Now that default_backing_dev_info is not used for writeback purposes we can git rid of it easily: - instead of using it's name for tracing unregistered bdi we just use "unknown" - btrfs and ceph can just assign the default read ahead window themselves like several other filesystems already do. - we can assign noop_backing_dev_info as the default one in alloc_super. All filesystems already either assigned their own or noop_backing_dev_info. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Tejun Heo <tj@xxxxxxxxxx> --- fs/btrfs/disk-io.c | 2 +- fs/ceph/super.c | 2 +- fs/super.c | 8 ++------ include/linux/backing-dev.h | 1 - include/trace/events/writeback.h | 6 ++---- mm/backing-dev.c | 9 --------- 6 files changed, 6 insertions(+), 22 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 1ec872e..1afb182 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1719,7 +1719,7 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi) if (err) return err; - bdi->ra_pages = default_backing_dev_info.ra_pages; + bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE; bdi->congested_fn = btrfs_congested_fn; bdi->congested_data = info; return 0; diff --git a/fs/ceph/super.c b/fs/ceph/super.c index e350cc1..5ae6258 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -899,7 +899,7 @@ static int ceph_register_bdi(struct super_block *sb, >> PAGE_SHIFT; else fsc->backing_dev_info.ra_pages = - default_backing_dev_info.ra_pages; + VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE; err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%ld", atomic_long_inc_return(&bdi_seq)); diff --git a/fs/super.c b/fs/super.c index eae088f..3b4dada 100644 --- a/fs/super.c +++ b/fs/super.c @@ -185,8 +185,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags) } init_waitqueue_head(&s->s_writers.wait); init_waitqueue_head(&s->s_writers.wait_unfrozen); + s->s_bdi = &noop_backing_dev_info; s->s_flags = flags; - s->s_bdi = &default_backing_dev_info; INIT_HLIST_NODE(&s->s_instances); INIT_HLIST_BL_HEAD(&s->s_anon); INIT_LIST_HEAD(&s->s_inodes); @@ -863,10 +863,7 @@ EXPORT_SYMBOL(free_anon_bdev); int set_anon_super(struct super_block *s, void *data) { - int error = get_anon_bdev(&s->s_dev); - if (!error) - s->s_bdi = &noop_backing_dev_info; - return error; + return get_anon_bdev(&s->s_dev); } EXPORT_SYMBOL(set_anon_super); @@ -1111,7 +1108,6 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data) sb = root->d_sb; BUG_ON(!sb); WARN_ON(!sb->s_bdi); - WARN_ON(sb->s_bdi == &default_backing_dev_info); sb->s_flags |= MS_BORN; error = security_sb_kern_mount(sb, flags, secdata); diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index ed59dee..d94077f 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -241,7 +241,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); #define BDI_CAP_NO_ACCT_AND_WRITEBACK \ (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB) -extern struct backing_dev_info default_backing_dev_info; extern struct backing_dev_info noop_backing_dev_info; int writeback_in_progress(struct backing_dev_info *bdi); diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index 74f5207..0e93109 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -156,10 +156,8 @@ DECLARE_EVENT_CLASS(writeback_work_class, __field(int, reason) ), TP_fast_assign( - struct device *dev = bdi->dev; - if (!dev) - dev = default_backing_dev_info.dev; - strncpy(__entry->name, dev_name(dev), 32); + strncpy(__entry->name, + bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32); __entry->nr_pages = work->nr_pages; __entry->sb_dev = work->sb ? work->sb->s_dev : 0; __entry->sync_mode = work->sync_mode; diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 3ebba25..c49026d 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -14,12 +14,6 @@ static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0); -struct backing_dev_info default_backing_dev_info = { - .name = "default", - .ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE, -}; -EXPORT_SYMBOL_GPL(default_backing_dev_info); - struct backing_dev_info noop_backing_dev_info = { .name = "noop", .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, @@ -250,9 +244,6 @@ static int __init default_bdi_init(void) if (!bdi_wq) return -ENOMEM; - err = bdi_init(&default_backing_dev_info); - if (!err) - bdi_register(&default_backing_dev_info, NULL, "default"); err = bdi_init(&noop_backing_dev_info); return err; -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>