btrfs: mount failure return value fix
I happened to pass swap partition as root partition in cmdline,
then kernel panic and tell me about "Cannot open root device".
It is not correct, in fact it is a fs type mismatch instead of 'no device'.
Eventually I found btrfs mounting failed with -EIO, it should be -EINVAL.
The logic in init/do_mounts.c:
for (p = fs_names; *p; p += strlen(p)+1) {
int err = do_mount_root(name, p, flags, root_mount_data);
switch (err) {
case 0:
goto out;
case -EACCES:
flags |= MS_RDONLY;
goto retry;
case -EINVAL:
continue;
}
print "Cannot open root device"
panic
}
SO fs type after btrfs will have no chance to mount
Here fix the return value as -EINVAL
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f88eb2c..f9efb68 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1713,8 +1713,10 @@
fs_info, BTRFS_ROOT_TREE_OBJECTID);
bh = btrfs_read_dev_super(fs_devices->latest_bdev);
- if (!bh)
+ if (!bh) {
+ err = -EINVAL;
goto fail_iput;
+ }
memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
memcpy(&fs_info->super_for_commit, &fs_info->super_copy,