Force unmount of fuse severes the connection between FUSE driver and its userspace counterpart. However, open file handles will prevent the superblock from being reclaimed. An attempt to remount the filesystem at the same endpoint will try re-using the superblock, if still present. Since the superblock re-use path doesn't go through the fs-specific superblock setup code, its state in FUSE case is already disfunctional, and that will prevent the mount from succeeding. Changes in v5: - Update commit messages to specify that only block-device-based superblocks are affected - Restrict retire_super call in FUSE to be issued for fuseblk only. Changes in v4: - Simplify condition according to Christoph Hellwig's comments. Changes in v3: - Back to state tracking from v1 - Use s_iflag to mark superblocked ignored - Only unregister private bdi in retire, without freeing Changes in v2: - Remove super from list of superblocks instead of using a flag Daniil Lunev (2): fs/super: function to prevent re-use of block-device-based superblocks FUSE: Retire block-device-based superblock on force unmount fs/fuse/inode.c | 10 ++++++++-- fs/super.c | 32 ++++++++++++++++++++++++++++++-- include/linux/fs.h | 2 ++ 3 files changed, 40 insertions(+), 4 deletions(-) -- 2.31.0
