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authorLars Ellenberg <lars.ellenberg@linbit.com>2013-03-19 21:16:53 +0400
committerJens Axboe <axboe@kernel.dk>2013-03-23 04:15:17 +0400
commit6c3c4355d6bfa418db828684e67910c559402264 (patch)
treee7cbaa778b1614342d562f56e98612b850c25046 /drivers/block/drbd/drbd_actlog.c
parentb5bc8e08641805391f2c7834c40d0f647e8563c6 (diff)
downloadlinux-6c3c4355d6bfa418db828684e67910c559402264.tar.xz
drbd: split out some helper functions to drbd_al_begin_io
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.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/drbd/drbd_actlog.c')
-rw-r--r--drivers/block/drbd/drbd_actlog.c49
1 files changed, 28 insertions, 21 deletions
diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index e4f1231c2ef2..ff03f9053316 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;
}