drbd: _req_conflicts(): Get rid of the epoch_entries tree

Instead of keeping a separate tree for local and remote write requests
for finding requests and for conflict detection, use the same tree for
both purposes.  Introduce a flag to allow distinguishing the two
possible types of entries in this tree.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 7922fa0403d03066a4d77c28d1b383100d2f98a7..7fcda713714f4abe9b736774ccb0a885aac24a37 100644 (file)
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1045,9 +1045,6 @@ struct drbd_conf {
        struct list_head read_ee;   /* IO in progress (any read) */
        struct list_head net_ee;    /* zero-copy network send in progress */
 
-       /* Interval tree of pending remote write requests (struct drbd_epoch_entry) */
-       struct rb_root epoch_entries;
-
        /* this one is protected by ee_lock, single thread */
        struct drbd_epoch_entry *last_write_w_barrier;
 

diff --git a/drivers/block/drbd/drbd_interval.h b/drivers/block/drbd/drbd_interval.h
index 9d1e5eb2d7eb6ebe37daa707b274fc6559c8f6a7..4010ad923948b0bafcd80b1f0c10da6017426e0b 100644 (file)
--- a/drivers/block/drbd/drbd_interval.h
+++ b/drivers/block/drbd/drbd_interval.h
@@ -9,6 +9,7 @@ struct drbd_interval {
        sector_t sector;        /* start sector of the interval */
        unsigned int size;      /* size in bytes */
        sector_t end;           /* highest interval end in subtree */
+       int local:1             /* local or remote request? */;
        int waiting:1;
 };
 

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 5da1df023a49d07b5eef9686cfe0bc8dfd51c07a..8c77476825e45dc96263c9809da1559d00ed6057 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -3450,7 +3450,6 @@ struct drbd_conf *drbd_new_device(unsigned int minor)
                goto out_no_tl;
        mdev->read_requests = RB_ROOT;
        mdev->write_requests = RB_ROOT;
-       mdev->epoch_entries = RB_ROOT;
 
        mdev->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
        if (!mdev->current_epoch)

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index b84a9c9fd3f84321762b1d786b402c8f3bba3660..b063ca234462b474c19644c97a355e45d44dd8f5 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -336,6 +336,7 @@ struct drbd_epoch_entry *drbd_alloc_ee(struct drbd_conf *mdev,
        drbd_clear_interval(&e->i);
        e->i.size = data_size;
        e->i.sector = sector;
+       e->i.local = false;
        e->i.waiting = false;
 
        e->epoch = NULL;
@@ -1508,7 +1509,7 @@ find_request(struct drbd_conf *mdev, struct rb_root *root, u64 id,
 
        /* Request object according to our peer */
        req = (struct drbd_request *)(unsigned long)id;
-       if (drbd_contains_interval(root, sector, &req->i))
+       if (drbd_contains_interval(root, sector, &req->i) && req->i.local)
                return req;
        if (!missing_ok) {
                dev_err(DEV, "%s: failed to find request %lu, sector %llus\n", func,
@@ -1788,17 +1789,12 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
                /* conflict detection and handling:
                 * 1. wait on the sequence number,
                 *    in case this data packet overtook ACK packets.
-                * 2. check our interval trees for conflicting requests:
-                *    we only need to check the write_requests tree; the
-                *    epoch_entries tree cannot contain any overlaps because
-                *    they were already eliminated on the submitting node.
+                * 2. check for conflicting write requests.
                 *
                 * Note: for two_primaries, we are protocol C,
                 * so there cannot be any request that is DONE
                 * but still on the transfer log.
                 *
-                * unconditionally add to the epoch_entries tree.
-                *
                 * if no conflicting request is found:
                 *    submit.
                 *
@@ -1823,12 +1819,9 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
 
                spin_lock_irq(&mdev->tconn->req_lock);
 
-               drbd_insert_interval(&mdev->epoch_entries, &e->i);
-
                first = 1;
                for (;;) {
                        struct drbd_interval *i;
-                       struct drbd_request *req2;
                        int have_unacked = 0;
                        int have_conflict = 0;
                        prepare_to_wait(&mdev->misc_wait, &wait,
@@ -1836,18 +1829,23 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
 
