Commit 742c8fdc authored by Joe Thornber's avatar Joe Thornber Committed by Mike Snitzer

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: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent c1ae3cfa
......@@ -11,6 +11,7 @@ dm-snapshot-y += dm-snap.o dm-exception-store.o dm-snap-transient.o \
dm-mirror-y += dm-raid1.o
dm-log-userspace-y \
+= dm-log-userspace-base.o dm-log-userspace-transfer.o
dm-bio-prison-y += dm-bio-prison-v1.o dm-bio-prison-v2.o
dm-thin-pool-y += dm-thin.o dm-thin-metadata.o
dm-cache-y += dm-cache-target.o dm-cache-metadata.o dm-cache-policy.o
dm-cache-smq-y += dm-cache-policy-smq.o
......
......@@ -5,7 +5,8 @@
*/
#include "dm.h"
#include "dm-bio-prison.h"
#include "dm-bio-prison-v1.h"
#include "dm-bio-prison-v2.h"
#include <linux/spinlock.h>
#include <linux/mempool.h>
......@@ -398,7 +399,7 @@ EXPORT_SYMBOL_GPL(dm_deferred_set_add_work);
/*----------------------------------------------------------------*/
static int __init dm_bio_prison_init(void)
static int __init dm_bio_prison_init_v1(void)
{
_cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0);
if (!_cell_cache)
......@@ -407,12 +408,51 @@ static int __init dm_bio_prison_init(void)
return 0;
}
static void __exit dm_bio_prison_exit(void)
static void dm_bio_prison_exit_v1(void)
{
kmem_cache_destroy(_cell_cache);
_cell_cache = NULL;
}
static int (*_inits[])(void) __initdata = {
dm_bio_prison_init_v1,
dm_bio_prison_init_v2,
};
static void (*_exits[])(void) = {
dm_bio_prison_exit_v1,
dm_bio_prison_exit_v2,
};
static int __init dm_bio_prison_init(void)
{
const int count = ARRAY_SIZE(_inits);
int r, i;
for (i = 0; i < count; i++) {
r = _inits[i]();
if (r)
goto bad;
}
return 0;
bad:
while (i--)
_exits[i]();
return r;
}
static void __exit dm_bio_prison_exit(void)
{
int i = ARRAY_SIZE(_exits);
while (i--)
_exits[i]();
}
/*
* module hooks
*/
......
/*
* Copyright (C) 2011-2012 Red Hat, Inc.
* Copyright (C) 2011-2017 Red Hat, Inc.
*
* This file is released under the GPL.
*/
......
/*
* Copyright (C) 2012-2017 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm.h"
#include "dm-bio-prison-v2.h"
#include <linux/spinlock.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
/*----------------------------------------------------------------*/
#define MIN_CELLS 1024
struct dm_bio_prison_v2 {
struct workqueue_struct *wq;
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_v2 *dm_bio_prison_create_v2(struct workqueue_struct *wq)
{
struct dm_bio_prison_v2 *prison = kmalloc(sizeof(*prison), GFP_KERNEL);
if (!prison)
return NULL;
prison->wq = wq;
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_v2);
void dm_bio_prison_destroy_v2(struct dm_bio_prison_v2 *prison)
{
mempool_destroy(prison->cell_pool);
kfree(prison);
}
EXPORT_SYMBOL_GPL(dm_bio_prison_destroy_v2);
struct dm_bio_prison_cell_v2 *dm_bio_prison_alloc_cell_v2(struct dm_bio_prison_v2 *prison, gfp_t gfp)
{
return mempool_alloc(prison->cell_pool, gfp);
}
EXPORT_SYMBOL_GPL(dm_bio_prison_alloc_cell_v2);
void dm_bio_prison_free_cell_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell)
{
mempool_free(cell, prison->cell_pool);
}
EXPORT_SYMBOL_GPL(dm_bio_prison_free_cell_v2);
static void __setup_new_cell(struct dm_cell_key_v2 *key,
struct dm_bio_prison_cell_v2 *cell)
{
memset(cell, 0, sizeof(*cell));
memcpy(&cell->key, key, sizeof(cell->key));
bio_list_init(&cell->bios);
}
static int cmp_keys(struct dm_cell_key_v2 *lhs,
struct dm_cell_key_v2 *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;
}
/*
* Returns true if node found, otherwise it inserts a new one.
