[Buildroot] [PATCH] fs/btrfs: remove destination file before generation

[Buildroot] [PATCH] fs/btrfs: remove destination file before generation

[Yann E. MORIN]

btrfs will happily use an existing destination file if it
already exists, increasing its size if needed. Hoever, it
will never decrease the size, even if the requested size
is smaller than the existing file.

So, remove any previously existing destination file before
generating the new filesystem.

Note: the original submission by Robert did that, but as
this case was not obvious, the removal was dropped by a
refactoring when the patch was initially applied.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Robert J. Heywood <robert.heywood@codethink.co.uk>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 fs/btrfs/btrfs.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/btrfs/btrfs.mk b/fs/btrfs/btrfs.mk
index ad00153c26..94bc499084 100644
--- a/fs/btrfs/btrfs.mk
+++ b/fs/btrfs/btrfs.mk
@@ -29,6 +29,7 @@ BTRFS_OPTS = \
 ROOTFS_BTRFS_DEPENDENCIES = host-btrfs-progs
 
 define ROOTFS_BTRFS_CMD
+	rm -f $(@)
 	$(HOST_DIR)/bin/mkfs.btrfs $(BTRFS_OPTS) $@
 endef
 
-- 
2.14.1

[Buildroot] [PATCH] fs/btrfs: remove destination file before generation

[Thomas Petazzoni]

Hello,

On Sat, 25 Aug 2018 19:47:14 +0200, Yann E. MORIN wrote:

>  define ROOTFS_BTRFS_CMD
> +	rm -f $(@)

I changed to use $(RM) instead of rm, and $@ instead of $(@), since we
use $@ everywhere.

With those changes: applied to next. Thanks for noticing this mistake
in my changes to Robert's patch!

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com