writeback: remove the always false bdi_cap_writeback_dirty() test

This is dead code because no bdi flush thread will be started for
!bdi_cap_writeback_dirty bdi.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 0 insertions, 18 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 9d5360c4c2af..0306c8e7d6b5 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -614,7 +614,6 @@ static void writeback_inodes_wb(struct bdi_writeback *wb,
                                 struct writeback_control *wbc)
 {
         struct super_block *sb = wbc->sb, *pin_sb = NULL;
-        const int is_blkdev_sb = sb_is_blkdev_sb(sb);
         const unsigned long start = jiffies;    /* livelock avoidance */
 
         spin_lock(&inode_lock);
@@ -635,23 +634,6 @@ static void writeback_inodes_wb(struct bdi_writeback *wb,
                         continue;
                 }
 
-                if (!bdi_cap_writeback_dirty(wb->bdi)) {
-                        redirty_tail(inode);
-                        if (is_blkdev_sb) {
-                                /*
-                                 * Dirty memory-backed blockdev: the ramdisk
-                                 * driver does this.  Skip just this inode
-                                 */
-                                continue;
-                        }
-                        /*
-                         * Dirty memory-backed inode against a filesystem other
-                         * than the kernel-internal bdev filesystem.  Skip the
-                         * entire superblock.
-                         */
-                        break;
-                }
-
                 if (inode->i_state & (I_NEW | I_WILL_FREE)) {
                         requeue_io(inode);
                         continue;