Re: [Libguestfs] [PATCH 5/6] New API: btrfs_subvolume_get_default

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(a)cn.fujitsu.com&gt; > --- > 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) ...).

> + 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.

> + 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.

> 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