From ba1ee149fe81cf4061e53eecb0ec0cc1aee63da7 Mon Sep 17 00:00:00 2001
From: Pino Toscano <ptoscano@redhat.com>
Date: Tue, 6 Dec 2016 16:08:12 +0100
Subject: [PATCH] inspect: gather info from /usr filesystems as well
 (RHBZ#1401474)

Flag the filesystems for Linux /usr properly as USR role, and detect
some data out of it, like the distro information from an os-release
(if present), and the architecture (since the binaries used for our
architecture check will be available there only).

Later on, collect the results in a way similar to what is done for
CoreOS: for each non-CoreOS root, try to find its /usr filesystem, and
if found then merge what is missing from root; in the last case, also
override the distro inspection data (version, product name) if available
in /usr.

(cherry picked from commit 1d86b3768956f818262a5189bb1ba996dedbf531)
---
 src/guestfs-internal.h |  1 +
 src/inspect-fs-unix.c  | 26 ++++++++++++++++
 src/inspect-fs.c       |  6 ++--
 src/inspect.c          | 81 ++++++++++++++++++++++++++++++++++++++++++++++++--
 4 files changed, 109 insertions(+), 5 deletions(-)

diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
index eb201aa..0f5f975 100644
--- a/src/guestfs-internal.h
+++ b/src/guestfs-internal.h
@@ -795,6 +795,7 @@ extern void guestfs_int_merge_fs_inspections (guestfs_h *g, struct inspect_fs *d
 
 /* inspect-fs-unix.c */
 extern int guestfs_int_check_linux_root (guestfs_h *g, struct inspect_fs *fs);
+extern int guestfs_int_check_linux_usr (guestfs_h *g, struct inspect_fs *fs);
 extern int guestfs_int_check_freebsd_root (guestfs_h *g, struct inspect_fs *fs);
 extern int guestfs_int_check_netbsd_root (guestfs_h *g, struct inspect_fs *fs);
 extern int guestfs_int_check_openbsd_root (guestfs_h *g, struct inspect_fs *fs);
diff --git a/src/inspect-fs-unix.c b/src/inspect-fs-unix.c
index 8b7a7ee..48c4fd2 100644
--- a/src/inspect-fs-unix.c
+++ b/src/inspect-fs-unix.c
@@ -813,6 +813,32 @@ guestfs_int_check_linux_root (guestfs_h *g, struct inspect_fs *fs)
   return 0;
 }
 
+/* The currently mounted device looks like a Linux /usr. */
+int
+guestfs_int_check_linux_usr (guestfs_h *g, struct inspect_fs *fs)
+{
+  int r;
+
+  fs->type = OS_TYPE_LINUX;
+  fs->role = OS_ROLE_USR;
+
+  if (guestfs_is_file_opts (g, "/lib/os-release",
+                            GUESTFS_IS_FILE_OPTS_FOLLOWSYMLINKS, 1, -1) > 0) {
+    r = parse_os_release (g, fs, "/lib/os-release");
+    if (r == -1)        /* error */
+      return -1;
+    if (r == 1)         /* ok - detected the release from this file */
+      goto skip_release_checks;
+  }
+
+ skip_release_checks:;
+
+  /* Determine the architecture. */
+  check_architecture (g, fs);
+
+  return 0;
+}
+
 /* The currently mounted device is known to be a FreeBSD root. */
 int
 guestfs_int_check_freebsd_root (guestfs_h *g, struct inspect_fs *fs)
diff --git a/src/inspect-fs.c b/src/inspect-fs.c
index 58f08b8..f6c2656 100644
--- a/src/inspect-fs.c
+++ b/src/inspect-fs.c
@@ -247,8 +247,10 @@ check_filesystem (guestfs_h *g, const char *mountable,
            is_dir_bin &&
            is_dir_share &&
            guestfs_is_dir (g, "/local") > 0 &&
-           guestfs_is_file (g, "/etc/fstab") == 0)
-    ;
+           guestfs_is_file (g, "/etc/fstab") == 0) {
+    if (guestfs_int_check_linux_usr (g, fs) == -1)
+      return -1;
+  }
   /* CoreOS /usr? */
   else if (is_dir_bin &&
            is_dir_share &&
diff --git a/src/inspect.c b/src/inspect.c
index e805291..db2a125 100644
--- a/src/inspect.c
+++ b/src/inspect.c
@@ -26,6 +26,7 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <libintl.h>
+#include <assert.h>
 
