[PATCH 18/45] init: refactor devt_from_partuuid

[Christoph Hellwig <hch@xxxxxx>]

The code in devt_from_partuuid is very convoluted.  Refactor a bit by
sanitizing the goto and variable name usage.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
---
 init/do_mounts.c | 68 ++++++++++++++++++++++--------------------------
 1 file changed, 31 insertions(+), 37 deletions(-)

diff --git a/init/do_mounts.c b/init/do_mounts.c
index aef2f24461c7f1..afa26a4028d25e 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -105,13 +105,10 @@ static int match_dev_by_uuid(struct device *dev, const 
void *data)
  */
 static dev_t devt_from_partuuid(const char *uuid_str)
 {
-       dev_t res = 0;
        struct uuidcmp cmp;
        struct device *dev = NULL;
-       struct gendisk *disk;
-       struct hd_struct *part;
+       dev_t devt = 0;
        int offset = 0;
-       bool clear_root_wait = false;
        char *slash;
 
        cmp.uuid = uuid_str;
@@ -120,52 +117,49 @@ static dev_t devt_from_partuuid(const char *uuid_str)
        /* Check for optional partition number offset attributes. */
        if (slash) {
                char c = 0;
+
                /* Explicitly fail on poor PARTUUID syntax. */
-               if (sscanf(slash + 1,
-                          "PARTNROFF=%d%c", &offset, &c) != 1) {
-                       clear_root_wait = true;
-                       goto done;
-               }
+               if (sscanf(slash + 1, "PARTNROFF=%d%c", &offset, &c) != 1)
+                       goto clear_root_wait;
                cmp.len = slash - uuid_str;
        } else {
                cmp.len = strlen(uuid_str);
        }
 
-       if (!cmp.len) {
-               clear_root_wait = true;
-               goto done;
-       }
+       if (!cmp.len)
+               goto clear_root_wait;
 
-       dev = class_find_device(&block_class, NULL, &cmp,
-                               &match_dev_by_uuid);
+       dev = class_find_device(&block_class, NULL, &cmp, &match_dev_by_uuid);
        if (!dev)
-               goto done;
-
-       res = dev->devt;
+               return 0;
 
-       /* Attempt to find the partition by offset. */
-       if (!offset)
-               goto no_offset;
+       if (offset) {
+               /*
+                * Attempt to find the requested partition by adding an offset
+                * to the partition number found by UUID.
+                */
+               struct hd_struct *part;
 
-       res = 0;
-       disk = part_to_disk(dev_to_part(dev));
-       part = disk_get_part(disk, dev_to_part(dev)->partno + offset);
-       if (part) {
-               res = part_devt(part);
-               put_device(part_to_dev(part));
+               part = disk_get_part(dev_to_disk(dev),
+                                    dev_to_part(dev)->partno + offset);
+               if (part) {
+                       devt = part_devt(part);
+                       put_device(part_to_dev(part));
+               }
+       } else {
+               devt = dev->devt;
        }
 
-no_offset:
        put_device(dev);
-done:
-       if (clear_root_wait) {
-               pr_err("VFS: PARTUUID= is invalid.\n"
-                      "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
-               if (root_wait)
-                       pr_err("Disabling rootwait; root= is invalid.\n");
-               root_wait = 0;
-       }
-       return res;
+       return devt;
+
+clear_root_wait:
+       pr_err("VFS: PARTUUID= is invalid.\n"
+              "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
+       if (root_wait)
+               pr_err("Disabling rootwait; root= is invalid.\n");
+       root_wait = 0;
+       return 0;
 }
 
 /**
-- 
2.29.2