libparted: enforce dos partition limit

The msdos partition table claimed a maximum partition count of 16
but would allow you to go beyond that.  This resulted in the kernel
not being informed of those partitions.  Corrected to enforce the
limit.

* NEWS (Bug fixes): Mention it.
* libparted/labels/dos.c (next_primary): Return -1 upon failure.
(next_logical): Stop no later than MAX_TOTAL_PART.
Throw exception and return -1 upon failure.
(msdos_partition_enumerate): Convert a negative partition number
return value from either of the above two to failure (return 0).
* tests/t9042-dos-partition-limit.sh: New file.
* tests/Makefile.am (TESTS): Add it.

diff --git a/NEWS b/NEWS
index 58a5f89..194903b 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,10 @@ GNU parted NEWS                                    -*- outline -*-
   parted has improved support for partitionable loopback devices
 
 ** Bug fixes
+  The msdos partition table claimed a maximum partition count of 16
+  but would allow you to go beyond that.  This resulted in the kernel
+  not being informed of those partitions.  Corrected to enforce the
+  limit.
 
   parted now exits nonzero for certain failures already diagnosed as "Error".
   For example, before this change, parted would exit successfully in spite

diff --git a/libparted/labels/dos.c b/libparted/labels/dos.c
index fc89170..3f3effe 100644 (file)
--- a/libparted/labels/dos.c
+++ b/libparted/labels/dos.c
@@ -2398,17 +2398,22 @@ next_primary (const PedDisk* disk)
                if (!ped_disk_get_partition (disk, i))
                        return i;
        }
-       return 0;
+       return -1;
 }
 
 static int _GL_ATTRIBUTE_PURE
 next_logical (const PedDisk* disk)
 {
        int     i;
-       for (i=5; 1; i++) {
+       for (i=5; i<=MAX_TOTAL_PART; i++) {
                if (!ped_disk_get_partition (disk, i))
                        return i;
        }
+       ped_exception_throw (
+               PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
+               _("cannot create any more partitions"),
+               disk->dev->path);
+       return -1;
 }
 
 static int
@@ -2427,7 +2432,8 @@ msdos_partition_enumerate (PedPartition* part)
                part->num = next_logical (part->disk);
        else
                part->num = next_primary (part->disk);
-
+       if (part->num == -1)
+               return 0;
        return 1;
 }
 

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 34b3bc5..77a1cae 100644 (file)
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -63,6 +63,7 @@ TESTS = \
   t9030-align-check.sh \
   t9040-many-partitions.sh \
   t9041-undetected-in-use-16th-partition.sh \
+  t9042-dos-partition-limit.sh \
   t9050-partition-table-types.sh
 
 EXTRA_DIST = \

diff --git a/tests/t9042-dos-partition-limit.sh b/tests/t9042-dos-partition-limit.sh
new file mode 100644 (file)
index 0000000..07e8f64
--- /dev/null
+++ b/tests/t9042-dos-partition-limit.sh
@@ -0,0 +1,74 @@
+#!/bin/sh
+# Ensure that parted enforces msdos partition limit
+
+# Copyright (C) 2010-2012 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../parted
+
+require_root_
+require_scsi_debug_module_
+
+grep '^#define USE_BLKID 1' "$CONFIG_HEADER" > /dev/null ||
+  skip_ 'this system lacks a new-enough libblkid'
+
+ss=$sector_size_
+partition_sectors=256  # sectors per partition
+n_partitions=13        # how many partitions to create
+start=2048             # start sector for the first partition
+
+n_sectors=$(($start + n_partitions * partition_sectors))
+
+sectors_per_MiB=$((1024 * 1024 / ss))
+n_MiB=$(((n_sectors + sectors_per_MiB - 1) / sectors_per_MiB))
+# create memory-backed device
+scsi_debug_setup_ sector_size=$ss dev_size_mb=$n_MiB > dev-name ||
+  skip_ 'failed to create scsi_debug device'
+scsi_dev=$(cat dev-name)
+
+n=$((n_MiB * sectors_per_MiB))
+printf '%s\n' "BYT;" \
+    "$scsi_dev:${n}s:scsi:$ss:$ss:msdos:Linux scsi_debug;" \
+    "1:$((start-2))s:$((start-2+4098-1))s:4098s:::lba;" \
+  > exp || fail=1
+
+parted -s $scsi_dev mklabel msdos || fail=1
+parted -s -a min $scsi_dev mkpart extended 2046s 100% || fail=1
+
+i=1
+while :; do
+    end=$((start + partition_sectors - 2))
+    parted -s -a min $scsi_dev mkpart logical ${start}s ${end}s || fail=1
+    printf "$((i+4)):${start}s:${end}s:$((end-start+1))s:::;\n" >> exp
+    test $i = $((n_partitions - 1)) && break
+    start=$((start + partition_sectors))
+    i=$((i+1))
+done
+
+parted -m -s $scsi_dev u s p > out || fail=1
+compare exp out || fail=1
+
+start=$((start + partition_sectors))
+end=$((start + partition_sectors - 2))
+
+#try one more partition than allowed, make sure it fails
+
+parted -s -a min $scsi_dev mkpart logical ${start}s ${end}s > out 2>&1
+cat <<EOF > exp
+Error: cannot create any more partitions
+EOF
+compare exp out || fail=1
+
+Exit $fail