From: Rob Landley Date: Wed, 11 Sep 2013 21:26:08 +0000 (-0700) Subject: initmpfs: move bdi setup from init_rootfs to init_ramfs X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=4bbee76bc986af326be0a84ad661000cf89b29f6;p=openwrt%2Fstaging%2Fblogic.git initmpfs: move bdi setup from init_rootfs to init_ramfs Even though ramfs hasn't got a backing device, commit e0bf68ddec4f ("mm: bdi init hooks") added one anyway, and put the initialization in init_rootfs() since that's the first user, leaving it out of init_ramfs() to avoid duplication. But initmpfs uses init_tmpfs() instead, so move the init into the filesystem's init function, add a "once" guard to prevent duplicate initialization, and call the filesystem init from rootfs init. This goes part of the way to allowing ramfs to be built as a module. [akpm@linux-foundation.org; using bit 1 was odd] Signed-off-by: Rob Landley Cc: Jeff Layton Cc: Jens Axboe Cc: Stephen Warren Cc: Rusty Russell Cc: Jim Cromie Cc: Sam Ravnborg Cc: Greg Kroah-Hartman Cc: "Eric W. Biederman" Cc: Alexander Viro Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c index 8f7fe323e049..fb99863598be 100644 --- a/fs/ramfs/inode.c +++ b/fs/ramfs/inode.c @@ -249,7 +249,7 @@ static struct dentry *rootfs_mount(struct file_system_type *fs_type, { static unsigned long once; - if (test_and_set_bit(1, &once)) + if (test_and_set_bit(0, &once)) return ERR_PTR(-ENODEV); return mount_nodev(fs_type, flags, data, ramfs_fill_super); @@ -275,21 +275,34 @@ static struct file_system_type rootfs_fs_type = { static int __init init_ramfs_fs(void) { - return register_filesystem(&ramfs_fs_type); + static unsigned long once; + int err; + + if (test_and_set_bit(0, &once)) + return 0; + + err = bdi_init(&ramfs_backing_dev_info); + if (err) + return err; + + err = register_filesystem(&ramfs_fs_type); + if (err) + bdi_destroy(&ramfs_backing_dev_info); + + return err; } module_init(init_ramfs_fs) int __init init_rootfs(void) { - int err; + int err = register_filesystem(&rootfs_fs_type); - err = bdi_init(&ramfs_backing_dev_info); if (err) return err; - err = register_filesystem(&rootfs_fs_type); + err = init_ramfs_fs(); if (err) - bdi_destroy(&ramfs_backing_dev_info); + unregister_filesystem(&rootfs_fs_type); return err; }