Libguestfs - Dec 2014 - [PATCH] inspection: Not an installer if there are multiple partitions (RHBZ#1171666).

Regular EFI disks have /EFI on the first (VFAT) partition, but they
are not installers.

Fix this by only considering something to be an installer if it has a
single partition (or whole disks like ISOs).

Implementing this is quite complex since when checking a filesystem,
we don't have information about whether we are even looking at a
partition, nor about whether it's the first partition out of how many.
The majority of the commit is changing the code to collect that
information.
---
 src/guestfs-internal.h |  1 +
 src/inspect-fs-unix.c  | 31 ++++---------------------------
 src/inspect-fs.c       | 44 ++++++++++++++++++++++++++++++++++++++------
 src/inspect.c          | 22 ++++++++++++++++++++++
 4 files changed, 65 insertions(+), 33 deletions(-)

diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
index 0a4a6f2..0b25407 100644
--- a/src/guestfs-internal.h
+++ b/src/guestfs-internal.h
@@ -766,6 +766,7 @@ extern int guestfs___set_backend (guestfs_h *g, const char
*method);
 extern void guestfs___free_inspect_info (guestfs_h *g);
 extern char *guestfs___download_to_tmp (guestfs_h *g, struct inspect_fs *fs,
const char *filename, const char *basename, uint64_t max_size);
 extern struct inspect_fs *guestfs___search_for_root (guestfs_h *g, const char
*root);
+extern int guestfs___is_partition (guestfs_h *g, const char *partition);
 
 /* inspect-fs.c */
 extern int guestfs___is_file_nocase (guestfs_h *g, const char *);
diff --git a/src/inspect-fs-unix.c b/src/inspect-fs-unix.c
index 750c27b..5ba8beb 100644
--- a/src/inspect-fs-unix.c
+++ b/src/inspect-fs-unix.c
@@ -96,7 +96,6 @@ static char *resolve_fstab_device (guestfs_h *g, const char
*spec,
                                    Hash_table *md_map,
                                    enum inspect_os_type os_type);
 static int inspect_with_augeas (guestfs_h *g, struct inspect_fs *fs, const char
**configfiles, int (*f) (guestfs_h *, struct inspect_fs *));
-static int is_partition (guestfs_h *g, const char *partition);
 
 /* Hash structure for uuid->path lookups */
 typedef struct md_uuid {
@@ -1431,7 +1430,7 @@ resolve_fstab_device_xdev (guestfs_h *g, const char *type,
const char *disk,
   ITER_DRIVES (g, i, drv) {
     if (drv->name && STREQ (drv->name, name)) {
       device = safe_asprintf (g, "%s%s", devices[i], part);
-      if (!is_partition (g, device)) {
+      if (!guestfs___is_partition (g, device)) {
         free (device);
         return 0;
       }
@@ -1458,7 +1457,7 @@ resolve_fstab_device_xdev (guestfs_h *g, const char *type,
const char *disk,
      */
     if (i < count) {
       device = safe_asprintf (g, "%s%s", devices[i], part);
-      if (!is_partition (g, device)) {
+      if (!guestfs___is_partition (g, device)) {
         free (device);
         return 0;
       }
@@ -1491,7 +1490,7 @@ resolve_fstab_device_cciss (guestfs_h *g, const char
*disk, const char *part,
     if (drv->name && STREQ (drv->name, disk)) {
       if (part) {
         device = safe_asprintf (g, "%s%s", devices[i], part);
-        if (!is_partition (g, device)) {
+        if (!guestfs___is_partition (g, device)) {
           free (device);
           return 0;
         }
@@ -1536,7 +1535,7 @@ resolve_fstab_device_diskbyid (guestfs_h *g, const char
*part,
 
   /* Make the partition name and check it exists. */
   device = safe_asprintf (g, "/dev/sda%s", part);
-  if (!is_partition (g, device)) {
+  if (!guestfs___is_partition (g, device)) {
     free (device);
     return 0;
   }
@@ -1786,25 +1785,3 @@ make_augeas_path_expression (guestfs_h *g, const char
**configfiles)
   debug (g, "augeas pathexpr = %s", ret);
   return ret;
 }
-
-static int
-is_partition (guestfs_h *g, const char *partition)
-{
-  CLEANUP_FREE char *device = NULL;
-
-  guestfs_push_error_handler (g, NULL, NULL);
-
-  if ((device = guestfs_part_to_dev (g, partition)) == NULL) {
-    guestfs_pop_error_handler (g);
-    return 0;
-  }
-
-  if (guestfs_device_index (g, device) == -1) {
-    guestfs_pop_error_handler (g);
-    return 0;
-  }
-
-  guestfs_pop_error_handler (g);
-
-  return 1;
-}
diff --git a/src/inspect-fs.c b/src/inspect-fs.c
index e9cc2e9..7b116db 100644
--- a/src/inspect-fs.c
+++ b/src/inspect-fs.c
@@ -48,6 +48,7 @@ static int check_filesystem (guestfs_h *g, const char
*mountable,
                              const struct guestfs_internal_mountable *m,
                              int whole_device);
 static int extend_fses (guestfs_h *g);
+static int get_partition_context (guestfs_h *g, const char *partition, int
*partnum_ret, int *nr_partitions_ret);
 
