fs/ext2/ioctl.c

Source file repositories/reference/linux-study-clean/fs/ext2/ioctl.c

File Facts

System
Linux kernel
Corpus path
fs/ext2/ioctl.c
Extension
.c
Size
3824 bytes
Lines
160
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

if (get_user(generation, (int __user *) arg)) {
			ret = -EFAULT;
			goto setversion_out;
		}

		inode_lock(inode);
		inode_set_ctime_current(inode);
		inode->i_generation = generation;
		inode_unlock(inode);

		mark_inode_dirty(inode);
setversion_out:
		mnt_drop_write_file(filp);
		return ret;
	}
	case EXT2_IOC_GETRSVSZ:
		if (test_opt(inode->i_sb, RESERVATION)
			&& S_ISREG(inode->i_mode)
			&& ei->i_block_alloc_info) {
			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
			return put_user(rsv_window_size, (int __user *)arg);
		}
		return -ENOTTY;
	case EXT2_IOC_SETRSVSZ: {

		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
			return -ENOTTY;

		if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
			return -EACCES;

		if (get_user(rsv_window_size, (int __user *)arg))
			return -EFAULT;

		ret = mnt_want_write_file(filp);
		if (ret)
			return ret;

		if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
			rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;

		/*
		 * need to allocate reservation structure for this inode
		 * before set the window size
		 */
		/*
		 * XXX What lock should protect the rsv_goal_size?
		 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
		 */
		mutex_lock(&ei->truncate_mutex);
		if (!ei->i_block_alloc_info)
			ext2_init_block_alloc_info(inode);

		if (ei->i_block_alloc_info){
			struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
			rsv->rsv_goal_size = rsv_window_size;
		} else {
			ret = -ENOMEM;
		}

		mutex_unlock(&ei->truncate_mutex);
		mnt_drop_write_file(filp);
		return ret;
	}
	default:
		return -ENOTTY;
	}
}

#ifdef CONFIG_COMPAT
long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	/* These are just misnamed, they actually get/put from/to user an int */
	switch (cmd) {
	case EXT2_IOC32_GETVERSION:
		cmd = EXT2_IOC_GETVERSION;
		break;
	case EXT2_IOC32_SETVERSION:
		cmd = EXT2_IOC_SETVERSION;
		break;
	default:
		return -ENOIOCTLCMD;
	}
	return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
}
#endif

Annotation

Implementation Notes