btrfs: make fs_devices a local variable in btrfs_parse_early_options

fs_devices is always passed to btrfs_scan_one_device which overrides it.
In the call stack below fs_devices is passed to btrfs_scan_one_device
from btrfs_mount_root.  In btrfs_mount_root the output fs_devices of
this call stack is not used.

btrfs_mount_root
  btrfs_parse_early_options
    btrfs_scan_one_device

So, it is not necessary to pass fs_devices from btrfs_mount_root, using
a local variable in btrfs_parse_early_options is enough.

Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 28ab75e..909ea25 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -884,10 +884,11 @@ out:
  * only when we need to allocate a new super block.
  */
 static int btrfs_parse_early_options(const char *options, fmode_t flags,
-               void *holder, struct btrfs_fs_devices **fs_devices)
+                                    void *holder)
 {
        substring_t args[MAX_OPT_ARGS];
        char *device_name, *opts, *orig, *p;
+       struct btrfs_fs_devices *fs_devices = NULL;
        int error = 0;
 
        lockdep_assert_held(&uuid_mutex);
@@ -918,7 +919,7 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
                                goto out;
                        }
                        error = btrfs_scan_one_device(device_name,
-                                       flags, holder, fs_devices);
+                                       flags, holder, &fs_devices);
                        kfree(device_name);
                        if (error)
                                goto out;
@@ -1554,7 +1555,7 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
        }
 
        mutex_lock(&uuid_mutex);
-       error = btrfs_parse_early_options(data, mode, fs_type, &fs_devices);
+       error = btrfs_parse_early_options(data, mode, fs_type);
        if (error) {
                mutex_unlock(&uuid_mutex);
                goto error_fs_info;