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group workqueue fns
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Group together workqueue functions.
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@kergon @jthornber
kergon authored and jthornber committed Oct 18, 2011
1 parent 1b365b5 commit 83a7fda
Showing 1 changed file with 137 additions and 123 deletions.
260 changes: 137 additions & 123 deletions drivers/md/dm-thin.c
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Expand Up @@ -529,15 +529,6 @@ struct thin_c {

/*----------------------------------------------------------------*/

static void save_and_set_endio(struct bio *bio, bio_end_io_t **save,
bio_end_io_t *fn)
{
*save = bio->bi_end_io;
bio->bi_end_io = fn;
}

/*----------------------------------------------------------------*/

/*
* A global list of pools that uses a struct mapped_device as a key.
*/
Expand Down Expand Up @@ -632,7 +623,6 @@ static void requeue_io(struct thin_c *tc)
* but most is exclusively called from the thin target rather than the thin-pool
* target.
*/
static void process_prepared_mapping(struct new_mapping *m);

static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
{
Expand Down Expand Up @@ -774,13 +764,129 @@ static void shared_read_endio(struct bio *bio, int err)

/*----------------------------------------------------------------*/

/*
* Workqueue.
*/

/*
* Prepared mapping jobs.
*/

/*
* This sends the bios in the cell back to the deferred_bios list.
*/
static void cell_defer(struct thin_c *tc, struct cell *cell,
dm_block_t data_block)
{
struct pool *pool = tc->pool;
unsigned long flags;

spin_lock_irqsave(&pool->lock, flags);
cell_release(cell, &pool->deferred_bios);
spin_unlock_irqrestore(&tc->pool->lock, flags);

wake_worker(pool);
}

/*
* Same as cell_defer above, except it omits one particular detainee,
* a write bio that covers the block and has already been processed.
*/
static void cell_defer_except(struct thin_c *tc, struct cell *cell,
struct bio *exception)
{
struct bio_list bios;
struct bio *bio;
struct pool *pool = tc->pool;
unsigned long flags;

bio_list_init(&bios);
cell_release(cell, &bios);

spin_lock_irqsave(&pool->lock, flags);
while ((bio = bio_list_pop(&bios)))
if (bio != exception)
bio_list_add(&pool->deferred_bios, bio);
spin_unlock_irqrestore(&pool->lock, flags);

wake_worker(pool);
}

static void process_prepared_mapping(struct new_mapping *m)
{
struct thin_c *tc = m->tc;
struct bio *bio;
int r;

bio = m->bio;
if (bio)
bio->bi_end_io = m->saved_bi_end_io;

if (m->err) {
cell_error(m->cell);
return;
}

/*
* Commit the prepared block into the mapping btree.
* Any I/O for this block arriving after this point will get
* remapped to it directly.
*/
r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);
if (r) {
DMERR("dm_thin_insert_block() failed");
cell_error(m->cell);
return;
}

/*
* Release any bios held while the block was being provisioned.
* If we are processing a write bio that completely covers the block,
* we already processed it so can ignore it now when processing
* the bios in the cell.
*/
if (bio) {
cell_defer_except(tc, m->cell, bio);
bio_endio(bio, 0);
} else
cell_defer(tc, m->cell, m->data_block);

list_del(&m->list);
mempool_free(m, tc->pool->mapping_pool);
}

static void process_prepared_mappings(struct pool *pool)
{
unsigned long flags;
struct list_head maps;
struct new_mapping *m, *tmp;

INIT_LIST_HEAD(&maps);
spin_lock_irqsave(&pool->lock, flags);
list_splice_init(&pool->prepared_mappings, &maps);
spin_unlock_irqrestore(&pool->lock, flags);

list_for_each_entry_safe(m, tmp, &maps, list)
process_prepared_mapping(m);
}

/*
* Deferred bio jobs.
*/
static int io_overwrites_block(struct pool *pool, struct bio *bio)
{
return ((bio_data_dir(bio) == WRITE) &&
!(bio->bi_sector & pool->offset_mask)) &&
(bio->bi_size == (pool->sectors_per_block << SECTOR_SHIFT));
}

static void save_and_set_endio(struct bio *bio, bio_end_io_t **save,
bio_end_io_t *fn)
{
*save = bio->bi_end_io;
bio->bi_end_io = fn;
}

static int ensure_next_mapping(struct pool *pool)
{
if (pool->next_mapping)
Expand Down Expand Up @@ -900,61 +1006,6 @@ static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
}
}