                        i = drbd_find_overlap(&mdev->write_requests, sector, size);
                        if (i) {
-                               req2 = container_of(i, struct drbd_request, i);
-
                                /* only ALERT on first iteration,
                                 * we may be woken up early... */
                                if (first)
-                                       dev_alert(DEV, "%s[%u] Concurrent local write detected!"
+                                       dev_alert(DEV, "%s[%u] Concurrent %s write detected!"
                                              " new: %llus +%u; pending: %llus +%u\n",
                                              current->comm, current->pid,
+                                             i->local ? "local" : "remote",
                                              (unsigned long long)sector, size,
-                                             (unsigned long long)req2->i.sector, req2->i.size);
-                               if (req2->rq_state & RQ_NET_PENDING)
-                                       ++have_unacked;
+                                             (unsigned long long)i->sector, i->size);
+
+                               if (i->local) {
+                                       struct drbd_request *req2;
+
+                                       req2 = container_of(i, struct drbd_request, i);
+                                       if (req2->rq_state & RQ_NET_PENDING)
+                                               ++have_unacked;
+                               }
                                ++have_conflict;
                        }
                        if (!have_conflict)
@@ -1873,7 +1871,6 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
                        }
 
                        if (signal_pending(current)) {
-                               drbd_remove_epoch_entry_interval(mdev, e);
                                spin_unlock_irq(&mdev->tconn->req_lock);
                                finish_wait(&mdev->misc_wait, &wait);
                                goto out_interrupted;
@@ -1896,6 +1893,8 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
                        spin_lock_irq(&mdev->tconn->req_lock);
                }
                finish_wait(&mdev->misc_wait, &wait);
+
+               drbd_insert_interval(&mdev->write_requests, &e->i);
        }
 
        list_add(&e->w.list, &mdev->active_ee);

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 078f77ba68fb29dc09a3d9b25d946ea5a34070a2..df5f106273275160be69478193a70f60deec5c83 100644 (file)
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -74,6 +74,7 @@ static struct drbd_request *drbd_req_new(struct drbd_conf *mdev,
        drbd_clear_interval(&req->i);
        req->i.sector     = bio_src->bi_sector;
        req->i.size      = bio_src->bi_size;
+       req->i.local = true;
        req->i.waiting = false;
 
        INIT_LIST_HEAD(&req->tl_requests);
@@ -317,8 +318,6 @@ static void _req_may_be_done_not_susp(struct drbd_request *req, struct bio_and_e
  * to happen, but this is the rationale why we also have to check for
  * conflicting requests with local origin, and why we have to do so regardless
  * of whether we allowed multiple primaries.
- *
- * In case we only have one primary, the epoch_entries tree is empty.
  */
 static int _req_conflicts(struct drbd_request *req)
 {
@@ -334,35 +333,16 @@ static int _req_conflicts(struct drbd_request *req)
 
        i = drbd_find_overlap(&mdev->write_requests, sector, size);
        if (i) {
-               struct drbd_request *req2 =
-                       container_of(i, struct drbd_request, i);
-
-               dev_alert(DEV, "%s[%u] Concurrent local write detected! "
+               dev_alert(DEV, "%s[%u] Concurrent %s write detected! "
                      "[DISCARD L] new: %llus +%u; "
                      "pending: %llus +%u\n",
                      current->comm, current->pid,
+                     i->local ? "local" : "remote",
                      (unsigned long long)sector, size,
-                     (unsigned long long)req2->i.sector, req2->i.size);
+                     (unsigned long long)i->sector, i->size);
                goto out_conflict;
        }
 
-       if (!RB_EMPTY_ROOT(&mdev->epoch_entries)) {
-               /* check for overlapping requests with remote origin */
-               i = drbd_find_overlap(&mdev->epoch_entries, sector, size);
-               if (i) {
-                       struct drbd_epoch_entry *e =
-                               container_of(i, struct drbd_epoch_entry, i);
-
-                       dev_alert(DEV, "%s[%u] Concurrent remote write detected!"
-                             " [DISCARD L] new: %llus +%u; "
-                             "pending: %llus +%u\n",
-                             current->comm, current->pid,
-                             (unsigned long long)sector, size,
-                             (unsigned long long)e->i.sector, e->i.size);
-                       goto out_conflict;
-               }
-       }
-
        /* this is like it should be, and what we expected.
         * our users do behave after all... */
        put_net_conf(mdev->tconn);

diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index afad8ea4d88876c734cd0a91aef22b356a1fc013..0359600f56350877835e63b34a2f8cedc42df385 100644 (file)
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -123,7 +123,7 @@ static void drbd_endio_write_sec_final(struct drbd_epoch_entry *e) __releases(lo
        list_add_tail(&e->w.list, &mdev->done_ee);
 
        /*
-        * Do not remove from the epoch_entries tree here: we did not send the
+        * Do not remove from the write_requests tree here: we did not send the
         * Ack yet and did not wake possibly waiting conflicting requests.
         * Removed from the tree from "drbd_process_done_ee" within the
         * appropriate w.cb (e_end_block/e_end_resync_block) or from