fs: deduplicate noop_backing_dev_info

hugetlbfs, kernfs and dlmfs can simply use noop_backing_dev_info instead
of creating a local duplicate.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

3 files changed, 1 insertions, 15 deletions

diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 985217626e66..06f06887b2d2 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -24,12 +24,6 @@ static const struct address_space_operations kernfs_aops = {
         .write_end      = simple_write_end,
 };
 
-static struct backing_dev_info kernfs_bdi = {
-        .name           = "kernfs",
-        .ra_pages       = 0,    /* No readahead */
-        .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
-};
-
 static const struct inode_operations kernfs_iops = {
         .permission     = kernfs_iop_permission,
         .setattr        = kernfs_iop_setattr,
@@ -40,12 +34,6 @@ static const struct inode_operations kernfs_iops = {
         .listxattr      = kernfs_iop_listxattr,
 };
 
-void __init kernfs_inode_init(void)
-{
-        if (bdi_init(&kernfs_bdi))
-                panic("failed to init kernfs_bdi");
-}
-
 static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)
 {
         static DEFINE_MUTEX(iattr_mutex);
@@ -298,7 +286,7 @@ static void kernfs_init_inode(struct kernfs_node *kn, struct inode *inode)
         kernfs_get(kn);
         inode->i_private = kn;
         inode->i_mapping->a_ops = &kernfs_aops;
-        inode->i_mapping->backing_dev_info = &kernfs_bdi;
+        inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
         inode->i_op = &kernfs_iops;
 
         set_default_inode_attr(inode, kn->mode);
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index dc84a3ef9ca2..af9fa7499919 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -88,7 +88,6 @@ int kernfs_iop_removexattr(struct dentry *dentry, const char *name);
 ssize_t kernfs_iop_getxattr(struct dentry *dentry, const char *name, void *buf,
                             size_t size);
 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size);
-void kernfs_inode_init(void);
 
 /*
  * dir.c
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index f973ae9b05f1..8eaf417187f1 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -246,5 +246,4 @@ void __init kernfs_init(void)
         kernfs_node_cache = kmem_cache_create("kernfs_node_cache",
                                               sizeof(struct kernfs_node),
                                               0, SLAB_PANIC, NULL);
-        kernfs_inode_init();
 }