lkml.org 
[lkml]   [2009]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 3/7] writeback: only use bdi_writeback_all() for WB_SYNC_NONE writeout
    On Mon 14-09-09 11:36:30, Jens Axboe wrote:
    > Data integrity writeback must use bdi_start_writeback() and ensure
    > that wbc->sb and wbc->bdi are set.
    This patch looks good.
    Acked-by: Jan Kara <jack@suse.cz>

    Honza

    >
    > Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
    > ---
    > fs/fs-writeback.c | 69 ++++++++++------------------------------------------
    > 1 files changed, 14 insertions(+), 55 deletions(-)
    >
    > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
    > index 1873fd0..5d4bd1c 100644
    > --- a/fs/fs-writeback.c
    > +++ b/fs/fs-writeback.c
    > @@ -187,7 +187,8 @@ static void bdi_wait_on_work_clear(struct bdi_work *work)
    > TASK_UNINTERRUPTIBLE);
    > }
    >
    > -static struct bdi_work *bdi_alloc_work(struct writeback_control *wbc)
    > +static void bdi_alloc_queue_work(struct backing_dev_info *bdi,
    > + struct writeback_control *wbc)
    > {
    > struct bdi_work *work;
    >
    > @@ -195,7 +196,7 @@ static struct bdi_work *bdi_alloc_work(struct writeback_control *wbc)
    > if (work)
    > bdi_work_init(work, wbc);
    >
    > - return work;
    > + bdi_queue_work(bdi, work);
    > }
    >
    > void bdi_start_writeback(struct writeback_control *wbc)
    > @@ -205,11 +206,9 @@ void bdi_start_writeback(struct writeback_control *wbc)
    > * 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) {
    > - struct bdi_work *w = bdi_alloc_work(wbc);
    > -
    > - bdi_queue_work(wbc->bdi, w);
    > - } else {
    > + if (wbc->sync_mode != WB_SYNC_ALL)
    > + bdi_alloc_queue_work(wbc->bdi, wbc);
    > + else {
    > struct bdi_work work;
    >
    > bdi_work_init(&work, wbc);
    > @@ -840,67 +839,26 @@ int bdi_writeback_task(struct bdi_writeback *wb)
    > }
    >
    > /*
    > - * Schedule writeback for all backing devices. Expensive! If this is a data
    > - * integrity operation, writeback will be complete when this returns. If
    > - * we are simply called for WB_SYNC_NONE, then writeback will merely be
    > - * scheduled to run.
    > + * Schedule writeback for all backing devices. Can only be used for
    > + * WB_SYNC_NONE writeback, WB_SYNC_ALL should use bdi_start_writeback()
    > + * and pass in the superblock.
    > */
    > static void bdi_writeback_all(struct writeback_control *wbc)
    > {
    > - const bool must_wait = wbc->sync_mode == WB_SYNC_ALL;
    > struct backing_dev_info *bdi;
    > - struct bdi_work *work;
    > - LIST_HEAD(list);
    >
    > -restart:
    > + WARN_ON(wbc->sync_mode == WB_SYNC_ALL);
    > +
    > spin_lock(&bdi_lock);
    >
    > list_for_each_entry(bdi, &bdi_list, bdi_list) {
    > - struct bdi_work *work;
    > -
    > if (!bdi_has_dirty_io(bdi))
    > continue;
    >
    > - /*
    > - * If work allocation fails, do the writes inline. We drop
    > - * the lock and restart the list writeout. This should be OK,
    > - * since this happens rarely and because the writeout should
    > - * eventually make more free memory available.
    > - */
    > - work = bdi_alloc_work(wbc);
    > - if (!work) {
    > - struct writeback_control __wbc;
    > -
    > - /*
    > - * Not a data integrity writeout, just continue
    > - */
    > - if (!must_wait)
    > - continue;
    > -
    > - spin_unlock(&bdi_lock);
    > - __wbc = *wbc;
    > - __wbc.bdi = bdi;
    > - writeback_inodes_wbc(&__wbc);
    > - goto restart;
    > - }
    > - if (must_wait)
    > - list_add_tail(&work->wait_list, &list);
    > -
    > - bdi_queue_work(bdi, work);
    > + bdi_alloc_queue_work(bdi, wbc);
    > }
    >
    > spin_unlock(&bdi_lock);
    > -
    > - /*
    > - * If this is for WB_SYNC_ALL, wait for pending work to complete
    > - * before returning.
    > - */
    > - while (!list_empty(&list)) {
    > - work = list_entry(list.next, struct bdi_work, wait_list);
    > - list_del(&work->wait_list);
    > - bdi_wait_on_work_clear(work);
    > - call_rcu(&work->rcu_head, bdi_work_free);
    > - }
    > }
    >
    > /*
    > @@ -1157,6 +1115,7 @@ 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,
    > @@ -1164,7 +1123,7 @@ long sync_inodes_sb(struct super_block *sb)
    > long nr_to_write = LONG_MAX; /* doesn't actually matter */
    >
    > wbc.nr_to_write = nr_to_write;
    > - bdi_writeback_all(&wbc);
    > + bdi_start_writeback(&wbc);
    > wait_sb_inodes(&wbc);
    > return nr_to_write - wbc.nr_to_write;
    > }
    > --
    > 1.6.4.1.207.g68ea
    >
    --
    Jan Kara <jack@suse.cz>
    SUSE Labs, CR


    \
     
     \ /
      Last update: 2009-09-14 15:15    [W:0.040 / U:0.192 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site