*/
static bool __find_or_insert(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **result)
{
int r;
struct rb_node **new = &prison->cells.rb_node, *parent = NULL;
while (*new) {
struct dm_bio_prison_cell_v2 *cell =
container_of(*new, struct dm_bio_prison_cell_v2, 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 {
*result = cell;
return true;
}
}
__setup_new_cell(key, cell_prealloc);
*result = cell_prealloc;
rb_link_node(&cell_prealloc->node, parent, new);
rb_insert_color(&cell_prealloc->node, &prison->cells);
return false;
}
static bool __get(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned lock_level,
struct bio *inmate,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell)
{
if (__find_or_insert(prison, key, cell_prealloc, cell)) {
if ((*cell)->exclusive_lock) {
if (lock_level <= (*cell)->exclusive_level) {
bio_list_add(&(*cell)->bios, inmate);
return false;
}
}
(*cell)->shared_count++;
} else
(*cell)->shared_count = 1;
return true;
}
bool dm_cell_get_v2(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned lock_level,
struct bio *inmate,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell_result)
{
int r;
unsigned long flags;
spin_lock_irqsave(&prison->lock, flags);
r = __get(prison, key, lock_level, inmate, cell_prealloc, cell_result);
spin_unlock_irqrestore(&prison->lock, flags);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_get_v2);
static bool __put(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell)
{
BUG_ON(!cell->shared_count);
cell->shared_count--;
// FIXME: shared locks granted above the lock level could starve this
if (!cell->shared_count) {
if (cell->exclusive_lock){
if (cell->quiesce_continuation) {
queue_work(prison->wq, cell->quiesce_continuation);
cell->quiesce_continuation = NULL;
}
} else {
rb_erase(&cell->node, &prison->cells);
return true;
}
}
return false;
}
bool dm_cell_put_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell)
{
bool r;
unsigned long flags;
spin_lock_irqsave(&prison->lock, flags);
r = __put(prison, cell);
spin_unlock_irqrestore(&prison->lock, flags);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_put_v2);
static int __lock(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned lock_level,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell_result)
{
struct dm_bio_prison_cell_v2 *cell;
if (__find_or_insert(prison, key, cell_prealloc, &cell)) {
if (cell->exclusive_lock)
return -EBUSY;
cell->exclusive_lock = true;
cell->exclusive_level = lock_level;
*cell_result = cell;
// FIXME: we don't yet know what level these shared locks
// were taken at, so have to quiesce them all.
return cell->shared_count > 0;
} else {
cell = cell_prealloc;
cell->shared_count = 0;
cell->exclusive_lock = true;
cell->exclusive_level = lock_level;
*cell_result = cell;
}
return 0;
}
int dm_cell_lock_v2(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned lock_level,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell_result)
{
int r;
unsigned long flags;
spin_lock_irqsave(&prison->lock, flags);
r = __lock(prison, key, lock_level, cell_prealloc, cell_result);
spin_unlock_irqrestore(&prison->lock, flags);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_lock_v2);
static void __quiesce(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct work_struct *continuation)
{
if (!cell->shared_count)
queue_work(prison->wq, continuation);
else
cell->quiesce_continuation = continuation;
}
void dm_cell_quiesce_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct work_struct *continuation)
{
unsigned long flags;
spin_lock_irqsave(&prison->lock, flags);
__quiesce(prison, cell, continuation);
spin_unlock_irqrestore(&prison->lock, flags);
}
EXPORT_SYMBOL_GPL(dm_cell_quiesce_v2);
static int __promote(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
unsigned new_lock_level)
{
if (!cell->exclusive_lock)
return -EINVAL;
cell->exclusive_level = new_lock_level;
return cell->shared_count > 0;
}
int dm_cell_lock_promote_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
unsigned new_lock_level)
{
int r;
unsigned long flags;
spin_lock_irqsave(&prison->lock, flags);
r = __promote(prison, cell, new_lock_level);
spin_unlock_irqrestore(&prison->lock, flags);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_lock_promote_v2);
static bool __unlock(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct bio_list *bios)
{
BUG_ON(!cell->exclusive_lock);
bio_list_merge(bios, &cell->bios);
bio_list_init(&cell->bios);
if (cell->shared_count) {
cell->exclusive_lock = 0;
return false;
}
rb_erase(&cell->node, &prison->cells);
return true;
}
bool dm_cell_unlock_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct bio_list *bios)
{
bool r;
unsigned long flags;
spin_lock_irqsave(&prison->lock, flags);
r = __unlock(prison, cell, bios);
spin_unlock_irqrestore(&prison->lock, flags);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_unlock_v2);
/*----------------------------------------------------------------*/
int __init dm_bio_prison_init_v2(void)
{
_cell_cache = KMEM_CACHE(dm_bio_prison_cell_v2, 0);
if (!_cell_cache)
return -ENOMEM;
return 0;
}
void dm_bio_prison_exit_v2(void)
{
kmem_cache_destroy(_cell_cache);
_cell_cache = NULL;
}
/*
* Copyright (C) 2011-2017 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#ifndef DM_BIO_PRISON_V2_H
#define DM_BIO_PRISON_V2_H
#include "persistent-data/dm-block-manager.h" /* FIXME: for dm_block_t */
#include "dm-thin-metadata.h" /* FIXME: for dm_thin_id */
#include <linux/bio.h>
#include <linux/rbtree.h>
#include <linux/workqueue.h>
/*----------------------------------------------------------------*/
int dm_bio_prison_init_v2(void);
void dm_bio_prison_exit_v2(void);
/*
* Sometimes we can't deal with a bio straight away. We put them in prison
* where they can't cause any mischief. Bios are put in a cell identified
* by a key, multiple bios can be in the same cell. When the cell is
* subsequently unlocked the bios become available.
