From: NeilBrown <neilb@xxxxxxx> Subject: remove bdi_congested() and wb_congested() and related functions These functions are no longer useful as no BDIs report congestions any more. Removing the test on bdi_write_contested() in current_may_throttle() could cause a small change in behaviour, but only when PF_LOCAL_THROTTLE is set. So replace the calls by 'false' and simplify the code - and remove the functions. [akpm@xxxxxxxxxxxxxxxxxxxx: fix build] Link: https://lkml.kernel.org/r/164549983742.9187.2570198746005819592.stgit@noble.brown Signed-off-by: NeilBrown <neilb@xxxxxxx> Acked-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> [nilfs] Cc: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> Cc: Chao Yu <chao@xxxxxxxxxx> Cc: Darrick J. Wong <djwong@xxxxxxxxxx> Cc: Ilya Dryomov <idryomov@xxxxxxxxx> Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Cc: Jeff Layton <jlayton@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx> Cc: Miklos Szeredi <miklos@xxxxxxxxxx> Cc: Paolo Valente <paolo.valente@xxxxxxxxxx> Cc: Philipp Reisner <philipp.reisner@xxxxxxxxxx> Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/block/drbd/drbd_int.h | 3 --- drivers/block/drbd/drbd_req.c | 3 +-- fs/ext2/ialloc.c | 5 ----- fs/nilfs2/segbuf.c | 16 ---------------- fs/xfs/xfs_buf.c | 3 --- include/linux/backing-dev.h | 26 -------------------------- mm/vmscan.c | 4 +--- 7 files changed, 2 insertions(+), 58 deletions(-) --- a/drivers/block/drbd/drbd_int.h~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/drivers/block/drbd/drbd_int.h @@ -638,9 +638,6 @@ enum { STATE_SENT, /* Do not change state/UUIDs while this is set */ CALLBACK_PENDING, /* Whether we have a call_usermodehelper(, UMH_WAIT_PROC) * pending, from drbd worker context. - * If set, bdi_write_congested() returns true, - * so shrink_page_list() would not recurse into, - * and potentially deadlock on, this drbd worker. */ DISCONNECT_SENT, --- a/drivers/block/drbd/drbd_req.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/drivers/block/drbd/drbd_req.c @@ -909,8 +909,7 @@ static bool remote_due_to_read_balancing switch (rbm) { case RB_CONGESTED_REMOTE: - return bdi_read_congested( - device->ldev->backing_bdev->bd_disk->bdi); + return 0; case RB_LEAST_PENDING: return atomic_read(&device->local_cnt) > atomic_read(&device->ap_pending_cnt) + atomic_read(&device->rs_pending_cnt); --- a/fs/ext2/ialloc.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/fs/ext2/ialloc.c @@ -170,11 +170,6 @@ static void ext2_preread_inode(struct in unsigned long offset; unsigned long block; struct ext2_group_desc * gdp; - struct backing_dev_info *bdi; - - bdi = inode_to_bdi(inode); - if (bdi_rw_congested(bdi)) - return; block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL); --- a/fs/nilfs2/segbuf.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/fs/nilfs2/segbuf.c @@ -341,18 +341,6 @@ static int nilfs_segbuf_submit_bio(struc int mode_flags) { struct bio *bio = wi->bio; - int err; - - if (segbuf->sb_nbio > 0 && - bdi_write_congested(segbuf->sb_super->s_bdi)) { - wait_for_completion(&segbuf->sb_bio_event); - segbuf->sb_nbio--; - if (unlikely(atomic_read(&segbuf->sb_err))) { - bio_put(bio); - err = -EIO; - goto failed; - } - } bio->bi_end_io = nilfs_end_bio_write; bio->bi_private = segbuf; @@ -365,10 +353,6 @@ static int nilfs_segbuf_submit_bio(struc wi->nr_vecs = min(wi->max_pages, wi->rest_blocks); wi->start = wi->end; return 0; - - failed: - wi->bio = NULL; - return err; } /** --- a/fs/xfs/xfs_buf.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/fs/xfs/xfs_buf.c @@ -843,9 +843,6 @@ xfs_buf_readahead_map( { struct xfs_buf *bp; - if (bdi_read_congested(target->bt_bdev->bd_disk->bdi)) - return; - xfs_buf_read_map(target, map, nmaps, XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops, __this_address); --- a/include/linux/backing-dev.h~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/include/linux/backing-dev.h @@ -135,11 +135,6 @@ static inline bool writeback_in_progress struct backing_dev_info *inode_to_bdi(struct inode *inode); -static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) -{ - return wb->congested & cong_bits; -} - long congestion_wait(int sync, long timeout); static inline bool mapping_can_writeback(struct address_space *mapping) @@ -391,27 +386,6 @@ static inline void wb_blkcg_offline(stru #endif /* CONFIG_CGROUP_WRITEBACK */ -static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits) -{ - return wb_congested(&bdi->wb, cong_bits); -} - -static inline int bdi_read_congested(struct backing_dev_info *bdi) -{ - return bdi_congested(bdi, 1 << WB_sync_congested); -} - -static inline int bdi_write_congested(struct backing_dev_info *bdi) -{ - return bdi_congested(bdi, 1 << WB_async_congested); -} - -static inline int bdi_rw_congested(struct backing_dev_info *bdi) -{ - return bdi_congested(bdi, (1 << WB_sync_congested) | - (1 << WB_async_congested)); -} - const char *bdi_dev_name(struct backing_dev_info *bdi); #endif /* _LINUX_BACKING_DEV_H */ --- a/mm/vmscan.c~remove-bdi_congested-and-wb_congested-and-related-functions +++ a/mm/vmscan.c @@ -2364,9 +2364,7 @@ static unsigned int move_pages_to_lru(st */ static int current_may_throttle(void) { - return !(current->flags & PF_LOCAL_THROTTLE) || - current->backing_dev_info == NULL || - bdi_write_congested(current->backing_dev_info); + return !(current->flags & PF_LOCAL_THROTTLE); } /* _
