[Libguestfs] Re: [nbdkit PATCH] linuxdisk: Simplify computation of last line of du

No need to re-strdup things in a loop of getline - since we are using popen to get the output in the first place, we can use the shell to hand us just the final line. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- Even though the POSIX folks ruled today that our "ab"use of a getline() loop to determine the final line of du output was non-portable [1], I was still miffed at the malloc overhead that our workaround for rawhide glibc entailed. So this is the result I came up with. [1] https://www.austingroupbugs.net/bug_view_page.php?bug_id=1953 plugins/linuxdisk/filesystem.c | 28 +++++++--------------------- 1 file changed, 7 insertions(+), 21 deletions(-) diff --git a/plugins/linuxdisk/filesystem.c b/plugins/linuxdisk/filesystem.c index 283af61a..aa4615e6 100644 --- a/plugins/linuxdisk/filesystem.c +++ b/plugins/linuxdisk/filesystem.c @@ -148,7 +148,7 @@ create_filesystem (struct virtual_disk *disk) static int64_t estimate_size (void) { - CLEANUP_FREE char *command = NULL, *line = NULL, *lastline = NULL; + CLEANUP_FREE char *command = NULL, *line = NULL;

+ /* Should only be one line of input. */ + if (getline (&line, &len, fp) == -1 || ferror (fp)) { nbdkit_error ("getline failed: %m"); pclose (fp); + free (line);

return -1;