[dm-devel] multipath disk size

[Christophe Varoqui]

Arsene Gschwind a écrit :
> I've found something strange, 2 declaration of SERIAL_SIZE with 
> different sizes
> libmultipath/structs.h:#define SERIAL_SIZE              17
> path_priority/pp_balance_units/pp_balance_units.c:#define SERIAL_SIZE 255
>
> In my case the first buffer size is to small because pp->serial has a 
> size of 17 chars and when you look at my output it has 40 chars.
> By setting libmultipath/structs.h:#define SERIAL_SIZE    to 255 it 
> works for me and the returned volume size is correct.
> I'm not sure if this is the right solution, it would be great if 
> someone could verify that issue.
>
> Thanks a lot for your work
> Arsène
>
>
Very good catch.
get_serial() was happily overflowing.
Sorry for your being the first with a long-serial-hardware :)


Please try the following 2 patchs, with testing between to 2, please.

=== 1===
diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
--- a/libmultipath/discovery.c
+++ b/libmultipath/discovery.c
@@ -339,24 +339,26 @@ do_inq(int sg_fd, int cmddt, int evpd, u
         return -1;
 }

-int
-get_serial (char * str, int fd)
+static int
+get_serial (char * str, int maxlen, int fd)
 {
         int len = 0;
         char buff[MX_ALLOC_LEN + 1] = {0};

        if (fd < 0)
-                return 0;
+                return 1;

        if (0 == do_inq(fd, 0, 1, 0x80, buff, MX_ALLOC_LEN, 0)) {
                len = buff[3];
+               if (len >= maxlen)
+                       return 1;
                if (len > 0) {
                        memcpy(str, buff + 4, len);
                        str[len] = '\0';
                }
-               return 1;
+               return 0;
        }
-        return 0;
+        return 1;
 }

 static int
@@ -597,7 +599,7 @@ static int
 scsi_ioctl_pathinfo (struct path * pp, int mask)
 {
        if (mask & DI_SERIAL) {
-               get_serial(pp->serial, pp->fd);
+               get_serial(pp->serial, SERIAL_SIZE, pp->fd);
                condlog(3, "%s: serial = %s", pp->dev, pp->serial);
        }

diff --git a/libmultipath/discovery.h b/libmultipath/discovery.h
--- a/libmultipath/discovery.h
+++ b/libmultipath/discovery.h
@@ -30,7 +30,6 @@ int sysfs_get_size (char * sysfs_path, c
 int path_discovery (vector pathvec, struct config * conf, int flag);

 void basename (char *, char *);
-int get_serial (char * buff, int fd);
 int do_tur (char *);
 int devt2devname (char *, char *);
 int pathinfo (struct path *, vector hwtable, int mask);
diff --git a/path_priority/pp_balance_units/pp_balance_units.c 
b/path_priority/pp_balance_units/pp_balance_units.c
--- a/path_priority/pp_balance_units/pp_balance_units.c
+++ b/path_priority/pp_balance_units/pp_balance_units.c
@@ -172,7 +172,7 @@ do_inq(int sg_fd, int cmddt, int evpd, u
 }

 static int
-get_serial (char * str, char * devt)
+get_serial (char * str, int maxlen, char * devt)
 {
        int fd;
         int len;
@@ -181,20 +181,22 @@ get_serial (char * str, char * devt)
        fd = opennode(devt, O_RDONLY);

        if (fd < 0)
-                return 0;
+                return 1;

        if (0 == do_inq(fd, 0, 1, 0x80, buff, MX_ALLOC_LEN, 0)) {
                len = buff[3];
+               if (len >= maxlen)
+                       return 1;
                if (len > 0) {
                        memcpy(str, buff + 4, len);
                        buff[len] = '\0';
                }
                close(fd);
-               return 1;
+               return 0;
        }

        closenode(devt, fd);
-        return 0;
+        return 1;
 }

 static void *
@@ -358,7 +360,7 @@ get_paths (vector pathvec)
                        if (pos == BEFOREPG)
                                pos = INPG;

-                       get_serial(pp->serial, pp->dev_t);
+                       get_serial(pp->serial, SERIAL_SIZE, pp->dev_t);
                        vector_alloc_slot(pathvec);
                        vector_set_slot(pathvec, pp);
                        debug("store %s [%s]",
@@ -449,7 +451,7 @@ main (int argc, char **argv)
        if (optind<argc)
                strncpy(ref_path->dev_t, argv[optind], WORD_SIZE);

-       get_serial(ref_path->serial, ref_path->dev_t);
+       get_serial(ref_path->serial, SERIAL_SIZE, ref_path->dev_t);

        if (!ref_path->serial || !strlen(ref_path->serial))
                exit_tool(0);


==== 2 ====
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -2,7 +2,7 @@
 #define _STRUCTS_H

 #define WWID_SIZE              64
-#define SERIAL_SIZE            17
+#define SERIAL_SIZE            64
 #define NODE_NAME_SIZE         19
 #define PATH_STR_SIZE                  16
 #define PARAMS_SIZE            1024