diff options
| -rw-r--r-- | drivers/md/dm-io.c | 122 | ||||
| -rw-r--r-- | drivers/md/dm-io.h | 52 |
2 files changed, 173 insertions, 1 deletions
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index 66db79208c1..0c63809ab70 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -103,6 +103,51 @@ void dm_io_put(unsigned int num_pages) 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 @@ -236,6 +281,9 @@ static void bvec_dp_init(struct dpages *dp, struct bio_vec *bvec) 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) { @@ -265,6 +313,31 @@ static void dm_bio_destructor(struct bio *bio) 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; +} + /*----------------------------------------------------------------- * IO routines that accept a list of pages. *---------------------------------------------------------------*/ @@ -451,6 +524,55 @@ int dm_io_async_vm(unsigned int num_regions, struct io_region *where, int rw, 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); EXPORT_SYMBOL(dm_io_sync); diff --git a/drivers/md/dm-io.h b/drivers/md/dm-io.h index f9035bfd1a9..05b13382558 100644 --- a/drivers/md/dm-io.h +++ b/drivers/md/dm-io.h @@ -20,13 +20,47 @@ 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 { + DM_IO_PAGE_LIST,/* Page list */ + DM_IO_BVEC, /* Bio vector */ + DM_IO_VMA, /* Virtual memory area */ + DM_IO_KMEM, /* Kernel memory */ +}; + +struct dm_io_memory { + enum dm_io_mem_type type; + + union { + struct page_list *pl; + struct bio_vec *bvec; + void *vma; + void *addr; + } ptr; + + unsigned offset; +}; + +struct dm_io_notify { + io_notify_fn fn; /* Callback for asynchronous requests */ + void *context; /* Passed to callback */ +}; + +/* + * IO request structure + */ +struct dm_io_client; +struct dm_io_request { + int bi_rw; /* READ|WRITE - not READA */ + struct dm_io_memory mem; /* Memory to use for io */ + struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */ + struct dm_io_client *client; /* Client memory handler */ +}; /* * Before anyone uses the IO interface they should call @@ -39,6 +73,16 @@ 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. + * + * Create/destroy may block. + */ +struct dm_io_client *dm_io_client_create(unsigned num_pages); +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 @@ -71,4 +115,10 @@ int dm_io_async_bvec(unsigned int num_regions, struct io_region *where, int rw, 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. + */ +int dm_io(struct dm_io_request *io_req, unsigned num_regions, + struct io_region *region, unsigned long *sync_error_bits); + #endif |