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Chunyan Liu

2012-Nov-16 06:02 UTC

[PATCH]xenstore-chmod: handle arbitrary number of perms rather than MAX_PERMS constant

Constant MAX_PERMS 16 is too small to use in some occasions, e.g. if
there are more than 16 domU(s) on one hypervisor (it''s easy to
achieve) and one wants to do xenstore-chmod PATH to all domU(s). So,
remove MAX_PERMS limitation and make it as arbitrary number of perms.

Signed-off-by: Chunyan Liu <cyliu@suse.com>

diff -r 8b93ac0c93f3 tools/xenstore/xenstore_client.c
--- a/tools/xenstore/xenstore_client.c  Tue Nov 13 11:19:17 2012 +0000
+++ b/tools/xenstore/xenstore_client.c  Thu Nov 15 16:33:32 2012 +0800
@@ -25,7 +25,6 @@
 #define PATH_SEP ''/''
 #define MAX_PATH_LEN 256

-#define MAX_PERMS 16

 enum mode {
     MODE_unknown,
@@ -416,31 +415,31 @@ perform(enum mode mode, int optind, int
            break;
         }
         case MODE_chmod: {
-            struct xs_permissions perms[MAX_PERMS];
-            int nperms = 0;
+            struct xs_permissions *perms;
             /* save path pointer: */
             char *path = argv[optind++];
+            int nperms = argc - optind;
+            int i;
+            perms = (struct xs_permissions *)malloc(nperms *
sizeof(struct xs_permissions));
+            if (!perms)
+               err(1, NULL);
-            for (; argv[optind]; optind++, nperms++)
+            for (i = 0; argv[optind]; optind++, i++)
             {
-                if (MAX_PERMS <= nperms)
-                    errx(1, "Too many permissions specified.  "
-                        "Maximum per invocation is %d.", MAX_PERMS);
-
-                perms[nperms].id = atoi(argv[optind]+1);
+                perms[i].id = atoi(argv[optind]+1);

                 switch (argv[optind][0])
                 {
                 case ''n'':
-                    perms[nperms].perms = XS_PERM_NONE;
+                    perms[i].perms = XS_PERM_NONE;
                     break;
                 case ''r'':
-                    perms[nperms].perms = XS_PERM_READ;
+                    perms[i].perms = XS_PERM_READ;
                     break;
                 case ''w'':
-                    perms[nperms].perms = XS_PERM_WRITE;
+                    perms[i].perms = XS_PERM_WRITE;
                     break;
                 case ''b'':
-                    perms[nperms].perms = XS_PERM_READ | XS_PERM_WRITE;
+                    perms[i].perms = XS_PERM_READ | XS_PERM_WRITE;
                     break;
                 default:
                     errx(1, "Invalid permission specification:
''%c''",
@@ -449,6 +448,7 @@ perform(enum mode mode, int optind, int
             }

             do_chmod(path, perms, nperms, upto, recurse, xsh, xth);
+            free(perms);
             break;
         }
         case MODE_watch: {

Ian Campbell

2012-Nov-19 11:24 UTC

head link

Re: [PATCH]xenstore-chmod: handle arbitrary number of perms rather than MAX_PERMS constant

