From: Lars Ellenberg <lars.ellenb...@linbit.com>
To make the code easier to follow,
use an explicit find_active_resync_extent(),
and add a "nonblock" parameter to _al_get().
Signed-off-by: Philipp Reisner <philipp.reis...@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenb...@linbit.com>
---
drivers/block/drbd/drbd_actlog.c | 49 ++++++++++++++++++++++----------------
1 file changed, 28 insertions(+), 21 deletions(-)
diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index e4f1231..ff03f90 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -222,25 +222,37 @@ int drbd_md_sync_page_io(struct drbd_conf *mdev, struct
drbd_backing_dev *bdev,
return err;
}
-static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr)
+static struct bm_extent *find_active_resync_extent(struct drbd_conf *mdev,
unsigned int enr)
{
- struct lc_element *al_ext;
struct lc_element *tmp;
- int wake;
-
- spin_lock_irq(&mdev->al_lock);
tmp = lc_find(mdev->resync, enr/AL_EXT_PER_BM_SECT);
if (unlikely(tmp != NULL)) {
struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent,
lce);
- if (test_bit(BME_NO_WRITES, &bm_ext->flags)) {
- wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags);
- spin_unlock_irq(&mdev->al_lock);
- if (wake)
- wake_up(&mdev->al_wait);
- return NULL;
- }
+ if (test_bit(BME_NO_WRITES, &bm_ext->flags))
+ return bm_ext;
}
- al_ext = lc_get(mdev->act_log, enr);
+ return NULL;
+}
+
+static struct lc_element *_al_get(struct drbd_conf *mdev, unsigned int enr,
bool nonblock)
+{
+ struct lc_element *al_ext;
+ struct bm_extent *bm_ext;
+ int wake;
+
+ spin_lock_irq(&mdev->al_lock);
+ bm_ext = find_active_resync_extent(mdev, enr);
+ if (bm_ext) {
+ wake = !test_and_set_bit(BME_PRIORITY, &bm_ext->flags);
+ spin_unlock_irq(&mdev->al_lock);
+ if (wake)
+ wake_up(&mdev->al_wait);
+ return NULL;
+ }
+ if (nonblock)
+ al_ext = lc_try_get(mdev->act_log, enr);
+ else
+ al_ext = lc_get(mdev->act_log, enr);
spin_unlock_irq(&mdev->al_lock);
return al_ext;
}
@@ -251,7 +263,6 @@ bool drbd_al_begin_io_fastpath(struct drbd_conf *mdev,
struct drbd_interval *i)
* we may need to activate two extents in one go */
unsigned first = i->sector >> (AL_EXTENT_SHIFT-9);
unsigned last = i->size == 0 ? first : (i->sector + (i->size >> 9) - 1)
>> (AL_EXTENT_SHIFT-9);
- bool fastpath_ok = true;
D_ASSERT((unsigned)(last - first) <= 1);
D_ASSERT(atomic_read(&mdev->local_cnt) > 0);
@@ -260,12 +271,7 @@ bool drbd_al_begin_io_fastpath(struct drbd_conf *mdev,
struct drbd_interval *i)
if (first != last)
return false;
- spin_lock_irq(&mdev->al_lock);
- fastpath_ok =
- lc_find(mdev->resync, first/AL_EXT_PER_BM_SECT) == NULL &&
- lc_try_get(mdev->act_log, first) != NULL;
- spin_unlock_irq(&mdev->al_lock);
- return fastpath_ok;
+ return _al_get(mdev, first, true);
}
bool drbd_al_begin_io_prepare(struct drbd_conf *mdev, struct drbd_interval *i)
@@ -282,7 +288,8 @@ bool drbd_al_begin_io_prepare(struct drbd_conf *mdev,
struct drbd_interval *i)
for (enr = first; enr <= last; enr++) {
struct lc_element *al_ext;
- wait_event(mdev->al_wait, (al_ext = _al_get(mdev, enr)) !=
NULL);
+ wait_event(mdev->al_wait,
+ (al_ext = _al_get(mdev, enr, false)) != NULL);
if (al_ext->lc_number != enr)
need_transaction = true;
}
--
1.7.9.5
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