Bug 853763

hi Rich,

i could found this commit in master branch, but didn't find in 1.16 branch, if we forget to backport this commit?



index 379ccf4..fa729f3 100644
--- a/sparsify/sparsify.ml
+++ b/sparsify/sparsify.ml
@@ -351,25 +351,10 @@ let output_format =
     | Some fmt -> fmt           (* user specified input format, use that *)
     | None ->
       (* Don't know, so we must autodetect. *)
-      let cmd = sprintf "file -bsL %s" (Filename.quote indisk) in
-      let chan = open_process_in cmd in
-      let line = input_line chan in
-      let stat = close_process_in chan in
-      (match stat with
-      | WEXITED 0 -> ()
-      | WEXITED _ ->
-        error (f_"external command failed: %s") cmd
-      | WSIGNALED i ->
-        error (f_"external command '%s' killed by signal %d") cmd i
-      | WSTOPPED i ->
-        error (f_"external command '%s' stopped by signal %d") cmd i
-      );
-      if string_prefix line "QEMU QCOW Image (v2)" then
-        "qcow2"
-      else if string_find line "VirtualBox" >= 0 then
-        "vdi"
-      else
-        "raw" (* XXX guess *)
+      match g#disk_format indisk  with
+      | "unknown" ->
+        error (f_"cannot detect input disk format; use the --format parameter")
+      | fmt -> fmt
 
 (* Now run qemu-img convert which copies the overlay to the
  * destination and automatically does sparsification.


but in 1.16, still get this, 


 *)
let output_format =
  match convert with
  | Some fmt -> fmt             (* user specified output conversion *)
  | None ->
    match format with
    | Some fmt -> fmt           (* user specified input format, use that *)
    | None ->
      (* Don't know, so we must autodetect. *)
      let cmd = sprintf "file -bsL %s" (Filename.quote indisk) in
      let chan = open_process_in cmd in
      let line = input_line chan in
      let stat = close_process_in chan in
      (match stat with
      | WEXITED 0 -> ()
      | WEXITED _ ->
        error "external command failed: %s" cmd
      | WSIGNALED i ->
        error "external command '%s' killed by signal %d" cmd i
      | WSTOPPED i ->
        error "external command '%s' stopped by signal %d" cmd i
      );
      if string_prefix line "QEMU QCOW Image (v2)" then
        "qcow2"
      else if string_find line "VirtualBox" >= 0 then
        "vdi"
      else
        "raw" (* XXX guess *)

This is the patch that I added to RHEL 6.  Note it fixes
the problem (different 'file' command output), but it does
not use the guestfs_disk_format method.  The reason for not
using the guestfs_disk_format method is that it doesn't exist
in RHEL 6 / libguestfs 1.16.  Backporting that method would
be possible, but I opted for the simple (safer?) one-line
fix instead.


commit 9a772e90efef6b0313367600f3ff71916fee0ecc
Author: Richard W.M. Jones <rjones>
Date:   Thu Sep 27 16:36:56 2012 +0100

    RHEL 6: Change virt-sparsify to work with old 'file' command (RHBZ#853763).
    
    The old 'file' command in RHEL produces different output from
    upstream / Fedora:
    
      rhel$ file -bsL /tmp/disk.qcow2
      Qemu Image, Format: Qcow , Version: 2
      fedora$ file -bsL /tmp/disk.qcow2
      QEMU QCOW Image (v2), 10485760 bytes
    
    Upstream solves this in a more robust way, but that would involve
    difficult backporting of a new API.

diff --git a/sparsify/sparsify.ml b/sparsify/sparsify.ml
index 544c8ab..bf0d3d0 100644
--- a/sparsify/sparsify.ml
+++ b/sparsify/sparsify.ml
@@ -299,7 +299,7 @@ let output_format =
       | WSTOPPED i ->
         error "external command '%s' stopped by signal %d" cmd i
       );
-      if string_prefix line "QEMU QCOW Image (v2)" then
+      if string_prefix line "Qemu Image, Format: Qcow , Version: 2" then
         "qcow2"
       else if string_find line "VirtualBox" >= 0 then
         "vdi"

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2013-0324.html