442 lines
10 KiB
C
442 lines
10 KiB
C
/*
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* JFFS2 -- Journalling Flash File System, Version 2.
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*
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* Copyright © 2001-2007 Red Hat, Inc.
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*
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* Created by David Woodhouse <dwmw2@infradead.org>
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*
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* For licensing information, see the file 'LICENCE' in this directory.
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/fs.h>
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#include <linux/err.h>
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#include <linux/mount.h>
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#include <linux/parser.h>
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#include <linux/jffs2.h>
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#include <linux/pagemap.h>
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#include <linux/mtd/super.h>
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#include <linux/ctype.h>
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#include <linux/namei.h>
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#include <linux/seq_file.h>
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#include <linux/exportfs.h>
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#include "compr.h"
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#include "nodelist.h"
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static void jffs2_put_super(struct super_block *);
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static struct kmem_cache *jffs2_inode_cachep;
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static struct inode *jffs2_alloc_inode(struct super_block *sb)
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{
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struct jffs2_inode_info *f;
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f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
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if (!f)
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return NULL;
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return &f->vfs_inode;
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}
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static void jffs2_i_callback(struct rcu_head *head)
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{
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struct inode *inode = container_of(head, struct inode, i_rcu);
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struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
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kfree(f->target);
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kmem_cache_free(jffs2_inode_cachep, f);
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}
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static void jffs2_destroy_inode(struct inode *inode)
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{
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call_rcu(&inode->i_rcu, jffs2_i_callback);
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}
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static void jffs2_i_init_once(void *foo)
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{
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struct jffs2_inode_info *f = foo;
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mutex_init(&f->sem);
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inode_init_once(&f->vfs_inode);
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}
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static const char *jffs2_compr_name(unsigned int compr)
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{
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switch (compr) {
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case JFFS2_COMPR_MODE_NONE:
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return "none";
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#ifdef CONFIG_JFFS2_LZO
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case JFFS2_COMPR_MODE_FORCELZO:
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return "lzo";
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#endif
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#ifdef CONFIG_JFFS2_ZLIB
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case JFFS2_COMPR_MODE_FORCEZLIB:
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return "zlib";
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#endif
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default:
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/* should never happen; programmer error */
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WARN_ON(1);
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return "";
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}
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}
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static int jffs2_show_options(struct seq_file *s, struct dentry *root)
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{
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struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
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struct jffs2_mount_opts *opts = &c->mount_opts;
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if (opts->override_compr)
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seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
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if (opts->rp_size)
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seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
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return 0;
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}
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static int jffs2_sync_fs(struct super_block *sb, int wait)
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{
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struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
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#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
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if (jffs2_is_writebuffered(c))
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cancel_delayed_work_sync(&c->wbuf_dwork);
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#endif
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mutex_lock(&c->alloc_sem);
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jffs2_flush_wbuf_pad(c);
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mutex_unlock(&c->alloc_sem);
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return 0;
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}
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static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
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uint32_t generation)
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{
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/* We don't care about i_generation. We'll destroy the flash
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before we start re-using inode numbers anyway. And even
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if that wasn't true, we'd have other problems...*/
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return jffs2_iget(sb, ino);
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}
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static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
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int fh_len, int fh_type)
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{
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return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
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jffs2_nfs_get_inode);
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}
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static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
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int fh_len, int fh_type)
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{
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return generic_fh_to_parent(sb, fid, fh_len, fh_type,
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jffs2_nfs_get_inode);
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}
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static struct dentry *jffs2_get_parent(struct dentry *child)
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{
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struct jffs2_inode_info *f;
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uint32_t pino;
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BUG_ON(!d_is_dir(child));
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f = JFFS2_INODE_INFO(d_inode(child));
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pino = f->inocache->pino_nlink;
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JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
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f->inocache->ino, pino);
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return d_obtain_alias(jffs2_iget(child->d_sb, pino));
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}
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static const struct export_operations jffs2_export_ops = {
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.get_parent = jffs2_get_parent,
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.fh_to_dentry = jffs2_fh_to_dentry,
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.fh_to_parent = jffs2_fh_to_parent,
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};
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/*
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* JFFS2 mount options.
