cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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super.c (10900B)


      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
     34static void jffs2_put_super(struct super_block *);
     35
     36static struct kmem_cache *jffs2_inode_cachep;
     37
     38static struct inode *jffs2_alloc_inode(struct super_block *sb)
     39{
     40	struct jffs2_inode_info *f;
     41
     42	f = alloc_inode_sb(sb, jffs2_inode_cachep, GFP_KERNEL);
     43	if (!f)
     44		return NULL;
     45	return &f->vfs_inode;
     46}
     47
     48static 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
     56static 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
     64static 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
     84static 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->set_rp_size)
     92		seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
     93
     94	return 0;
     95}
     96
     97static 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
    112static 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
    121static 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
    128static 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
    135static 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
    152static 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 */
    165enum {
    166	Opt_override_compr,
    167	Opt_rp_size,
    168};
    169
    170static const struct constant_table jffs2_param_compr[] = {
    171	{"none",	JFFS2_COMPR_MODE_NONE },
    172#ifdef CONFIG_JFFS2_LZO
    173	{"lzo",		JFFS2_COMPR_MODE_FORCELZO },
    174#endif
    175#ifdef CONFIG_JFFS2_ZLIB
    176	{"zlib",	JFFS2_COMPR_MODE_FORCEZLIB },
    177#endif
    178	{}
    179};
    180
    181static const struct fs_parameter_spec jffs2_fs_parameters[] = {
    182	fsparam_enum	("compr",	Opt_override_compr, jffs2_param_compr),
    183	fsparam_u32	("rp_size",	Opt_rp_size),
    184	{}
    185};
    186
    187static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
    188{
    189	struct fs_parse_result result;
    190	struct jffs2_sb_info *c = fc->s_fs_info;
    191	int opt;
    192
    193	opt = fs_parse(fc, jffs2_fs_parameters, param, &result);
    194	if (opt < 0)
    195		return opt;
    196
    197	switch (opt) {
    198	case Opt_override_compr:
    199		c->mount_opts.compr = result.uint_32;
    200		c->mount_opts.override_compr = true;
    201		break;
    202	case Opt_rp_size:
    203		if (result.uint_32 > UINT_MAX / 1024)
    204			return invalf(fc, "jffs2: rp_size unrepresentable");
    205		c->mount_opts.rp_size = result.uint_32 * 1024;
    206		c->mount_opts.set_rp_size = true;
    207		break;
    208	default:
    209		return -EINVAL;
    210	}
    211
    212	return 0;
    213}
    214
    215static inline void jffs2_update_mount_opts(struct fs_context *fc)
    216{
    217	struct jffs2_sb_info *new_c = fc->s_fs_info;
    218	struct jffs2_sb_info *c = JFFS2_SB_INFO(fc->root->d_sb);
    219
    220	mutex_lock(&c->alloc_sem);
    221	if (new_c->mount_opts.override_compr) {
    222		c->mount_opts.override_compr = new_c->mount_opts.override_compr;
    223		c->mount_opts.compr = new_c->mount_opts.compr;
    224	}
    225	if (new_c->mount_opts.set_rp_size) {
    226		c->mount_opts.set_rp_size = new_c->mount_opts.set_rp_size;
    227		c->mount_opts.rp_size = new_c->mount_opts.rp_size;
    228	}
    229	mutex_unlock(&c->alloc_sem);
    230}
    231
    232static int jffs2_reconfigure(struct fs_context *fc)
    233{
    234	struct super_block *sb = fc->root->d_sb;
    235
    236	sync_filesystem(sb);
    237	jffs2_update_mount_opts(fc);
    238
    239	return jffs2_do_remount_fs(sb, fc);
    240}
    241
    242static const struct super_operations jffs2_super_operations =
    243{
    244	.alloc_inode =	jffs2_alloc_inode,
    245	.free_inode =	jffs2_free_inode,
    246	.put_super =	jffs2_put_super,
    247	.statfs =	jffs2_statfs,
    248	.evict_inode =	jffs2_evict_inode,
    249	.dirty_inode =	jffs2_dirty_inode,
    250	.show_options =	jffs2_show_options,
    251	.sync_fs =	jffs2_sync_fs,
    252};
    253
    254/*
    255 * fill in the superblock
    256 */
    257static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
    258{
    259	struct jffs2_sb_info *c = sb->s_fs_info;
    260
    261	jffs2_dbg(1, "jffs2_get_sb_mtd():"
    262		  " New superblock for device %d (\"%s\")\n",
    263		  sb->s_mtd->index, sb->s_mtd->name);
    264
    265	c->mtd = sb->s_mtd;
    266	c->os_priv = sb;
    267
    268	if (c->mount_opts.rp_size > c->mtd->size)
    269		return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
    270			      c->mtd->size / 1024);
    271
    272	/* Initialize JFFS2 superblock locks, the further initialization will
    273	 * be done later */
    274	mutex_init(&c->alloc_sem);
    275	mutex_init(&c->erase_free_sem);
    276	init_waitqueue_head(&c->erase_wait);
    277	init_waitqueue_head(&c->inocache_wq);
    278	spin_lock_init(&c->erase_completion_lock);
    279	spin_lock_init(&c->inocache_lock);
    280
    281	sb->s_op = &jffs2_super_operations;
