/*
* Copyright (C) 2003 Sistina Software
+ * Copyright (C) 2006 Red Hat GmbH
*
* This file is released under the GPL.
*/
static struct bio_set *_bios;
+struct dm_io_client {
+ mempool_t *pool;
+ struct bio_set *bios;
+};
+
/* FIXME: can we shrink this ? */
struct io {
unsigned long error;
atomic_t count;
struct task_struct *sleeper;
+ struct dm_io_client *client;
io_notify_fn callback;
void *context;
};
/*
* io contexts are only dynamically allocated for asynchronous
* io. Since async io is likely to be the majority of io we'll
- * have the same number of io contexts as buffer heads ! (FIXME:
- * must reduce this).
+ * 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 ? */
if (!_io_pool)
return -ENOMEM;
- _bios = bioset_create(16, 16, 4);
+ _bios = bioset_create(16, 16);
if (!_bios) {
mempool_destroy(_io_pool);
_io_pool = NULL;
resize_pool(_num_ios - pages_to_ios(num_pages));
}
+/*
+ * Create a client with mempool and bioset.
+ */
+struct dm_io_client *dm_io_client_create(unsigned num_pages)
+{
+ unsigned ios = pages_to_ios(num_pages);
+ struct dm_io_client *client;
+
+ client = kmalloc(sizeof(*client), GFP_KERNEL);
+ if (!client)
+ return ERR_PTR(-ENOMEM);
+
+ client->pool = mempool_create_kmalloc_pool(ios, sizeof(struct io));
+ if (!client->pool)
+ goto bad;
+
+ client->bios = bioset_create(16, 16);
+ if (!client->bios)
+ goto bad;
+
+ return client;
+
+ bad:
+ if (client->pool)
+ mempool_destroy(client->pool);
+ kfree(client);
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL(dm_io_client_create);
+
+int dm_io_client_resize(unsigned num_pages, struct dm_io_client *client)
+{
+ return mempool_resize(client->pool, pages_to_ios(num_pages),
+ GFP_KERNEL);
+}
+EXPORT_SYMBOL(dm_io_client_resize);
+
+void dm_io_client_destroy(struct dm_io_client *client)
+{
+ mempool_destroy(client->pool);
+ bioset_free(client->bios);
+ kfree(client);
+}
+EXPORT_SYMBOL(dm_io_client_destroy);
+
/*-----------------------------------------------------------------
* We need to keep track of which region a bio is doing io for.
* In order to save a memory allocation we store this the last
*---------------------------------------------------------------*/
static inline void bio_set_region(struct bio *bio, unsigned region)
{
- bio->bi_io_vec[bio->bi_max_vecs - 1].bv_len = region;
+ bio->bi_io_vec[bio->bi_max_vecs].bv_len = region;
}
static inline unsigned bio_get_region(struct bio *bio)
{
- return bio->bi_io_vec[bio->bi_max_vecs - 1].bv_len;
+ return bio->bi_io_vec[bio->bi_max_vecs].bv_len;
}
/*-----------------------------------------------------------------
io_notify_fn fn = io->callback;
void *context = io->context;
- mempool_free(io, _io_pool);
+ mempool_free(io, io_pool(io->client));
fn(r, context);
}
}
static int endio(struct bio *bio, unsigned int done, int error)
{
- struct io *io = (struct io *) bio->bi_private;
+ struct io *io;
+ unsigned region;
/* keep going until we've finished */
if (bio->bi_size)
if (error && bio_data_dir(bio) == READ)
zero_fill_bio(bio);
- dec_count(io, bio_get_region(bio), error);
+ /*
+ * The bio destructor in bio_put() may use the io object.
+ */
+ io = bio->bi_private;
+ region = bio_get_region(bio);
+
+ bio->bi_max_vecs++;
bio_put(bio);
+ dec_count(io, region, error);
+
return 0;
}
dp->context_ptr = bvec;
}
+/*
+ * Functions for getting the pages from a VMA.
+ */
static void vm_get_page(struct dpages *dp,
struct page **p, unsigned long *len, unsigned *offset)
{
static void dm_bio_destructor(struct bio *bio)
{
- bio_free(bio, _bios);
+ struct io *io = bio->bi_private;
+
+ bio_free(bio, bios(io->client));
+}
+
+/*
+ * Functions for getting the pages from kernel memory.
+ */
+static void km_get_page(struct dpages *dp, struct page **p, unsigned long *len,
+ unsigned *offset)
+{
+ *p = virt_to_page(dp->context_ptr);
+ *offset = dp->context_u;
+ *len = PAGE_SIZE - dp->context_u;
+}
+
+static void km_next_page(struct dpages *dp)
+{
+ dp->context_ptr += PAGE_SIZE - dp->context_u;
+ dp->context_u = 0;
+}
+
+static void km_dp_init(struct dpages *dp, void *data)
+{
+ dp->get_page = km_get_page;
+ dp->next_page = km_next_page;
+ dp->context_u = ((unsigned long) data) & (PAGE_SIZE - 1);
+ dp->context_ptr = data;
}
/*-----------------------------------------------------------------
while (remaining) {
/*
- * Allocate a suitably sized bio, we add an extra
- * bvec for bio_get/set_region().