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*
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* Opt_override_compr: override default compressor
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* Opt_rp_size: size of reserved pool in KiB
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* Opt_err: just end of array marker
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*/
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enum {
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Opt_override_compr,
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Opt_rp_size,
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Opt_err,
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};
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static const match_table_t tokens = {
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{Opt_override_compr, "compr=%s"},
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{Opt_rp_size, "rp_size=%u"},
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{Opt_err, NULL},
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};
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static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
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{
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substring_t args[MAX_OPT_ARGS];
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char *p, *name;
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unsigned int opt;
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if (!data)
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return 0;
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while ((p = strsep(&data, ","))) {
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int token;
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if (!*p)
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continue;
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token = match_token(p, tokens, args);
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switch (token) {
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case Opt_override_compr:
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name = match_strdup(&args[0]);
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if (!name)
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return -ENOMEM;
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if (!strcmp(name, "none"))
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c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
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#ifdef CONFIG_JFFS2_LZO
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else if (!strcmp(name, "lzo"))
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c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
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#endif
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#ifdef CONFIG_JFFS2_ZLIB
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else if (!strcmp(name, "zlib"))
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c->mount_opts.compr =
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JFFS2_COMPR_MODE_FORCEZLIB;
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#endif
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else {
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pr_err("Error: unknown compressor \"%s\"\n",
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name);
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kfree(name);
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return -EINVAL;
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}
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kfree(name);
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c->mount_opts.override_compr = true;
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break;
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case Opt_rp_size:
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if (match_int(&args[0], &opt))
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return -EINVAL;
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opt *= 1024;
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if (opt > c->mtd->size) {
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pr_warn("Too large reserve pool specified, max "
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"is %llu KB\n", c->mtd->size / 1024);
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return -EINVAL;
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}
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c->mount_opts.rp_size = opt;
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break;
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default:
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pr_err("Error: unrecognized mount option '%s' or missing value\n",
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p);
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return -EINVAL;
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}
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}
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return 0;
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}
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static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
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{
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struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
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int err;
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sync_filesystem(sb);
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err = jffs2_parse_options(c, data);
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if (err)
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return -EINVAL;
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return jffs2_do_remount_fs(sb, flags, data);
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}
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static const struct super_operations jffs2_super_operations =
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{
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.alloc_inode = jffs2_alloc_inode,
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.destroy_inode =jffs2_destroy_inode,
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.put_super = jffs2_put_super,
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.statfs = jffs2_statfs,
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.remount_fs = jffs2_remount_fs,
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.evict_inode = jffs2_evict_inode,
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.dirty_inode = jffs2_dirty_inode,
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.show_options = jffs2_show_options,
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.sync_fs = jffs2_sync_fs,
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};
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/*
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* fill in the superblock
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*/
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static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
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{
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struct jffs2_sb_info *c;
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int ret;
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jffs2_dbg(1, "jffs2_get_sb_mtd():"
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" New superblock for device %d (\"%s\")\n",
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sb->s_mtd->index, sb->s_mtd->name);
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c = kzalloc(sizeof(*c), GFP_KERNEL);
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if (!c)
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return -ENOMEM;
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c->mtd = sb->s_mtd;
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c->os_priv = sb;
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sb->s_fs_info = c;
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ret = jffs2_parse_options(c, data);
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if (ret)
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return -EINVAL;
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/* Initialize JFFS2 superblock locks, the further initialization will
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* be done later */
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mutex_init(&c->alloc_sem);
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mutex_init(&c->erase_free_sem);
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init_waitqueue_head(&c->erase_wait);
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init_waitqueue_head(&c->inocache_wq);
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spin_lock_init(&c->erase_completion_lock);
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spin_lock_init(&c->inocache_lock);
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sb->s_op = &jffs2_super_operations;
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sb->s_export_op = &jffs2_export_ops;
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sb->s_flags = sb->s_flags | MS_NOATIME;
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sb->s_xattr = jffs2_xattr_handlers;
