On Tue, 23 Mar 2010 09:04:19 +0100
Luca Berra <bluca@xxxxxxxxxx> wrote:
> On Mon, Mar 22, 2010 at 09:56:01PM -0600, Randy Terbush wrote:
> >Having a go at building a raid5 array using the new imsm support and
> >having good luck keeping drives in the array, etc. Nice work. I have a
> >few questions though as I am having some trouble figuring out how to
> >properly start this container.
> >
> ># mdadm --version
> >mdadm - v3.1.2 - 10th March 2010
> >
> ># mdadm -Es
> >ARRAY metadata=imsm UUID=30223250:76fd248b:50280919:0836b7f0
> >ARRAY /dev/md/Volume0 container=30223250:76fd248b:50280919:0836b7f0
> >member=0 UUID=8a4ae452:da1e7832:70ecf895:eb58229c
> >
> ># ls -l /dev/md/
> >total 0
> >lrwxrwxrwx 1 root root 6 Mar 22 20:54 0 -> ../md0
> >lrwxrwxrwx 1 root root 8 Mar 22 20:54 127 -> ../md127
> >lrwxrwxrwx 1 root root 8 Mar 22 20:54 Volume0_0 -> ../md127
> >
> >As you can see, the name for the link in /dev/md does not agree with
> >the name that the Examine is coming up with.
> please read mdadm.conf manpage, under the section "HOMEHOST"
>
> >Is it better to just forgo the ARRAY statements and go with an AUTO +imsm?
> >
> >And last, does the concept of a write-intent bitmap make sense on an
> >imsm container? If so, I get a segv if trying to run mdadm /dev/mdX
> >-Gb internal on either device.
>
> i don't believe it makes sense at all, surely imsm do not support an
> internal bitmap (no provisioning for it in the metadata)
>
> The attached patch completely disables bitmap support for arrays with
> externally managed metadata.
Thanks for the patch. However I would prefer to disable bitmap support for
those metadata formats which report that they don't support it.
Thus the following patch.
Thanks,
NeilBrown
diff --git a/Create.c b/Create.c
index 909ac5d..8f6e6e7 100644
--- a/Create.c
+++ b/Create.c
@@ -651,6 +651,11 @@ int Create(struct supertype *st, char *mddev,
fprintf(stderr, Name ": internal bitmaps not supported by this kernel.\n");
goto abort;
}
+ if (!st->ss->add_internal_bitmap) {
+ fprintf(stderr, Name ": internal bitmaps not supported with %s metadata\n",
+ st->ss->name);
+ goto abort;
+ }
if (!st->ss->add_internal_bitmap(st, &bitmap_chunk,
delay, write_behind,
bitmapsize, 1, major_num)) {
diff --git a/Grow.c b/Grow.c
index 6264996..053a372 100644
--- a/Grow.c
+++ b/Grow.c
@@ -288,6 +288,11 @@ int Grow_addbitmap(char *devname, int fd, char *file, int chunk, int delay, int
return 1;
} else if (strcmp(file, "internal") == 0) {
int d;
+ if (st->ss->add_internal_bitmap == NULL) {
+ fprintf(stderr, Name ": Internal bitmaps not supported "
+ "with %s metadata\n", st->ss->name);
+ return 1;
+ }
for (d=0; d< st->max_devs; d++) {
mdu_disk_info_t disk;
char *dv;
diff --git a/bitmap.c b/bitmap.c
index 088e37d..beef2dc 100644
--- a/bitmap.c
+++ b/bitmap.c
@@ -227,9 +227,13 @@ bitmap_info_t *bitmap_file_read(char *filename, int brief, struct supertype **st
if (!st) {
/* just look at device... */
lseek(fd, 0, 0);
- } else {
+ } else if (!st->ss->locate_bitmap) {
+ fprintf(stderr, Name ": No bitmap possible with %s metadata\n",
+ st->ss->name);
+ return NULL;
+ } else
st->ss->locate_bitmap(st, fd);
- }
+
ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
*stp = st;
} else {
--
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