#include <linux/sched.h>
#include <linux/slab.h>
-static struct bio_set *_bios;
-
struct dm_io_client {
mempool_t *pool;
struct bio_set *bios;
* io. Since async io is likely to be the majority of io we'll
* have the same number of io contexts as bios! (FIXME: must reduce this).
*/
-static unsigned _num_ios;
-static mempool_t *_io_pool;
-
-/*
- * Temporary functions to allow old and new interfaces to co-exist.
- */
-static struct bio_set *bios(struct dm_io_client *client)
-{
- return client ? client->bios : _bios;
-}
-
-static mempool_t *io_pool(struct dm_io_client *client)
-{
- return client ? client->pool : _io_pool;
-}
static unsigned int pages_to_ios(unsigned int pages)
{
return 4 * pages; /* too many ? */
}
-static int resize_pool(unsigned int new_ios)
-{
- int r = 0;
-
- if (_io_pool) {
- if (new_ios == 0) {
- /* free off the pool */
- mempool_destroy(_io_pool);
- _io_pool = NULL;
- bioset_free(_bios);
-
- } else {
- /* resize the pool */
- r = mempool_resize(_io_pool, new_ios, GFP_KERNEL);
- }
-
- } else {
- /* create new pool */
- _io_pool = mempool_create_kmalloc_pool(new_ios,
- sizeof(struct io));
- if (!_io_pool)
- return -ENOMEM;
-
- _bios = bioset_create(16, 16);
- if (!_bios) {
- mempool_destroy(_io_pool);
- _io_pool = NULL;
- return -ENOMEM;
- }
- }
-
- if (!r)
- _num_ios = new_ios;
-
- return r;
-}
-
-int dm_io_get(unsigned int num_pages)
-{
- return resize_pool(_num_ios + pages_to_ios(num_pages));
-}
-
-void dm_io_put(unsigned int num_pages)
-{
- resize_pool(_num_ios - pages_to_ios(num_pages));
-}
-
/*
* Create a client with mempool and bioset.
*/
io_notify_fn fn = io->callback;
void *context = io->context;
- mempool_free(io, io_pool(io->client));
+ mempool_free(io, io->client->pool);
fn(r, context);
}
}
{
struct io *io = bio->bi_private;
- bio_free(bio, bios(io->client));
+ bio_free(bio, io->client->bios);
}
/*
* to hide it from bio_add_page().
*/
num_bvecs = (remaining / (PAGE_SIZE >> SECTOR_SHIFT)) + 2;
- bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, bios(io->client));
+ bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios);
bio->bi_sector = where->sector + (where->count - remaining);
bio->bi_bdev = where->bdev;
bio->bi_end_io = endio;
return -EIO;
}
- io = mempool_alloc(io_pool(client), GFP_NOIO);
+ io = mempool_alloc(client->pool, GFP_NOIO);
io->error = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = NULL;
return 0;
}
-int dm_io_sync(unsigned int num_regions, struct io_region *where, int rw,
- struct page_list *pl, unsigned int offset,
- unsigned long *error_bits)
-{
- struct dpages dp;
- list_dp_init(&dp, pl, offset);
- return sync_io(NULL, num_regions, where, rw, &dp, error_bits);
-}
-
-int dm_io_sync_bvec(unsigned int num_regions, struct io_region *where, int rw,
- struct bio_vec *bvec, unsigned long *error_bits)
-{
- struct dpages dp;
- bvec_dp_init(&dp, bvec);
- return sync_io(NULL, num_regions, where, rw, &dp, error_bits);
-}
-
-int dm_io_sync_vm(unsigned int num_regions, struct io_region *where, int rw,
- void *data, unsigned long *error_bits)
-{
- struct dpages dp;
- vm_dp_init(&dp, data);
- return sync_io(NULL, num_regions, where, rw, &dp, error_bits);
-}
-
-int dm_io_async(unsigned int num_regions, struct io_region *where, int rw,
- struct page_list *pl, unsigned int offset,
- io_notify_fn fn, void *context)
-{
- struct dpages dp;
- list_dp_init(&dp, pl, offset);
- return async_io(NULL, num_regions, where, rw, &dp, fn, context);
-}
-
