[PATCH v4 06/10] loop: Factor out configuring loop from status

[Martijn Coenen]

Factor out this code into a separate function, so it can be reused by
other code more easily.

Signed-off-by: Martijn Coenen <m...@android.com>
---
 drivers/block/loop.c | 117 +++++++++++++++++++++++++------------------
 1 file changed, 67 insertions(+), 50 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 32755e874326..4a36a3f47503 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1266,13 +1266,78 @@ static int loop_clr_fd(struct loop_device *lo)
        return __loop_clr_fd(lo, false);
 }
 
+/**
+ * loop_set_status_from_info - configure device from loop_info
+ * @lo: struct loop_device to configure
+ * @info: struct loop_info64 to configure the device with
+ *
+ * Configures the loop device parameters according to the passed
+ * in loop_info64 configuration.
+ */
 static int
-loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
+loop_set_status_from_info(struct loop_device *lo,
+                         const struct loop_info64 *info)
 {
        int err;
        struct loop_func_table *xfer;
        kuid_t uid = current_uid();
+
+       if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE)
+               return -EINVAL;
+
+       err = loop_release_xfer(lo);
+       if (err)
+               return err;
+
+       if (info->lo_encrypt_type) {
+               unsigned int type = info->lo_encrypt_type;
+
+               if (type >= MAX_LO_CRYPT)
+                       return -EINVAL;
+               xfer = xfer_funcs[type];
+               if (xfer == NULL)
+                       return -EINVAL;
+       } else
+               xfer = NULL;
+
+       err = loop_init_xfer(lo, xfer, info);
+       if (err)
+               return err;
+
+       lo->lo_offset = info->lo_offset;
+       lo->lo_sizelimit = info->lo_sizelimit;
+       memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
+       memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE);
+       lo->lo_file_name[LO_NAME_SIZE-1] = 0;
+       lo->lo_crypt_name[LO_NAME_SIZE-1] = 0;
+
+       if (!xfer)
+               xfer = &none_funcs;
+       lo->transfer = xfer->transfer;
+       lo->ioctl = xfer->ioctl;
+
+       if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) !=
+            (info->lo_flags & LO_FLAGS_AUTOCLEAR))
+               lo->lo_flags ^= LO_FLAGS_AUTOCLEAR;
+
+       lo->lo_encrypt_key_size = info->lo_encrypt_key_size;
+       lo->lo_init[0] = info->lo_init[0];
+       lo->lo_init[1] = info->lo_init[1];
+       if (info->lo_encrypt_key_size) {
+               memcpy(lo->lo_encrypt_key, info->lo_encrypt_key,
+                      info->lo_encrypt_key_size);
+               lo->lo_key_owner = uid;
+       }
+
+       return 0;
+}
+
+static int
+loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
+{
+       int err;
        struct block_device *bdev;
+       kuid_t uid = current_uid();
        bool partscan = false;
        bool size_changed = false;
        loff_t validated_size;
@@ -1290,10 +1355,6 @@ loop_set_status(struct loop_device *lo, const struct 
loop_info64 *info)
                err = -ENXIO;
                goto out_unlock;
        }
-       if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) {
-               err = -EINVAL;
-               goto out_unlock;
-       }
 
        if (lo->lo_offset != info->lo_offset ||
            lo->lo_sizelimit != info->lo_sizelimit) {
@@ -1320,54 +1381,10 @@ loop_set_status(struct loop_device *lo, const struct 
loop_info64 *info)
                goto out_unfreeze;
        }
 
-       err = loop_release_xfer(lo);
+       err = loop_set_status_from_info(lo, info);
        if (err)
                goto out_unfreeze;
 
-       if (info->lo_encrypt_type) {
-               unsigned int type = info->lo_encrypt_type;
-
-               if (type >= MAX_LO_CRYPT) {
-                       err = -EINVAL;
-                       goto out_unfreeze;
-               }
-               xfer = xfer_funcs[type];
-               if (xfer == NULL) {
-                       err = -EINVAL;
-                       goto out_unfreeze;
-               }
-       } else
-               xfer = NULL;
-
-       err = loop_init_xfer(lo, xfer, info);
-       if (err)
-               goto out_unfreeze;
-
-       lo->lo_offset = info->lo_offset;
-       lo->lo_sizelimit = info->lo_sizelimit;
-       memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
-       memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE);
-       lo->lo_file_name[LO_NAME_SIZE-1] = 0;
-       lo->lo_crypt_name[LO_NAME_SIZE-1] = 0;
-
-       if (!xfer)
-               xfer = &none_funcs;
-       lo->transfer = xfer->transfer;
-       lo->ioctl = xfer->ioctl;
-
-       if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) !=
-            (info->lo_flags & LO_FLAGS_AUTOCLEAR))
-               lo->lo_flags ^= LO_FLAGS_AUTOCLEAR;
-
-       lo->lo_encrypt_key_size = info->lo_encrypt_key_size;
-       lo->lo_init[0] = info->lo_init[0];
-       lo->lo_init[1] = info->lo_init[1];
-       if (info->lo_encrypt_key_size) {
-               memcpy(lo->lo_encrypt_key, info->lo_encrypt_key,
-                      info->lo_encrypt_key_size);
-               lo->lo_key_owner = uid;
-       }
-
        if (size_changed)
                loop_set_size(lo, validated_size);
 
-- 
2.26.2.303.gf8c07b1a785-goog