ext4: add cleancache support

This seventh patch of eight in this cleancache series "opts-in"
cleancache for ext4.  Filesystems must explicitly enable cleancache
by calling cleancache_init_fs anytime an instance of the filesystem
is mounted. For ext4, all other cleancache hooks are in
the VFS layer including the matching cleancache_flush_fs
hook which must be called on unmount.

Details and a FAQ can be found in Documentation/vm/cleancache.txt

[v6-v8: no changes]
[v5: [email protected]: simplify init hook and any future fs init changes]
Signed-off-by: Dan Magenheimer <[email protected]>
Reviewed-by: Jeremy Fitzhardinge <[email protected]>
Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>
Acked-by: Andreas Dilger <[email protected]>
Cc: Ted Ts'o <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Rik Van Riel <[email protected]>
Cc: Jan Beulich <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Mark Fasheh <[email protected]>
Cc: Joel Becker <[email protected]>
Cc: Nitin Gupta <[email protected]>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 8553dfb310afd7ac2209d186125287e99a867f61..51476477c818e97d900c36bbd325f3dec44e40d0 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -38,6 +38,7 @@
 #include <linux/ctype.h>
 #include <linux/log2.h>
 #include <linux/crc16.h>
+#include <linux/cleancache.h>
 #include <asm/uaccess.h>
 
 #include <linux/kthread.h>
@@ -1932,6 +1933,7 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
                        EXT4_INODES_PER_GROUP(sb),
                        sbi->s_mount_opt, sbi->s_mount_opt2);
 
+       cleancache_init_fs(sb);
        return res;
 }