[PATCH] eccryptfs: select CONFIG_BUFFER_HEAD

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

The ecryptfs file system uses functions from fs/buffer.c that
are only available when CONFIG_BUFFER_HEAD is enabled:

ld.lld-20: error: undefined symbol: block_dirty_folio
>>>               vmlinux.o:(ecryptfs_aops)
ld.lld-20: error: undefined symbol: block_invalidate_folio
>>>               vmlinux.o:(ecryptfs_aops)

When CONFIG_BLOCK is turned off completely, this is not needed,
so add a conditional 'select BUFFER_HEAD'.

Fixes: 7ba13abbd31e ("fs: Turn block_invalidatepage into block_invalidate_folio")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
Ideally we would not depend on buffer heads and instead remove
the dependency here, but I could not immediately figure out how
to do that.
---
 fs/ecryptfs/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ecryptfs/Kconfig b/fs/ecryptfs/Kconfig
index 1bdeaa6d5790..b3c603c4f808 100644
--- a/fs/ecryptfs/Kconfig
+++ b/fs/ecryptfs/Kconfig
@@ -2,6 +2,7 @@
 config ECRYPT_FS
 	tristate "eCrypt filesystem layer support"
 	depends on KEYS && CRYPTO && (ENCRYPTED_KEYS || ENCRYPTED_KEYS=n)
+	select BUFFER_HEAD if BLOCK
 	select CRYPTO_ECB
 	select CRYPTO_CBC
 	select CRYPTO_MD5
-- 
2.39.5