mm: bdi init hooks

provide BDI constructor/destructor hooks

[akpm@linux-foundation.org: compile fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 17 insertions, 0 deletions

diff --git a/mm/readahead.c b/mm/readahead.c
index 2297888..c9c50ca 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -233,6 +233,12 @@ unsigned long max_sane_readahead(unsigned long nr)
 		+ node_page_state(numa_node_id(), NR_FREE_PAGES)) / 2);
 }
 
+static int __init readahead_init(void)
+{
+	return bdi_init(&default_backing_dev_info);
+}
+subsys_initcall(readahead_init);
+
 /*
  * Submit IO for the read-ahead request in file_ra_state.
  */
diff --git a/mm/shmem.c b/mm/shmem.c
index 8a82342..2f039f3 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2464,6 +2464,10 @@ static int __init init_tmpfs(void)
 {
 	int error;
 
+	error = bdi_init(&shmem_backing_dev_info);
+	if (error)
+		goto out4;
+
 	error = init_inodecache();
 	if (error)
 		goto out3;
@@ -2488,6 +2492,8 @@ out1:
 out2:
 	destroy_inodecache();
 out3:
+	bdi_destroy(&shmem_backing_dev_info);
+out4:
 	shm_mnt = ERR_PTR(error);
 	return error;
 }
diff --git a/mm/swap.c b/mm/swap.c
index d034b21..a65eff8 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -28,6 +28,7 @@
 #include <linux/percpu.h>
 #include <linux/cpu.h>
 #include <linux/notifier.h>
+#include <linux/backing-dev.h>
 
 /* How many pages do we try to swap or page in/out together? */
 int page_cluster;
@@ -547,6 +548,10 @@ void __init swap_setup(void)
 {
 	unsigned long megs = num_physpages >> (20 - PAGE_SHIFT);
 
+#ifdef CONFIG_SWAP
+	bdi_init(swapper_space.backing_dev_info);
+#endif
+
 	/* Use a smaller cluster for small-memory machines */
 	if (megs < 16)
 		page_cluster = 2;