Kernel bump from 4.1.3-rt to 4.1.7-rt.

[kvmfornfv.git] / kernel / drivers / md / dm-cache-policy-mq.c

diff --git a/kernel/drivers/md/dm-cache-policy-mq.c b/kernel/drivers/md/dm-cache-policy-mq.c
index 3ddd116..515d44b 100644 (file)
--- a/kernel/drivers/md/dm-cache-policy-mq.c
+++ b/kernel/drivers/md/dm-cache-policy-mq.c
@@ -693,9 +693,10 @@ static void requeue(struct mq_policy *mq, struct entry *e)
  * - set the hit count to a hard coded value other than 1, eg, is it better
  *   if it goes in at level 2?
  */
-static int demote_cblock(struct mq_policy *mq, dm_oblock_t *oblock)
+static int demote_cblock(struct mq_policy *mq,
+                        struct policy_locker *locker, dm_oblock_t *oblock)
 {
-       struct entry *demoted = pop(mq, &mq->cache_clean);
+       struct entry *demoted = peek(&mq->cache_clean);
 
        if (!demoted)
                /*
@@ -707,6 +708,13 @@ static int demote_cblock(struct mq_policy *mq, dm_oblock_t *oblock)
                 */
                return -ENOSPC;
 
+       if (locker->fn(locker, demoted->oblock))
+               /*
+                * We couldn't lock the demoted block.
+                */
+               return -EBUSY;
+
+       del(mq, demoted);
        *oblock = demoted->oblock;
        free_entry(&mq->cache_pool, demoted);
 
@@ -795,6 +803,7 @@ static int cache_entry_found(struct mq_policy *mq,
  * finding which cache block to use.
  */
 static int pre_cache_to_cache(struct mq_policy *mq, struct entry *e,
+                             struct policy_locker *locker,
                              struct policy_result *result)
 {
        int r;
@@ -803,11 +812,12 @@ static int pre_cache_to_cache(struct mq_policy *mq, struct entry *e,
        /* Ensure there's a free cblock in the cache */
        if (epool_empty(&mq->cache_pool)) {
                result->op = POLICY_REPLACE;
-               r = demote_cblock(mq, &result->old_oblock);
+               r = demote_cblock(mq, locker, &result->old_oblock);
                if (r) {
                        result->op = POLICY_MISS;
                        return 0;
                }
+
        } else
                result->op = POLICY_NEW;
 
@@ -829,7 +839,8 @@ static int pre_cache_to_cache(struct mq_policy *mq, struct entry *e,
 
 static int pre_cache_entry_found(struct mq_policy *mq, struct entry *e,
                                 bool can_migrate, bool discarded_oblock,
-                                int data_dir, struct policy_result *result)
+                                int data_dir, struct policy_locker *locker,
+                                struct policy_result *result)
 {
        int r = 0;
 
@@ -842,7 +853,7 @@ static int pre_cache_entry_found(struct mq_policy *mq, struct entry *e,
 
        else {
                requeue(mq, e);
-               r = pre_cache_to_cache(mq, e, result);
+               r = pre_cache_to_cache(mq, e, locker, result);
        }
 
        return r;
@@ -872,6 +883,7 @@ static void insert_in_pre_cache(struct mq_policy *mq,
 }
 
 static void insert_in_cache(struct mq_policy *mq, dm_oblock_t oblock,
+                           struct policy_locker *locker,
                            struct policy_result *result)
 {
        int r;
@@ -879,7 +891,7 @@ static void insert_in_cache(struct mq_policy *mq, dm_oblock_t oblock,
 
        if (epool_empty(&mq->cache_pool)) {
                result->op = POLICY_REPLACE;
-               r = demote_cblock(mq, &result->old_oblock);
+               r = demote_cblock(mq, locker, &result->old_oblock);
                if (unlikely(r)) {
                        result->op = POLICY_MISS;
                        insert_in_pre_cache(mq, oblock);
@@ -907,11 +919,12 @@ static void insert_in_cache(struct mq_policy *mq, dm_oblock_t oblock,
 
 static int no_entry_found(struct mq_policy *mq, dm_oblock_t oblock,
                          bool can_migrate, bool discarded_oblock,
-                         int data_dir, struct policy_result *result)
+                         int data_dir, struct policy_locker *locker,
+                         struct policy_result *result)
 {
        if (adjusted_promote_threshold(mq, discarded_oblock, data_dir) <= 1) {
                if (can_migrate)
-                       insert_in_cache(mq, oblock, result);
+                       insert_in_cache(mq, oblock, locker, result);
                else
                        return -EWOULDBLOCK;
        } else {
@@ -928,7 +941,8 @@ static int no_entry_found(struct mq_policy *mq, dm_oblock_t oblock,
  */
 static int map(struct mq_policy *mq, dm_oblock_t oblock,
               bool can_migrate, bool discarded_oblock,
-              int data_dir, struct policy_result *result)
+              int data_dir, struct policy_locker *locker,
+              struct policy_result *result)
 {
        int r = 0;
        struct entry *e = hash_lookup(mq, oblock);
@@ -942,11 +956,11 @@ static int map(struct mq_policy *mq, dm_oblock_t oblock,
 
        else if (e)
                r = pre_cache_entry_found(mq, e, can_migrate, discarded_oblock,
-                                         data_dir, result);
+                                         data_dir, locker, result);
 
        else
                r = no_entry_found(mq, oblock, can_migrate, discarded_oblock,
-                                  data_dir, result);
+                                  data_dir, locker, result);
 
        if (r == -EWOULDBLOCK)
                result->op = POLICY_MISS;
@@ -1012,7 +1026,8 @@ static void copy_tick(struct mq_policy *mq)
 
 static int mq_map(struct dm_cache_policy *p, dm_oblock_t oblock,
                  bool can_block, bool can_migrate, bool discarded_oblock,
-                 struct bio *bio, struct policy_result *result)
+                 struct bio *bio, struct policy_locker *locker,
+                 struct policy_result *result)
 {
        int r;
        struct mq_policy *mq = to_mq_policy(p);
@@ -1028,7 +1043,7 @@ static int mq_map(struct dm_cache_policy *p, dm_oblock_t oblock,
 
        iot_examine_bio(&mq->tracker, bio);
        r = map(mq, oblock, can_migrate, discarded_oblock,
-               bio_data_dir(bio), result);
+               bio_data_dir(bio), locker, result);
 
        mutex_unlock(&mq->lock);