    282	sb->s_export_op = &jffs2_export_ops;
    283	sb->s_flags = sb->s_flags | SB_NOATIME;
    284	sb->s_xattr = jffs2_xattr_handlers;
    285#ifdef CONFIG_JFFS2_FS_POSIX_ACL
    286	sb->s_flags |= SB_POSIXACL;
    287#endif
    288	return jffs2_do_fill_super(sb, fc);
    289}
    290
    291static int jffs2_get_tree(struct fs_context *fc)
    292{
    293	return get_tree_mtd(fc, jffs2_fill_super);
    294}
    295
    296static void jffs2_free_fc(struct fs_context *fc)
    297{
    298	kfree(fc->s_fs_info);
    299}
    300
    301static const struct fs_context_operations jffs2_context_ops = {
    302	.free		= jffs2_free_fc,
    303	.parse_param	= jffs2_parse_param,
    304	.get_tree	= jffs2_get_tree,
    305	.reconfigure	= jffs2_reconfigure,
    306};
    307
    308static int jffs2_init_fs_context(struct fs_context *fc)
    309{
    310	struct jffs2_sb_info *ctx;
    311
    312	ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
    313	if (!ctx)
    314		return -ENOMEM;
    315
    316	fc->s_fs_info = ctx;
    317	fc->ops = &jffs2_context_ops;
    318	return 0;
    319}
    320
    321static void jffs2_put_super (struct super_block *sb)
    322{
    323	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
    324
    325	jffs2_dbg(2, "%s()\n", __func__);
    326
    327	mutex_lock(&c->alloc_sem);
    328	jffs2_flush_wbuf_pad(c);
    329	mutex_unlock(&c->alloc_sem);
    330
    331	jffs2_sum_exit(c);
    332
    333	jffs2_free_ino_caches(c);
    334	jffs2_free_raw_node_refs(c);
    335	kvfree(c->blocks);
    336	jffs2_flash_cleanup(c);
    337	kfree(c->inocache_list);
    338	jffs2_clear_xattr_subsystem(c);
    339	mtd_sync(c->mtd);
    340	jffs2_dbg(1, "%s(): returning\n", __func__);
    341}
    342
    343static void jffs2_kill_sb(struct super_block *sb)
    344{
    345	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
    346	if (c && !sb_rdonly(sb))
    347		jffs2_stop_garbage_collect_thread(c);
    348	kill_mtd_super(sb);
    349	kfree(c);
    350}
    351
    352static struct file_system_type jffs2_fs_type = {
    353	.owner =	THIS_MODULE,
    354	.name =		"jffs2",
    355	.init_fs_context = jffs2_init_fs_context,
    356	.parameters =	jffs2_fs_parameters,
    357	.kill_sb =	jffs2_kill_sb,
    358};
    359MODULE_ALIAS_FS("jffs2");
    360
    361static int __init init_jffs2_fs(void)
    362{
    363	int ret;
    364
    365	/* Paranoia checks for on-medium structures. If we ask GCC
    366	   to pack them with __attribute__((packed)) then it _also_
    367	   assumes that they're not aligned -- so it emits crappy
    368	   code on some architectures. Ideally we want an attribute
    369	   which means just 'no padding', without the alignment
    370	   thing. But GCC doesn't have that -- we have to just
    371	   hope the structs are the right sizes, instead. */
    372	BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
    373	BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
    374	BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
    375	BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
    376
    377	pr_info("version 2.2."
    378#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
    379	       " (NAND)"
    380#endif
    381#ifdef CONFIG_JFFS2_SUMMARY
    382	       " (SUMMARY) "
    383#endif
    384	       " © 2001-2006 Red Hat, Inc.\n");
    385
    386	jffs2_inode_cachep = kmem_cache_create("jffs2_i",
    387					     sizeof(struct jffs2_inode_info),
    388					     0, (SLAB_RECLAIM_ACCOUNT|
    389						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
    390					     jffs2_i_init_once);
    391	if (!jffs2_inode_cachep) {
    392		pr_err("error: Failed to initialise inode cache\n");
    393		return -ENOMEM;
    394	}
    395	ret = jffs2_compressors_init();
    396	if (ret) {
    397		pr_err("error: Failed to initialise compressors\n");
    398		goto out;
    399	}
    400	ret = jffs2_create_slab_caches();
    401	if (ret) {
    402		pr_err("error: Failed to initialise slab caches\n");
    403		goto out_compressors;
    404	}
    405	ret = register_filesystem(&jffs2_fs_type);
    406	if (ret) {
    407		pr_err("error: Failed to register filesystem\n");
    408		goto out_slab;
    409	}
    410	return 0;
    411
    412 out_slab:
    413	jffs2_destroy_slab_caches();
    414 out_compressors:
    415	jffs2_compressors_exit();
    416 out:
    417	kmem_cache_destroy(jffs2_inode_cachep);
    418	return ret;
    419}
    420
    421static void __exit exit_jffs2_fs(void)
    422{
    423	unregister_filesystem(&jffs2_fs_type);
    424	jffs2_destroy_slab_caches();
    425	jffs2_compressors_exit();
    426
    427	/*
    428	 * Make sure all delayed rcu free inodes are flushed before we
    429	 * destroy cache.
    430	 */
    431	rcu_barrier();
    432	kmem_cache_destroy(jffs2_inode_cachep);
    433}
    434
    435module_init(init_jffs2_fs);
    436module_exit(exit_jffs2_fs);
    437
    438MODULE_DESCRIPTION("The Journalling Flash File System, v2");
    439MODULE_AUTHOR("Red Hat, Inc.");
    440MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
    441		       // the sake of this tag. It's Free Software.