[PATCH] BLOCK: Move the loop device ioctl compat stuff to the loop driver [try #6]
Move the loop device ioctl compat stuff from fs/compat_ioctl.c to the loop
driver so that the loop header file doesn't need to be included.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 68b0471..d6bb8da 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -66,6 +66,7 @@
#include <linux/swap.h>
#include <linux/slab.h>
#include <linux/loop.h>
+#include <linux/compat.h>
#include <linux/suspend.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h> /* for invalidate_bdev() */
@@ -1165,6 +1166,162 @@
return err;
}
+#ifdef CONFIG_COMPAT
+struct compat_loop_info {
+ compat_int_t lo_number; /* ioctl r/o */
+ compat_dev_t lo_device; /* ioctl r/o */
+ compat_ulong_t lo_inode; /* ioctl r/o */
+ compat_dev_t lo_rdevice; /* ioctl r/o */
+ compat_int_t lo_offset;
+ compat_int_t lo_encrypt_type;
+ compat_int_t lo_encrypt_key_size; /* ioctl w/o */
+ compat_int_t lo_flags; /* ioctl r/o */
+ char lo_name[LO_NAME_SIZE];
+ unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
+ compat_ulong_t lo_init[2];
+ char reserved[4];
+};
+
+/*
+ * Transfer 32-bit compatibility structure in userspace to 64-bit loop info
+ * - noinlined to reduce stack space usage in main part of driver
+ */
+static noinline int
+loop_info64_from_compat(const struct compat_loop_info *arg,
+ struct loop_info64 *info64)
+{
+ struct compat_loop_info info;
+
+ if (copy_from_user(&info, arg, sizeof(info)))
+ return -EFAULT;
+
+ memset(info64, 0, sizeof(*info64));
+ info64->lo_number = info.lo_number;
+ info64->lo_device = info.lo_device;
+ info64->lo_inode = info.lo_inode;
+ info64->lo_rdevice = info.lo_rdevice;
+ info64->lo_offset = info.lo_offset;
+ info64->lo_sizelimit = 0;
+ info64->lo_encrypt_type = info.lo_encrypt_type;
+ info64->lo_encrypt_key_size = info.lo_encrypt_key_size;
+ info64->lo_flags = info.lo_flags;
+ info64->lo_init[0] = info.lo_init[0];
+ info64->lo_init[1] = info.lo_init[1];
+ if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI)
+ memcpy(info64->lo_crypt_name, info.lo_name, LO_NAME_SIZE);
+ else
+ memcpy(info64->lo_file_name, info.lo_name, LO_NAME_SIZE);
+ memcpy(info64->lo_encrypt_key, info.lo_encrypt_key, LO_KEY_SIZE);
+ return 0;
+}
+
+/*
+ * Transfer 64-bit loop info to 32-bit compatibility structure in userspace
+ * - noinlined to reduce stack space usage in main part of driver
+ */
+static noinline int
+loop_info64_to_compat(const struct loop_info64 *info64,
+ struct compat_loop_info __user *arg)
+{
+ struct compat_loop_info info;
+
+ memset(&info, 0, sizeof(info));
+ info.lo_number = info64->lo_number;
+ info.lo_device = info64->lo_device;
+ info.lo_inode = info64->lo_inode;
+ info.lo_rdevice = info64->lo_rdevice;
+ info.lo_offset = info64->lo_offset;
+ info.lo_encrypt_type = info64->lo_encrypt_type;
+ info.lo_encrypt_key_size = info64->lo_encrypt_key_size;
+ info.lo_flags = info64->lo_flags;
+ info.lo_init[0] = info64->lo_init[0];
+ info.lo_init[1] = info64->lo_init[1];
+ if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI)
+ memcpy(info.lo_name, info64->lo_crypt_name, LO_NAME_SIZE);
+ else
+ memcpy(info.lo_name, info64->lo_file_name, LO_NAME_SIZE);
+ memcpy(info.lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE);
+
+ /* error in case values were truncated */
+ if (info.lo_device != info64->lo_device ||
+ info.lo_rdevice != info64->lo_rdevice ||
+ info.lo_inode != info64->lo_inode ||
+ info.lo_offset != info64->lo_offset ||
+ info.lo_init[0] != info64->lo_init[0] ||
+ info.lo_init[1] != info64->lo_init[1])
+ return -EOVERFLOW;
+
+ if (copy_to_user(arg, &info, sizeof(info)))
+ return -EFAULT;
+ return 0;
+}
+
+static int
+loop_set_status_compat(struct loop_device *lo,
+ const struct compat_loop_info __user *arg)
+{
+ struct loop_info64 info64;
+ int ret;
+
+ ret = loop_info64_from_compat(arg, &info64);
+ if (ret < 0)
+ return ret;
+ return loop_set_status(lo, &info64);
+}
+
+static int
+loop_get_status_compat(struct loop_device *lo,
+ struct compat_loop_info __user *arg)
+{
+ struct loop_info64 info64;
+ int err = 0;
+
+ if (!arg)
+ err = -EINVAL;
+ if (!err)
+ err = loop_get_status(lo, &info64);
+ if (!err)
+ err = loop_info64_to_compat(&info64, arg);
+ return err;
+}
+
+static long lo_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
+ int err;
+
+ lock_kernel();
+ switch(cmd) {
+ case LOOP_SET_STATUS:
+ mutex_lock(&lo->lo_ctl_mutex);
+ err = loop_set_status_compat(
+ lo, (const struct compat_loop_info __user *) arg);
+ mutex_unlock(&lo->lo_ctl_mutex);
+ break;
+ case LOOP_GET_STATUS:
+ mutex_lock(&lo->lo_ctl_mutex);
+ err = loop_get_status_compat(
+ lo, (struct compat_loop_info __user *) arg);
+ mutex_unlock(&lo->lo_ctl_mutex);
+ break;
+ case LOOP_CLR_FD:
+ case LOOP_GET_STATUS64:
+ case LOOP_SET_STATUS64:
+ arg = (unsigned long) compat_ptr(arg);
+ case LOOP_SET_FD:
+ case LOOP_CHANGE_FD:
+ err = lo_ioctl(inode, file, cmd, arg);
+ break;
+ default:
+ err = -ENOIOCTLCMD;
+ break;
+ }
+ unlock_kernel();
+ return err;
+}
+#endif
+
static int lo_open(struct inode *inode, struct file *file)
{
struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
@@ -1192,6 +1349,9 @@
.open = lo_open,
.release = lo_release,
.ioctl = lo_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = lo_compat_ioctl,
+#endif
};
/*
