From: NeilBrown <neilb@xxxxxxx> Subject: remove inode_congested() inode_congested() reports if the backing-device for the inode is congested. No bdi reports congestion any more, so this always returns 'false'. So remove inode_congested() and related functions, and remove the call sites, assuming that inode_congested() always returns 'false'. Link: https://lkml.kernel.org/r/164549983741.9187.2174285592262191311.stgit@noble.brown Signed-off-by: NeilBrown <neilb@xxxxxxx> 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: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/fs-writeback.c | 37 ---------------------------------- include/linux/backing-dev.h | 22 -------------------- mm/fadvise.c | 5 +--- mm/readahead.c | 6 ----- mm/vmscan.c | 17 --------------- 5 files changed, 3 insertions(+), 84 deletions(-) --- a/fs/fs-writeback.c~remove-inode_congested +++ a/fs/fs-writeback.c @@ -894,43 +894,6 @@ void wbc_account_cgroup_owner(struct wri EXPORT_SYMBOL_GPL(wbc_account_cgroup_owner); /** - * inode_congested - test whether an inode is congested - * @inode: inode to test for congestion (may be NULL) - * @cong_bits: mask of WB_[a]sync_congested bits to test - * - * Tests whether @inode is congested. @cong_bits is the mask of congestion - * bits to test and the return value is the mask of set bits. - * - * If cgroup writeback is enabled for @inode, the congestion state is - * determined by whether the cgwb (cgroup bdi_writeback) for the blkcg - * associated with @inode is congested; otherwise, the root wb's congestion - * state is used. - * - * @inode is allowed to be NULL as this function is often called on - * mapping->host which is NULL for the swapper space. - */ -int inode_congested(struct inode *inode, int cong_bits) -{ - /* - * Once set, ->i_wb never becomes NULL while the inode is alive. - * Start transaction iff ->i_wb is visible. - */ - if (inode && inode_to_wb_is_valid(inode)) { - struct bdi_writeback *wb; - struct wb_lock_cookie lock_cookie = {}; - bool congested; - - wb = unlocked_inode_to_wb_begin(inode, &lock_cookie); - congested = wb_congested(wb, cong_bits); - unlocked_inode_to_wb_end(inode, &lock_cookie); - return congested; - } - - return wb_congested(&inode_to_bdi(inode)->wb, cong_bits); -} -EXPORT_SYMBOL_GPL(inode_congested); - -/** * wb_split_bdi_pages - split nr_pages to write according to bandwidth * @wb: target bdi_writeback to split @nr_pages to * @nr_pages: number of pages to write for the whole bdi --- a/include/linux/backing-dev.h~remove-inode_congested +++ a/include/linux/backing-dev.h @@ -162,7 +162,6 @@ struct bdi_writeback *wb_get_create(stru gfp_t gfp); void wb_memcg_offline(struct mem_cgroup *memcg); void wb_blkcg_offline(struct blkcg *blkcg); -int inode_congested(struct inode *inode, int cong_bits); /** * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode @@ -390,29 +389,8 @@ static inline void wb_blkcg_offline(stru { } -static inline int inode_congested(struct inode *inode, int cong_bits) -{ - return wb_congested(&inode_to_bdi(inode)->wb, cong_bits); -} - #endif /* CONFIG_CGROUP_WRITEBACK */ -static inline int inode_read_congested(struct inode *inode) -{ - return inode_congested(inode, 1 << WB_sync_congested); -} - -static inline int inode_write_congested(struct inode *inode) -{ - return inode_congested(inode, 1 << WB_async_congested); -} - -static inline int inode_rw_congested(struct inode *inode) -{ - return inode_congested(inode, (1 << WB_sync_congested) | - (1 << WB_async_congested)); -} - static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits) { return wb_congested(&bdi->wb, cong_bits); --- a/mm/fadvise.c~remove-inode_congested +++ a/mm/fadvise.c @@ -109,9 +109,8 @@ int generic_fadvise(struct file *file, l case POSIX_FADV_NOREUSE: break; case POSIX_FADV_DONTNEED: - if (!inode_write_congested(mapping->host)) - __filemap_fdatawrite_range(mapping, offset, endbyte, - WB_SYNC_NONE); + __filemap_fdatawrite_range(mapping, offset, endbyte, + WB_SYNC_NONE); /* * First and last FULL page! Partial pages are deliberately --- a/mm/readahead.c~remove-inode_congested +++ a/mm/readahead.c @@ -709,12 +709,6 @@ void page_cache_async_ra(struct readahea folio_clear_readahead(folio); - /* - * Defer asynchronous read-ahead on IO congestion. - */ - if (inode_read_congested(ractl->mapping->host)) - return; - if (blk_cgroup_congested()) return; --- a/mm/vmscan.c~remove-inode_congested +++ a/mm/vmscan.c @@ -989,17 +989,6 @@ static inline int is_page_cache_freeable return page_count(page) - page_has_private(page) == 1 + page_cache_pins; } -static int may_write_to_inode(struct inode *inode) -{ - if (current->flags & PF_SWAPWRITE) - return 1; - if (!inode_write_congested(inode)) - return 1; - if (inode_to_bdi(inode) == current->backing_dev_info) - return 1; - return 0; -} - /* * We detected a synchronous write error writing a page out. Probably * -ENOSPC. We need to propagate that into the address_space for a subsequent @@ -1201,8 +1190,6 @@ static pageout_t pageout(struct page *pa } if (mapping->a_ops->writepage == NULL) return PAGE_ACTIVATE; - if (!may_write_to_inode(mapping->host)) - return PAGE_KEEP; if (clear_page_dirty_for_io(page)) { int res; @@ -1578,9 +1565,7 @@ retry: * end of the LRU a second time. */ mapping = page_mapping(page); - if (((dirty || writeback) && mapping && - inode_write_congested(mapping->host)) || - (writeback && PageReclaim(page))) + if (writeback && PageReclaim(page)) stat->nr_congested++; /* _
