libfdisk: (dos) fix default partition start

The current code implements the default start as first free space, but
it does not check if the space is large enough.

Addresses: https://github.com/karelzak/util-linux/issues/1044
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libfdisk/src/alignment.c b/libfdisk/src/alignment.c
index cf7918056336145acfd548f4a2a079716bd68699..3d02546341145b6ec2d04f67a2b14cff860ea36d 100644 (file)
--- a/libfdisk/src/alignment.c
+++ b/libfdisk/src/alignment.c
@@ -110,7 +110,7 @@ fdisk_sector_t fdisk_align_lba(struct fdisk_context *cxt, fdisk_sector_t lba, in
                                res += sects_in_phy;
                }
        }
-
+/*
        if (lba != res)
                DBG(CXT, ul_debugobj(cxt, "LBA %12ju aligned-%s %12ju [grain=%lus]",
                                (uintmax_t) lba,
@@ -120,7 +120,7 @@ fdisk_sector_t fdisk_align_lba(struct fdisk_context *cxt, fdisk_sector_t lba, in
                                cxt->grain / cxt->sector_size));
        else
                DBG(CXT, ul_debugobj(cxt, "LBA %12ju already aligned", (uintmax_t)lba));
-
+*/
        return res;
 }
 
@@ -140,7 +140,7 @@ fdisk_sector_t fdisk_align_lba_in_range(struct fdisk_context *cxt,
 {
        fdisk_sector_t res;
 
-       DBG(CXT, ul_debugobj(cxt, "LBA: align in range <%ju..%ju>", (uintmax_t) start, (uintmax_t) stop));
+       /*DBG(CXT, ul_debugobj(cxt, "LBA: align in range <%ju..%ju>", (uintmax_t) start, (uintmax_t) stop));*/
 
        if (start + (cxt->grain / cxt->sector_size) <= stop) {
                start = fdisk_align_lba(cxt, start, FDISK_ALIGN_UP);

diff --git a/libfdisk/src/dos.c b/libfdisk/src/dos.c
index b30835897b149d1e0078d83562f3c2641a8cc5ce..bc7477b8e63f12e3d905cd640f7004759e474e50 100644 (file)
--- a/libfdisk/src/dos.c
+++ b/libfdisk/src/dos.c
@@ -988,6 +988,52 @@ static int get_start_from_user(    struct fdisk_context *cxt,
        return 0;
 }
 
+/* Returns last available sector in the free space pointed to by start. */
+static int find_last_free(
+                       struct fdisk_context *cxt,
+                       int logical,
+                       fdisk_sector_t begin,
+                       fdisk_sector_t stop,
+                       fdisk_sector_t *result)
+{
+       fdisk_sector_t last = stop;
+
+       size_t i = logical ? 4 : 0;
+
+       for ( ; i < cxt->label->nparts_max; i++) {
+               struct pte *pe = self_pte(cxt, i);
+
+               assert(pe);
+               fdisk_sector_t p_start = get_abs_partition_start(pe);
+               fdisk_sector_t p_end = get_abs_partition_end(pe);
+
+               if (is_cleared_partition(pe->pt_entry))
+                       continue;
+               /* count EBR and begin of the logical partition as used area */
+               if (pe->offset)
+                       p_start -= cxt->first_lba;
+
+               if ((p_start >= begin && p_start <= last) ||
+                   (p_end >= begin && p_end <= last)) {
+                       last = p_start - 1;
+               }
+               if (last < begin) {
+                       DBG(LABEL, ul_debug("no free space <%ju,%ju>",
+                                       (uintmax_t) begin, (uintmax_t) stop));
+                       return -ENOSPC;
+               }
+       }
+
+       if (last == begin)
+               last = stop;
+
+       DBG(LABEL, ul_debug("DOS: last free sector  <%ju,%ju>: %ju",
+                       (uintmax_t) begin, (uintmax_t) stop, (uintmax_t) last));
+
+       *result = last;
+       return 0;
+}
+
 static int find_last_free_sector_in_range(
                        struct fdisk_context *cxt,
                        int logical,
@@ -1113,6 +1159,7 @@ static int get_disk_ranges(struct fdisk_context *cxt, int logical,
        return 0;
 }
 
+/* first free sector on disk */
 static int find_first_free_sector(struct fdisk_context *cxt,
                                int logical,
                                fdisk_sector_t start,
@@ -1182,6 +1229,7 @@ static int add_partition(struct fdisk_context *cxt, size_t n,
 
                temp = start;
 
+               DBG(LABEL, ul_debug("DOS: >>> search for first free from %ju", start));
                rc = find_first_free_sector(cxt, is_logical, start, &dflt);
                if (rc == -ENOSPC)
                        fdisk_warnx(cxt, _("No free sectors available."));
@@ -1208,12 +1256,11 @@ static int add_partition(struct fdisk_context *cxt, size_t n,
                        break;
                if (start >= temp + fdisk_get_units_per_sector(cxt)
                    && read) {
-                       fdisk_info(cxt, _("Sector %llu is already allocated."),
-                                       temp);
+                       if (!pa || !pa->start_follow_default)
+                               fdisk_info(cxt, _("Sector %llu is already allocated."), temp);
                        temp = start;
                        read = 0;
-                       if (pa && (fdisk_partition_has_start(pa) ||
-                                  pa->start_follow_default))
+                       if (pa && fdisk_partition_has_start(pa))
                                break;
                }
 
@@ -1223,6 +1270,30 @@ static int add_partition(struct fdisk_context *cxt, size_t n,
                                return rc;
                        read = 1;
                }
+               if (pa && fdisk_partition_has_size(pa)) {
+                       fdisk_sector_t last;
+
+                       rc = find_last_free(cxt, is_logical, start, limit, &last);
+
+                       if (rc == 0 && last - start + 1 < fdisk_partition_get_size(pa)) {
+                               DBG(LABEL, ul_debug("DOS: area <%ju,%ju> too small [wanted=%ju aval=%ju]",
+                                                       (uintmax_t) start, (uintmax_t) last,
+                                                       fdisk_partition_get_size(pa),
+                                                       last - start));
+
+                               if (fdisk_partition_has_start(pa))
+                                       rc = -ENOSPC;
+                               else {
+                                       start = last + 1;
+                                       continue;
+                               }
+                       }
+                       if (rc == -ENOSPC) {
+                               fdisk_warnx(cxt, _("No free sectors available."));
+                               return rc;
+                       }
+               }
+
        } while (start != temp || !read);
 
        if (n == 4) {
@@ -1248,7 +1319,7 @@ static int add_partition(struct fdisk_context *cxt, size_t n,
                }
        }
 
-       rc = find_last_free_sector_in_range(cxt, is_logical, start, limit, &stop);
+       rc = find_last_free(cxt, is_logical, start, limit, &stop);
        if (rc == -ENOSPC)
                fdisk_warnx(cxt, _("No free sectors available."));
        if (rc)