Since now on the fdinfo image only contains plain fdinfo_entry-es.
The tpye == FDINFO_REG files are described by regfiles.img entries
and are matched by te ID in both.
At dump stage each new ID generated results in a new entry in the
regfiles.img. At restore stage open_fe_fd should open a regfile by
the fdinfo's ID. Now this is done in suboptimal way, need to improve.
Show shows both images separately.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Make fdinfo_entry carry only the minimal info describing a file
descriptor -- the fd value itself, the fd type (regular file, exe
link, cwd, filemap and it will be pipes, sockets, inotifies, etc.)
and the describing file ID.
The mentioned ID will identify the type-d object, e.g. for regfiles
this ID is already generated with file-ids.c code.
The other part of this structure describes a regfile (i.e. a file
opened with open syscall). I put this new entry at the end of the
fdinfo_entry just to make the patching simpler. Soon this entry
will be dumped into its own file.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The unique id is 32 bit and consists only of the subid value. This
is _really_ enough. The genid part is just a hint for the tree-search
algirythm to avoid unneeded sys_kcmp calls.
Plus, generate IDs for special files. This will make it easier to
move the regfiles into into separate files (see the respective patch
for details).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Hide the structure - it's not required.
[ xemul: Ranem long id into u32 id and adopt to current tree ]
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This is a cleanup patch. This tree is merged only once. So it's image file can
be opened by opne_image() call and dumped right after collect stage.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The core image now contains only core per-task stuff.
The new file resurrects Tula magic number removed earlier.
Acked-by: Andrey Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
vma_entry contains shmid and all shared memory are dumped in own files.
The most interesting thing is restore.
A maping is restored by process with the smallest pid. The mamping
is created before executing restorer.
We map a full mapping and restore it's conten, then we open a file from
/proc/pid/map_files and store a descriptor in vma_info. The mapping is
unmaped. Now we can map any region of this mapping in the restorer.
We use this trick, because a target process may have this mapping in
some places and the restorer has not function to open proc files.
v2: fix error hangling
xemul: Fixed static-s and args for cr_dump_shmem
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It will be used to restore shared mappings
v2: clean up
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
No need in checking the pid in every task loop cycle, just dump it
at the beginning and that's it.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
cr_dump_tasks does assign ret = -1 by default but
dump_namespaces does shadow this variable with own
error code so that if any subsequent calls will fail
we will not notice the error.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This is a cleanup patch. Use file entry type variable for special files
instead of file entry addr variable.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The messages are filtered by their type
LOG_MSG - plain messages, they escape any (!) log level
filtration and go to stdout
LOG_ERROR - error messages
LOG_WARN - warning messages
LOG_INFO - informative messages
LOG_DEBUG - debug messages
By default the LOG_WARN log level is used, thus LOG_INFO
and LOG_DEBUG messages will not appear in output stream.
pr_panic helper was replaced with pr_err, pr_warning
shorthanded to pr_warn and old printk if rather pr_msg
now.
Because we share messages between "show" and "dump" actions,
before the "show" action proceed we need to tune up
log level and set it to LOG_INFO.
Also note that printing of VMA and siginfo now
became LOG_INFO messages, it was not that correct
to print them regardless the log level.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Empty list on scan error means, that the very top task ran away from
us. There's no point in trying to catch one.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This can happen while dumping a pid-namespace (we can't do it now), thus
put this check not to forget one in the future.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Tasks can fork or die while we try to seize them. It's much more simpler
and much more reliably to unseize what was seized and walk the tree again
in case of some tree check failed.
Yes, this makes it impossible to suspend a big tree which constantly forks :(
but I'd prefer fixing more urgent issues before.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Remove CR_TASK_XXX states, use the TASK_XXX ones (for image). This is
required to unseize tasks properly in the next patches.
Plus, make sure that pstree_list and the seized set coincide (i.e.
handle error in collect_task).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
When we've seized all the tasks and threads found in /proc check for
the /proc contents be the same. Do it one-by-one as we descend the tree.
This is OK, since tasks cannot create kids for anyone but themselves or
their parents (reparent will be handled later).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
While we try to seize task it can die and give its pid to
somebody else. This can break pstree consistency. Check for
parent being valid after task is seized.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Move proc checks for Z-state into seize_task().
