The gnulib 'error' module uses 'program_name'. On some platforms --
but not Linux / glibc -- it references it as:
extern char *program_name;
This means when you compile libguestfs on non-glibc (eg. Mac OS X)
gnulib requires 'program_name' as an external string reference, which
we don't provide.
This change doesn't define this string reference for gnulib, but it
does change the name of the macro we use to avoid conflicts if we
eventually need to export 'program_name' as a string.
Thanks: Margaret Lewicka
Just like --long-options, it makes it possible to know which short
options are supported by each tool; this can help improving the bash
completion, for example.
The existing APIs guestfs_stat, guestfs_lstat and guestfs_lstatlist
return a stat structure that contains atime, mtime and ctime fields
that store only the timestamp in seconds.
Modern filesystems can store timestamps down to nanosecond
granularity, and the ordinary glibc stat(2) wrapper will return these
in "hidden" stat fields:
struct timespec st_atim; /* Time of last access. */
struct timespec st_mtim; /* Time of last modification. */
struct timespec st_ctim; /* Time of last status change. */
with the following macros defined for backwards compatibility:
#define st_atime st_atim.tv_sec
#define st_mtime st_mtim.tv_sec
#define st_ctime st_ctim.tv_sec
It is not possible to redefine guestfs_stat to return a longer struct
guestfs_stat with room for the extra nanosecond fields, because that
would break the ABI of guestfs_lstatlist as it returns an array
containing consecutive stat structs (not pointers). Changing the
return type of guestfs_stat would break API. Changing the generator
to support symbol versioning is judged to be too intrusive.
Therefore this adds a new struct (guestfs_statns) and new APIs:
guestfs_statns
guestfs_lstatns
guestfs_lstatnslist
which return the new struct (or array of structs in the last case).
The old APIs may of course still be used, forever, but are deprecated
and shouldn't be used in new programs.
Because virt tools are compiled with -DGUESTFS_WARN_DEPRECATED=1, I
have updated all the places calling the deprecated functions. This
has revealed some areas for improvement: in particular virt-diff and
virt-ls could be changed to print the nanosecond fields.
FUSE now returns nanoseconds in stat calls where available, fixing
https://bugzilla.redhat.com/show_bug.cgi?id=1144891
Notes about the implementation:
- guestfs_internal_lstatlist has been removed and replaced by
guestfs_internal_lstatnslist. As the former was an internal API no
one should have been calling it, or indeed can call it unless they
start defining their own header files.
- guestfs_stat and guestfs_lstat have been changed into library-side
functions. They, along with guestfs_lstatlist, are now implemented
as wrappers around the new functions which just throw away the
nanosecond fields.
In most C tools, virt-sysprep and virt-customize, you have to put the
--format parameter before the corresponding -a parameter. ie. The
following is correct:
guestfish --format qcow2 -a disk1 -a disk2
But the following is incorrect. The --format parameter is dangling
and prior to this commit would have been silently ignored:
guestfish -a disk1 -a disk2 --format qcow2
After this change, dangling --format parameters now lead to an error:
guestfish: --format parameter must appear before -a parameter
In virt-customize, also check that --attach-format parameter appears
before --attach parameter.
Thanks: Lingfei Kong
