On Tue, Jul 24, 2012 at 12:41:50PM +0200, Davidlohr Bueso wrote:
> On Tue, 2012-07-24 at 11:52 +0200, Petr Uzel wrote:
> > On Sun, Jul 22, 2012 at 07:05:04PM +0200, Davidlohr Bueso wrote:
> > > From: Davidlohr Bueso <dave@xxxxxxx>
> > >
> > > A new fdisk_label_change() function is added for situations when the disk label is
> > > changed (ie: creating a new sun label). This function only updates the label pointer
> > > in the context to use the newly specified label type.
> >
> > Why can't we just call __probe_labels() after creating new label, e.g.
> > in soon-to-be introduced fdisk_label_create()?
>
> Because this way we give users extra functionality in the API. There
> should be a way of changing label types on the fly, and since we don't
> export __probe_labels(), this is the other option.
What operation could change label type besides creating a new label?
>
> Thanks,
> Davidlohr
>
> >
> > >
> > > Signed-off-by: Davidlohr Bueso <dave@xxxxxxx>
> > > ---
> > > fdisks/fdisk.h | 2 ++
> > > fdisks/fdiskdoslabel.c | 1 +
> > > fdisks/fdisksgilabel.c | 2 ++
> > > fdisks/fdisksunlabel.c | 1 +
> > > fdisks/utils.c | 37 +++++++++++++++++++++++++++++++++++++
> > > 5 files changed, 43 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/fdisks/fdisk.h b/fdisks/fdisk.h
> > > index d716824..d7e85f5 100644
> > > --- a/fdisks/fdisk.h
> > > +++ b/fdisks/fdisk.h
> > > @@ -104,6 +104,7 @@ enum fdisk_error {
> > > FDISK_ERROR_WRITE,
> > > FDISK_ERROR_IOCTL,
> > > FDISK_ERROR_PROBE,
> > > + FDISK_ERROR_NOLABEL,
> > > FDISK_ERROR_UNKNOWN
> > > };
> > >
> > > @@ -164,6 +165,7 @@ extern void fdisk_mbr_zeroize(struct fdisk_context *cxt);
> > > extern void fdisk_geom_set_cyls(struct fdisk_context *cxt);
> > > extern const char *fdisk_error_name(enum fdisk_error errcode);
> > > extern void fdisk_error_fatal(struct fdisk_context *cxt, enum fdisk_error errcode);
> > > +extern int fdisk_label_change(struct fdisk_context *cxt, const char *name);
> > >
> > > /* prototypes for fdisk.c */
> > > extern char *disk_device, *line_ptr;
> > > diff --git a/fdisks/fdiskdoslabel.c b/fdisks/fdiskdoslabel.c
> > > index 535afdc..9b9b23a 100644
> > > --- a/fdisks/fdiskdoslabel.c
> > > +++ b/fdisks/fdiskdoslabel.c
> > > @@ -230,6 +230,7 @@ void create_doslabel(struct fdisk_context *cxt)
> > >
> > > dos_init(cxt);
> > > fdisk_mbr_zeroize(cxt);
> > > + fdisk_label_change(cxt, "dos");
> > > set_all_unchanged();
> > > set_changed(0);
> > >
> > > diff --git a/fdisks/fdisksgilabel.c b/fdisks/fdisksgilabel.c
> > > index e38d98f..6001038 100644
> > > --- a/fdisks/fdisksgilabel.c
> > > +++ b/fdisks/fdisksgilabel.c
> > > @@ -780,6 +780,8 @@ create_sgilabel(struct fdisk_context *cxt)
> > > }
> > >
> > > fdisk_mbr_zeroize(cxt);
> > > + fdisk_label_change(cxt, "sgi");
> > > +
> > > sgilabel->magic = SSWAP32(SGI_LABEL_MAGIC);
> > > sgilabel->boot_part = SSWAP16(0);
> > > sgilabel->swap_part = SSWAP16(1);
> > > diff --git a/fdisks/fdisksunlabel.c b/fdisks/fdisksunlabel.c
> > > index 4123806..b63335c 100644
> > > --- a/fdisks/fdisksunlabel.c
> > > +++ b/fdisks/fdisksunlabel.c
> > > @@ -161,6 +161,7 @@ void create_sunlabel(struct fdisk_context *cxt)
> > >
> > > init();
> > > fdisk_mbr_zeroize(cxt);
> > > + fdisk_label_change(cxt, "sun");
> > >
> > > sunlabel->magic = SSWAP16(SUN_LABEL_MAGIC);
> > > sunlabel->sanity = SSWAP32(SUN_LABEL_SANE);
> > > diff --git a/fdisks/utils.c b/fdisks/utils.c
> > > index cf9484c..48dedfb 100644
> > > --- a/fdisks/utils.c
> > > +++ b/fdisks/utils.c
> > > @@ -44,6 +44,43 @@ static const struct fdisk_label *labels[] =
> > > &mac_label,
> > > };
> > >
> > > +/**
> > > + * fdisk_label_change:
> > > + * @cxt: fdisk context
> > > + * @name: new label name
> > > + *
> > > + * Updates the disk label type to the one specified by @name.
> > > + *
> > > + * Returns 0 on success, otherwise, a corresponding error.
> > > + */
> > > +int fdisk_label_change(struct fdisk_context *cxt, const char *name)
> > > +{
> > > + int i;
> > > +
> > > + if (!cxt || !cxt->label || !name)
> > > + return FDISK_ERROR_UNKNOWN;
> > > +
> > > + /* not really changing the label */
> > > + if (!strncmp(name, cxt->label->name, strlen(name)))
> > > + goto done;
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(labels); i++) {
> > > + if (strncmp(name, labels[i]->name, strlen(name)))
> > > + continue;
> > > +
> > > + /* found the new label */
> > > + memset(cxt->label, 0, sizeof(struct fdisk_label));
> > > + memcpy(cxt->label, labels[i], sizeof(struct fdisk_label));
> > > + DBG(LABEL, dbgprint("changing to a %s label\n", labels[i]->name));
> > > + goto done;
> > > + }
> > > +
> > > + /* couldn't find the requested label type */
> > > + return FDISK_ERROR_NOLABEL;
> > > +done:
> > > + return 0;
> > > +}
> > > +
> > > static int __probe_labels(struct fdisk_context *cxt)
> > > {
> > > int i, rc = 0;
> > > --
> > > 1.7.4.1
> > >
> > >
> > >
> > >
> > > --
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> > > the body of a message to majordomo@xxxxxxxxxxxxxxx
> > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
> > Petr
> >
>
>
> --
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Petr
--
Petr Uzel
IRC: ptr_uzl @ freenode
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