[src/trunk]: src/lib/libutil Teach getdiskrawname and getdiskcookedname about...

[brad <brad%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a652c14462ec
branches:  trunk
changeset: 964920:a652c14462ec
user:      brad <brad%NetBSD.org@localhost>
date:      Thu Aug 22 20:23:43 2019 +0000

description:
Teach getdiskrawname and getdiskcookedname about zvols.

Reviewed by Christos

diffstat:

 lib/libutil/getdiskrawname.c |  92 +++++++++++++++++++++++++++++++++----------
 1 files changed, 71 insertions(+), 21 deletions(-)

diffs (151 lines):

diff -r c0d046275233 -r a652c14462ec lib/libutil/getdiskrawname.c
--- a/lib/libutil/getdiskrawname.c      Thu Aug 22 18:15:44 2019 +0000
+++ b/lib/libutil/getdiskrawname.c      Thu Aug 22 20:23:43 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: getdiskrawname.c,v 1.5 2014/09/17 23:54:42 christos Exp $      */
+/*     $NetBSD: getdiskrawname.c,v 1.6 2019/08/22 20:23:43 brad Exp $  */
 
 /*-
  * Copyright (c) 2012 The NetBSD Foundation, Inc.
@@ -29,7 +29,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: getdiskrawname.c,v 1.5 2014/09/17 23:54:42 christos Exp $");
+__RCSID("$NetBSD: getdiskrawname.c,v 1.6 2019/08/22 20:23:43 brad Exp $");
 
 #include <sys/stat.h>
 
@@ -70,10 +70,74 @@
        return buf;
 }
 
+/*
+ * zvol device names look like:
+ * /dev/zvol/dsk/pool_name/.../volume_name
+ * /dev/zvol/rdsk/pool_name/.../volume_name
+ *
+ * ZFS pools can be divided nearly to infinity
+ *
+ * This allows for 16 pool names, which one would hope would be enough
+ */
+#define DISKMAXPARTS 20
+static int
+calc_zvol_name(char *buf, size_t bufsiz, const char *name, const char *raw)
+{
+       char copyname[PATH_MAX];
+       char *names[DISKMAXPARTS];
+       char *last, *p;
+       size_t i = 0;
+
+       strlcpy(copyname, name, sizeof(copyname));
+       for (p = strtok_r(copyname, "/", &last); p;
+            p = strtok_r(NULL, "/", &last)) {
+               if (i >= DISKMAXPARTS) {
+                       errno =  ENOSPC;
+                       return -1;
+               }
+               names[i++] = p;
+       }
+
+       if (i < 4) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       snprintf(buf, bufsiz, "/dev/zvol/%sdsk", raw);
+       for (size_t j = 3; j < i; j++) {
+               strlcat(buf, "/", bufsiz);
+               strlcat(buf, names[j], bufsiz);
+       }
+       return 0;
+}
+
+static int
+calc_name(char *buf, size_t bufsiz, const char *name, const char *raw)
+{
+       int skip = 1;
+
+       if (strncmp("/dev/zvol/", name, 10) == 0)
+               return calc_zvol_name(buf, bufsiz, name, raw);
+
+       const char *dp = strrchr(name, '/');
+       if (!*raw && ((dp != NULL && dp[1] != 'r')
+               || (dp == NULL && name[0] != 'r'))) {
+               errno = EINVAL;
+               return -1;
+       }
+       if (raw[0] != 'r')
+               skip = 2;
+       if (dp != NULL)
+               snprintf(buf, bufsiz, "%.*s/%s%s", (int)(dp - name),
+                   name, raw, dp + skip);
+       else
+               snprintf(buf, bufsiz, "%s%s", raw, name);
+       return 0;
+}
+
 const char *
 getdiskrawname(char *buf, size_t bufsiz, const char *name)
 {
-       const char *dp;
        struct stat st;
        char dest[PATH_MAX];
 
@@ -82,8 +146,6 @@
                return NULL;
        }
 
-       dp = strrchr(name, '/');
-
        if (stat(name, &st) == -1)
                return NULL;
 
@@ -92,10 +154,8 @@
                return NULL;
        }
 
-       if (dp != NULL)
-               (void)snprintf(buf, bufsiz, "%.*s/r%s", (int)(dp - name), name, dp + 1);
-       else
-               (void)snprintf(buf, bufsiz, "r%s", name);
+       if (calc_name(buf, bufsiz, name, "r") == -1)
+               return NULL;
 
        return buf;
 }
@@ -103,7 +163,6 @@
 const char *
 getdiskcookedname(char *buf, size_t bufsiz, const char *name)
 {
-       const char *dp;
        struct stat st;
        char dest[PATH_MAX];
 
@@ -112,13 +171,6 @@
                return NULL;
        }
 
-       dp = strrchr(name, '/');
-
-       if ((dp != NULL && dp[1] != 'r') || (dp == NULL && name[0] != 'r')) {
-               errno = EINVAL;
-               return NULL;
-       }
-
        if (stat(name, &st) == -1)
                return NULL;
 
@@ -127,10 +179,8 @@
                return NULL;
        }
 
-       if (dp != NULL)
-               (void)snprintf(buf, bufsiz, "%.*s/%s", (int)(dp - name), name, dp + 2);
-       else
-               (void)snprintf(buf, bufsiz, "%s", name + 1);
+       if (calc_name(buf, bufsiz, name, "") == -1)
+               return NULL;
 
        return buf;
 }