dm bio prison v2: new interface for the bio prison

The deferred set is gone and all methods have _v2 appended to the end of
their names to allow for continued use of the original bio prison in DM
thin-provisioning.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

1 files changed, 0 insertions, 424 deletions

diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c
deleted file mode 100644
index 03af174485d3..000000000000
--- a/drivers/md/dm-bio-prison.c
+++ /dev/null
@@ -1,424 +0,0 @@
-/*
- * Copyright (C) 2012 Red Hat, Inc.
- *
- * This file is released under the GPL.
- */
-
-#include "dm.h"
-#include "dm-bio-prison.h"
-
-#include <linux/spinlock.h>
-#include <linux/mempool.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-
-/*----------------------------------------------------------------*/
-
-#define MIN_CELLS 1024
-
-struct dm_bio_prison {
-	spinlock_t lock;
-	mempool_t *cell_pool;
-	struct rb_root cells;
-};
-
-static struct kmem_cache *_cell_cache;
-
-/*----------------------------------------------------------------*/
-
-/*
- * @nr_cells should be the number of cells you want in use _concurrently_.
- * Don't confuse it with the number of distinct keys.
- */
-struct dm_bio_prison *dm_bio_prison_create(void)
-{
-	struct dm_bio_prison *prison = kmalloc(sizeof(*prison), GFP_KERNEL);
-
-	if (!prison)
-		return NULL;
-
-	spin_lock_init(&prison->lock);
-
-	prison->cell_pool = mempool_create_slab_pool(MIN_CELLS, _cell_cache);
-	if (!prison->cell_pool) {
-		kfree(prison);
-		return NULL;
-	}
-
-	prison->cells = RB_ROOT;
-
-	return prison;
-}
-EXPORT_SYMBOL_GPL(dm_bio_prison_create);
-
-void dm_bio_prison_destroy(struct dm_bio_prison *prison)
-{
-	mempool_destroy(prison->cell_pool);
-	kfree(prison);
-}
-EXPORT_SYMBOL_GPL(dm_bio_prison_destroy);
-
-struct dm_bio_prison_cell *dm_bio_prison_alloc_cell(struct dm_bio_prison *prison, gfp_t gfp)
-{
-	return mempool_alloc(prison->cell_pool, gfp);
-}
-EXPORT_SYMBOL_GPL(dm_bio_prison_alloc_cell);
-
-void dm_bio_prison_free_cell(struct dm_bio_prison *prison,
-			     struct dm_bio_prison_cell *cell)
-{
-	mempool_free(cell, prison->cell_pool);
-}
-EXPORT_SYMBOL_GPL(dm_bio_prison_free_cell);
-
-static void __setup_new_cell(struct dm_cell_key *key,
-			     struct bio *holder,
-			     struct dm_bio_prison_cell *cell)
-{
-       memcpy(&cell->key, key, sizeof(cell->key));
-       cell->holder = holder;
-       bio_list_init(&cell->bios);
-}
-
-static int cmp_keys(struct dm_cell_key *lhs,
-		    struct dm_cell_key *rhs)
-{
-	if (lhs->virtual < rhs->virtual)
-		return -1;
-
-	if (lhs->virtual > rhs->virtual)
-		return 1;
-
-	if (lhs->dev < rhs->dev)
-		return -1;
-
-	if (lhs->dev > rhs->dev)
-		return 1;
-
-	if (lhs->block_end <= rhs->block_begin)
-		return -1;
-
-	if (lhs->block_begin >= rhs->block_end)
-		return 1;
-
-	return 0;
-}
-
-static int __bio_detain(struct dm_bio_prison *prison,
-			struct dm_cell_key *key,
-			struct bio *inmate,
-			struct dm_bio_prison_cell *cell_prealloc,
-			struct dm_bio_prison_cell **cell_result)
-{
-	int r;
-	struct rb_node **new = &prison->cells.rb_node, *parent = NULL;
-
-	while (*new) {
-		struct dm_bio_prison_cell *cell =
-			container_of(*new, struct dm_bio_prison_cell, node);
-
-		r = cmp_keys(key, &cell->key);
-
-		parent = *new;
-		if (r < 0)
-			new = &((*new)->rb_left);
-		else if (r > 0)
-			new = &((*new)->rb_right);
-		else {
-			if (inmate)
-				bio_list_add(&cell->bios, inmate);
-			*cell_result = cell;
-			return 1;
-		}
-	}
-
-	__setup_new_cell(key, inmate, cell_prealloc);
-	*cell_result = cell_prealloc;
-
-	rb_link_node(&cell_prealloc->node, parent, new);