/*
* This sends the bios in the cell back to the deferred_bios list.
*/
static void cell_defer(struct thin_c *tc, struct cell *cell,
dm_block_t data_block)
{
struct pool *pool = tc->pool;
unsigned long flags;

spin_lock_irqsave(&pool->lock, flags);
cell_release(cell, &pool->deferred_bios);
spin_unlock_irqrestore(&tc->pool->lock, flags);

wake_worker(pool);
}

/*
* Same as cell_defer above, except it omits one particular detainee,
* a write bio that covers the block and has already been processed.
*/
static void cell_defer_except(struct thin_c *tc, struct cell *cell,
struct bio *exception)
{
struct bio_list bios;
struct bio *bio;
struct pool *pool = tc->pool;
unsigned long flags;

bio_list_init(&bios);
cell_release(cell, &bios);

spin_lock_irqsave(&pool->lock, flags);
while ((bio = bio_list_pop(&bios)))
if (bio != exception)
bio_list_add(&pool->deferred_bios, bio);
spin_unlock_irqrestore(&pool->lock, flags);

wake_worker(pool);
}

/*
* If we have run out of space, queue bios until the device is
* resumed, presumably after having been reloaded with more space.
*/
static void retry_on_resume(struct bio *bio)
{
struct thin_c *tc = dm_get_mapinfo(bio)->ptr;
struct pool *pool = tc->pool;
unsigned long flags;

spin_lock_irqsave(&pool->lock, flags);
bio_list_add(&pool->retry_on_resume_list, bio);
spin_unlock_irqrestore(&pool->lock, flags);
}

static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
{
int r;
Expand Down Expand Up @@ -1016,6 +1067,21 @@ static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
return 0;
}

/*
* If we have run out of space, queue bios until the device is
* resumed, presumably after having been reloaded with more space.
*/
static void retry_on_resume(struct bio *bio)
{
struct thin_c *tc = dm_get_mapinfo(bio)->ptr;
struct pool *pool = tc->pool;
unsigned long flags;

spin_lock_irqsave(&pool->lock, flags);
bio_list_add(&pool->retry_on_resume_list, bio);
spin_unlock_irqrestore(&pool->lock, flags);
}

static void no_space(struct cell *cell)
{
struct bio *bio;
Expand Down Expand Up @@ -1232,64 +1298,6 @@ static void process_deferred_bios(struct pool *pool)
generic_make_request(bio);
}

static void process_prepared_mapping(struct new_mapping *m)
{
struct thin_c *tc = m->tc;
struct bio *bio;
int r;

bio = m->bio;
if (bio)
bio->bi_end_io = m->saved_bi_end_io;

if (m->err) {
cell_error(m->cell);
return;
}

/*
* Commit the prepared block into the mapping btree.
* Any I/O for this block arriving after this point will get
* remapped to it directly.
*/
r = dm_thin_insert_block(tc->td, m->virt_block, m->data_block);
if (r) {
DMERR("dm_thin_insert_block() failed");
cell_error(m->cell);
return;
}

/*
* Release any bios held while the block was being provisioned.
* If we are processing a write bio that completely covers the block,
* we already processed it so can ignore it now when processing
* the bios in the cell.
*/
if (bio) {
cell_defer_except(tc, m->cell, bio);
bio_endio(bio, 0);
} else
cell_defer(tc, m->cell, m->data_block);

list_del(&m->list);
mempool_free(m, tc->pool->mapping_pool);
}

static void process_prepared_mappings(struct pool *pool)
{
unsigned long flags;
struct list_head maps;
struct new_mapping *m, *tmp;

INIT_LIST_HEAD(&maps);
spin_lock_irqsave(&pool->lock, flags);
list_splice_init(&pool->prepared_mappings, &maps);
spin_unlock_irqrestore(&pool->lock, flags);

list_for_each_entry_safe(m, tmp, &maps, list)
process_prepared_mapping(m);
}

static void do_worker(struct work_struct *ws)
{
struct pool *pool = container_of(ws, struct pool, worker);
Expand All @@ -1298,6 +1306,12 @@ static void do_worker(struct work_struct *ws)
process_deferred_bios(pool);
}

/*----------------------------------------------------------------*/

/*
* Mapping functions.
*/

/*
* Called only while mapping a thin bio to hand it over to the workqueue.
*/
Expand Down

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