[Libguestfs] [PATCH 5/6] New API: btrfs_subvolume_get_default
Hu Tao
hutao at cn.fujitsu.com
Mon Nov 24 05:44:11 UTC 2014
On Fri, Nov 21, 2014 at 12:11:36PM +0100, Pino Toscano wrote:
> On Friday 21 November 2014 13:17:59 Hu Tao wrote:
> > btrfs_subvolume_get_default is for getting the default subvolume of
> > a btrfs filesystem.
> >
> > Signed-off-by: Hu Tao <hutao at cn.fujitsu.com>
> > ---
> > daemon/btrfs.c | 38 ++++++++++++++++++++++++++++++++++++++
> > generator/actions.ml | 9 +++++++++
> > src/MAX_PROC_NR | 2 +-
> > 3 files changed, 48 insertions(+), 1 deletion(-)
> >
> > diff --git a/daemon/btrfs.c b/daemon/btrfs.c
> > index 0f525fa..e179b57 100644
> > --- a/daemon/btrfs.c
> > +++ b/daemon/btrfs.c
> > @@ -549,6 +549,44 @@ do_btrfs_subvolume_set_default (int64_t id, const
> char *fs)
> > }
> >
> > int
> > +do_btrfs_subvolume_get_default (const char *fs)
> > +{
> > + const size_t MAX_ARGS = 64;
> > + const char *argv[MAX_ARGS];
> > + size_t i = 0;
> > + CLEANUP_FREE char *fs_buf = NULL;
> > + CLEANUP_FREE char *err = NULL;
> > + CLEANUP_FREE char *out = NULL;
> > + int r;
> > +
> > + fs_buf = sysroot_path (fs);
> > + if (fs_buf == NULL) {
> > + reply_with_perror ("malloc");
> > + return -1;
> > + }
> > +
> > + ADD_ARG (argv, i, str_btrfs);
> > + ADD_ARG (argv, i, "subvolume");
> > + ADD_ARG (argv, i, "get-default");
> > + ADD_ARG (argv, i, fs_buf);
> > + ADD_ARG (argv, i, NULL);
> > +
> > + r = commandv (&out, &err, argv);
> > + fprintf(stderr, "%s\n", out);
>
> This looks like a leftover? Otherwise, print it only when "debug" is
> enabled (if (debug) ...).
Oops, I will just remove the line.
>
> > + if (r == -1) {
> > + reply_with_error ("%s: %s", fs, err);
> > + return -1;
> > + }
> > + r = -1;
>
> Most probably it is not needed to manually reset r.
>
> > + if (sscanf (out, "ID %" SCNi32, &r) != 1) {
>
> It would be simplier to just use xstrtol to parse the output.
Then we should skip "ID " firstly.
>
> > + reply_with_error ("%s: expected output, but got nothing",
> argv[0]);
>
> More than "nothing", "not a number". I'd also append the whole output
> here.
Sounds good.
>
> > diff --git a/generator/actions.ml b/generator/actions.ml
> > index 1c1fcff..cf96039 100644
> > --- a/generator/actions.ml
> > +++ b/generator/actions.ml
> > @@ -12005,6 +12005,15 @@ This is the same as the C<lstat(2)> system
> call." };
> > longdesc = "\
> > This is the internal call which implements C<guestfs_lstatnslist>."
> };
> >
> > + { defaults with
> > + name = "btrfs_subvolume_get_default";
> > + style = RInt "id", [Pathname "mountpoint"], [];
> > + proc_nr = Some 424;
> > + optional = Some "btrfs"; camel_name = "BTRFSSubvolumeGetDefault";
> > + shortdesc = "get the default subvolume or snapshot of a
> filesystem";
> > + longdesc = "\
> > +Get the default subvolume or snapshot of a filesystem mounted at
> C<mountpoint>." };
> > +
> > ]
> >
> > (* Non-API meta-commands available only in guestfish.
> > diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
> > index 5721413..9524ef4 100644
> > --- a/src/MAX_PROC_NR
> > +++ b/src/MAX_PROC_NR
> > @@ -1 +1 @@
> > -423
> > +424
> > --
> > 1.9.3
> >
> --
> Pino Toscano
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