-	rb_insert_color(&cell_prealloc->node, &prison->cells);
-
-	return 0;
-}
-
-static int bio_detain(struct dm_bio_prison *prison,
-		      struct dm_cell_key *key,
-		      struct bio *inmate,
-		      struct dm_bio_prison_cell *cell_prealloc,
-		      struct dm_bio_prison_cell **cell_result)
-{
-	int r;
-	unsigned long flags;
-
-	spin_lock_irqsave(&prison->lock, flags);
-	r = __bio_detain(prison, key, inmate, cell_prealloc, cell_result);
-	spin_unlock_irqrestore(&prison->lock, flags);
-
-	return r;
-}
-
-int dm_bio_detain(struct dm_bio_prison *prison,
-		  struct dm_cell_key *key,
-		  struct bio *inmate,
-		  struct dm_bio_prison_cell *cell_prealloc,
-		  struct dm_bio_prison_cell **cell_result)
-{
-	return bio_detain(prison, key, inmate, cell_prealloc, cell_result);
-}
-EXPORT_SYMBOL_GPL(dm_bio_detain);
-
-int dm_get_cell(struct dm_bio_prison *prison,
-		struct dm_cell_key *key,
-		struct dm_bio_prison_cell *cell_prealloc,
-		struct dm_bio_prison_cell **cell_result)
-{
-	return bio_detain(prison, key, NULL, cell_prealloc, cell_result);
-}
-EXPORT_SYMBOL_GPL(dm_get_cell);
-
-/*
- * @inmates must have been initialised prior to this call
- */
-static void __cell_release(struct dm_bio_prison *prison,
-			   struct dm_bio_prison_cell *cell,
-			   struct bio_list *inmates)
-{
-	rb_erase(&cell->node, &prison->cells);
-
-	if (inmates) {
-		if (cell->holder)
-			bio_list_add(inmates, cell->holder);
-		bio_list_merge(inmates, &cell->bios);
-	}
-}
-
-void dm_cell_release(struct dm_bio_prison *prison,
-		     struct dm_bio_prison_cell *cell,
-		     struct bio_list *bios)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&prison->lock, flags);
-	__cell_release(prison, cell, bios);
-	spin_unlock_irqrestore(&prison->lock, flags);
-}
-EXPORT_SYMBOL_GPL(dm_cell_release);
-
-/*
- * Sometimes we don't want the holder, just the additional bios.
- */
-static void __cell_release_no_holder(struct dm_bio_prison *prison,
-				     struct dm_bio_prison_cell *cell,
-				     struct bio_list *inmates)
-{
-	rb_erase(&cell->node, &prison->cells);
-	bio_list_merge(inmates, &cell->bios);
-}
-
-void dm_cell_release_no_holder(struct dm_bio_prison *prison,
-			       struct dm_bio_prison_cell *cell,
-			       struct bio_list *inmates)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&prison->lock, flags);
-	__cell_release_no_holder(prison, cell, inmates);
-	spin_unlock_irqrestore(&prison->lock, flags);
-}
-EXPORT_SYMBOL_GPL(dm_cell_release_no_holder);
-
-void dm_cell_error(struct dm_bio_prison *prison,
-		   struct dm_bio_prison_cell *cell, int error)
-{
-	struct bio_list bios;
-	struct bio *bio;
-
-	bio_list_init(&bios);
-	dm_cell_release(prison, cell, &bios);
-
-	while ((bio = bio_list_pop(&bios))) {
-		bio->bi_error = error;
-		bio_endio(bio);
-	}
-}
-EXPORT_SYMBOL_GPL(dm_cell_error);
-
-void dm_cell_visit_release(struct dm_bio_prison *prison,
-			   void (*visit_fn)(void *, struct dm_bio_prison_cell *),
-			   void *context,
-			   struct dm_bio_prison_cell *cell)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&prison->lock, flags);
-	visit_fn(context, cell);
-	rb_erase(&cell->node, &prison->cells);
-	spin_unlock_irqrestore(&prison->lock, flags);
-}
-EXPORT_SYMBOL_GPL(dm_cell_visit_release);
-
-static int __promote_or_release(struct dm_bio_prison *prison,
-				struct dm_bio_prison_cell *cell)
-{
-	if (bio_list_empty(&cell->bios)) {
-		rb_erase(&cell->node, &prison->cells);
-		return 1;
-	}
-
-	cell->holder = bio_list_pop(&cell->bios);
-	return 0;
-}
-
-int dm_cell_promote_or_release(struct dm_bio_prison *prison,
-			       struct dm_bio_prison_cell *cell)