-int dm_io_async_bvec(unsigned int num_regions, struct io_region *where, int rw,
- struct bio_vec *bvec, io_notify_fn fn, void *context)
-{
- struct dpages dp;
- bvec_dp_init(&dp, bvec);
- return async_io(NULL, num_regions, where, rw, &dp, fn, context);
-}
-
-int dm_io_async_vm(unsigned int num_regions, struct io_region *where, int rw,
- void *data, io_notify_fn fn, void *context)
-{
- struct dpages dp;
- vm_dp_init(&dp, data);
- return async_io(NULL, num_regions, where, rw, &dp, fn, context);
-}
-
static int dp_init(struct dm_io_request *io_req, struct dpages *dp)
{
/* Set up dpages based on memory type */
&dp, io_req->notify.fn, io_req->notify.context);
}
EXPORT_SYMBOL(dm_io);
-
-EXPORT_SYMBOL(dm_io_get);
-EXPORT_SYMBOL(dm_io_put);
-EXPORT_SYMBOL(dm_io_sync);
-EXPORT_SYMBOL(dm_io_async);
-EXPORT_SYMBOL(dm_io_sync_bvec);
-EXPORT_SYMBOL(dm_io_async_bvec);
-EXPORT_SYMBOL(dm_io_sync_vm);
-EXPORT_SYMBOL(dm_io_async_vm);
struct io_region {
struct block_device *bdev;
sector_t sector;
- sector_t count;
+ sector_t count; /* If this is zero the region is ignored. */
};
struct page_list {
struct page *page;
};
-/*
- * 'error' is a bitset, with each bit indicating whether an error
- * occurred doing io to the corresponding region.
- */
typedef void (*io_notify_fn)(unsigned long error, void *context);
enum dm_io_mem_type {
struct dm_io_client *client; /* Client memory handler */
};
-/*
- * Before anyone uses the IO interface they should call
- * dm_io_get(), specifying roughly how many pages they are
- * expecting to perform io on concurrently.
- *
- * This function may block.
- */
-int dm_io_get(unsigned int num_pages);
-void dm_io_put(unsigned int num_pages);
-
/*
* For async io calls, users can alternatively use the dm_io() function below
* and dm_io_client_create() to create private mempools for the client.
int dm_io_client_resize(unsigned num_pages, struct dm_io_client *client);
void dm_io_client_destroy(struct dm_io_client *client);
-/*
- * Synchronous IO.
- *
- * Please ensure that the rw flag in the next two functions is
- * either READ or WRITE, ie. we don't take READA. Any
- * regions with a zero count field will be ignored.
- */
-int dm_io_sync(unsigned int num_regions, struct io_region *where, int rw,
- struct page_list *pl, unsigned int offset,
- unsigned long *error_bits);
-
-int dm_io_sync_bvec(unsigned int num_regions, struct io_region *where, int rw,
- struct bio_vec *bvec, unsigned long *error_bits);
-
-int dm_io_sync_vm(unsigned int num_regions, struct io_region *where, int rw,
- void *data, unsigned long *error_bits);
-
-/*
- * Aynchronous IO.
- *
- * The 'where' array may be safely allocated on the stack since
- * the function takes a copy.
- */
-int dm_io_async(unsigned int num_regions, struct io_region *where, int rw,
- struct page_list *pl, unsigned int offset,
- io_notify_fn fn, void *context);
-
-int dm_io_async_bvec(unsigned int num_regions, struct io_region *where, int rw,
- struct bio_vec *bvec, io_notify_fn fn, void *context);
-
-int dm_io_async_vm(unsigned int num_regions, struct io_region *where, int rw,
- void *data, io_notify_fn fn, void *context);
-
/*
* IO interface using private per-client pools.
+ * Each bit in the optional 'sync_error_bits' bitset indicates whether an
+ * error occurred doing io to the corresponding region.
*/
int dm_io(struct dm_io_request *io_req, unsigned num_regions,
struct io_region *region, unsigned long *sync_error_bits);
projects / linux-2.6 / commitdiff