Todo

component	task	complexity	potential/willing assignee	comments
kernel/crtools	Make proper "check lock present" API in the kernel	medium	-	Currently we detect where a file lock belongs to by locking the file again with the alternative lock type and check how kernel reacts on that. This is not nice as it may tune the lock state on a file. Instead we need the "check lock on fd" call in the kernel.
kernel/crtools	Put call to mmap into VDSO	easy	Cyrill	To put the parasite code into target process we modify its code to call the mmap() system call (and the unmodify it back) and put the parasite into new area. Oleg Nesterov suggests not to patch victim, but to always have one on VDSO.
crtools	Integration with other projects	hard	-	CRIU is not working great by itself. There's alway some specific about what user wants to dump. Integrating CRIU with other projects will make CRIU work at its best.
crtools	Restore tasks into fresh new pid namespace	easy	-	When we dumped processes, it can be hard to restore it back, if they didn't live in a pid namespace, due to PIDs conflict. It would be nice to have the ability to ask CRIU to create the pid namespace for those guys and restore them there. A thing to worry about is this new namespace's init task.
crtools	Rollback tree state	medium	-	When we checkpointed process tree with -R option (let them run after checkpoint) we might want to return the tasks into checkpointed state on the same machine. Currently this can only be done by killing the processes and restoring them from scratch. If we could ask CRIU to restore the images into the ready processes that could speed things up, especially if carefully caring about memory changes tracking.
crtools	AIO with pending events	medium	-	When we dump AIO ring we check it not to contain events inside and abort the dump otherwise. Need to dump events too and put them back on restore.
crtools	Restore arbitrary mountpoints tree	hard	-	Linux kernel can construct tricky knows with mount points. We don't support arbitrary configuration of such things, only those that are in active use by software. Need to fix them up.
crtools	Lazy migration using userfaultd	medium	xemul	Lazy migration is when we move all the tasks on another node, but leave theirs memory on the source one. Not to allow tasks read garbage from empty address space we protect all of it as inaccessible. When tasks start reading/writing the mem they got page-fault-ed. With the userfaultfd technology it can be possible to intercept the #PF, pull the page from source node and map it into expected address.
crtools	Dump tasks from cgroup	easy	-	Currently criu dumps a subtree from given pid
crtools	Speed up logging	medium	Cyrill	Synchronous formatting and writes to log files slow things down (Logging)
crtools	Sanitize logging messages	hard	-	Currently log messages are placed w/o any logic. Need to improve that ... somehow.
crtools	Support OFD posix locks	easy	-
crtools	Optimize kcmp calls	medium	-	For fs/fdt/vm/etc we can pre-generate ID based on objects that live on them. If pre-ID matches, then call kcmp.
crtools	Shmem changes tracking	medium	-
crtools	Page transfer filters	medium	-	Packing or encrypting the data would be nice. Maybe it's purely for P.Haul?
crtools	FUSE mount points	hard	-
crtools	32-bit tasks	hard	Cyrill
crtools	Generate task's core file out of images with CRIT	medium	Ruslan Kuprieiev
crtools	Modify restored resources run-time in CRIT daemon	medium	-	Need (probably) some way to alter what is being restored. Usage example -- change the IP address of sockets from task above.
crtools	TCP socket migration with changed IP	medium	-	CRIT it might make sense to migrate a tcp connection on a box with changed IP address _if_ both boxes are NAT-ed to the destination. We will then have to go to NAT box and fix the conntracks, but this might make sense.
crtools	Applying images	hard	xemul@ w/ students	Think about ability to take images and apply them to a living task(s). E.g. -- repopulate fdtable according to data from image. Another use-case -- when doing partial migration we'll need to modify one part to switch from pipes to sockets
crtools	Partial migration	hard	-	migrate some tasks while proxying IPC to existing others (pipes->sockets, etc.)
crtools	Shared objects (mm/fs) support	medium	-	Now we have the kcmp syscall and can do it. The first candidate is mm sharing, as we do know, that MySQL does so sometimes.
crtools	Smart paths resolution	hard	-	Need a way to resolve paths to overmounted files. There are two ways: 1. Move mounts, that overlap the desired path temprarily. 2. When creating a new mount pre-open an fd keeping the mountpoint. Later, do accurate path resolve and call openat() on proper mountpoint fd
kernel/crtools	TCP repair fixes	hard	-	TCP repair TODO
kernel?/crtools	TCP conntrack-ed connections	medium	-	Need to check whether connection tracking is ON, dump the needed conntrack info and put the tracker back.
crtools	Bridges in container	medium	-
crtools	VLANs in containers	medium	-
crtools	PPP support	medium	-
crtools/kernel	NFS mount points support	hard	-
kernel	Seamless kernel upgrade	hard	xemul
crtools	Validate .img files	easy	-	CRIT For a given set of image files check, that they are in "restorable" shape
crtools	Restore arbitrary process tree	hard	-	Need to restore any process tree, which could be created with help PR_SET_CHILD_SUBREAPER and CLONE_PARENT. Processes can share other resources clone(2). Look at session02
crtools	C/R X app	hard	Ruslan Kuprieiev	Dump/restore of graphical applications (see about integration)
crtools/kernel	Undo semaphores	medium	Cyrill Gorcunov	Require mods from both sides -- criu and kernel
crtools	More detailed RPC fail codes	easy	-	Currently only 3 typical errors are reported(see include/cr-errno.h)
kernel/criu	FS-notify queues	hard	-	Fsnotify