On Fri, 22 Jul 2011 14:31:51 +0900 Namhyung Kim <namhyung@xxxxxxxxx> wrote:
> NeilBrown <neilb@xxxxxxx> writes:
>
> > Adding these three fields will allow more common code to be moved
> > to handle_stripe()
> >
> > Signed-off-by: NeilBrown <neilb@xxxxxxx>
>
> Reviewed-by: Namhyung Kim <namhyung@xxxxxxxxx>
>
> and nitpick below.
>
>
> > ---
> >
> > drivers/md/raid5.c | 54 +++++++++++++++++++++++-----------------------------
> > drivers/md/raid5.h | 4 ++++
> > 2 files changed, 28 insertions(+), 30 deletions(-)
> >
> > diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> > index c32ffb5..3327e82 100644
> > --- a/drivers/md/raid5.c
> > +++ b/drivers/md/raid5.c
> > @@ -3003,12 +3003,9 @@ static void handle_stripe5(struct stripe_head *sh)
> > {
> > raid5_conf_t *conf = sh->raid_conf;
> > int disks = sh->disks, i;
> > - struct bio *return_bi = NULL;
> > struct stripe_head_state s;
> > struct r5dev *dev;
> > - mdk_rdev_t *blocked_rdev = NULL;
> > int prexor;
> > - int dec_preread_active = 0;
> >
> > memset(&s, 0, sizeof(s));
> > pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
> > @@ -3058,9 +3055,9 @@ static void handle_stripe5(struct stripe_head *sh)
> > if (dev->written)
> > s.written++;
> > rdev = rcu_dereference(conf->disks[i].rdev);
> > - if (blocked_rdev == NULL &&
> > + if (s.blocked_rdev == NULL &&
> > rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
> > - blocked_rdev = rdev;
> > + s.blocked_rdev = rdev;
> > atomic_inc(&rdev->nr_pending);
> > }
> > clear_bit(R5_Insync, &dev->flags);
> > @@ -3088,15 +3085,15 @@ static void handle_stripe5(struct stripe_head *sh)
> > spin_unlock_irq(&conf->device_lock);
> > rcu_read_unlock();
> >
> > - if (unlikely(blocked_rdev)) {
> > + if (unlikely(s.blocked_rdev)) {
> > if (s.syncing || s.expanding || s.expanded ||
> > s.to_write || s.written) {
> > set_bit(STRIPE_HANDLE, &sh->state);
> > goto unlock;
> > }
> > /* There is nothing for the blocked_rdev to block */
> > - rdev_dec_pending(blocked_rdev, conf->mddev);
> > - blocked_rdev = NULL;
> > + rdev_dec_pending(s.blocked_rdev, conf->mddev);
> > + s.blocked_rdev = NULL;
> > }
> >
> > if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
> > @@ -3112,7 +3109,7 @@ static void handle_stripe5(struct stripe_head *sh)
> > * need to be failed
> > */
> > if (s.failed > 1 && s.to_read+s.to_write+s.written)
> > - handle_failed_stripe(conf, sh, &s, disks, &return_bi);
> > + handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
> > if (s.failed > 1 && s.syncing) {
> > md_done_sync(conf->mddev, STRIPE_SECTORS,0);
> > clear_bit(STRIPE_SYNCING, &sh->state);
> > @@ -3128,7 +3125,7 @@ static void handle_stripe5(struct stripe_head *sh)
> > !test_bit(R5_LOCKED, &dev->flags) &&
> > test_bit(R5_UPTODATE, &dev->flags)) ||
> > (s.failed == 1 && s.failed_num[0] == sh->pd_idx)))
> > - handle_stripe_clean_event(conf, sh, disks, &return_bi);
> > + handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
> >
> > /* Now we might consider reading some blocks, either to check/generate
> > * parity, or to satisfy requests
> > @@ -3166,7 +3163,7 @@ static void handle_stripe5(struct stripe_head *sh)
> > }
> > }
> > if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
> > - dec_preread_active = 1;
> > + s.dec_preread_active = 1;
> > }
> >
> > /* Now to consider new write requests and what else, if anything
> > @@ -3264,15 +3261,15 @@ static void handle_stripe5(struct stripe_head *sh)
> > unlock:
> >
> > /* wait for this device to become unblocked */
> > - if (unlikely(blocked_rdev))
> > - md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
> > + if (unlikely(s.blocked_rdev))
> > + md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev);
> >
> > if (s.ops_request)
> > raid_run_ops(sh, s.ops_request);
> >
> > ops_run_io(sh, &s);
> >
> > - if (dec_preread_active) {
> > + if (s.dec_preread_active) {
> > /* We delay this until after ops_run_io so that if make_request
> > * is waiting on a flush, it won't continue until the writes
> > * have actually been submitted.
