We need to update the mount's destination after we resolve symlinks so
that it properly creates and mounts the correct location.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Right now if one passes a mount propagation flag in spec file, it
does not take effect. For example, try following in spec json file.
{
"type": "bind",
"source": "/root/mnt-source",
"destination": "/root/mnt-dest",
"options": "rbind,shared"
}
One would expect that /root/mnt-dest will be shared inside the container
but that's not the case.
#findmnt -o TARGET,PROPAGATION
`-/root/mnt-dest private
Reason being that propagation flags can't be passed in along with other
regular flags. They need to be passed in a separate call to mount syscall.
That too, one propagation flag at a time. (from mount man page).
Hence, store propagation flags separately in a slice and apply these
in that order after the mount call wherever appropriate. This allows
user to control the propagation property of mount point inside
the container.
Storing them separately also solves another problem where recursive flag
(syscall.MS_REC) can get mixed up. For example, options "rbind,private"
and "bind,rprivate" will be same and there will be no way to differentiate
between these if all the flags are stored in a single integer.
This patch would allow one to pass propagation flags "[r]shared,[r]slave,
[r]private,[r]unbindable" in spec file as per mount property.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
- Check if Selinux is enabled before relabeling. This is a bug.
- Make exclusion detection constant time. Kinda buggy too, imo.
- Do not depend on a magic string to create a new Selinux context.
Signed-off-by: David Calavera <david.calavera@gmail.com>
TL;DR: check for IsExist(err) after a failed MkdirAll() is both
redundant and wrong -- so two reasons to remove it.
Quoting MkdirAll documentation:
> MkdirAll creates a directory named path, along with any necessary
> parents, and returns nil, or else returns an error. If path
> is already a directory, MkdirAll does nothing and returns nil.
This means two things:
1. If a directory to be created already exists, no error is
returned.
2. If the error returned is IsExist (EEXIST), it means there exists
a non-directory with the same name as MkdirAll need to use for
directory. Example: we want to MkdirAll("a/b"), but file "a"
(or "a/b") already exists, so MkdirAll fails.
The above is a theory, based on quoted documentation and my UNIX
knowledge.
3. In practice, though, current MkdirAll implementation [1] returns
ENOTDIR in most of cases described in #2, with the exception when
there is a race between MkdirAll and someone else creating the
last component of MkdirAll argument as a file. In this very case
MkdirAll() will indeed return EEXIST.
Because of #1, IsExist check after MkdirAll is not needed.
Because of #2 and #3, ignoring IsExist error is just plain wrong,
as directory we require is not created. It's cleaner to report
the error now.
Note this error is all over the tree, I guess due to copy-paste,
or trying to follow the same usage pattern as for Mkdir(),
or some not quite correct examples on the Internet.
[1] https://github.com/golang/go/blob/f9ed2f75/src/os/path.go
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Actually cgroup mounts are bind-mounts, so they should be
handled by the same way.
Reported-by: Ross Boucher <rboucher@gmail.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
And allow cgroup mount take flags from user configs.
As we show ro in the recommendation, so hard-coded
read-only flag should be removed.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Fixes: https://github.com/docker/docker/issues/14543
Fixes: https://github.com/docker/docker/pull/14610
Before this, we got mount info in container:
```
sysfs /sys sysfs ro,seclabel,nosuid,nodev,noexec,relatime 0 0
/sys/fs/cgroup tmpfs rw,seclabel,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,relatime,cpuset 0 0
```
It has no mount source, so in `parseInfoFile` in Docker code,
we'll get:
```
Error found less than 3 fields post '-' in "84 83 0:41 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs rw,seclabel"
```
After this fix, we have mount info corrected:
```
sysfs /sys sysfs ro,seclabel,nosuid,nodev,noexec,relatime 0 0
tmpfs /sys/fs/cgroup tmpfs rw,seclabel,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,relatime,cpuset 0 0
```
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Michael Crosby
Antonio Murdaca
Vivek Goyal
Mrunal Patel
Andrey Vagin
Qiang Huang
rajasec
Mrunal Patel
David Calavera
Kir Kolyshkin
Alexander Morozov