 #ifdef HAVE_ENDIAN_H
 #include <endian.h>
@@ -41,6 +42,8 @@ COMPILE_REGEXP (re_primary_partition, "^/dev/(?:h|s|v)d.[1234]$", 0)
 
 static void check_for_duplicated_bsd_root (guestfs_h *g);
 static void collect_coreos_inspection_info (guestfs_h *g);
+static void collect_linux_inspection_info (guestfs_h *g);
+static void collect_linux_inspection_info_for (guestfs_h *g, struct inspect_fs *root);
 
 /* The main inspection code. */
 char **
@@ -81,6 +84,12 @@ guestfs_impl_inspect_os (guestfs_h *g)
    */
   check_for_duplicated_bsd_root (g);
 
+  /* For Linux guests with a separate /usr filesyste, merge some of the
+   * inspected information in that partition to the inspect_fs struct
+   * of the root filesystem.
+   */
+  collect_linux_inspection_info (g);
+
   /* At this point we have, in the handle, a list of all filesystems
    * found and data about each one.  Now we assemble the list of
    * filesystems which are root devices and return that to the user.
@@ -143,9 +152,75 @@ collect_coreos_inspection_info (guestfs_h *g)
   guestfs_int_merge_fs_inspections (g, root, usr);
 }
 
-/* On *BSD systems, sometimes /dev/sda[1234] is a shadow of the real root
- * filesystem that is probably /dev/sda5
- * (see: http://www.freebsd.org/doc/handbook/disk-organization.html)
+/**
+ * Traverse through the filesystems and find the /usr filesystem for
+ * the specified C<root>: if found, merge its basic inspection details
+ * to the root when they were set (i.e. because the /usr had os-release
+ * or other ways to identify the OS).
+ */
+static void
+collect_linux_inspection_info_for (guestfs_h *g, struct inspect_fs *root)
+{
+  size_t i;
+  struct inspect_fs *usr = NULL;
+
+  for (i = 0; i < g->nr_fses; ++i) {
+    struct inspect_fs *fs = &g->fses[i];
+    size_t j;
+
+    if (!(fs->distro == root->distro || fs->distro == OS_DISTRO_UNKNOWN) ||
+        fs->role != OS_ROLE_USR)
+      continue;
+
+    for (j = 0; j < root->nr_fstab; ++j) {
+      if (STREQ (fs->mountable, root->fstab[j].mountable)) {
+        usr = fs;
+        goto got_usr;
+      }
+    }
+  }
+
+  assert (usr == NULL);
+  return;
+
+ got_usr:
+  /* If the version information in /usr is not null, then most probably
+   * there was an os-release file there, so reset what is in root
+   * and pick the results from /usr.
+   */
+  if (!(usr->major_version == 0 && usr->minor_version == 0)) {
+    root->distro = OS_DISTRO_UNKNOWN;
+    free (root->product_name);
+    root->product_name = NULL;
+  }
+
+  guestfs_int_merge_fs_inspections (g, root, usr);
+}
+
+/**
+ * Traverse through the filesystem list and find out if it contains
+ * the C</> and C</usr> filesystems of a Linux image (but not CoreOS,
+ * for which there is a separate C<collect_coreos_inspection_info>).
+ * If this is the case, sum up all the collected information on each
+ * root fs from the respective /usr filesystems.
+ */
+static void
+collect_linux_inspection_info (guestfs_h *g)
+{
+  size_t i;
+
+  for (i = 0; i < g->nr_fses; ++i) {
+    struct inspect_fs *fs = &g->fses[i];
+
+    if (fs->distro != OS_DISTRO_COREOS && fs->role == OS_ROLE_ROOT)
+      collect_linux_inspection_info_for (g, fs);
+  }
+}
+
+/**
+ * On *BSD systems, sometimes F</dev/sda[1234]> is a shadow of the
+ * real root filesystem that is probably F</dev/sda5> (see:
+ * L<http://www.freebsd.org/doc/handbook/disk-organization.html>)
  */
 static void
 check_for_duplicated_bsd_root (guestfs_h *g)
-- 
2.7.4