[Libguestfs] [PATCH v2 1/3] daemon: parted: Always use -s option even with -m.

See: https://bugzilla.redhat.com/show_bug.cgi?id=1232241#c3 However adding the -s parameter changes the error code returned by parted when it processes a blank disk (or other unrecognized partition table). Without -s it prints an error but returns a non-error exit code (0). With -s it prints an error and return an error exit code. Because it's useful to be able to catch this case in user code, turn "unrecognised disk label" into EINVAL. Change virt-alignment-scan to catch this error and ignore it. --- align/scan.c | 14 ++++++++++---- daemon/parted.c | 14 ++++++++++---- 2 files changed, 20 insertions(+), 8 deletions(-) diff --git a/align/scan.c b/align/scan.c index 202b148..188450c 100644 --- a/align/scan.c +++ b/align/scan.c @@ -282,11 +282,17 @@ scan (guestfs_h *g, const char *prefix, FILE *fp) for (i = 0; devices[i] != NULL; ++i) { CLEANUP_FREE char *name = NULL; + CLEANUP_FREE_PARTITION_LIST struct guestfs_partition_list *parts = NULL; - CLEANUP_FREE_PARTITION_LIST struct guestfs_partition_list *parts = - guestfs_part_list (g, devices[i]); - if (parts == NULL) - return -1; + guestfs_push_error_handler (g, NULL, NULL); + parts = guestfs_part_list (g, devices[i]); + guestfs_pop_error_handler (g); + if (parts == NULL) { + if (guestfs_last_errno (g) == EINVAL) /* unrecognised disk label */ + continue; + else + return -1; + } /* Canonicalize the name of the device for printing. */ name = guestfs_canonical_device_name (g, devices[i]); diff --git a/daemon/parted.c b/daemon/parted.c index a36e4e7..b516067 100644 --- a/daemon/parted.c +++ b/daemon/parted.c @@ -356,7 +356,7 @@ print_partition_table (const char *device, int r; if (PARTED_OPT_HAS_M == parted_has_m_opt) - r = command (&out, &err, str_parted, "-m", "--", device, + r = command (&out, &err, str_parted, "-m", "-s", "--", device, "unit", "b", "print", NULL); else @@ -364,9 +364,15 @@ print_partition_table (const char *device, "unit", "b", "print", NULL); if (r == -1) { - reply_with_error ("parted print: %s: %s", device, - /* Hack for parted 1.x which sends errors to stdout. */ - *err ? err : out); + /* Hack for parted 1.x which sends errors to stdout. */ + const char *msg = *err ? err : out; + int errcode = 0; + + /* Translate "unrecognised disk label" into an errno code. */ + if (msg && strstr (msg, "unrecognised disk label") != NULL) + errcode = EINVAL; + + reply_with_error_errno (errcode, "parted print: %s: %s", device, msg); free (out); return NULL; } -- 2.3.1