inode-v23.c

mtd最新cvs jffs文件系统分析

	result = 0;
jffs_mkdir_end:
	D3(printk (KERN_NOTICE "mkdir(): up biglock\n"));
	up(&c->fmc->biglock);
	return result;
} /* jffs_mkdir()  */


/* Remove a directory.  */
static int
jffs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct jffs_control *c = (struct jffs_control *)dir->i_sb->u.generic_sbp;
	int ret;
	D3(printk("***jffs_rmdir()\n"));
	D3(printk (KERN_NOTICE "rmdir(): down biglock\n"));
	down(&c->fmc->biglock);
	ret = jffs_remove(dir, dentry, S_IFDIR);
	D3(printk (KERN_NOTICE "rmdir(): up biglock\n"));
	up(&c->fmc->biglock);
	return ret;
}


/* Remove any kind of file except for directories.  */
static int
jffs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct jffs_control *c = (struct jffs_control *)dir->i_sb->u.generic_sbp;
	int ret; 

	D3(printk("***jffs_unlink()\n"));
	D3(printk (KERN_NOTICE "unlink(): down biglock\n"));
	down(&c->fmc->biglock);
	ret = jffs_remove(dir, dentry, 0);
	D3(printk (KERN_NOTICE "unlink(): up biglock\n"));
	up(&c->fmc->biglock);
	return ret;
}


/* Remove a JFFS entry, i.e. plain files, directories, etc.  Here we
   shouldn't test for free space on the device.  */
static int
jffs_remove(struct inode *dir, struct dentry *dentry, int type)
{
	struct jffs_raw_inode raw_inode;
	struct jffs_control *c;
	struct jffs_file *dir_f; /* The file-to-remove's parent.  */
	struct jffs_file *del_f; /* The file to remove.  */
	struct jffs_node *del_node;
	struct inode *inode = 0;
	int result = 0;

	D1({
		int len = dentry->d_name.len;
		const char *name = dentry->d_name.name;
		char *_name = (char *) kmalloc(len + 1, GFP_KERNEL);
		memcpy(_name, name, len);
		_name[len] = '\0';
		printk("***jffs_remove(): file = \"%s\", ino = %ld\n", _name, dentry->d_inode->i_ino);
		kfree(_name);
	});

	dir_f = (struct jffs_file *) dir->u.generic_ip;
	c = dir_f->c;

	result = -ENOENT;
	if (!(del_f = jffs_find_child(dir_f, dentry->d_name.name,
				      dentry->d_name.len))) {
		D(printk("jffs_remove(): jffs_find_child() failed.\n"));
		goto jffs_remove_end;
	}

	if (S_ISDIR(type)) {
		struct jffs_file *child = del_f->children;
		while(child) {
			if( !child->deleted ) {
				result = -ENOTEMPTY;
				goto jffs_remove_end;
			}
			child = child->sibling_next;
		}
	}            
	else if (S_ISDIR(del_f->mode)) {
		D(printk("jffs_remove(): node is a directory "
			 "but it shouldn't be.\n"));
		result = -EPERM;
		goto jffs_remove_end;
	}

	inode = dentry->d_inode;

	result = -EIO;
	if (del_f->ino != inode->i_ino)
		goto jffs_remove_end;

	if (!inode->i_nlink) {
		printk("Deleting nonexistent file inode: %lu, nlink: %d\n",
		       inode->i_ino, inode->i_nlink);
		inode->i_nlink=1;
	}

	/* Create a node for the deletion.  */
	result = -ENOMEM;
	if (!(del_node = jffs_alloc_node())) {
		D(printk("jffs_remove(): Allocation failed!\n"));
		goto jffs_remove_end;
	}
	del_node->data_offset = 0;
	del_node->removed_size = 0;

	/* Initialize the raw inode.  */
	raw_inode.magic = JFFS_MAGIC_BITMASK;
	raw_inode.ino = del_f->ino;
	raw_inode.pino = del_f->pino;
/*  	raw_inode.version = del_f->highest_version + 1; */
	raw_inode.mode = del_f->mode;
	raw_inode.uid = current->fsuid;
	raw_inode.gid = current->fsgid;
	raw_inode.atime = CURRENT_TIME;
	raw_inode.mtime = del_f->mtime;
	raw_inode.ctime = raw_inode.atime;
	raw_inode.offset = 0;
	raw_inode.dsize = 0;
	raw_inode.rsize = 0;
	raw_inode.nsize = 0;
	raw_inode.nlink = del_f->nlink;
	raw_inode.spare = 0;
	raw_inode.rename = 0;
	raw_inode.deleted = 1;

	/* Write the new node to the flash memory.  */
	if (jffs_write_node(c, del_node, &raw_inode, 0, 0, 1, del_f) < 0) {
		jffs_free_node(del_node);
		result = -EIO;
		goto jffs_remove_end;
	}

