = jffs2_fh_to_parent,
 156 };
 157 
 158 /*
 159  * JFFS2 mount options.
 160  *
 161  * Opt_source: The source device
 162  * Opt_override_compr: override default compressor
 163  * Opt_rp_size: size of reserved pool in KiB
 164  */
 165 enum {
 166         Opt_override_compr,
 167         Opt_rp_size,
 168 };
 169 
 170 static const struct fs_parameter_spec jffs2_param_specs[] = {
 171         fsparam_enum    ("compr",       Opt_override_compr),
 172         fsparam_u32     ("rp_size",     Opt_rp_size),
 173         {}
 174 };
 175 
 176 static const struct fs_parameter_enum jffs2_param_enums[] = {
 177         { Opt_override_compr,   "none", JFFS2_COMPR_MODE_NONE },
 178 #ifdef CONFIG_JFFS2_LZO
 179         { Opt_override_compr,   "lzo",  JFFS2_COMPR_MODE_FORCELZO },
 180 #endif
 181 #ifdef CONFIG_JFFS2_ZLIB
 182         { Opt_override_compr,   "zlib", JFFS2_COMPR_MODE_FORCEZLIB },
 183 #endif
 184         {}
 185 };
 186 
 187 const struct fs_parameter_description jffs2_fs_parameters = {
 188         .name           = "jffs2",
 189         .specs          = jffs2_param_specs,
 190         .enums          = jffs2_param_enums,
 191 };
 192 
 193 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
 194 {
 195         struct fs_parse_result result;
 196         struct jffs2_sb_info *c = fc->s_fs_info;
 197         int opt;
 198 
 199         opt = fs_parse(fc, &jffs2_fs_parameters, param, &result);
 200         if (opt < 0)
 201                 return opt;
 202 
 203         switch (opt) {
 204         case Opt_override_compr:
 205                 c->mount_opts.compr = result.uint_32;
 206                 c->mount_opts.override_compr = true;
 207                 break;
 208         case Opt_rp_size:
 209                 if (result.uint_32 > UINT_MAX / 1024)
 210                         return invalf(fc, "jffs2: rp_size unrepresentable");
 211                 opt = result.uint_32 * 1024;
 212                 if (opt > c->mtd->size)
 213                         return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
 214                                       c->mtd->size / 1024);
 215                 c->mount_opts.rp_size = opt;
 216                 break;
 217         default:
 218                 return -EINVAL;
 219         }
 220 
 221         return 0;
 222 }
 223 
 224 static int jffs2_reconfigure(struct fs_context *fc)
 225 {
 226         struct super_block *sb = fc->root->d_sb;
 227 
 228         sync_filesystem(sb);
 229         return jffs2_do_remount_fs(sb, fc);
 230 }
 231 
 232 static const struct super_operations jffs2_super_operations =
 233 {
 234         .alloc_inode =  jffs2_alloc_inode,
 235         .free_inode =   jffs2_free_inode,
 236         .put_super =    jffs2_put_super,
 237         .statfs =       jffs2_statfs,
 238         .evict_inode =  jffs2_evict_inode,
 239         .dirty_inode =  jffs2_dirty_inode,
 240         .show_options = jffs2_show_options,
 241         .sync_fs =      jffs2_sync_fs,
 242 };
 243 
 244 /*
 245  * fill in the superblock
 246  */
 247 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
 248 {
 249         struct jffs2_sb_info *c = sb->s_fs_info;
 250 
 251         jffs2_dbg(1, "jffs2_get_sb_mtd():"
 252                   " New superblock for device %d (\"%s\")\n",
 253                   sb->s_mtd->index, sb->s_mtd->name);
 254 
 255         c->mtd = sb->s_mtd;
 256         c->os_priv = sb;
 257 
 258         /* Initialize JFFS2 superblock locks, the further initialization will
 259          * be done later */
 260         mutex_init(&c->alloc_sem);
 261         mutex_init(&c->erase_free_sem);
 262         init_waitqueue_head(&c->erase_wait);
 263         init_waitqueue_head(&c->inocache_wq);
 264         spin_lock_init(&c->erase_completion_lock);
 265         spin_lock_init(&c->inocache_lock);
 266 
 267         sb->s_op = &jffs2_super_operations;
 268         sb->s_export_op = &jffs2_export_ops;
 269         sb->s_flags = sb->s_flags | SB_NOATIME;
 270         sb->s_xattr = jffs2_xattr_handlers;
 271 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 272         sb->s_flags |= SB_POSIXACL;
 273 #endif
 274         return jffs2_do_fill_super(sb, fc);
 275 }
 276 
 277 static int jffs2_get_tree(struct fs_context *fc)
 278 {
 279         return get_tree_mtd(fc, jffs2_fill_super);
 280 }
 281 
 282 static void jffs2_free_fc(struct fs_context *fc)
 283 {
 284         kfree(fc->s_fs_info);
 285 }
 286 
 287 static const struct fs_context_operations jffs2_context_ops = {
 288         .free           = jffs2_free_fc,
 289         .parse_param    = jffs2_parse_param,
 290         .get_tree       = jffs2_get_tree,
 291         .reconfigure    = jffs2_reconfigure,
 292 };
 293 
 294 static int jffs2_init_fs_context(struct fs_context *fc)
 295 {
 296         struct jffs2_sb_info *ctx;
 297 
