GCC 7.0.1 can determine if there is likely to be sufficient space in
the output buffer when using sprintf/snprintf, based on the format
string.
The errors were all either of this form:
bindtests.c:717:29: error: '%zu' directive output may be truncated writing between 1 and 19 bytes into a region of size 16 [-Werror=format-truncation=]
snprintf (strs[i], 16, "%zu", i);
^~~
bindtests.c:717:28: note: directive argument in the range [0, 2305843009213693951]
snprintf (strs[i], 16, "%zu", i);
^~~~~
or this form:
sync.c: In function 'fsync_devices':
sync.c:108:50: error: '%s' directive output may be truncated writing up to 255 bytes into a region of size 251 [-Werror=format-truncation=]
snprintf (dev_path, sizeof dev_path, "/dev/%s", d->d_name);
^~
Fixed by converting these into dynamic allocation, or making the
output buffer larger, whichever was easier.
There is a gnulib macro we can use to make this simpler for integers.
It requires a new gnulib module (intprops), but it turns out that we
were already pulling that in through dependencies, so the change to
bootstrap is a no-op. (thanks: Dan Berrange)
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.)
Declare most of the stringsbuf as CLEANUP_FREE_STRINGSBUF, so they are
freed completely on stack unwind: use take_stringsbuf() in return
places to take away from the stringsbuf its content, and remove all the
manual calls to free_stringslen (no more needed now).
This requires to not use free_stringslen anymore on failure in the
helper functions of stringsbuf, which now leave the content as-is (might
be still useful even on error).
This allows us to simplify the memory management of stringsbuf's, which
are not properly fully freed, fixing memory leaks in some error paths
(which were not calling free_stringslen).
If add_string_nodup fails free the passed string instead of leaking it,
as that string would have been owned by the stringbuf.
Adapt few places to this behaviour.
If there are no labels set for the disks, the directory with the
symlinks will not even exists, causing list-disk-labels to fail with
ENOENT. In this situation, act as if the directory was there, but
empty.
Because of previous automated commits, such as changing 'guestfs___'
-> 'guestfs_int_', several function calls no longer lined up with
their parameters, and some lines were too long.
The bulk of this commit was done using emacs batch mode and the
technique described here:
http://www.cslab.pepperdine.edu/warford/BatchIndentationEmacs.html
The changes suggested by emacs were then reviewed by hand.
New API: list-disk-labels
Allow the user to pass an optional disk label when adding a drive.
This is passed through to qemu / libvirt using the disk serial field,
and from there to the appliance which exposes it through udev,
creating a special alias of the device /dev/disk/guestfs/<label>.
Partitions are named /dev/disk/guestfs/<label><partnum>.
virtio-blk and virtio-scsi limit the serial field to 20 bytes. We
further limit the name to maximum 20 ASCII characters in [a-zA-Z].
list-devices and list-partitions are not changed: these calls still
return raw block device names. However a new call, list-disk-labels,
returns a hash table allowing callers to map between disk labels, and
block device and partition names.
This commit also includes a test.
This returns the number of whole block devices added. It is usually
simpler to call this than to list the devices and count them, which
is what we do in some places in the current codebase.
This returns the index of the device, eg. /dev/sdb => 1.
Or you can think of it as the order that the device was
added, or the index of the device in guestfs_list_devices.
The presumption is that all file descriptors should be created with
the close-on-exec flag set. The only exception are file descriptors
that we want passed through to exec'd subprocesses (mainly pipes and
stdin/stdout/stderr).
For open calls, we pass O_CLOEXEC as an extra flag, eg:
fd = open ("foo", O_RDONLY|O_CLOEXEC);
This is a Linux-ism, but using a macro we can easily make it portable.
For sockets, similarly:
sock = socket (..., SOCK_STREAM|SOCK_CLOEXEC, ...);
For accepted sockets, we use the Linux accept4 system call which
allows flags to be supplied, but we use the Gnulib 'accept4' module to
make this portable.
For dup, dup2, we use the Linux dup3 system call, and the Gnulib
modules 'dup3' and 'cloexec'.
Previously a lot of daemon code used three variables (a string list,
'int size' and 'int alloc') to track growable strings buffers. This
commit implements a simple struct containing the same variables, but
using size_t instead of int:
struct stringsbuf {
char **argv;
size_t size;
size_t alloc;
};
Use it like this:
DECLARE_STRINGSBUF (ret);
//...
if (add_string (&ret, str) == -1)
return NULL;
//...
if (end_stringsbuf (&ret) == -1)
return NULL;
return ret.argv;
This converts a partition device name (eg. /dev/sda1) to a partition
number (eg. 1). This is useful in conjunction with the parted APIs
that mostly take a disk device + partnum.
This changes the method used to build the supermin appliance
to use the new ext2-based appliance supported by latest febootstrap.
The appliance can also be cached, so we avoid rebuilding it
each time it is used.
Mailing list discussion goes into the rationale and details:
https://www.redhat.com/archives/libguestfs/2010-August/msg00028.html
Requires febootstrap >= 2.8.
mkfs-b: Pass the -b (blocksize) parameter to mkfs.
mke2journal and friends: Lets you create external ext2 journals on
devices.
mke2fs-J and friends: Lets you create ext2/3/4 filesystems with
external journals.
Nearly every file-related function in daemons/*.c is affected:
Remove this pair of statements from each affected do_* function:
- NEED_ROOT (return -1);
- ABS_PATH (dir, return -1);
and change the type of the corresponding parameter to "const char *".
* src/generator.ml: Emit NEED_ROOT just once, even when there are two or
more Pathname args.
virtio_blk is the fast, virt-native block device driver
supported by qemu and KVM. Note that virtio_blk device
names are called /dev/vd*.
Existing scripts should continue working because device name
translation will silently change device names of the form
/dev/sd* to /dev/vd* as required.
See also:
http://libguestfs.org/guestfs.3.html#block_device_naming