*/
struct dm_bio_prison_v2;
/*
* Keys define a range of blocks within either a virtual or physical
* device.
*/
struct dm_cell_key_v2 {
int virtual;
dm_thin_id dev;
dm_block_t block_begin, block_end;
};
/*
* Treat this as opaque, only in header so callers can manage allocation
* themselves.
*/
struct dm_bio_prison_cell_v2 {
// FIXME: pack these
bool exclusive_lock;
unsigned exclusive_level;
unsigned shared_count;
struct work_struct *quiesce_continuation;
struct rb_node node;
struct dm_cell_key_v2 key;
struct bio_list bios;
};
struct dm_bio_prison_v2 *dm_bio_prison_create_v2(struct workqueue_struct *wq);
void dm_bio_prison_destroy_v2(struct dm_bio_prison_v2 *prison);
/*
* These two functions just wrap a mempool. This is a transitory step:
* Eventually all bio prison clients should manage their own cell memory.
*
* Like mempool_alloc(), dm_bio_prison_alloc_cell_v2() can only fail if called
* in interrupt context or passed GFP_NOWAIT.
*/
struct dm_bio_prison_cell_v2 *dm_bio_prison_alloc_cell_v2(struct dm_bio_prison_v2 *prison,
gfp_t gfp);
void dm_bio_prison_free_cell_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell);
/*
* Shared locks have a bio associated with them.
*
* If the lock is granted the caller can continue to use the bio, and must
* call dm_cell_put_v2() to drop the reference count when finished using it.
*
* If the lock cannot be granted then the bio will be tracked within the
* cell, and later given to the holder of the exclusive lock.
*
* See dm_cell_lock_v2() for discussion of the lock_level parameter.
*
* Compare *cell_result with cell_prealloc to see if the prealloc was used.
* If cell_prealloc was used then inmate wasn't added to it.
*
* Returns true if the lock is granted.
*/
bool dm_cell_get_v2(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned lock_level,
struct bio *inmate,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell_result);
/*
* Decrement the shared reference count for the lock. Returns true if
* returning ownership of the cell (ie. you should free it).
*/
bool dm_cell_put_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell);
/*
* Locks a cell. No associated bio. Exclusive locks get priority. These
* locks constrain whether the io locks are granted according to level.
*
* Shared locks will still be granted if the lock_level is > (not = to) the
* exclusive lock level.
*
* If an _exclusive_ lock is already held then -EBUSY is returned.
*
* Return values:
* < 0 - error
* 0 - locked; no quiescing needed
* 1 - locked; quiescing needed
*/
int dm_cell_lock_v2(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned lock_level,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell_result);
void dm_cell_quiesce_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct work_struct *continuation);
/*
* Promotes an _exclusive_ lock to a higher lock level.
*
* Return values:
* < 0 - error
* 0 - promoted; no quiescing needed
* 1 - promoted; quiescing needed
*/
int dm_cell_lock_promote_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
unsigned new_lock_level);
/*
* Adds any held bios to the bio list.
*
* There may be shared locks still held at this point even if you quiesced
* (ie. different lock levels).
*
* Returns true if returning ownership of the cell (ie. you should free
* it).
*/
bool dm_cell_unlock_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct bio_list *bios);
/*----------------------------------------------------------------*/
#endif
......@@ -5,7 +5,7 @@
*/
#include "dm.h"
#include "dm-bio-prison.h"
#include "dm-bio-prison-v1.h"
#include "dm-bio-record.h"
#include "dm-cache-metadata.h"
......
......@@ -5,7 +5,7 @@
*/
#include "dm-thin-metadata.h"
#include "dm-bio-prison.h"
#include "dm-bio-prison-v1.h"
#include "dm.h"
#include <linux/device-mapper.h>
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment