bdi_start_writeback() is currently split into two paths, one for WB_SYNC_NONE and one for WB_SYNC_ALL. Add bdi_sync_writeback() for WB_SYNC_ALL writeback and let bdi_start_writeback() handle only WB_SYNC_NONE. Signed-off-by: Jens Axboe <jens.axboe@xxxxxxxxxx> --- fs/fs-writeback.c | 51 ++++++++++++++++++++++++++++++++++----------------- mm/page-writeback.c | 1 - 2 files changed, 34 insertions(+), 18 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 5cd8b3b..64ca471 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -204,24 +204,42 @@ static void bdi_alloc_queue_work(struct backing_dev_info *bdi, } } -void bdi_start_writeback(struct writeback_control *wbc) +/** + * bdi_sync_writeback - start and wait for writeback + * @wbc: writeback parameters + * + * Description: + * This does WB_SYNC_ALL data integrity writeback and waits for the + * IO to complete. Callers must hold the sb s_umount semaphore for + * reading, to avoid having the super disappear before we are done. + */ +static void bdi_sync_writeback(struct writeback_control *wbc) { - /* - * WB_SYNC_NONE is opportunistic writeback. If this allocation fails, - * bdi_queue_work() will wake up the thread and flush old data. This - * should ensure some amount of progress in freeing memory. - */ - if (wbc->sync_mode != WB_SYNC_ALL) - bdi_alloc_queue_work(wbc->bdi, wbc); - else { - struct bdi_work work; + struct bdi_work work; - bdi_work_init(&work, wbc); - work.state |= WS_ONSTACK; + wbc->sync_mode = WB_SYNC_ALL; - bdi_queue_work(wbc->bdi, &work); - bdi_wait_on_work_clear(&work); - } + bdi_work_init(&work, wbc); + work.state |= WS_ONSTACK; + + bdi_queue_work(wbc->bdi, &work); + bdi_wait_on_work_clear(&work); +} + +/** + * bdi_start_writeback - start writeback + * @wbc: writeback parameters + * + * Description: + * This does WB_SYNC_NONE opportunistic writeback. The IO is only + * started when this function returns, we make no guarentees on + * completion. Caller need not hold sb s_umount semaphore. + * + */ +void bdi_start_writeback(struct writeback_control *wbc) +{ + wbc->sync_mode = WB_SYNC_NONE; + bdi_alloc_queue_work(wbc->bdi, wbc); } /* @@ -1119,14 +1137,13 @@ long sync_inodes_sb(struct super_block *sb) struct writeback_control wbc = { .sb = sb, .bdi = sb->s_bdi, - .sync_mode = WB_SYNC_ALL, .range_start = 0, .range_end = LLONG_MAX, }; long nr_to_write = LONG_MAX; /* doesn't actually matter */ wbc.nr_to_write = nr_to_write; - bdi_start_writeback(&wbc); + bdi_sync_writeback(&wbc); wait_sb_inodes(&wbc); return nr_to_write - wbc.nr_to_write; } diff --git a/mm/page-writeback.c b/mm/page-writeback.c index a5f0f76..f61f0cc 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -585,7 +585,6 @@ static void balance_dirty_pages(struct address_space *mapping) > background_thresh))) { struct writeback_control wbc = { .bdi = bdi, - .sync_mode = WB_SYNC_NONE, .nr_to_write = nr_writeback, }; -- 1.6.4.1.207.g68ea -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html