	/* Update the file.  This operation will make the file disappear
	   from the in-memory file system structures.  */
	jffs_insert_node(c, del_f, &raw_inode, 0, del_node);

	dir->i_version = ++event;
	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
	mark_inode_dirty(dir);
	inode->i_nlink--;
	inode->i_ctime = dir->i_ctime;
	mark_inode_dirty(inode);

	d_delete(dentry);	/* This also frees the inode */

	result = 0;
jffs_remove_end:
	return result;
} /* jffs_remove()  */


static int
jffs_mknod(struct inode *dir, struct dentry *dentry, int mode, int rdev)
{
	struct jffs_raw_inode raw_inode;
	struct jffs_file *dir_f;
	struct jffs_node *node = 0;
	struct jffs_control *c;
	struct inode *inode;
	int result = 0;
	kdev_t dev = to_kdev_t(rdev);
	int err;

	D1(printk("***jffs_mknod()\n"));

	dir_f = (struct jffs_file *)dir->u.generic_ip;
	c = dir_f->c;

	D3(printk (KERN_NOTICE "mknod(): down biglock\n"));
	down(&c->fmc->biglock);

	/* Create and initialize a new node.  */
	if (!(node = jffs_alloc_node())) {
		D(printk("jffs_mknod(): Allocation failed!\n"));
		result = -ENOMEM;
		goto jffs_mknod_err;
	}
	node->data_offset = 0;
	node->removed_size = 0;

	/* Initialize the raw inode.  */
	raw_inode.magic = JFFS_MAGIC_BITMASK;
	raw_inode.ino = c->next_ino++;
	raw_inode.pino = dir_f->ino;
	raw_inode.version = 1;
	raw_inode.mode = mode;
	raw_inode.uid = current->fsuid;
	raw_inode.gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
	/*	raw_inode.gid = current->fsgid; */
	raw_inode.atime = CURRENT_TIME;
	raw_inode.mtime = raw_inode.atime;
	raw_inode.ctime = raw_inode.atime;
	raw_inode.offset = 0;
	raw_inode.dsize = sizeof(kdev_t);
	raw_inode.rsize = 0;
	raw_inode.nsize = dentry->d_name.len;
	raw_inode.nlink = 1;
	raw_inode.spare = 0;
	raw_inode.rename = 0;
	raw_inode.deleted = 0;

	/* Write the new node to the flash.  */
	if ((err = jffs_write_node(c, node, &raw_inode, dentry->d_name.name,
				   (unsigned char *)&dev, 0, NULL)) < 0) {
		D(printk("jffs_mknod(): jffs_write_node() failed.\n"));
		result = err;
		goto jffs_mknod_err;
	}

	/* Insert the new node into the file system.  */
	if ((err = jffs_insert_node(c, 0, &raw_inode, dentry->d_name.name,
				    node)) < 0) {
		result = err;
		goto jffs_mknod_end;
	}

	inode = jffs_new_inode(dir, &raw_inode, &err);
	if (inode == NULL) {
		result = err;
		goto jffs_mknod_end;
	}

	init_special_inode(inode, mode, rdev);

	d_instantiate(dentry, inode);

	goto jffs_mknod_end;

jffs_mknod_err:
	if (node) {
		jffs_free_node(node);
	}

jffs_mknod_end:
	D3(printk (KERN_NOTICE "mknod(): up biglock\n"));
	up(&c->fmc->biglock);
	return result;
} /* jffs_mknod()  */


static int
jffs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
	struct jffs_raw_inode raw_inode;
	struct jffs_control *c;
	struct jffs_file *dir_f;
	struct jffs_node *node;
	struct inode *inode;

	int symname_len = strlen(symname);
	int err;

	D1({
		int len = dentry->d_name.len; 
		char *_name = (char *)kmalloc(len + 1, GFP_KERNEL);
		char *_symname = (char *)kmalloc(symname_len + 1, GFP_KERNEL);
		memcpy(_name, dentry->d_name.name, len);
		_name[len] = '\0';
		memcpy(_symname, symname, symname_len);
		_symname[symname_len] = '\0';
		printk("***jffs_symlink(): dir = 0x%p, "
		       "dentry->dname.name = \"%s\", "
		       "symname = \"%s\"\n", dir, _name, _symname);
		kfree(_name);
		kfree(_symname);
	});

	dir_f = (struct jffs_file *)dir->u.generic_ip;
	ASSERT(if (!dir_f) {
		printk(KERN_ERR "jffs_symlink(): No reference to a "
		       "jffs_file struct in inode.\n");
		return -EIO;
	});

	c = dir_f->c;

	/* Create a node and initialize it as much as needed.  */
	if (!(node = jffs_alloc_node())) {
		D(printk("jffs_symlink(): Allocation failed: node = NULL\n"));
		return -ENOMEM;
	}
	D3(printk (KERN_NOTICE "symlink(): down biglock\n"));
	down(&c->fmc->biglock);

	node->data_offset = 0;
	node->removed_size = 0;

