[Libguestfs] [PATCH v2 09/18] virt-format: Discard the data on the disks.
If possible, this means that the host will be able to reclaim most of
the space used by formatted disks.
---
fish/options.c | 5 +++++
fish/options.h | 1 +
format/format.c | 13 +++++++++++++
3 files changed, 19 insertions(+)
diff --git a/fish/options.c b/fish/options.c
index cfdbdfe..80b71ec 100644
--- a/fish/options.c
+++ b/fish/options.c
@@ -134,6 +134,10 @@ add_drives_handle (guestfs_h *g, struct drv *drv, char next_drive)
ad_optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_CACHEMODE_BITMASK;
ad_optargs.cachemode = drv->a.cachemode;
}
+ if (drv->a.discard) {
+ ad_optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_DISCARD_BITMASK;
+ ad_optargs.discard = drv->a.discard;
+ }
r = guestfs_add_drive_opts_argv (g, drv->a.filename, &ad_optargs);
if (r == -1)
@@ -279,6 +283,7 @@ free_drives (struct drv *drv)
free (drv->a.filename);
/* a.format is an optarg, so don't free it */
/* a.cachemode is a static string, so don't free it */
+ /* a.discard is a static string, so don't free it */
break;
case drv_uri:
free (drv->uri.path);
diff --git a/fish/options.h b/fish/options.h
index a7b8277..dbf9163 100644
--- a/fish/options.h
+++ b/fish/options.h
@@ -61,6 +61,7 @@ struct drv {
char *filename; /* disk filename */
const char *format; /* format (NULL == autodetect) */
const char *cachemode;/* cachemode (NULL == default) */
+ const char *discard; /* discard (NULL == disable) */
} a;
struct {
char *path; /* disk path */
diff --git a/format/format.c b/format/format.c
index cff0d82..684bffd 100644
--- a/format/format.c
+++ b/format/format.c
@@ -188,6 +188,11 @@ main (int argc, char *argv[])
case 'a':
OPTION_a;
+
+ /* Enable discard on all drives added on the command line. */
+ assert (drvs != NULL);
+ assert (drvs->type == drv_a);
+ drvs->a.discard = "besteffort";
break;
case 'v':
@@ -342,6 +347,14 @@ do_format (void)
}
}
+ /* Send TRIM/UNMAP to all block devices, to give back the space to
+ * the host. However don't fail if this doesn't work.
+ */
+ guestfs_push_error_handler (g, NULL, NULL);
+ for (i = 0; devices[i] != NULL; ++i)
+ guestfs_blkdiscard (g, devices[i]);
+ guestfs_pop_error_handler (g);
+
if (do_rescan (devices))
return 1; /* which means, reopen the handle and retry */
--
1.8.5.3