A service fd should be created, otherwise get_service_fd returns -1.
This patch removes this functionality from other subsystems and
allows to clone service descriptors.
v2: rename open_service_fd to install_service_fd
v3: two patches were merged for bisecting
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It looks like a namespace for service descriptors.
It will be used for restoring tasks with shared fd tables.
Service descriptors should be own for each process.
v2: clone_service_fd doesn't know about sub-systems like log, proc, etc
v3: Don't try to find a free name-space.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
* The following files goes into the directory arch/x86/include/asm unmodified:
- include/atomic.h,
- include/linkage.h,
- include/memcpy_64.h,
- include/types.h,
- include/bitops.h,
- pie/parasite-head-x86-64.S,
- include/processor-flags.h,
- include/syscall-x86-64.def.
* Changed include directives in the source files that include the headers
listed above.
* Modified build scripts to reflect the source moves.
Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It reads /proc/PID/fd and close all descriptors except service fds.
v2: s/is_one_of_service_fds/is_any_service_fd
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
For executing an external tools we need to block a SIGCHLD
and to juggle file descriptors.
SIGCHLD is blocked for getting an exit code.
A problem with file descriptors can be if we want to set 2 to STDIN,
1 to STDERR, 0 to STDOUT for example.
v2: use helpers reopen_fd_as and move_img_fd
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We're using get_service_fd in file engine,
better to make it fast. This patch caches
the limits system provides us, instead of
calling getrlimit() every time.
This patch introduces is_service_fd helper
which will be used instead of get_service_fd
where it make sense.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Actually a gurad page is a part of a stack vma and we don't want to remap
it by a restorer vma.
The crtools on restore find a place for a restorer vma, which will not
intersect with other VMAs. A guard page is a part of a stack VMA, if
we don't take into account it, we can place the restorer VMA on it and
that case is a bug.
Would not this lead to situation where we expand stack manually? Every new
c/r cycle add one page to the bottom of stack, no? No:
strace:
mmap(0x5f4d0e0cc000, 4096, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS|MAP_GROWSDOWN, -1, 0) =
0x5f4d0e0cc000
/proc/PID/maps:
5f4d0e0cd000-5f4d0e0cd000 rw-p 00000000 00:00 0
.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When a pidns is dumped, crtools uses procfs from this pidns
for getting information about zombies.
v2: Use close_proc() instead of restore_proc_fd().
A current proc will be opened again, if it's required.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
/proc/PID/maps can contains not up to date information about a stack vma.
A kernel marks a VMA as stack, if thread_struct->usersp is in it,
but usersp is updated, when a process calls a syscall.
This problem is occured, when we try to dump/restore a process in a loop.
When a restorer resumes a process, a restorer vma will be marked as stack.
A thread stack should not be marked as stack, because its vma is mapped
w/o MAP_GROWSDOWN.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This one allocates a memory, that will be shared (MAP_SHARED)
between all the subsequent children. This can now be just used
for fd resote, later it will be required at inet socket port
binding.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Strictly speaking the fd link can point to PATH_MAX string, but for the sake of
is_anonfd_link 32 bytes is enough -- even if the target string is longer it will not
match the required anon_inode:xxx string.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Util it's very critical for speed we should
not use unsafe sprintf helper, we're root-granted
program and must be as safe as possible.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
v2: rework this by using openat() and service fds for proc root.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
On some systems PAGE_SIZE is declared as sysconf(_SC_PAGESIZE) in <sys/user.h>
this is non-constant expression, so it cannot be used in type declarations.
This breaks compilation with a very non-obvious error message:
CC parasite-syscall.o
In file included from parasite-syscall.c:30:0:
./include/parasite.h:90:8: error: variably modified ‘fds’ at file scope
crtools doesn't uses anything from <sys/user.h>, so we can drop its usage.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Our loggin engine prints file:line only at invoke point,
so it's unable to see where exactly reopen_fd_as_safe is
failed.
With this patch the output is more human readable
| Error (util.c:96): fd 7 already in use (called at files.c:359)
Ideally we need full backtrace here, but it's different task.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
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>
Now a name of an image file is hard coded ("smth-%d.img", pid),
but the images of namespaces, shared memery, etc belong to
not one task, so they may have other formats of names, which
will describe objects.
For example a image of shared memory content may have name like
this ("pages-shmem-%ld.img", shmid)
v2: fix comment
v3: rebase
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Before this patch it may contain only a few megabytes.
I think a real application may have a bigger mappings.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Using absolute paths for this is dangerous - while doing c/r we should
be extremely carefully and not change tasks' roots and mount namespaces
too early. Sometimes it will not work -- when restoring containers we'll
be unable to switch to new CT and still have the ability to open images.
Rework the images opening via openat and keep the image dir fd open all
the time as the service fd (introduced earlier).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
These are the fds that help us to do c/r. We want them not to intersect
with any "real-life" ones and thus store them close the the file rlimit
boundary. For now only the logfd one is such.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Due to code sharing, especially in IPC area,
the unbinding is done via helper macros and
sysclt engine tuning (new CTL_SHOW action
added).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-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>
This is a place where they should belong to.
util.c is too big already.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
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>
To be used by the next patch
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
* kid -> child
* First letter should be uppercase
* Misc typos in messages and comments
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
- Fix printing the same address on every line (ie p+i, not p).
- Use GNU %p to print pointer, to avoid messing with width etc.
Side effect: 0x is added, hope that's ok.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
To eliminate format problem
| util.c:60:10: error: format ‘%lx’ expects argument of
| type ‘long unsigned int’, but argument 2 has type
| ‘unsigned char *’ [-Werror=format]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This is a standard convention to print error message (i.e. strerror(errno))
at the end of line, like this:
Cannot remove file: Permission denied
So pr_perror is fixed to follow this convention (using GNU extension
%m helps a lot here). Unfortunately, due to this we have to make
pr_perror() print a new line character, too, so we had to strip it
from the all pr_perror() invocations.
That (appending a newline) also makes pr_perror() a black sheep
in the herd of pr_* helpers, but what can we do? Worst case scenario
is an extra newline after an error message, not too harmful.
An alternative approach (stripping the newline from the passed format
string and re-adding it) was discussed thoroughly, and it was decided
that such a hack looks a bit too dirty.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
It may be legal. E.g. for zombie
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Make it shorter and simpler and use one in open_image_ro_nocheck.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