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#ifdef CONFIG_JFFS2_FS_POSIX_ACL
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sb->s_flags |= MS_POSIXACL;
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#endif
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ret = jffs2_do_fill_super(sb, data, silent);
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return ret;
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}
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static struct dentry *jffs2_mount(struct file_system_type *fs_type,
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int flags, const char *dev_name,
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void *data)
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{
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return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
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}
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static void jffs2_put_super (struct super_block *sb)
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{
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struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
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jffs2_dbg(2, "%s()\n", __func__);
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mutex_lock(&c->alloc_sem);
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jffs2_flush_wbuf_pad(c);
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mutex_unlock(&c->alloc_sem);
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jffs2_sum_exit(c);
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jffs2_free_ino_caches(c);
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jffs2_free_raw_node_refs(c);
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kvfree(c->blocks);
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jffs2_flash_cleanup(c);
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kfree(c->inocache_list);
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jffs2_clear_xattr_subsystem(c);
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mtd_sync(c->mtd);
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jffs2_dbg(1, "%s(): returning\n", __func__);
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}
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static void jffs2_kill_sb(struct super_block *sb)
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{
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struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
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if (c && !(sb->s_flags & MS_RDONLY))
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jffs2_stop_garbage_collect_thread(c);
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kill_mtd_super(sb);
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kfree(c);
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}
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static struct file_system_type jffs2_fs_type = {
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.owner = THIS_MODULE,
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.name = "jffs2",
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.mount = jffs2_mount,
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.kill_sb = jffs2_kill_sb,
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};
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MODULE_ALIAS_FS("jffs2");
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static int __init init_jffs2_fs(void)
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{
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int ret;
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/* Paranoia checks for on-medium structures. If we ask GCC
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to pack them with __attribute__((packed)) then it _also_
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assumes that they're not aligned -- so it emits crappy
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code on some architectures. Ideally we want an attribute
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which means just 'no padding', without the alignment
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thing. But GCC doesn't have that -- we have to just
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hope the structs are the right sizes, instead. */
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BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
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BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
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BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
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BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
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pr_info("version 2.2."
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#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
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" (NAND)"
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#endif
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#ifdef CONFIG_JFFS2_SUMMARY
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" (SUMMARY) "
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#endif
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" © 2001-2006 Red Hat, Inc.\n");
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jffs2_inode_cachep = kmem_cache_create("jffs2_i",
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sizeof(struct jffs2_inode_info),
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0, (SLAB_RECLAIM_ACCOUNT|
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SLAB_MEM_SPREAD|SLAB_ACCOUNT),
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jffs2_i_init_once);
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if (!jffs2_inode_cachep) {
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pr_err("error: Failed to initialise inode cache\n");
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return -ENOMEM;
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}
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ret = jffs2_compressors_init();
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if (ret) {
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pr_err("error: Failed to initialise compressors\n");
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goto out;
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}
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ret = jffs2_create_slab_caches();
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if (ret) {
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pr_err("error: Failed to initialise slab caches\n");
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goto out_compressors;
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}
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ret = register_filesystem(&jffs2_fs_type);
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if (ret) {
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pr_err("error: Failed to register filesystem\n");
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goto out_slab;
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}
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return 0;
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out_slab:
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jffs2_destroy_slab_caches();
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out_compressors:
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jffs2_compressors_exit();
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out:
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kmem_cache_destroy(jffs2_inode_cachep);
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return ret;
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}
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static void __exit exit_jffs2_fs(void)
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{
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unregister_filesystem(&jffs2_fs_type);
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jffs2_destroy_slab_caches();
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jffs2_compressors_exit();
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/*
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* Make sure all delayed rcu free inodes are flushed before we
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* destroy cache.
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*/
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rcu_barrier();
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kmem_cache_destroy(jffs2_inode_cachep);
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}
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module_init(init_jffs2_fs);
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module_exit(exit_jffs2_fs);
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MODULE_DESCRIPTION("The Journalling Flash File System, v2");
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MODULE_AUTHOR("Red Hat, Inc.");
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MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
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// the sake of this tag. It's Free Software.
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