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Without the patch all files starting with "." will be ommited.
Use of strcmp() - explicit check for "." and ".." looks clearer.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
- drop double file-ids.h inclusion
- rename fd_id_entry to plain entry, it's
used just in a couple of lines only, no
need for complex name
Reported-by: Kir Kolyshkin <kir@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This patch was designed to be generic and thus usable for all kinds of
sockets. Not sure, thah this goal has been reached, but at least I tried.
Key ideas:
1) On-stack structure for collecting sockets queues and then passing them to
parasite code.
2) Singly linked list is used for collecting structures, representing sockets
of any kind (!) with queues.
Based on xemul@ patches.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
We switch generic-object-id concept with sys_kcmp approach,
which implies changes of image format a bit (and since it's
early time for project overall, we're allowed to).
In short -- previously every file descriptor had an ID
generated by a kernel and exported via procfs. If the
appropriate file descriptors were the same objects in
kernel memory -- the IDs did match up to bit. It allows
us to figure out which files were actually the identical
ones and should be restored in a special way.
Once sys_kcmp system call was merged into the kernel,
we've got a new opprotunity -- to use this syscall instead.
The syscall basically compares kernel objects and returns
ordered results suitable for objects sorting in a userspace.
For us it means -- we treat every file descriptor as a combination
of 'genid' and 'subid'. While 'genid' serves for fast comparison
between fds, the 'subid' is kind of a second key, which guarantees
uniqueness of genid+subid tuple over all file descritors found
in a process (or group of processes).
To be able to find and dump file descriptors in a single pass we
collect every fd into a global rbtree, where (!) each node might
become a root for a subtree as well.
The main tree carries only non-equal genid. If we find genid which
is already in tree, we need to make sure that it's either indeed
a duplicate or not. For this we use sys_kcmp syscall and if we
find that file descriptors are different -- we simply put new
fd into a subtree.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
The ptrace seize doesn't prevent signals from delivery. That said,
we should block the signals in the target task before dumping
anything which is signals-related, i.e. memory and registers.
But once we've blocked signals, we should dump registers before
unblocking them, since any postponed signal will screw things up.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This patch tries to introduce lazy and hidden pid_dir support,
meaning one don't have to worry about pid_dir but the optimization
is still there.
The patch relies on the fact that we work with many /proc/pid files for
one pid, then for another pid and so on, i.e. not in a random manner.
The idea is when we call open_proc() with a new pid for the first time,
the appropriate /proc/PID directory is opened and its fd is stored.
Next call to open_proc() with the same PID only need to check that
the PID is not changed. In case PID is changed, we close the old one
and open/store a new one.
Now the code using open_proc() and friends:
- does not need to carry proc_pid around, pid is enough
- does not need to call open_pid_proc()
The only thing that can't be done in that "lazy" mode is closing the last
PID fd, thus close_pid_proc().
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
...and make it correctly print the file name we were unable to open.
Also, error from fdopen[dir]() is now reported with file name as well.
Note that open_proc() and friends need to be macros in order for
pr_perror() to show actual file name and line number where error occured.
Historical note: the original version of this patch was way more radical,
changing openat() to open() and thus removing pid_dir (replacing with pid
when needed) and open_proc_dir(), changing openat() to open(). The word
from Pavel is he wants to keep the openat/pid_dir optimization because
it saves two dentry lookups in kernel code for each open(). Because of
this optimization (and desire to print correct file name in case
of error) we have to carry both pid and pid_dir everywhere.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
- make control block to keep all information
needed to run injected syscall and parasite
blobs
- add ptrace_swap_area helper
- handle both parasite engine calls and injected
syscalls by single __parasite_execute function
- drop jerr() usage
- bring back handling of inflight signals from
original program inside parasite code
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
I don't like that we poke the parasite into remote space with 4k calls
to ptrace. Now we have the /proc/pid/map_files/ dir which helps us sharing
a mapping with some other process.
Use this -- map the remote area for parasite locally and put the parasite
blob into it with simple memcpy.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Right now we do syscall_seized for this, but we have the misc dumping command
and the core is (after patch #3) dump after parasite, so we can get brk from
the misc dump, thus avoiding one more switch to parasite.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