-{
-	int r;
-	unsigned long flags;
-
-	spin_lock_irqsave(&prison->lock, flags);
-	r = __promote_or_release(prison, cell);
-	spin_unlock_irqrestore(&prison->lock, flags);
-
-	return r;
-}
-EXPORT_SYMBOL_GPL(dm_cell_promote_or_release);
-
-/*----------------------------------------------------------------*/
-
-#define DEFERRED_SET_SIZE 64
-
-struct dm_deferred_entry {
-	struct dm_deferred_set *ds;
-	unsigned count;
-	struct list_head work_items;
-};
-
-struct dm_deferred_set {
-	spinlock_t lock;
-	unsigned current_entry;
-	unsigned sweeper;
-	struct dm_deferred_entry entries[DEFERRED_SET_SIZE];
-};
-
-struct dm_deferred_set *dm_deferred_set_create(void)
-{
-	int i;
-	struct dm_deferred_set *ds;
-
-	ds = kmalloc(sizeof(*ds), GFP_KERNEL);
-	if (!ds)
-		return NULL;
-
-	spin_lock_init(&ds->lock);
-	ds->current_entry = 0;
-	ds->sweeper = 0;
-	for (i = 0; i < DEFERRED_SET_SIZE; i++) {
-		ds->entries[i].ds = ds;
-		ds->entries[i].count = 0;
-		INIT_LIST_HEAD(&ds->entries[i].work_items);
-	}
-
-	return ds;
-}
-EXPORT_SYMBOL_GPL(dm_deferred_set_create);
-
-void dm_deferred_set_destroy(struct dm_deferred_set *ds)
-{
-	kfree(ds);
-}
-EXPORT_SYMBOL_GPL(dm_deferred_set_destroy);
-
-struct dm_deferred_entry *dm_deferred_entry_inc(struct dm_deferred_set *ds)
-{
-	unsigned long flags;
-	struct dm_deferred_entry *entry;
-
-	spin_lock_irqsave(&ds->lock, flags);
-	entry = ds->entries + ds->current_entry;
-	entry->count++;
-	spin_unlock_irqrestore(&ds->lock, flags);
-
-	return entry;
-}
-EXPORT_SYMBOL_GPL(dm_deferred_entry_inc);
-
-static unsigned ds_next(unsigned index)
-{
-	return (index + 1) % DEFERRED_SET_SIZE;
-}
-
-static void __sweep(struct dm_deferred_set *ds, struct list_head *head)
-{
-	while ((ds->sweeper != ds->current_entry) &&
-	       !ds->entries[ds->sweeper].count) {
-		list_splice_init(&ds->entries[ds->sweeper].work_items, head);
-		ds->sweeper = ds_next(ds->sweeper);
-	}
-
-	if ((ds->sweeper == ds->current_entry) && !ds->entries[ds->sweeper].count)
-		list_splice_init(&ds->entries[ds->sweeper].work_items, head);
-}
-
-void dm_deferred_entry_dec(struct dm_deferred_entry *entry, struct list_head *head)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&entry->ds->lock, flags);
-	BUG_ON(!entry->count);
-	--entry->count;
-	__sweep(entry->ds, head);
-	spin_unlock_irqrestore(&entry->ds->lock, flags);
-}
-EXPORT_SYMBOL_GPL(dm_deferred_entry_dec);
-
-/*
- * Returns 1 if deferred or 0 if no pending items to delay job.
- */
-int dm_deferred_set_add_work(struct dm_deferred_set *ds, struct list_head *work)
-{
-	int r = 1;
-	unsigned long flags;
-	unsigned next_entry;
-
-	spin_lock_irqsave(&ds->lock, flags);
-	if ((ds->sweeper == ds->current_entry) &&
-	    !ds->entries[ds->current_entry].count)
-		r = 0;
-	else {
-		list_add(work, &ds->entries[ds->current_entry].work_items);
-		next_entry = ds_next(ds->current_entry);
-		if (!ds->entries[next_entry].count)
-			ds->current_entry = next_entry;
-	}
-	spin_unlock_irqrestore(&ds->lock, flags);
-
-	return r;
-}
-EXPORT_SYMBOL_GPL(dm_deferred_set_add_work);
-
-/*----------------------------------------------------------------*/
-
-static int __init dm_bio_prison_init(void)
-{
-	_cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0);
-	if (!_cell_cache)
-		return -ENOMEM;
-
-	return 0;
-}
-
-static void __exit dm_bio_prison_exit(void)
-{
-	kmem_cache_destroy(_cell_cache);
-	_cell_cache = NULL;
-}
-
-/*
- * module hooks
- */
-module_init(dm_bio_prison_init);
-module_exit(dm_bio_prison_exit);
-
-MODULE_DESCRIPTION(DM_NAME " bio prison");
-MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
-MODULE_LICENSE("GPL");