On Fri, 2012-11-16 at 06:02 +0000, Chunyan Liu wrote:> Constant MAX_PERMS 16 is too small to use in some occasions, e.g. if
> there are more than 16 domU(s) on one hypervisor (it''s easy to
> achieve) and one wants to do xenstore-chmod PATH to all domU(s). So,
> remove MAX_PERMS limitation and make it as arbitrary number of perms.
> 
> Signed-off-by: Chunyan Liu <cyliu@suse.com>
> 
> diff -r 8b93ac0c93f3 tools/xenstore/xenstore_client.c
> --- a/tools/xenstore/xenstore_client.c  Tue Nov 13 11:19:17 2012 +0000
> +++ b/tools/xenstore/xenstore_client.c  Thu Nov 15 16:33:32 2012 +0800
> @@ -25,7 +25,6 @@
>  #define PATH_SEP ''/''
>  #define MAX_PATH_LEN 256
> 
> -#define MAX_PERMS 16
> 
>  enum mode {
>      MODE_unknown,
> @@ -416,31 +415,31 @@ perform(enum mode mode, int optind, int
>             break;
>          }
>          case MODE_chmod: {
> -            struct xs_permissions perms[MAX_PERMS];
> -            int nperms = 0;
> +            struct xs_permissions *perms;
>              /* save path pointer: */
>              char *path = argv[optind++];
> +            int nperms = argc - optind;
> +            int i;
> +            perms = (struct xs_permissions *)malloc(nperms *
> sizeof(struct xs_permissions));
You could just do:
		struct xs_permissions perms[nperms];
and let the compiler allocate enough space on the stack.
> +            if (!perms)
> +               err(1, NULL);
> -            for (; argv[optind]; optind++, nperms++)
> +            for (i = 0; argv[optind]; optind++, i++)
>              {
> -                if (MAX_PERMS <= nperms)
> -                    errx(1, "Too many permissions specified.  "
> -                        "Maximum per invocation is %d.",
MAX_PERMS);
> -
> -                perms[nperms].id = atoi(argv[optind]+1);
> +                perms[i].id = atoi(argv[optind]+1);
> 
>                  switch (argv[optind][0])
>                  {
>                  case ''n'':
> -                    perms[nperms].perms = XS_PERM_NONE;
> +                    perms[i].perms = XS_PERM_NONE;
>                      break;
>                  case ''r'':
> -                    perms[nperms].perms = XS_PERM_READ;
> +                    perms[i].perms = XS_PERM_READ;
>                      break;
>                  case ''w'':
> -                    perms[nperms].perms = XS_PERM_WRITE;
> +                    perms[i].perms = XS_PERM_WRITE;
>                      break;
>                  case ''b'':
> -                    perms[nperms].perms = XS_PERM_READ | XS_PERM_WRITE;
> +                    perms[i].perms = XS_PERM_READ | XS_PERM_WRITE;
>                      break;
>                  default:
>                      errx(1, "Invalid permission specification:
''%c''",
> @@ -449,6 +448,7 @@ perform(enum mode mode, int optind, int
>              }
> 
>              do_chmod(path, perms, nperms, upto, recurse, xsh, xth);
> +            free(perms);
>              break;
>          }
>          case MODE_watch: {
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

Chunyan Liu

2012-Nov-20 02:51 UTC

head link

Re: [PATCH]xenstore-chmod: handle arbitrary number of perms rather than MAX_PERMS constant