	/* Initialize the raw inode.  */
	raw_inode.magic = JFFS_MAGIC_BITMASK;
	raw_inode.ino = c->next_ino++;
	raw_inode.pino = dir_f->ino;
	raw_inode.version = 1;
	raw_inode.mode = S_IFLNK | S_IRWXUGO;
	raw_inode.uid = current->fsuid;
	raw_inode.gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
	raw_inode.atime = CURRENT_TIME;
	raw_inode.mtime = raw_inode.atime;
	raw_inode.ctime = raw_inode.atime;
	raw_inode.offset = 0;
	raw_inode.dsize = symname_len;
	raw_inode.rsize = 0;
	raw_inode.nsize = dentry->d_name.len;
	raw_inode.nlink = 1;
	raw_inode.spare = 0;
	raw_inode.rename = 0;
	raw_inode.deleted = 0;

	/* Write the new node to the flash.  */
	if ((err = jffs_write_node(c, node, &raw_inode, dentry->d_name.name,
				   (const unsigned char *)symname, 0, NULL)) < 0) {
		D(printk("jffs_symlink(): jffs_write_node() failed.\n"));
		jffs_free_node(node);
		goto jffs_symlink_end;
	}

	/* Insert the new node into the file system.  */
	if ((err = jffs_insert_node(c, 0, &raw_inode, dentry->d_name.name,
				    node)) < 0) {
		goto jffs_symlink_end;
	}

	inode = jffs_new_inode(dir, &raw_inode, &err);
	if (inode == NULL) {
		goto jffs_symlink_end;
	}
	err = 0;
	inode->i_op = &page_symlink_inode_operations;
	inode->i_mapping->a_ops = &jffs_address_operations;

	d_instantiate(dentry, inode);
 jffs_symlink_end:
	D3(printk (KERN_NOTICE "symlink(): up biglock\n"));
	up(&c->fmc->biglock);
	return err;
} /* jffs_symlink()  */


/* Create an inode inside a JFFS directory (dir) and return it.
 *
 * By the time this is called, we already have created
 * the directory cache entry for the new file, but it
 * is so far negative - it has no inode.
 *
 * If the create succeeds, we fill in the inode information
 * with d_instantiate().
 */
static int
jffs_create(struct inode *dir, struct dentry *dentry, int mode)
{
	struct jffs_raw_inode raw_inode;
	struct jffs_control *c;
	struct jffs_node *node;
	struct jffs_file *dir_f; /* JFFS representation of the directory.  */
	struct inode *inode;
	int err;

	D1({
		int len = dentry->d_name.len;
		char *s = (char *)kmalloc(len + 1, GFP_KERNEL);
		memcpy(s, dentry->d_name.name, len);
		s[len] = '\0';
		printk("jffs_create(): dir: 0x%p, name: \"%s\"\n", dir, s);
		kfree(s);
	});

	dir_f = (struct jffs_file *)dir->u.generic_ip;
	ASSERT(if (!dir_f) {
		printk(KERN_ERR "jffs_create(): No reference to a "
		       "jffs_file struct in inode.\n");
		return -EIO;
	});

	c = dir_f->c;

	/* Create a node and initialize as much as needed.  */
	if (!(node = jffs_alloc_node())) {
		D(printk("jffs_create(): Allocation failed: node == 0\n"));
		return -ENOMEM;
	}
	D3(printk (KERN_NOTICE "create(): down biglock\n"));
	down(&c->fmc->biglock);

	node->data_offset = 0;
	node->removed_size = 0;

	/* Initialize the raw inode.  */
	raw_inode.magic = JFFS_MAGIC_BITMASK;
	raw_inode.ino = c->next_ino++;
	raw_inode.pino = dir_f->ino;
	raw_inode.version = 1;
	raw_inode.mode = mode;
	raw_inode.uid = current->fsuid;
	raw_inode.gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
	raw_inode.atime = CURRENT_TIME;
	raw_inode.mtime = raw_inode.atime;
	raw_inode.ctime = raw_inode.atime;
	raw_inode.offset = 0;
	raw_inode.dsize = 0;
	raw_inode.rsize = 0;
	raw_inode.nsize = dentry->d_name.len;
	raw_inode.nlink = 1;
	raw_inode.spare = 0;
	raw_inode.rename = 0;
	raw_inode.deleted = 0;

	/* Write the new node to the flash.  */
	if ((err = jffs_write_node(c, node, &raw_inode,
				   dentry->d_name.name, 0, 0, NULL)) < 0) {
		D(printk("jffs_create(): jffs_write_node() failed.\n"));
		jffs_free_node(node);
		goto jffs_create_end;
	}

	/* Insert the new node into the file system.  */
	if ((err = jffs_insert_node(c, 0, &raw_inode, dentry->d_name.name,
				    node)) < 0) {
		goto jffs_create_end;
	}

	/* Initialize an inode.  */
	inode = jffs_new_inode(dir, &raw_inode, &err);
	if (inode == NULL) {
		goto jffs_create_end;
	}
	err = 0;
	inode->i_op = &jffs_file_inode_operations;
	inode->i_fop = &jffs_file_operations;
	inode->i_mapping->a_ops = &jffs_address_operations;
	inode->i_mapping->nrpages = 0;

	d_instantiate(dentry, inode);
 jffs_create_end:
	D3(printk (KERN_NOTICE "create(): up biglock\n"));
	up(&c->fmc->biglock);
	return err;
} /* jffs_create()  */