2:49 a.m.
Add a new launch command for direct backend, which allows specifying the
blocksize to the disks. The name is `launch_blocksize`, accompanied alias is
`run-blocksize`.
Example:
$ guestfish --listen -a raw.img
$ guestfish --remote -- launch_blocksize 4096
The actual qemu command is:
[...]
-device virtio-scsi-ccw,id=scsi
-drive file=raw.img,cache=writeback,id=hd0,if=none
-device scsi-hd,drive=hd0,physical_block_size=4096,logical_block_size=4096
[...]
Ideally it would be better to invoke optional option to `launch` command
like:
$ guestfish --remote -- launch --blocksize 4096
Signed-off-by: Tuan Hoang <tmhoang(a)linux.ibm.com>
---
generator/actions_core.ml | 11 +++++++++++
lib/guestfs-internal.h | 3 +++
lib/launch-direct.c | 6 ++++++
lib/launch.c | 14 ++++++++++++++
4 files changed, 34 insertions(+)
diff --git a/generator/actions_core.ml b/generator/actions_core.ml
index 7b6568b..cfe735a 100644
--- a/generator/actions_core.ml
+++ b/generator/actions_core.ml
@@ -38,6 +38,17 @@ it will not give an error (for historical reasons), the precise
behaviour when you do this is not well defined. Handles are
very cheap to create, so create a new one for each launch." };
+ { defaults with
+ name = "launch_blocksize"; added = (1, 40, 2);
+ style = RErr, [Int "blocksize"], [];
+ fish_alias = ["run-blocksize"]; progress = true; config_only = true;
+ shortdesc = "launch the backend with blocksize for disks";
+ longdesc = "\
+Similar to \"launch\" call, but requires an integer as blocksize for disks.
+
+A call of \"launch_blocksize 512\" is equivalent of \"launch\" since
the
+default blocksize for qemu is 512." };
+
{ defaults with
name = "add_drive_ro"; added = (1, 0, 38);
style = RErr, [String (PlainString, "filename")], [];
diff --git a/lib/guestfs-internal.h b/lib/guestfs-internal.h
index 75b8a5c..e9b7057 100644
--- a/lib/guestfs-internal.h
+++ b/lib/guestfs-internal.h
@@ -513,6 +513,9 @@ struct guestfs_h {
/* Used by lib/info.c. -1 = not tested or error; else 0 or 1. */
int qemu_img_supports_U_option;
+
+ /* Used by guestfish's launch_blocksize call */
+ int blocksize;
};
/**
diff --git a/lib/launch-direct.c b/lib/launch-direct.c
index ee2dcb8..54cd8c6 100644
--- a/lib/launch-direct.c
+++ b/lib/launch-direct.c
@@ -315,6 +315,12 @@ add_drive (guestfs_h *g, struct backend_direct_data *data,
start_list ("-device") {
append_list ("scsi-hd");
append_list_format ("drive=hd%zu", i);
+ if (g->blocksize >= 512 && g->blocksize <= 32768
+ && (g->blocksize & (g->blocksize-1)) == 0)
+ {
+ append_list_format ("physical_block_size=%d", g->blocksize);
+ append_list_format ("logical_block_size=%d", g->blocksize);
+ }
if (drv->disk_label)
append_list_format ("serial=%s", drv->disk_label);
} end_list ();
diff --git a/lib/launch.c b/lib/launch.c
index eb7f85c..8edf7b1 100644
--- a/lib/launch.c
+++ b/lib/launch.c
@@ -53,6 +53,20 @@ static struct backend {
const struct backend_ops *ops;
} *backends = NULL;
+int
+guestfs_impl_launch_blocksize (guestfs_h *g, int blocksize)
+{
+ if (blocksize >= 512 && blocksize <= 32768
+ && (blocksize & (blocksize-1)) == 0) {
+ g->blocksize = blocksize;
+ return guestfs_impl_launch (g);
+ }
+ else {
+ error (g, _("blocksize must be a power of 2 between 512 and 32768"));
+ return -1;
+ }
+}
+
int
guestfs_impl_launch (guestfs_h *g)
{
--
2.21.0