Libguestfs - Jun 2010 - [PATCH 0/4] Fix RHBZ#597112 (get-e2uuid command)

This series of patches fixes:

https://bugzilla.redhat.com/show_bug.cgi?id=597112

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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-------------- next part --------------
>From 85c71f8fff3e80f549342bf995b686ba7303c2b4 Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at redhat.com>
Date: Tue, 1 Jun 2010 13:39:25 +0100
Subject: [PATCH 1/4] daemon: Generalize the implementation of vfs-type.

Note that there is no change to the semantics of the code.
---
 daemon/blkid.c |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/daemon/blkid.c b/daemon/blkid.c
index dcfac65..1ddc8cd 100644
--- a/daemon/blkid.c
+++ b/daemon/blkid.c
@@ -27,14 +27,14 @@
 #include "daemon.h"
 #include "actions.h"
 
-char *
-do_vfs_type (const char *device)
+static char *
+get_blkid_tag (const char *device, const char *tag)
 {
   char *out, *err;
   int r;
 
   r = command (&out, &err,
-               "blkid", "-o", "value",
"-s", "TYPE", device, NULL);
+               "blkid", "-o", "value",
"-s", tag, device, NULL);
   if (r == -1) {
     reply_with_error ("%s: %s", device, err);
     free (out);
@@ -51,3 +51,9 @@ do_vfs_type (const char *device)
 
   return out;                   /* caller frees */
 }
+
+char *
+do_vfs_type (const char *device)
+{
+  return get_blkid_tag (device, "TYPE");
+}
-- 
1.6.6.1

-- 
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-------------- next part --------------
>From 21c42e9fabf6cea3d564e338a314479ef120502a Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at redhat.com>
Date: Tue, 1 Jun 2010 15:27:57 +0100
Subject: [PATCH 2/4] daemon: Kill blkid cache to improve reliability of blkid
commands.

By killing the cache file, we make blkid work in situations such
as a just-created filesystem.
---
 daemon/blkid.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/daemon/blkid.c b/daemon/blkid.c
index 1ddc8cd..a619730 100644
--- a/daemon/blkid.c
+++ b/daemon/blkid.c
@@ -33,6 +33,13 @@ get_blkid_tag (const char *device, const char *tag)
   char *out, *err;
   int r;
 
+  /* Kill the cache file, forcing blkid to reread values from the
+   * original filesystems.  In blkid there is a '-p' option which is
+   * supposed to do this, but (a) it doesn't work and (b) that option
+   * is not supported in RHEL 5.
+   */
+  unlink ("/etc/blkid/blkid.tab");
+
   r = command (&out, &err,
                "blkid", "-o", "value",
"-s", tag, device, NULL);
   if (r == -1) {
-- 
1.6.6.1

-- 
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-------------- next part --------------
>From 27b730a6820b80a49a4da1af9f4c8e8a952f735e Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at redhat.com>
Date: Tue, 1 Jun 2010 13:57:12 +0100
Subject: [PATCH 3/4] New APIs: vfs-label and vfs-uuid return label and uuid for
many fs types.

These APIs generalize the existing 'get-e2label' and
'get-e2uuid'
calls, to provide calls which should be able to get the label
and UUID for most filesystem types.  These use 'blkid' to do the
work.

I have tested that the blkid commands themselves work on RHEL 5.

(Suggested by Yufang Zhang).
---
 daemon/blkid.c   |   12 ++++++++++++
 src/MAX_PROC_NR  |    2 +-
 src/generator.ml |   23 +++++++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletions(-)

diff --git a/daemon/blkid.c b/daemon/blkid.c
index a619730..108eee6 100644
--- a/daemon/blkid.c
+++ b/daemon/blkid.c
@@ -64,3 +64,15 @@ do_vfs_type (const char *device)
 {
   return get_blkid_tag (device, "TYPE");
 }
+
+char *
+do_vfs_label (const char *device)
+{
+  return get_blkid_tag (device, "LABEL");
+}
+
+char *
+do_vfs_uuid (const char *device)
+{
+  return get_blkid_tag (device, "UUID");
+}
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 2197544..f1aaa90 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-252
+254
diff --git a/src/generator.ml b/src/generator.ml
index 58eaee4..85a867e 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -4754,6 +4754,29 @@ Do not confuse this with the guestfish-specific
 C<alloc> and C<sparse> commands which create
 a file in the host and attach it as a device.");
 
+  ("vfs_label", (RString "label", [Device
"device"]), 253, [],
+   [InitBasicFS, Always, TestOutput (
+       [["set_e2label"; "/dev/sda1"; "LTEST"];
+        ["vfs_label"; "/dev/sda1"]], "LTEST")],
+   "get the filesystem label",
+   "\
+This returns the filesystem label of the filesystem on
+C<device>.
+
+If the filesystem is unlabeled, this returns the empty string.");
+
+  ("vfs_uuid", (RString "uuid", [Device
"device"]), 254, [],
+   (let uuid = uuidgen () in
+    [InitBasicFS, Always, TestOutput (
+       [["set_e2uuid"; "/dev/sda1"; uuid];
+        ["vfs_uuid"; "/dev/sda1"]], uuid)]),
+   "get the filesystem UUID",
+   "\
+This returns the filesystem UUID of the filesystem on
+C<device>.
+
+If the filesystem does not have a UUID, this returns the empty string.");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions
-- 
1.6.6.1

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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-------------- next part --------------
>From da4812ab6b44c29cb3cf181c7aa896420ecb8aa6 Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at redhat.com>
Date: Tue, 1 Jun 2010 14:04:51 +0100
Subject: [PATCH 4/4] Fix and deprecate get_e2label and get_e2uuid (RHBZ#597112).

