Re: [Xen-devel] [PATCH] blktap2: fix gap in tapdisk2 disk_type numbering

[Daniel Stodden <daniel.stodden@xxxxxxxxxx>]

On Fri, 2011-02-25 at 13:41 -0500, Shriram Rajagopalan wrote:
> # HG changeset patch
> # User Shriram Rajagopalan <rshriram@xxxxxxxxx>
> # Date 1298659167 28800
> # Node ID f16d772fdb6c58518299d4c3780b846bcbee6165
> # Parent  d9c73cceb29715bfafada4d80e79787cb4666816
> blktap2: fix gap in tapdisk2 disk_type numbering
> 
> Make the DISK_TYPE_* id numbering in tapdisk-disktypes.h contiguous.
> Currently, id 8 is unallocated causing a null disk type entry in
> tapdisk_disk_drivers array in tapdisk-disktypes.c. This causes the
> function tapdisk_disktype_find() to return an error on encountering
> disk types >7 (remus:, log:, etc.).
> 
> Signed-off-by: Shriram Rajagopalan <rshriram@xxxxxxxxx>
> 
> diff -r d9c73cceb297 -r f16d772fdb6c tools/blktap2/drivers/tapdisk-disktype.h
> --- a/tools/blktap2/drivers/tapdisk-disktype.h        Fri Feb 25 10:29:53 
> 2011 -0800
> +++ b/tools/blktap2/drivers/tapdisk-disktype.h        Fri Feb 25 10:39:27 
> 2011 -0800
> @@ -37,9 +37,9 @@
>  #define DISK_TYPE_RAM         5
>  #define DISK_TYPE_QCOW        6
>  #define DISK_TYPE_BLOCK_CACHE 7
> -#define DISK_TYPE_LOG         9
> -#define DISK_TYPE_REMUS       10
> -#define DISK_TYPE_VINDEX      11
> +#define DISK_TYPE_LOG         8
> +#define DISK_TYPE_REMUS       9
> +#define DISK_TYPE_VINDEX      10
>  
>  #define DISK_TYPE_NAME_MAX    32

Ack, unless you think the the option of making tapdisk_disktype_find
just skip over holes be cleaner?

Not sure if the patch below applies cleanly, but you'll get the idea.

Daniel

changeset:   583:d83dab01b6fa
user:        Daniel Stodden <daniel.stodden@xxxxxxxxxx>
date:        Tue Feb 15 01:37:44 2011 -0800
summary:     Allow for holes in tapdisk_disk_types.

diff -r 37f55e6d34ca -r d83dab01b6fa drivers/tapdisk-disktype.c
--- a/drivers/tapdisk-disktype.c        Tue Feb 15 01:37:44 2011 -0800
+++ b/drivers/tapdisk-disktype.c        Tue Feb 15 01:37:44 2011 -0800
@@ -154,13 +154,19 @@
        0,
 };
 
+#define ARRAY_SIZE(_a) (sizeof(_a)/sizeof((_a)[0]))
+
 int
 tapdisk_disktype_find(const char *name)
 {
-       const disk_info_t *info;
        int i;
 
-       for (i = 0; info = tapdisk_disk_types[i], info != NULL; ++i) {
+       for (i = 0; i < ARRAY_SIZE(tapdisk_disk_types); i++) {
+               const disk_info_t *info = tapdisk_disk_types[i];
+
+               if (!info)
+                       continue;
+
                if (strcmp(name, info->name))
                        continue;



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel