On Thu, 30 Apr 2015 10:44:23 +0800 Guoqing Jiang <gqJiang@xxxxxxxx> wrote:
> NeilBrown wrote:
> > On Fri, 24 Apr 2015 15:30:34 +0800 gqjiang@xxxxxxxx wrote:
> >
> >
> >> From: Guoqing Jiang <gqjiang@xxxxxxxx>
> >>
> >> For a clustered MD, create bitmaps equal to number of nodes so
> >> each node has an independent bitmap.
> >>
> >> Only the first bitmap is has the bits set so that the first node
> >> that assembles the device also performs the sync.
> >>
> >> The bitmaps are aligned to 4k boundaries.
> >>
> >> On-disk format:
> >>
> >> 0 4k 8k 12k
> >> -------------------------------------------------------------------
> >> | idle | md super | bm super [0] + bits |
> >> | bm bits[0, contd] | bm super[1] + bits | bm bits[1, contd] |
> >> | bm super[2] + bits | bm bits [2, contd] | bm super[3] + bits |
> >> | bm bits [3, contd] | | |
> >>
> >> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
> >> Signed-off-by: Guoqing Jiang <gqjiang@xxxxxxxx>
> >> ---
> >> Create.c | 3 ++-
> >> bitmap.h | 7 +++++--
> >> mdadm.8.in | 7 ++++++-
> >> mdadm.c | 17 ++++++++++++++++-
> >> super1.c | 59 +++++++++++++++++++++++++++++++++++++++++------------------
> >> 5 files changed, 70 insertions(+), 23 deletions(-)
> >>
> >> diff --git a/Create.c b/Create.c
> >> index cd5485b..9663dc4 100644
> >> --- a/Create.c
> >> +++ b/Create.c
> >> @@ -752,7 +752,8 @@ int Create(struct supertype *st, char *mddev,
> >> #endif
> >> }
> >>
> >> - if (s->bitmap_file && strcmp(s->bitmap_file, "internal")==0) {
> >> + if (s->bitmap_file && (strcmp(s->bitmap_file, "internal")==0
> >> + || strcmp(s->bitmap_file, "clustered")==0)) {
> >> if ((vers%100) < 2) {
> >> pr_err("internal bitmaps not supported by this kernel.\n");
> >> goto abort_locked;
> >> diff --git a/bitmap.h b/bitmap.h
> >> index c8725a3..adbf0b4 100644
> >> --- a/bitmap.h
> >> +++ b/bitmap.h
> >> @@ -154,8 +154,11 @@ typedef struct bitmap_super_s {
> >> __u32 chunksize; /* 52 the bitmap chunk size in bytes */
> >> __u32 daemon_sleep; /* 56 seconds between disk flushes */
> >> __u32 write_behind; /* 60 number of outstanding write-behind writes */
> >> -
> >> - __u8 pad[256 - 64]; /* set to zero */
> >> + __u32 sectors_reserved; /* 64 number of 512-byte sectors that are
> >> + * reserved for the bitmap. */
> >> + __u32 nodes; /* 68 the maximum number of nodes in cluster. */
> >> + __u8 cluster_name[64]; /* 72 cluster name to which this md belongs */
> >> + __u8 pad[256 - 136]; /* set to zero */
> >> } bitmap_super_t;
> >>
> >
> > I missed this the first time, but these fields that you have added need to be
> > added to sb_le_to_cpu().
> >
> >
> I guess only nodes need to be added as follows:
> sb->nodes = __le32_to_cpu(sb->nodes);
Why not "sectors_reserved". It may not be used, but best to be consistent.
>
> Does the cluster_name need to be addressed too? Like.
> for (i = 0; i < 64; i++)
> sb->cluster_name[i] = (unsigned
> char)__le16_to_cpu(sb->cluster_name[i]);
No, cluster_name is __u8, and they aren't affected by CPU endian-ness.
Thanks,
NeilBrown
>
> Thanks,
> Guoqing
> > NeilBrown
> >
>
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