Fix these calls (see description in RHBZ#597112), but also
deprecate them since the new calls vfs_label and vfs_uuid can
work on any filesystem type.

This also adds a regression test for the original bug reported
in RHBZ#597112.
---
 daemon/ext2.c    |   84 +----------------------------------------------------
 src/generator.ml |   11 +++++--
 2 files changed, 10 insertions(+), 85 deletions(-)

diff --git a/daemon/ext2.c b/daemon/ext2.c
index 3a075e5..7f9d2e0 100644
--- a/daemon/ext2.c
+++ b/daemon/ext2.c
@@ -170,29 +170,7 @@ do_set_e2label (const char *device, const char *label)
 char *
 do_get_e2label (const char *device)
 {
-  int r, len;
-  char *out, *err;
-
-  char prog[] = "e2label";
-  if (e2prog (prog) == -1)
-    return NULL;
-
-  r = command (&out, &err, prog, device, NULL);
-  if (r == -1) {
-    reply_with_error ("%s", err);
-    free (out);
-    free (err);
-    return NULL;
-  }
-
-  free (err);
-
-  /* Remove any trailing \n from the label. */
-  len = strlen (out);
-  if (len > 0 && out[len-1] == '\n')
-    out[len-1] = '\0';
-
-  return out;			/* caller frees */
+  return do_vfs_label (device);
 }
 
 int
@@ -219,65 +197,7 @@ do_set_e2uuid (const char *device, const char *uuid)
 char *
 do_get_e2uuid (const char *device)
 {
-  int r;
-  char *out, *err, *p, *q;
-
-  /* It's not so straightforward to get the volume UUID.  We have
-   * to use tune2fs -l and then look for a particular string in
-   * the output.
-   */
-  char prog[] = "tune2fs";
-  if (e2prog (prog) == -1)
-    return NULL;
-
-  r = command (&out, &err, prog, "-l", device, NULL);
-  if (r == -1) {
-    reply_with_error ("%s", err);
-    free (out);
-    free (err);
-    return NULL;
-  }
-
-  free (err);
-
-  /* Look for /\nFilesystem UUID:\s+/ in the output. */
-  p = strstr (out, "\nFilesystem UUID:");
-  if (p == NULL) {
-    reply_with_error ("no Filesystem UUID in the output of tune2fs
-l");
-    free (out);
-    return NULL;
-  }
-
-  p += 17;
-  while (*p && c_isspace (*p))
-    p++;
-  if (!*p) {
-    reply_with_error ("malformed Filesystem UUID in the output of tune2fs
-l");
-    free (out);
-    return NULL;
-  }
-
-  /* Now 'p' hopefully points to the start of the UUID. */
-  q = p;
-  while (*q && (c_isxdigit (*q) || *q == '-'))
-    q++;
-  if (!*q) {
-    reply_with_error ("malformed Filesystem UUID in the output of tune2fs
-l");
-    free (out);
-    return NULL;
-  }
-
-  *q = '\0';
-
-  p = strdup (p);
-  if (!p) {
-    reply_with_perror ("strdup");
-    free (out);
-    return NULL;
-  }
-
-  free (out);
-  return p;			/* caller frees */
+  return do_vfs_uuid (device);
 }
 
 int
diff --git a/src/generator.ml b/src/generator.ml
index 85a867e..ff772f5 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -2222,7 +2222,7 @@ C<device> to C<label>.  Filesystem labels are
limited to
 You can use either C<guestfs_tune2fs_l> or C<guestfs_get_e2label>
 to return the existing label on a filesystem.");
 
-  ("get_e2label", (RString "label", [Device
"device"]), 81, [],
+  ("get_e2label", (RString "label", [Device
"device"]), 81, [DeprecatedBy "vfs_label"],
    [],
    "get the ext2/3/4 filesystem label",
    "\
@@ -2252,8 +2252,13 @@ L<tune2fs(8)> manpage.
 You can use either C<guestfs_tune2fs_l> or C<guestfs_get_e2uuid>
 to return the existing UUID of a filesystem.");
 
-  ("get_e2uuid", (RString "uuid", [Device
"device"]), 83, [],
-   [],
+  ("get_e2uuid", (RString "uuid", [Device
"device"]), 83, [DeprecatedBy "vfs_uuid"],
+   (* Regression test for RHBZ#597112. *)
+   (let uuid = uuidgen () in
+    [InitBasicFS, Always, TestOutput (
+       [["mke2journal"; "1024"; "/dev/sdb"];
+        ["set_e2uuid"; "/dev/sdb"; uuid];
+        ["get_e2uuid"; "/dev/sdb"]], uuid)]),
    "get the ext2/3/4 filesystem UUID",
    "\
 This returns the ext2/3/4 filesystem UUID of the filesystem on
-- 
1.6.6.1