bdi: initialize ->ra_pages and ->io_pages in bdi_init

Set up a readahead size by default, as very few users have a good
reason to change it.  This means code, ecryptfs, and orangefs now
set up the values while they were previously missing it, while ubifs,
mtd and vboxsf manually set it to 0 to avoid readahead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Richard Weinberger <richard@nod.at> [ubifs, mtd]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -538,8 +538,6 @@ struct request_queue *blk_alloc_queue(int node_id)
 	if (!q->stats)
 		goto fail_stats;
 
-	q->backing_dev_info->ra_pages = VM_READAHEAD_PAGES;
-	q->backing_dev_info->io_pages = VM_READAHEAD_PAGES;
 	q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK;
 	q->node = node_id;
 

drivers/mtd/mtdcore.c

@@ -2196,6 +2196,8 @@ static struct backing_dev_info * __init mtd_bdi_init(char *name)
 	bdi = bdi_alloc(NUMA_NO_NODE);
 	if (!bdi)
 		return ERR_PTR(-ENOMEM);
+	bdi->ra_pages = 0;
+	bdi->io_pages = 0;
 
 	/*
 	 * We put '-0' suffix to the name to get the same name format as we

fs/9p/vfs_super.c

@@ -80,8 +80,10 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
 	if (ret)
 		return ret;
 
-	if (v9ses->cache)
-		sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
+	if (!v9ses->cache) {
+		sb->s_bdi->ra_pages = 0;
+		sb->s_bdi->io_pages = 0;
+	}
 
 	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
 	if (!v9ses->cache)

fs/afs/super.c

@@ -456,7 +456,6 @@ static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
 	ret = super_setup_bdi(sb);
 	if (ret)
 		return ret;
-	sb->s_bdi->ra_pages	= VM_READAHEAD_PAGES;
 
 	/* allocate the root inode and dentry */
 	if (as->dyn_root) {

fs/btrfs/disk-io.c

@@ -3092,7 +3092,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 	}
 
 	sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
-	sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
 	sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
 	sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
 

fs/fuse/inode.c

@@ -1049,7 +1049,6 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 	if (err)
 		return err;
 
-	sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
 	/* fuse does it's own writeback accounting */
 	sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 

fs/nfs/super.c

@@ -1200,13 +1200,6 @@ static void nfs_get_cache_cookie(struct super_block *sb,
 }
 #endif
 
-static void nfs_set_readahead(struct backing_dev_info *bdi,
-			      unsigned long iomax_pages)
-{
-	bdi->ra_pages = VM_READAHEAD_PAGES;
-	bdi->io_pages = iomax_pages;
-}
-
 int nfs_get_tree_common(struct fs_context *fc)
 {
 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
@@ -1251,7 +1244,7 @@ int nfs_get_tree_common(struct fs_context *fc)
 					     MINOR(server->s_dev));
 		if (error)
 			goto error_splat_super;
-		nfs_set_readahead(s->s_bdi, server->rpages);
+		s->s_bdi->io_pages = server->rpages;
 		server->super = s;
 	}
 

fs/ubifs/super.c

@@ -2177,6 +2177,8 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
 				   c->vi.vol_id);
 	if (err)
 		goto out_close;
+	sb->s_bdi->ra_pages = 0;
+	sb->s_bdi->io_pages = 0;
 
 	sb->s_fs_info = c;
 	sb->s_magic = UBIFS_SUPER_MAGIC;

fs/vboxsf/super.c

@@ -167,6 +167,8 @@ static int vboxsf_fill_super(struct super_block *sb, struct fs_context *fc)
 	err = super_setup_bdi_name(sb, "vboxsf-%d", sbi->bdi_id);
 	if (err)
 		goto fail_free;
+	sb->s_bdi->ra_pages = 0;
+	sb->s_bdi->io_pages = 0;
 
 	/* Turn source into a shfl_string and map the folder */
 	size = strlen(fc->source) + 1;

mm/backing-dev.c

@@ -746,6 +746,8 @@ struct backing_dev_info *bdi_alloc(int node_id)
 		kfree(bdi);
 		return NULL;
 	}
+	bdi->ra_pages = VM_READAHEAD_PAGES;
+	bdi->io_pages = VM_READAHEAD_PAGES;
 	return bdi;
 }
 EXPORT_SYMBOL(bdi_alloc);