8:35 a.m.
We use ‘tar tRvf’ to parse the locations of files within the tarball.
However examination of tar.git:src/list.c shows various other messages
which can appear in the output:
block <offset>: ** Block of NULs **
block <offset>: ** End of File **
Indeed it was easy to produce the first message just by using modern
tar to create a tarball:
$ tar tRvf '/var/tmp/bz1570407-reproducer.ova'
block 0: -rw-r--r-- rjones/rjones 100 2018-04-22 17:06
RHEL7_3_042218_extra-disk1.vmdk.000000000
block 2: -rw-r--r-- rjones/rjones 243 2018-04-22 17:07 RHEL7_3_042218_extra.mf
block 4: -rw-r--r-- rjones/rjones 13066 2018-04-22 15:08 RHEL7_3_042218_extra.ovf
block 31: ** Block of NULs **
Ignore these messages.
---
v2v/utils.ml | 71 ++++++++++++++++++++++++++++++++++--------------------------
1 file changed, 40 insertions(+), 31 deletions(-)
diff --git a/v2v/utils.ml b/v2v/utils.ml
index 372ad8aaa..d73011f9f 100644
--- a/v2v/utils.ml
+++ b/v2v/utils.ml
@@ -147,6 +147,7 @@ let error_if_no_ssh_agent () =
error (f_"ssh-agent authentication has not been set up ($SSH_AUTH_SOCK is not
set). This is required by qemu to do passwordless ssh access. See the virt-v2v(1) man
page for more information.")
let ws = PCRE.compile "\\s+"
+let re_tar_message = PCRE.compile "\\*\\* [^*]+ \\*\\*$"
let find_file_in_tar tar filename =
let lines = external_command (sprintf "tar tRvf %s" (Filename.quote tar)) in
@@ -156,42 +157,50 @@ let find_file_in_tar tar filename =
| line :: lines -> (
(* Lines have the form:
* block <offset>: <perms> <owner>/<group> <size>
<mdate> <mtime> <file>
+ * or:
+ * block <offset>: ** Block of NULs **
+ * block <offset>: ** End of File **
*)
- let elems = PCRE.nsplit ~max:8 ws line in
- if List.length elems = 8 && List.hd elems = "block" then (
- let elems = Array.of_list elems in
- let offset = elems.(1) in
- let size = elems.(4) in
- let fname = elems.(7) in
+ if PCRE.matches re_tar_message line then
+ loop lines (* ignore "** Block of NULs **" etc. *)
+ else (
+ let elems = PCRE.nsplit ~max:8 ws line in
+ if List.length elems = 8 && List.hd elems = "block" then (
+ let elems = Array.of_list elems in
+ let offset = elems.(1) in
+ let size = elems.(4) in
+ let fname = elems.(7) in
- if fname <> filename then
- loop lines
- else (
- let offset =
- try
- (* There should be a colon at the end *)
- let i = String.rindex offset ':' in
- if i == (String.length offset)-1 then
- Int64.of_string (String.sub offset 0 i)
- else
- failwith "colon at wrong position"
- with Failure _ | Not_found ->
- failwithf (f_"invalid offset returned by tar: %S") offset in
+ if fname <> filename then
+ loop lines
+ else (
+ let offset =
+ try
+ (* There should be a colon at the end *)
+ let i = String.rindex offset ':' in
+ if i == (String.length offset)-1 then
+ Int64.of_string (String.sub offset 0 i)
+ else
+ failwith "colon at wrong position"
+ with Failure _ | Not_found ->
+ failwithf (f_"invalid offset returned by tar: %S") offset in
- let size =
- try Int64.of_string size
- with Failure _ ->
- failwithf (f_"invalid size returned by tar: %S") size in
+ let size =
+ try Int64.of_string size
+ with Failure _ ->
+ failwithf (f_"invalid size returned by tar: %S") size in
- (* Note: Offset is actualy block number and there is a single
- * block with tar header at the beginning of the file. So skip
- * the header and convert the block number to bytes before
- * returning.
- *)
- (offset +^ 1L) *^ 512L, size
+ (* Note: Offset is actualy block number and there is a single
+ * block with tar header at the beginning of the file. So skip
+ * the header and convert the block number to bytes before
+ * returning.
+ *)
+ (offset +^ 1L) *^ 512L, size
+ )
)
- ) else
- failwithf (f_"failed to parse line returned by tar: %S") line
+ else
+ failwithf (f_"failed to parse line returned by tar: %S") line
+ )
)
in
loop lines
--
2.16.2