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>

5 files changed, 4 insertions, 42 deletions

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 5eba47f593f8..de7c95c7d840 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -62,12 +62,6 @@ static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
         return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
 }
 
-static struct backing_dev_info hugetlbfs_backing_dev_info = {
-        .name           = "hugetlbfs",
-        .ra_pages       = 0,    /* No readahead */
-        .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
-};
-
 int sysctl_hugetlb_shm_group;
 
 enum {
@@ -498,7 +492,7 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
                 lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
                                 &hugetlbfs_i_mmap_rwsem_key);
                 inode->i_mapping->a_ops = &hugetlbfs_aops;
-                inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
+                inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
                 inode->i_mapping->private_data = resv_map;
                 info = HUGETLBFS_I(inode);
@@ -1032,10 +1026,6 @@ static int __init init_hugetlbfs_fs(void)
                 return -ENOTSUPP;
         }
 
-        error = bdi_init(&hugetlbfs_backing_dev_info);
-        if (error)
-                return error;
-
         error = -ENOMEM;
         hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
                                         sizeof(struct hugetlbfs_inode_info),
@@ -1071,7 +1061,6 @@ static int __init init_hugetlbfs_fs(void)
  out:
         kmem_cache_destroy(hugetlbfs_inode_cachep);
  out2:
-        bdi_destroy(&hugetlbfs_backing_dev_info);
         return error;
 }
 
@@ -1091,7 +1080,6 @@ static void __exit exit_hugetlbfs_fs(void)
         for_each_hstate(h)
                 kern_unmount(hugetlbfs_vfsmount[i++]);
         unregister_filesystem(&hugetlbfs_fs_type);
-        bdi_destroy(&hugetlbfs_backing_dev_info);
 }
 
 module_init(init_hugetlbfs_fs)
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();
 }
diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c
index 57c40e34f56f..6000d3029b26 100644
--- a/fs/ocfs2/dlmfs/dlmfs.c
+++ b/fs/ocfs2/dlmfs/dlmfs.c
@@ -390,12 +390,6 @@ clear_fields:
         ip->ip_conn = NULL;
 }
 
-static struct backing_dev_info dlmfs_backing_dev_info = {
-        .name           = "ocfs2-dlmfs",
-        .ra_pages       = 0,    /* No readahead */
-        .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
-};
-
 static struct inode *dlmfs_get_root_inode(struct super_block *sb)
 {
         struct inode *inode = new_inode(sb);
@@ -404,7 +398,7 @@ static struct inode *dlmfs_get_root_inode(struct super_block *sb)
         if (inode) {
                 inode->i_ino = get_next_ino();
                 inode_init_owner(inode, NULL, mode);
-                inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
+                inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
                 inc_nlink(inode);
 
@@ -428,7 +422,7 @@ static struct inode *dlmfs_get_inode(struct inode *parent,
 
         inode->i_ino = get_next_ino();
         inode_init_owner(inode, parent, mode);
-        inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
+        inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 
         ip = DLMFS_I(inode);
@@ -643,10 +637,6 @@ static int __init init_dlmfs_fs(void)
         int status;
         int cleanup_inode = 0, cleanup_worker = 0;
 
-        status = bdi_init(&dlmfs_backing_dev_info);
-        if (status)
-                return status;
-
         dlmfs_inode_cache = kmem_cache_create("dlmfs_inode_cache",
                                 sizeof(struct dlmfs_inode_private),
                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
@@ -673,7 +663,6 @@ bail:
                         kmem_cache_destroy(dlmfs_inode_cache);
                 if (cleanup_worker)
                         destroy_workqueue(user_dlm_worker);
-                bdi_destroy(&dlmfs_backing_dev_info);
         } else
                 printk("OCFS2 User DLM kernel interface loaded\n");
         return status;
@@ -693,7 +682,6 @@ static void __exit exit_dlmfs_fs(void)
         rcu_barrier();
         kmem_cache_destroy(dlmfs_inode_cache);
 
-        bdi_destroy(&dlmfs_backing_dev_info);
 }
 
 MODULE_AUTHOR("Oracle");