> > @@ -3282,19 +3279,16 @@ static void handle_stripe5(struct stripe_head *sh)
> > IO_THRESHOLD)
> > md_wakeup_thread(conf->mddev->thread);
> > }
> > - return_io(return_bi);
> > + return_io(s.return_bi);
> > }
> >
> > static void handle_stripe6(struct stripe_head *sh)
> > {
> > raid5_conf_t *conf = sh->raid_conf;
> > int disks = sh->disks;
> > - struct bio *return_bi = NULL;
> > int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
> > struct stripe_head_state s;
> > struct r5dev *dev, *pdev, *qdev;
> > - mdk_rdev_t *blocked_rdev = NULL;
> > - int dec_preread_active = 0;
> >
> > pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
> > "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
> > @@ -3345,9 +3339,9 @@ static void handle_stripe6(struct stripe_head *sh)
> > if (dev->written)
> > s.written++;
> > rdev = rcu_dereference(conf->disks[i].rdev);
> > - if (blocked_rdev == NULL &&
> > + if (s.blocked_rdev == NULL &&
> > rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
> > - blocked_rdev = rdev;
> > + s.blocked_rdev = rdev;
> > atomic_inc(&rdev->nr_pending);
> > }
> > clear_bit(R5_Insync, &dev->flags);
> > @@ -3376,15 +3370,15 @@ static void handle_stripe6(struct stripe_head *sh)
> > spin_unlock_irq(&conf->device_lock);
> > rcu_read_unlock();
> >
> > - if (unlikely(blocked_rdev)) {
> > + if (unlikely(s.blocked_rdev)) {
> > if (s.syncing || s.expanding || s.expanded ||
> > s.to_write || s.written) {
> > set_bit(STRIPE_HANDLE, &sh->state);
> > goto unlock;
> > }
> > /* There is nothing for the blocked_rdev to block */
> > - rdev_dec_pending(blocked_rdev, conf->mddev);
> > - blocked_rdev = NULL;
> > + rdev_dec_pending(s.blocked_rdev, conf->mddev);
> > + s.blocked_rdev = NULL;
> > }
> >
> > if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
> > @@ -3400,7 +3394,7 @@ static void handle_stripe6(struct stripe_head *sh)
> > * might need to be failed
> > */
> > if (s.failed > 2 && s.to_read+s.to_write+s.written)
> > - handle_failed_stripe(conf, sh, &s, disks, &return_bi);
> > + handle_failed_stripe(conf, sh, &s, disks, &s.return_bi);
> > if (s.failed > 2 && s.syncing) {
> > md_done_sync(conf->mddev, STRIPE_SECTORS,0);
> > clear_bit(STRIPE_SYNCING, &sh->state);
> > @@ -3425,7 +3419,7 @@ static void handle_stripe6(struct stripe_head *sh)
> > (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
> > && !test_bit(R5_LOCKED, &qdev->flags)
> > && test_bit(R5_UPTODATE, &qdev->flags)))))
> > - handle_stripe_clean_event(conf, sh, disks, &return_bi);
> > + handle_stripe_clean_event(conf, sh, disks, &s.return_bi);
> >
> > /* Now we might consider reading some blocks, either to check/generate
> > * parity, or to satisfy requests
> > @@ -3461,7 +3455,7 @@ static void handle_stripe6(struct stripe_head *sh)
> > }
> > }
> > if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
> > - dec_preread_active = 1;
> > + s.dec_preread_active = 1;
> > }
> >
> > /* Now to consider new write requests and what else, if anything
> > @@ -3561,8 +3555,8 @@ static void handle_stripe6(struct stripe_head *sh)
> > unlock:
> >
> > /* wait for this device to become unblocked */
> > - if (unlikely(blocked_rdev))
> > - md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
> > + if (unlikely(s.blocked_rdev))
> > + md_wait_for_blocked_rdev(s.blocked_rdev, conf->mddev);
> >
> > if (s.ops_request)
> > raid_run_ops(sh, s.ops_request);
> > @@ -3570,7 +3564,7 @@ static void handle_stripe6(struct stripe_head *sh)
> > ops_run_io(sh, &s);
> >
> >
> > - if (dec_preread_active) {
> > + if (s.dec_preread_active) {
> > /* We delay this until after ops_run_io so that if make_request
> > * is waiting on a flush, it won't continue until the writes
> > * have actually been submitted.
> > @@ -3581,7 +3575,7 @@ static void handle_stripe6(struct stripe_head *sh)
> > md_wakeup_thread(conf->mddev->thread);
> > }
> >
> > - return_io(return_bi);
> > + return_io(s.return_bi);
> > }
> >
> > static void handle_stripe(struct stripe_head *sh)
> > diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
> > index d3c61d3..9ceb574 100644
> > --- a/drivers/md/raid5.h
> > +++ b/drivers/md/raid5.h
> > @@ -248,6 +248,10 @@ struct stripe_head_state {
> > int failed_num[2];
> > unsigned long ops_request;
> > int p_failed, q_failed;
> > +
> > + struct bio *return_bi;
> > + mdk_rdev_t *blocked_rdev;
> > + int dec_preread_active;
> > };
>
> I'd rather rearrange the struct to reduce paddings on 64-bit:
>
> /* stripe_head_state - collects and tracks the dynamic state of a stripe_head
> * for handle_stripe. It is only valid under spin_lock(sh->lock);
> */
> struct stripe_head_state {
> int syncing, expanding, expanded;
> int locked, uptodate, to_read, to_write, failed, written;
> int to_fill, compute, req_compute, non_overwrite;
> int failed_num[2];
> int p_failed, q_failed;
> int dec_preread_active;
> unsigned long ops_request;
>
> struct bio *return_bi;
> mdk_rdev_t *blocked_rdev;
> };
I've made that change, thanks.
>
> BTW, comment above mentions sh->lock which is disappeared in previous
> patch. It should be fixed as well (in patch 08/34?).
True ... and there are lots of other mentions made of the stripe lock in all
those comments.
I have fixed some of them up but I really need to review all of that
commentary.
Thanks,
NeilBrown
>
> Thanks.
>
>
> >
> > /* Flags */
> >
> >
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