 /* Find out if 'device' contains a filesystem.  If it does, add
  * another entry in g->fses.
@@ -140,17 +141,18 @@ check_filesystem (guestfs_h *g, const char *mountable,
                   const struct guestfs_internal_mountable *m,
                   int whole_device)
 {
+  int partnum = -1, nr_partitions = -1;
   /* Not CLEANUP_FREE, as it will be cleaned up with inspection info */
   char *windows_systemroot = NULL;
 
   if (extend_fses (g) == -1)
     return -1;
 
-  int partnum = -1;
-  if (!whole_device && m->im_type == MOUNTABLE_DEVICE) {
-    guestfs_push_error_handler (g, NULL, NULL);
-    partnum = guestfs_part_to_partnum (g, m->im_device);
-    guestfs_pop_error_handler (g);
+  if (!whole_device && m->im_type == MOUNTABLE_DEVICE &&
+      guestfs___is_partition (g, m->im_device)) {
+    if (get_partition_context (g, m->im_device,
+                               &partnum, &nr_partitions) == -1)
+      return -1;
   }
 
   struct inspect_fs *fs = &g->fses[g->nr_fses-1];
@@ -285,7 +287,7 @@ check_filesystem (guestfs_h *g, const char *mountable,
    * Skip these checks if it's not a whole device (eg. CD) or the
    * first partition (eg. bootable USB key).
    */
-  else if ((whole_device || partnum == 1) &&
+  else if ((whole_device || (partnum == 1 && nr_partitions == 1))
&&
            (guestfs_is_file (g, "/isolinux/isolinux.cfg") > 0 ||
             guestfs_is_dir (g, "/EFI/BOOT") > 0 ||
             guestfs_is_file (g, "/images/install.img") > 0 ||
@@ -330,6 +332,36 @@ extend_fses (guestfs_h *g)
   return 0;
 }
 
+/* Given a partition (eg. /dev/sda2) then return the partition number
+ * (eg. 2) and the total number of other partitions.
+ */
+static int
+get_partition_context (guestfs_h *g, const char *partition,
+                       int *partnum_ret, int *nr_partitions_ret)
+{
+  int partnum, nr_partitions;
+  CLEANUP_FREE char *device = NULL;
+  CLEANUP_FREE_PARTITION_LIST struct guestfs_partition_list *partitions = NULL;
+
+  partnum = guestfs_part_to_partnum (g, partition);
+  if (partnum == -1)
+    return -1;
+
+  device = guestfs_part_to_dev (g, partition);
+  if (device == NULL)
+    return -1;
+
+  partitions = guestfs_part_list (g, device);
+  if (partitions == NULL)
+    return -1;
+
+  nr_partitions = partitions->len;
+
+  *partnum_ret = partnum;
+  *nr_partitions_ret = nr_partitions;
+  return 0;
+}
+
 int
 guestfs___is_file_nocase (guestfs_h *g, const char *path)
 {
diff --git a/src/inspect.c b/src/inspect.c
index bdb45c3..8c00f80 100644
--- a/src/inspect.c
+++ b/src/inspect.c
@@ -638,3 +638,25 @@ guestfs___search_for_root (guestfs_h *g, const char *root)
          root);
   return NULL;
 }
+
+int
+guestfs___is_partition (guestfs_h *g, const char *partition)
+{
+  CLEANUP_FREE char *device = NULL;
+
+  guestfs_push_error_handler (g, NULL, NULL);
+
+  if ((device = guestfs_part_to_dev (g, partition)) == NULL) {
+    guestfs_pop_error_handler (g);
+    return 0;
+  }
+
+  if (guestfs_device_index (g, device) == -1) {
+    guestfs_pop_error_handler (g);
+    return 0;
+  }
+
+  guestfs_pop_error_handler (g);
+
+  return 1;
+}
-- 
2.1.0