Hi Christoph, On 2024/10/8 19:49, Christoph Hellwig wrote:
On Tue, Oct 08, 2024 at 05:56:05PM +0800, Gao Xiang wrote:As Allison reported [1], currently get_tree_bdev() will store "Can't lookup blockdev" error message. Although it makes sense for pure bdev-based fses, this message may mislead users who try to use EROFS file-backed mounts since get_tree_nodev() is used as a fallback then. Add get_tree_bdev_by_dev() to specify a device number explicitly instead of the hardcoded fc->source as mentioned in [2], there are other benefits like: - Filesystems can have other ways to get a bdev-based sb in addition to the current hard-coded source path; - Pseudo-filesystems can utilize this method to generate a filesystem from given device numbers too. - Like get_tree_nodev(), it doesn't strictly tie to fc->source either.Do you have concrete plans for any of those? If so send pointers.
Thanks for your comment. I don't have any pointer for now, just listing the potential use cases for reference. But the error message out of get_tree_bdev() is inflexible and IMHO it's too coupled to `fc->source`.
Otherwise just passing a quiet flag of some form feels like a much saner interface.
I'm fine with this way, but that will be a treewide change, I will send out a version with a flag later. Thanks, Gao Xiang
