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/volumes.c b/fs/btrfs/volumes.c
index 0c7f478..e8be478 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -600,8 +600,10 @@
set_blocksize(bdev, 4096);
bh = btrfs_read_dev_super(bdev);
- if (!bh)
+ if (!bh) {
+ ret = -EINVAL;
goto error_close;
+ }
disk_super = (struct btrfs_super_block *)bh->b_data;
devid = btrfs_stack_device_id(&disk_super->dev_item);
@@ -702,7 +704,7 @@
goto error_close;
bh = btrfs_read_dev_super(bdev);
if (!bh) {
- ret = -EIO;
+ ret = -EINVAL;
goto error_close;
}
disk_super = (struct btrfs_super_block *)bh->b_data;
@@ -1302,7 +1304,7 @@
set_blocksize(bdev, 4096);
bh = btrfs_read_dev_super(bdev);
if (!bh) {
- ret = -EIO;
+ ret = -EINVAL;
goto error_close;
}
disk_super = (struct btrfs_super_block *)bh->b_data;