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.
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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>
> Petr
>
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