sysctl diskinit tailq foreach

[Alexander Bluhm]

Hi,

I would like to use TAILQ_FOREACH to traverse the disk list.
Code is easier to read.

ok?

bluhm

Index: kern/kern_sysctl.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/kern/kern_sysctl.c,v
retrieving revision 1.396
diff -u -p -r1.396 kern_sysctl.c
--- kern/kern_sysctl.c  30 Oct 2021 23:24:48 -0000      1.396
+++ kern/kern_sysctl.c  21 Dec 2021 14:23:02 -0000
@@ -121,7 +121,6 @@
 extern struct forkstat forkstat;
 extern struct nchstats nchstats;
 extern int nselcoll, fscale;
-extern struct disklist_head disklist;
 extern fixpt_t ccpu;
 extern long numvnodes;
 extern int allowdt;
@@ -2132,14 +2131,14 @@ sysctl_diskinit(int update, struct proc 
        struct diskstats *sdk;
        struct disk *dk;
        const char *duid;
-       int i, tlen, l;
+       int error, tlen, l;
 
-       if ((i = rw_enter(&sysctl_disklock, RW_WRITE|RW_INTR)) != 0)
-               return i;
+       if ((error = rw_enter(&sysctl_disklock, RW_WRITE|RW_INTR)) != 0)
+               return error;
 
        if (disk_change) {
-               for (dk = TAILQ_FIRST(&disklist), tlen = 0; dk;
-                   dk = TAILQ_NEXT(dk, dk_link)) {
+               tlen = 0;
+               TAILQ_FOREACH(dk, &disklist, dk_link) {
                        if (dk->dk_name)
                                tlen += strlen(dk->dk_name);
                        tlen += 18;     /* label uid + separators */
@@ -2159,8 +2158,9 @@ sysctl_diskinit(int update, struct proc 
                disknameslen = tlen;
                disknames[0] = '\0';
 
-               for (dk = TAILQ_FIRST(&disklist), i = 0, l = 0; dk;
-                   dk = TAILQ_NEXT(dk, dk_link), i++) {
+               l = 0;
+               sdk = diskstats;
+               TAILQ_FOREACH(dk, &disklist, dk_link) {
                        duid = NULL;
                        if (dk->dk_label && !duid_iszero(dk->dk_label->d_uid))
                                duid = duid_format(dk->dk_label->d_uid);
@@ -2168,7 +2168,6 @@ sysctl_diskinit(int update, struct proc 
                            dk->dk_name ? dk->dk_name : "",
                            duid ? duid : "");
                        l += strlen(disknames + l);
-                       sdk = diskstats + i;
                        strlcpy(sdk->ds_name, dk->dk_name,
                            sizeof(sdk->ds_name));
                        mtx_enter(&dk->dk_mtx);
@@ -2182,6 +2181,7 @@ sysctl_diskinit(int update, struct proc 
                        sdk->ds_timestamp = dk->dk_timestamp;
                        sdk->ds_time = dk->dk_time;
                        mtx_leave(&dk->dk_mtx);
+                       sdk++;
                }
 
                /* Eliminate trailing comma */
@@ -2190,9 +2190,8 @@ sysctl_diskinit(int update, struct proc 
                disk_change = 0;
        } else if (update) {
                /* Just update, number of drives hasn't changed */
-               for (dk = TAILQ_FIRST(&disklist), i = 0; dk;
-                   dk = TAILQ_NEXT(dk, dk_link), i++) {
-                       sdk = diskstats + i;
+               sdk = diskstats;
+               TAILQ_FOREACH(dk, &disklist, dk_link) {
                        strlcpy(sdk->ds_name, dk->dk_name,
                            sizeof(sdk->ds_name));
                        mtx_enter(&dk->dk_mtx);
@@ -2206,6 +2205,7 @@ sysctl_diskinit(int update, struct proc 
                        sdk->ds_timestamp = dk->dk_timestamp;
                        sdk->ds_time = dk->dk_time;
                        mtx_leave(&dk->dk_mtx);
+                       sdk++;
                }
        }
        rw_exit_write(&sysctl_disklock);