 298         ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
 299         if (!ctx)
 300                 return -ENOMEM;
 301 
 302         fc->s_fs_info = ctx;
 303         fc->ops = &jffs2_context_ops;
 304         return 0;
 305 }
 306 
 307 static void jffs2_put_super (struct super_block *sb)
 308 {
 309         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 310 
 311         jffs2_dbg(2, "%s()\n", __func__);
 312 
 313         mutex_lock(&c->alloc_sem);
 314         jffs2_flush_wbuf_pad(c);
 315         mutex_unlock(&c->alloc_sem);
 316 
 317         jffs2_sum_exit(c);
 318 
 319         jffs2_free_ino_caches(c);
 320         jffs2_free_raw_node_refs(c);
 321         kvfree(c->blocks);
 322         jffs2_flash_cleanup(c);
 323         kfree(c->inocache_list);
 324         jffs2_clear_xattr_subsystem(c);
 325         mtd_sync(c->mtd);
 326         jffs2_dbg(1, "%s(): returning\n", __func__);
 327 }
 328 
 329 static void jffs2_kill_sb(struct super_block *sb)
 330 {
 331         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 332         if (c && !sb_rdonly(sb))
 333                 jffs2_stop_garbage_collect_thread(c);
 334         kill_mtd_super(sb);
 335         kfree(c);
 336 }
 337 
 338 static struct file_system_type jffs2_fs_type = {
 339         .owner =        THIS_MODULE,
 340         .name =         "jffs2",
 341         .init_fs_context = jffs2_init_fs_context,
 342         .parameters =   &jffs2_fs_parameters,
 343         .kill_sb =      jffs2_kill_sb,
 344 };
 345 MODULE_ALIAS_FS("jffs2");
 346 
 347 static int __init init_jffs2_fs(void)
 348 {
 349         int ret;
 350 
 351         /* Paranoia checks for on-medium structures. If we ask GCC
 352            to pack them with __attribute__((packed)) then it _also_
 353            assumes that they're not aligned -- so it emits crappy
 354            code on some architectures. Ideally we want an attribute
 355            which means just 'no padding', without the alignment
 356            thing. But GCC doesn't have that -- we have to just
 357            hope the structs are the right sizes, instead. */
 358         BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
 359         BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
 360         BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
 361         BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
 362 
 363         pr_info("version 2.2."
 364 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 365                " (NAND)"
 366 #endif
 367 #ifdef CONFIG_JFFS2_SUMMARY
 368                " (SUMMARY) "
 369 #endif
 370                " © 2001-2006 Red Hat, Inc.\n");
 371 
 372         jffs2_inode_cachep = kmem_cache_create("jffs2_i",
 373                                              sizeof(struct jffs2_inode_info),
 374                                              0, (SLAB_RECLAIM_ACCOUNT|
 375                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 376                                              jffs2_i_init_once);
 377         if (!jffs2_inode_cachep) {
 378                 pr_err("error: Failed to initialise inode cache\n");
 379                 return -ENOMEM;
 380         }
 381         ret = jffs2_compressors_init();
 382         if (ret) {
 383                 pr_err("error: Failed to initialise compressors\n");
 384                 goto out;
 385         }
 386         ret = jffs2_create_slab_caches();
 387         if (ret) {
 388                 pr_err("error: Failed to initialise slab caches\n");
 389                 goto out_compressors;
 390         }
 391         ret = register_filesystem(&jffs2_fs_type);
 392         if (ret) {
 393                 pr_err("error: Failed to register filesystem\n");
 394                 goto out_slab;
 395         }
 396         return 0;
 397 
 398  out_slab:
 399         jffs2_destroy_slab_caches();
 400  out_compressors:
 401         jffs2_compressors_exit();
 402  out:
 403         kmem_cache_destroy(jffs2_inode_cachep);
 404         return ret;
 405 }
 406 
 407 static void __exit exit_jffs2_fs(void)
 408 {
 409         unregister_filesystem(&jffs2_fs_type);
 410         jffs2_destroy_slab_caches();
 411         jffs2_compressors_exit();
 412 
 413         /*
 414          * Make sure all delayed rcu free inodes are flushed before we
 415          * destroy cache.
 416          */
 417         rcu_barrier();
 418         kmem_cache_destroy(jffs2_inode_cachep);
 419 }
 420 
 421 module_init(init_jffs2_fs);
 422 module_exit(exit_jffs2_fs);
 423 
 424 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
 425 MODULE_AUTHOR("Red Hat, Inc.");
 426 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
 427                        // the sake of this tag. It's Free Software.

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