From c4a77a6c7dcff04a2abc7fe4b6b2ae605be41c5b Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 16 Sep 2009 15:18:25 +0200 Subject: [PATCH] writeback: make wb_writeback() take an argument structure We need to be able to pass in range_cyclic as well, so instead of growing yet another argument, split the arguments into a struct wb_writeback_args structure that we can use internally. Also makes it easier to just copy all members to an on-stack struct, since we can't access work after clearing the pending bit. Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 78 +++++++++++++++++++++++++++++------------------ 1 file changed, 49 insertions(+), 29 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 783ed44c7cfe..c5e91225501d 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -34,6 +34,17 @@ */ int nr_pdflush_threads; +/* + * Passed into wb_writeback(), essentially a subset of writeback_control + */ +struct wb_writeback_args { + long nr_pages; + struct super_block *sb; + enum writeback_sync_modes sync_mode; + int for_kupdate; + int range_cyclic; +}; + /* * Work items for the bdi_writeback threads */ @@ -45,9 +56,7 @@ struct bdi_work { unsigned long seen; atomic_t pending; - struct super_block *sb; - unsigned long nr_pages; - enum writeback_sync_modes sync_mode; + struct wb_writeback_args args; unsigned long state; }; @@ -69,9 +78,11 @@ static inline void bdi_work_init(struct bdi_work *work, struct writeback_control *wbc) { INIT_RCU_HEAD(&work->rcu_head); - work->sb = wbc->sb; - work->nr_pages = wbc->nr_to_write; - work->sync_mode = wbc->sync_mode; + work->args.sb = wbc->sb; + work->args.nr_pages = wbc->nr_to_write; + work->args.sync_mode = wbc->sync_mode; + work->args.range_cyclic = wbc->range_cyclic; + work->args.for_kupdate = 0; work->state = WS_USED; } @@ -106,7 +117,7 @@ static void bdi_work_free(struct rcu_head *head) static void wb_work_complete(struct bdi_work *work) { - const enum writeback_sync_modes sync_mode = work->sync_mode; + const enum writeback_sync_modes sync_mode = work->args.sync_mode; /* * For allocated work, we can clear the done/seen bit right here. @@ -653,17 +664,16 @@ static inline bool over_bground_thresh(void) * older_than_this takes precedence over nr_to_write. So we'll only write back * all dirty pages if they are all attached to "old" mappings. */ -static long wb_writeback(struct bdi_writeback *wb, long nr_pages, - struct super_block *sb, - enum writeback_sync_modes sync_mode, int for_kupdate) +static long wb_writeback(struct bdi_writeback *wb, + struct wb_writeback_args *args) { struct writeback_control wbc = { .bdi = wb->bdi, - .sb = sb, - .sync_mode = sync_mode, + .sb = args->sb, + .sync_mode = args->sync_mode, .older_than_this = NULL, - .for_kupdate = for_kupdate, - .range_cyclic = 1, + .for_kupdate = args->for_kupdate, + .range_cyclic = args->range_cyclic, }; unsigned long oldest_jif; long wrote = 0; @@ -673,13 +683,18 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages, oldest_jif = jiffies - msecs_to_jiffies(dirty_expire_interval * 10); } + if (!wbc.range_cyclic) { + wbc.range_start = 0; + wbc.range_end = LLONG_MAX; + } for (;;) { /* * Don't flush anything for non-integrity writeback where * no nr_pages was given */ - if (!for_kupdate && nr_pages <= 0 && sync_mode == WB_SYNC_NONE) + if (!args->for_kupdate && args->nr_pages <= 0 && + args->sync_mode == WB_SYNC_NONE) break; /* @@ -687,7 +702,8 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages, * periodic background writeout and we are below the * background dirty threshold, don't do anything */ - if (for_kupdate && nr_pages <= 0 && !over_bground_thresh()) + if (args->for_kupdate && args->nr_pages <= 0 && + !over_bground_thresh()) break; wbc.more_io = 0; @@ -695,7 +711,7 @@ static long wb_writeback(struct bdi_writeback *wb, long nr_pages, wbc.nr_to_write = MAX_WRITEBACK_PAGES; wbc.pages_skipped = 0; writeback_inodes_wb(wb, &wbc); - nr_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write; + args->nr_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write; wrote += MAX_WRITEBACK_PAGES - wbc.nr_to_write; /* @@ -749,8 +765,16 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb) global_page_state(NR_UNSTABLE_NFS) + (inodes_stat.nr_inodes - inodes_stat.nr_unused); - if (nr_pages) - return wb_writeback(wb, nr_pages, NULL, WB_SYNC_NONE, 1); + if (nr_pages) { + struct wb_writeback_args args = { + .nr_pages = nr_pages, + .sync_mode = WB_SYNC_NONE, + .for_kupdate = 1, + .range_cyclic = 1, + }; + + return wb_writeback(wb, &args); + } return 0; } @@ -762,35 +786,31 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait) { struct backing_dev_info *bdi = wb->bdi; struct bdi_work *work; - long nr_pages, wrote = 0; + long wrote = 0; while ((work = get_next_work_item(bdi, wb)) != NULL) { - enum writeback_sync_modes sync_mode; - - nr_pages = work->nr_pages; + struct wb_writeback_args args = work->args; /* * Override sync mode, in case we must wait for completion */ if (force_wait) - work->sync_mode = sync_mode = WB_SYNC_ALL; - else - sync_mode = work->sync_mode; + work->args.sync_mode = args.sync_mode = WB_SYNC_ALL; /* * If this isn't a data integrity operation, just notify * that we have seen this work and we are now starting it. */ - if (sync_mode == WB_SYNC_NONE) + if (args.sync_mode == WB_SYNC_NONE) wb_clear_pending(wb, work); - wrote += wb_writeback(wb, nr_pages, work->sb, sync_mode, 0); + wrote += wb_writeback(wb, &args); /* * This is a data integrity writeback, so only do the * notification when we have completed the work. */ - if (sync_mode == WB_SYNC_ALL) + if (args.sync_mode == WB_SYNC_ALL) wb_clear_pending(wb, work); } -- 2.25.1