Use size of largest chunk of free space, not total of all chunks

of free space, when checking for sufficient space to add a
partition. As a side-benefit the list of free chunks only needs
to be built once.

diff --git a/sbin/disklabel/editor.c b/sbin/disklabel/editor.c
index 5369a7f..c148f6b 100644 (file)
--- a/sbin/disklabel/editor.c
+++ b/sbin/disklabel/editor.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: editor.c,v 1.388 2023/01/14 18:21:46 krw Exp $        */
+/*     $OpenBSD: editor.c,v 1.389 2023/01/16 16:49:16 krw Exp $        */
 
 /*
  * Copyright (c) 1997-2000 Todd C. Miller <millert@openbsd.org>
@@ -816,20 +816,26 @@ editor_add(struct disklabel *lp, char *p)
        const struct diskchunk *chunk;
        char buf[2];
        int partno;
-       u_int64_t freesectors, new_offset, new_size;
+       u_int64_t new_offset, new_size;
 
-       freesectors = editor_countfree(lp);
+       chunk = free_chunks(lp, -1);
+       new_size = new_offset = 0;
+       for (; chunk->start != 0 || chunk->stop != 0; chunk++) {
+               if (chunk->stop - chunk->start > new_size) {
+                       new_size = chunk->stop - chunk->start;
+                       new_offset = chunk->start;
+               }
+       }
 
-       /* XXX - prompt user to steal space from another partition instead */
 #ifdef SUN_CYLCHECK
-       if ((lp->d_flags & D_VENDOR) && freesectors < lp->d_secpercyl) {
+       if ((lp->d_flags & D_VENDOR) && new_size < lp->d_secpercyl) {
                fputs("No space left, you need to shrink a partition "
                    "(need at least one full cylinder)\n",
                    stderr);
                return;
        }
 #endif
-       if (freesectors == 0) {
+       if (new_size == 0) {
                fputs("No space left, you need to shrink a partition\n",
                    stderr);
                return;
@@ -862,11 +868,13 @@ editor_add(struct disklabel *lp, char *p)
        }
        pp = &lp->d_partitions[partno];
 
-       if (pp->p_fstype != FS_UNUSED && DL_GETPSIZE(pp) != 0) {
+       if (partno < lp->d_npartitions && pp->p_fstype != FS_UNUSED &&
+           DL_GETPSIZE(pp) != 0) {
                fprintf(stderr, "Partition '%c' exists.  Delete it first.\n",
                    p[0]);
                return;
        }
+       memset(pp, 0, sizeof(*pp));
 
        /*
         * Increase d_npartitions if necessary. Ensure all new partitions are
@@ -875,22 +883,6 @@ editor_add(struct disklabel *lp, char *p)
        for(; lp->d_npartitions <= partno; lp->d_npartitions++)
                memset(&lp->d_partitions[lp->d_npartitions], 0, sizeof(*pp));
 
-       /* Make sure selected partition is zero'd too. */
-       memset(pp, 0, sizeof(*pp));
-       chunk = free_chunks(lp, -1);
-
-       /*
-        * Since we know there's free space, there must be at least one
-        * chunk. So find the largest chunk and assume we want to add the
-        * partition in that free space.
-        */
-       new_size = new_offset = 0;
-       for (; chunk->start != 0 || chunk->stop != 0; chunk++) {
-               if (chunk->stop - chunk->start > new_size) {
-                       new_size = chunk->stop - chunk->start;
-                       new_offset = chunk->start;
-               }
-       }
        DL_SETPSIZE(pp, new_size);
        DL_SETPOFFSET(pp, new_offset);
        pp->p_fstype = partno == 1 ? FS_SWAP : FS_BSDFFS;