We have traditionally used custom printf formatters %Q and %R, where
%Q replaces the argument with a shell-quoted string, and %R replaces
the argument with a sysroot-prefixed shell-quoted string. They are
actually pretty useful, but unfortunately only supported by glibc.
We only used them in about a dozen places in the daemon (much code
having been replaced by OCaml which does not need them).
In every remaining case we were constructing a command using code like
this:
asprintf_nowarn (&cmd,
"cd %Q && find -print0 | %s -0 -o -H %s --quiet", ...);
We can replace this with:
char *cmd;
size_t cmd_size;
fp = open_memstream (&cmd, &cmd_size);
fprintf (fp, "cd ");
shell_quote (dir, fp);
fprintf (fp, " && find -print0 | %s -0 -o -H %s --quiet", ...);
fclose (fp);
(cherry picked from commit 0b3c6cc0c0)
Linux from around 5.6 now enumerates individual disks in any order
(whereas previously it enumerated only drivers in parallel). This
means that /dev/sdX ordering is no longer stable - in particular we
cannot be sure that /dev/sda inside the guest is the first disk that
was attached to the appliance, /dev/sdb the second disk and so on.
However we can still use SCSI PCI device numbering as found in
/dev/disk/by-path. Use this to translate device names in and out of
the appliance.
Thanks: Vitaly Kuznetsov, Paolo Bonzini, Dan Berrangé.
Move the read_whole_file function to the common utilities of the daemon,
so other parts can use it. For this purpose, add an out parameter to
get the amount of bytes read.
Except from the parameter addition, this should be just refactoring.
When the daemon starts up it creates a fresh (empty) LVM configuration
and starts up lvmetad (which depends on the LVM configuration).
However this appears to cause problems: Some types of PV seem to
require lvmetad and don't work without it
(https://bugzilla.redhat.com/show_bug.cgi?id=1581810). If we don't
start lvmetad earlier, the device nodes are not created.
Therefore move the whole initialization step into appliance/init.
Two further changes had to be made:
Now we are using lvmetad all the time, using vgchange is incorrect.
With lvmetad activated early we must use ‘pvscan --cache --activate ay’
to scan all disks for PVs and activate any VGs on them (although the
documentation is complex, confusing and contradictory so I'm not
completely sure about this).
The ‘lvm_system_dir’ local variable in ‘daemon/lvm-filter.c’
previously contained the path of the directory above $LVM_SYSTEM_DIR
(eg. $LVM_SYSTEM_DIR = "/etc/lvm", lvm_system_dir = "/etc"). As this
was highly confusing, I have changed it so the local variable and the
environment variable have identical contents. This involved removing
the ‘lvm/’ component from a couple of paths since it is now included
in the local variable.
For Device parameters we expect a block device name. However we were
only testing for "/dev/..." and so chardevs (from the appliance) could
be passed here, resulting in strange effects. This adds a function
is_device_parameter which tests for a valid block device name.
For Dev_or_Path parameters much the same, except we can also use the
is_device_parameter function elsewhere in the daemon to distinguish if
we were called with a device or path parameter. Previously we used a
simple test if the path begins with "/dev/...".
Reported by Mathieu Tarral.
LVM is fine with a completely empty configuration file (meaning "all
defaults"), so start with one instead of copying the system
configuration file.
Also this means we can very easily implement lvm_set_filter
functionality without using Augeas, since we no longer have to worry
about existing filters being present.
Thanks: Alasdair Kergon, Zdenek Kabelac.
GUESTFSD_EXT_CMD was used by OpenSUSE to track which external commands
are run by the daemon and package those commands into the appliance.
It is no longer used by recent SUSE builds, so remove it.
Thanks: Pino Toscano, Olaf Hering.
After the previous refactoring, we are able to link the daemon to
common/utils, and also remove some of the "duplicate" functions that
the daemon carried ("duplicate" in quotes because they were often not
exact duplicates).
Also this removes the duplicate reimplementation of (most) cleanup
functions in the daemon, since those are provided by libutils now.
It also allows us in future (but not in this commit) to move utility
functions from the daemon into libutils.
Previously the generator did not change any string returned from the
daemon. Thus guestfs_list_devices (for example) might return internal
device names like /dev/vda (if virtio-blk was in use).
This changes calls to the daemon so that returned strings are
annotated as plain strings, devices or mountables:
old ---> new
RString "uuid" RString (RPlainString "uuid")
RString "device" RString (RDevice "device")
RString "fs" RString (RMountable "fs")
For hash tables, keys and values must be annotated separately. For
example a hash table of mountables (keys) -> plain strings (values)
would be annotated like this:
old ---> new
RHashtable "fses" RHashtable (RMountable, RPlainString, "fses")
The daemon calls reverse_device_name_translation (currently a no-op)
for devices and mountables.
Note that this has no effect for calls which are handled on the
library side.
(cherry picked from commit 6b77cc196ecb8d7e1d73592ef65a189a7412c97c)
In every instance where we used the ‘cancel_stmt’ parameter of
these macros:
ABS_PATH
NEED_ROOT
the value was only ever ‘cancel_receive ()’ or empty. We only use
‘cancel_receive’ for FileIn functions, so replace it with a simple
flag for whether the current function is a FileIn function.
This also removes some incorrect comments about macros that cannot be
used with FileIn functions when in fact they can.
Add udev_settle_file() to run 'udevadm settle' with --exit-if-exists option. It
will slightly reduce the waiting-time for pending events if we need to wait
for events related to a particular device/file.
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
RWMJ:
- Use local variable for MAX_ARGS.
- Use commandv instead of commandrv, fix checking of return code.
It will be useful also for APIs different than tar-out, so move it to
guestfsd.c, and add it a parameter to specify the function name that
invoked it.
This is mostly code motion.
Run the following command over the source:
perl -pi.bak -e 's/(20[01][0-9])-2016/$1-2017/g' `git ls-files`
(Thanks Rich for the perl snippet, as used in past years.)
Currently lvmetad is started in init, and thus using the system
(= appliance) configuration of lvm. Later on, in the daemon, a local
copy of the lvm configuration is setup, and set it for use using the
LVM_SYSTEM_DIR environment variable: this means only the programmes
executed by the daemon will use the local lvm configuration, and not
lvmetad.
Thus manually start lvmetad from the daemon, right after having setup
the local lvm configuration, and still without failing if it cannot be
executed.
Additionally, since lvmetad now respects the right configuration, make
sure to update its cache when rescanning the VGs by passing --cache to
vgscan.
It's a bitmask, so unsigned is the right choice. eg. We can more
easily print it using %x.
This patch changes the size of the fd mask and the values of the
COMMAND_FLAG_* constants, but since these are internal definitions
that doesn't matter.
- add a flag to request chroot for the process, which is done only as
very last (before chdir) operation before exec'ing the process in the
child: this avoids using CHROOT_IN & CHROOT_OUT around command*
invocations, and reduces the code spent in chroot mode
- add failure checks for dup2, open, and chdir done in child, not
proceeding to executing the process if they fail
- open /dev/null without O_CLOEXEC, so it stays available for the
exec'ed process, and thus we don't need to provide an own fd for stdin
Followup of commit fd2f175ee7, thanks also
to the notes and hints provided by Mateusz Guzik.
Mold split_lines_sb from split_lines, so it returns the strings buffer
with the result of the split. This way, we can have the number of lines
in the array, with no need to count them again later.
split_lines is rewritten to take the ownership of the result of
split_lines_sb.
