Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid

[karo-tx-linux.git] / drivers / md / persistent-data / dm-space-map-metadata.c

diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
index 906cf3df71af33365e460cbca0a82b0077fc6abf..1c959684caef7512fafd3c1a5505c29c798a9c11 100644 (file)
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -16,6 +16,55 @@
 
 /*----------------------------------------------------------------*/
 
+/*
+ * An edge triggered threshold.
+ */
+struct threshold {
+       bool threshold_set;
+       bool value_set;
+       dm_block_t threshold;
+       dm_block_t current_value;
+       dm_sm_threshold_fn fn;
+       void *context;
+};
+
+static void threshold_init(struct threshold *t)
+{
+       t->threshold_set = false;
+       t->value_set = false;
+}
+
+static void set_threshold(struct threshold *t, dm_block_t value,
+                         dm_sm_threshold_fn fn, void *context)
+{
+       t->threshold_set = true;
+       t->threshold = value;
+       t->fn = fn;
+       t->context = context;
+}
+
+static bool below_threshold(struct threshold *t, dm_block_t value)
+{
+       return t->threshold_set && value <= t->threshold;
+}
+
+static bool threshold_already_triggered(struct threshold *t)
+{
+       return t->value_set && below_threshold(t, t->current_value);
+}
+
+static void check_threshold(struct threshold *t, dm_block_t value)
+{
+       if (below_threshold(t, value) &&
+           !threshold_already_triggered(t))
+               t->fn(t->context);
+
+       t->value_set = true;
+       t->current_value = value;
+}
+
+/*----------------------------------------------------------------*/
+
 /*
  * Space map interface.
  *
@@ -54,6 +103,8 @@ struct sm_metadata {
        unsigned allocated_this_transaction;
        unsigned nr_uncommitted;
        struct block_op uncommitted[MAX_RECURSIVE_ALLOCATIONS];
+
+       struct threshold threshold;
 };
 
 static int add_bop(struct sm_metadata *smm, enum block_op_type type, dm_block_t b)
@@ -144,12 +195,6 @@ static void sm_metadata_destroy(struct dm_space_map *sm)
        kfree(smm);
 }
 
-static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
-{
-       DMERR("doesn't support extend");
-       return -EINVAL;
-}
-
 static int sm_metadata_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
 {
        struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
@@ -335,9 +380,19 @@ static int sm_metadata_new_block_(struct dm_space_map *sm, dm_block_t *b)
 
 static int sm_metadata_new_block(struct dm_space_map *sm, dm_block_t *b)
 {
+       dm_block_t count;
+       struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
+
        int r = sm_metadata_new_block_(sm, b);
        if (r)
                DMERR("unable to allocate new metadata block");
+
+       r = sm_metadata_get_nr_free(sm, &count);
+       if (r)
+               DMERR("couldn't get free block count");
+
+       check_threshold(&smm->threshold, count);
+
        return r;
 }
 
@@ -357,6 +412,18 @@ static int sm_metadata_commit(struct dm_space_map *sm)
        return 0;
 }
 
+static int sm_metadata_register_threshold_callback(struct dm_space_map *sm,
+                                                  dm_block_t threshold,
+                                                  dm_sm_threshold_fn fn,
+                                                  void *context)
+{
+       struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
+
+       set_threshold(&smm->threshold, threshold, fn, context);
+
+       return 0;
+}
+
 static int sm_metadata_root_size(struct dm_space_map *sm, size_t *result)
 {
        *result = sizeof(struct disk_sm_root);
@@ -382,6 +449,8 @@ static int sm_metadata_copy_root(struct dm_space_map *sm, void *where_le, size_t
        return 0;
 }
 
+static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks);
+
 static struct dm_space_map ops = {
        .destroy = sm_metadata_destroy,
        .extend = sm_metadata_extend,
@@ -395,7 +464,8 @@ static struct dm_space_map ops = {
        .new_block = sm_metadata_new_block,
        .commit = sm_metadata_commit,
        .root_size = sm_metadata_root_size,
-       .copy_root = sm_metadata_copy_root
+       .copy_root = sm_metadata_copy_root,
+       .register_threshold_callback = sm_metadata_register_threshold_callback
 };
 
 /*----------------------------------------------------------------*/
@@ -410,7 +480,7 @@ static void sm_bootstrap_destroy(struct dm_space_map *sm)
 
 static int sm_bootstrap_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
 {
-       DMERR("boostrap doesn't support extend");
+       DMERR("bootstrap doesn't support extend");
 
        return -EINVAL;
 }
@@ -450,7 +520,7 @@ static int sm_bootstrap_count_is_more_than_one(struct dm_space_map *sm,
 static int sm_bootstrap_set_count(struct dm_space_map *sm, dm_block_t b,
                                  uint32_t count)
 {
-       DMERR("boostrap doesn't support set_count");
+       DMERR("bootstrap doesn't support set_count");
 
        return -EINVAL;
 }
@@ -491,7 +561,7 @@ static int sm_bootstrap_commit(struct dm_space_map *sm)
 
 static int sm_bootstrap_root_size(struct dm_space_map *sm, size_t *result)
 {
-       DMERR("boostrap doesn't support root_size");
+       DMERR("bootstrap doesn't support root_size");
 
        return -EINVAL;
 }
@@ -499,7 +569,7 @@ static int sm_bootstrap_root_size(struct dm_space_map *sm, size_t *result)
 static int sm_bootstrap_copy_root(struct dm_space_map *sm, void *where,
                                  size_t max)
 {
-       DMERR("boostrap doesn't support copy_root");
+       DMERR("bootstrap doesn't support copy_root");
 
        return -EINVAL;
 }
@@ -517,11 +587,42 @@ static struct dm_space_map bootstrap_ops = {
        .new_block = sm_bootstrap_new_block,
        .commit = sm_bootstrap_commit,
        .root_size = sm_bootstrap_root_size,
-       .copy_root = sm_bootstrap_copy_root
+       .copy_root = sm_bootstrap_copy_root,
+       .register_threshold_callback = NULL
 };
 
 /*----------------------------------------------------------------*/
 
+static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
+{
+       int r, i;
+       enum allocation_event ev;
+       struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
+       dm_block_t old_len = smm->ll.nr_blocks;
+
+       /*
+        * Flick into a mode where all blocks get allocated in the new area.
+        */
+       smm->begin = old_len;
+       memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
+
+       /*
+        * Extend.
+        */
+       r = sm_ll_extend(&smm->ll, extra_blocks);
+
+       /*
+        * Switch back to normal behaviour.
+        */
+       memcpy(&smm->sm, &ops, sizeof(smm->sm));
+       for (i = old_len; !r && i < smm->begin; i++)
+               r = sm_ll_inc(&smm->ll, i, &ev);
+
+       return r;
+}
+
+/*----------------------------------------------------------------*/
+
 struct dm_space_map *dm_sm_metadata_init(void)
 {
        struct sm_metadata *smm;
@@ -549,6 +650,7 @@ int dm_sm_metadata_create(struct dm_space_map *sm,
        smm->recursion_count = 0;
        smm->allocated_this_transaction = 0;
        smm->nr_uncommitted = 0;
+       threshold_init(&smm->threshold);
 
        memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
 
@@ -590,6 +692,7 @@ int dm_sm_metadata_open(struct dm_space_map *sm,
        smm->recursion_count = 0;
        smm->allocated_this_transaction = 0;
        smm->nr_uncommitted = 0;
+       threshold_init(&smm->threshold);
 
        memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
        return 0;