+ * Allocate a suitably sized-bio: we add an extra
+ * bvec for bio_get/set_region() and decrement bi_max_vecs
+ * to hide it from bio_add_page().
*/
- num_bvecs = (remaining / (PAGE_SIZE >> 9)) + 2;
- bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, _bios);
+ num_bvecs = (remaining / (PAGE_SIZE >> SECTOR_SHIFT)) + 2;
+ bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, bios(io->client));
bio->bi_sector = where->sector + (where->count - remaining);
bio->bi_bdev = where->bdev;
bio->bi_end_io = endio;
bio->bi_private = io;
bio->bi_destructor = dm_bio_destructor;
+ bio->bi_max_vecs--;
bio_set_region(bio, region);
/*
}
/*
- * Drop the extra refence that we were holding to avoid
+ * Drop the extra reference that we were holding to avoid
* the io being completed too early.
*/
dec_count(io, 0, 0);
}
-static int sync_io(unsigned int num_regions, struct io_region *where,
- int rw, struct dpages *dp, unsigned long *error_bits)
+static int sync_io(struct dm_io_client *client, unsigned int num_regions,
+ struct io_region *where, int rw, struct dpages *dp,
+ unsigned long *error_bits)
{
struct io io;
io.error = 0;
atomic_set(&io.count, 1); /* see dispatch_io() */
io.sleeper = current;
+ io.client = client;
dispatch_io(rw, num_regions, where, dp, &io, 1);
if (atomic_read(&io.count))
return -EINTR;
- *error_bits = io.error;
+ if (error_bits)
+ *error_bits = io.error;
+
return io.error ? -EIO : 0;
}
-static int async_io(unsigned int num_regions, struct io_region *where, int rw,
- struct dpages *dp, io_notify_fn fn, void *context)
+static int async_io(struct dm_io_client *client, unsigned int num_regions,
+ struct io_region *where, int rw, struct dpages *dp,
+ io_notify_fn fn, void *context)
{
struct io *io;
return -EIO;
}
- io = mempool_alloc(_io_pool, GFP_NOIO);
+ io = mempool_alloc(io_pool(client), GFP_NOIO);
io->error = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->sleeper = NULL;
+ io->client = client;
io->callback = fn;
io->context = context;
{
struct dpages dp;
list_dp_init(&dp, pl, offset);
- return sync_io(num_regions, where, rw, &dp, error_bits);
+ 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 dpages dp;
bvec_dp_init(&dp, bvec);
- return sync_io(num_regions, where, rw, &dp, error_bits);
+ 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,
{
struct dpages dp;
vm_dp_init(&dp, data);
- return sync_io(num_regions, where, rw, &dp, error_bits);
+ 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 dpages dp;
list_dp_init(&dp, pl, offset);
- return async_io(num_regions, where, rw, &dp, fn, context);
+ 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 dpages dp;
bvec_dp_init(&dp, bvec);
- return async_io(num_regions, where, rw, &dp, fn, context);
+ 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,
{
struct dpages dp;
vm_dp_init(&dp, data);
- return async_io(num_regions, where, rw, &dp, fn, context);
+ 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 */
+ switch (io_req->mem.type) {
+ case DM_IO_PAGE_LIST:
+ list_dp_init(dp, io_req->mem.ptr.pl, io_req->mem.offset);
+ break;
+
+ case DM_IO_BVEC:
+ bvec_dp_init(dp, io_req->mem.ptr.bvec);
+ break;
+
+ case DM_IO_VMA:
+ vm_dp_init(dp, io_req->mem.ptr.vma);
+ break;
+
+ case DM_IO_KMEM:
+ km_dp_init(dp, io_req->mem.ptr.addr);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/*
+ * New collapsed (a)synchronous interface
+ */
+int dm_io(struct dm_io_request *io_req, unsigned num_regions,
+ struct io_region *where, unsigned long *sync_error_bits)
+{
+ int r;
+ struct dpages dp;
+
+ r = dp_init(io_req, &dp);
+ if (r)
+ return r;
+
+ if (!io_req->notify.fn)
+ return sync_io(io_req->client, num_regions, where,
+ io_req->bi_rw, &dp, sync_error_bits);
+
+ return async_io(io_req->client, num_regions, where, io_req->bi_rw,
+ &dp, io_req->notify.fn, io_req->notify.context);
}
+EXPORT_SYMBOL(dm_io);
EXPORT_SYMBOL(dm_io_get);
EXPORT_SYMBOL(dm_io_put);
projects / mirror_ubuntu-zesty-kernel.git / blobdiff