"FSS_UNLINK_ON_CREATE" to unlink the backing store before
the snapshot gets created.
With this change dump(8) no longer dumps the zero-sized, but named
snapshot it is working on. Same applies to fsck_ffs(8).
- Add FSSIOFSET and FSSIOFGET ioctl() to set/get the flags.
- Add FSS_UNCONFIG_ON_CLOSE flag to unconfigure the snapshot device
on the last close.
Reviewed by: Jason R. Thorpe <thorpej@netbsd.org>
- Document the kernel thread.
- Rename some functions and variables.
- Return EROFS where appropriate.
- Use shifts instead of 64-bit divide.
- Use a simple_lock to make it MP-safe.
- Add M_CANFAIL to malloc to avoid panic on large cluster size.
- Allow sparse file for backing store and use VOP_BALLOC() to allocate
space. Default size of backing store is the size of the file system.
Uses a hook in spec_strategy() to save data written from a mounted
file system to its block device and a hook in dounmount().
Not enabled by default in any kernel config.
Approved by: Frank van der Linden <fvdl@netbsd.org>