2012/11/19 Ian Campbell <Ian.Campbell@citrix.com>:> On Fri, 2012-11-16 at 06:02 +0000, Chunyan Liu wrote:
>> Constant MAX_PERMS 16 is too small to use in some occasions, e.g. if
>> there are more than 16 domU(s) on one hypervisor (it''s easy to
>> achieve) and one wants to do xenstore-chmod PATH to all domU(s). So,
>> remove MAX_PERMS limitation and make it as arbitrary number of perms.
>>
>> Signed-off-by: Chunyan Liu <cyliu@suse.com>
>>
>> diff -r 8b93ac0c93f3 tools/xenstore/xenstore_client.c
>> --- a/tools/xenstore/xenstore_client.c  Tue Nov 13 11:19:17 2012 +0000
>> +++ b/tools/xenstore/xenstore_client.c  Thu Nov 15 16:33:32 2012 +0800
>> @@ -25,7 +25,6 @@
>>  #define PATH_SEP ''/''
>>  #define MAX_PATH_LEN 256
>>
>> -#define MAX_PERMS 16
>>
>>  enum mode {
>>      MODE_unknown,
>> @@ -416,31 +415,31 @@ perform(enum mode mode, int optind, int
>>             break;
>>          }
>>          case MODE_chmod: {
>> -            struct xs_permissions perms[MAX_PERMS];
>> -            int nperms = 0;
>> +            struct xs_permissions *perms;
>>              /* save path pointer: */
>>              char *path = argv[optind++];
>> +            int nperms = argc - optind;
>> +            int i;
>> +            perms = (struct xs_permissions *)malloc(nperms *
>> sizeof(struct xs_permissions));
>
> You could just do:
>                 struct xs_permissions perms[nperms];
> and let the compiler allocate enough space on the stack.Will update.
>> +            if (!perms)
>> +               err(1, NULL);
>> -            for (; argv[optind]; optind++, nperms++)
>> +            for (i = 0; argv[optind]; optind++, i++)
>>              {
>> -                if (MAX_PERMS <= nperms)
>> -                    errx(1, "Too many permissions specified. 
"
>> -                        "Maximum per invocation is %d.",
MAX_PERMS);
>> -
>> -                perms[nperms].id = atoi(argv[optind]+1);
>> +                perms[i].id = atoi(argv[optind]+1);
>>
>>                  switch (argv[optind][0])
>>                  {
>>                  case ''n'':
>> -                    perms[nperms].perms = XS_PERM_NONE;
>> +                    perms[i].perms = XS_PERM_NONE;
>>                      break;
>>                  case ''r'':
>> -                    perms[nperms].perms = XS_PERM_READ;
>> +                    perms[i].perms = XS_PERM_READ;
>>                      break;
>>                  case ''w'':
>> -                    perms[nperms].perms = XS_PERM_WRITE;
>> +                    perms[i].perms = XS_PERM_WRITE;
>>                      break;
>>                  case ''b'':
>> -                    perms[nperms].perms = XS_PERM_READ |
XS_PERM_WRITE;
>> +                    perms[i].perms = XS_PERM_READ | XS_PERM_WRITE;
>>                      break;
>>                  default:
>>                      errx(1, "Invalid permission specification:
''%c''",
>> @@ -449,6 +448,7 @@ perform(enum mode mode, int optind, int
>>              }
>>
>>              do_chmod(path, perms, nperms, upto, recurse, xsh, xth);
>> +            free(perms);
>>              break;
>>          }
>>          case MODE_watch: {
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xen.org
>> http://lists.xen.org/xen-devel
>
>
>
> _______________________________________________>
>> +            if (!perms)
>> +               err(1, NULL);
>> -            for (; argv[optind]; optind++, nperms++)
>> +            for (i = 0; argv[optind]; optind++, i++)
>>              {
>> -                if (MAX_PERMS <= nperms)
>> -                    errx(1, "Too many permissions specified. 
"
>> -                        "Maximum per invocation is %d.",
MAX_PERMS);
>> -
>> -                perms[nperms].id = atoi(argv[optind]+1);
>> +                perms[i].id = atoi(argv[optind]+1);
>>
>>                  switch (argv[optind][0])
>>                  {
>>                  case ''n'':
>> -                    perms[nperms].perms = XS_PERM_NONE;
>> +                    perms[i].perms = XS_PERM_NONE;
>>                      break;
>>                  case ''r'':
>> -                    perms[nperms].perms = XS_PERM_READ;
>> +                    perms[i].perms = XS_PERM_READ;
>>                      break;
>>                  case ''w'':
>> -                    perms[nperms].perms = XS_PERM_WRITE;
>> +                    perms[i].perms = XS_PERM_WRITE;
>>                      break;
>>                  case ''b'':
>> -                    perms[nperms].perms = XS_PERM_READ |
XS_PERM_WRITE;
>> +                    perms[i].perms = XS_PERM_READ | XS_PERM_WRITE;
>>                      break;
>>                  default:
>>                      errx(1, "Invalid permission specification:
''%c''",
>> @@ -449,6 +448,7 @@ perform(enum mode mode, int optind, int
>>              }
>>
>>              do_chmod(path, perms, nperms, upto, recurse, xsh, xth);
>> +            free(perms);
>>              break;
>>          }
>>          case MODE_watch: {
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xen.org
>> http://lists.xen.org/xen-devel
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
>
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
>

Xen devel - Nov 2012 - [PATCH]xenstore-chmod: handle arbitrary number of perms rather than MAX_PERMS constant

[PATCH]xenstore-chmod: handle arbitrary number of perms rather than MAX_PERMS constant

Re: [PATCH]xenstore-chmod: handle arbitrary number of perms rather than MAX_PERMS constant

Re: [PATCH]xenstore-chmod: handle arbitrary number of perms rather than MAX_PERMS constant