diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/md/dm-io.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/md/dm-io.c | 523 |
1 files changed, 0 insertions, 523 deletions
diff --git a/ANDROID_3.4.5/drivers/md/dm-io.c b/ANDROID_3.4.5/drivers/md/dm-io.c deleted file mode 100644 index ea5dd289..00000000 --- a/ANDROID_3.4.5/drivers/md/dm-io.c +++ /dev/null @@ -1,523 +0,0 @@ -/* - * Copyright (C) 2003 Sistina Software - * Copyright (C) 2006 Red Hat GmbH - * - * This file is released under the GPL. - */ - -#include "dm.h" - -#include <linux/device-mapper.h> - -#include <linux/bio.h> -#include <linux/mempool.h> -#include <linux/module.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/dm-io.h> - -#define DM_MSG_PREFIX "io" - -#define DM_IO_MAX_REGIONS BITS_PER_LONG -#define MIN_IOS 16 -#define MIN_BIOS 16 - -struct dm_io_client { - mempool_t *pool; - struct bio_set *bios; -}; - -/* - * Aligning 'struct io' reduces the number of bits required to store - * its address. Refer to store_io_and_region_in_bio() below. - */ -struct io { - unsigned long error_bits; - atomic_t count; - struct task_struct *sleeper; - struct dm_io_client *client; - io_notify_fn callback; - void *context; - void *vma_invalidate_address; - unsigned long vma_invalidate_size; -} __attribute__((aligned(DM_IO_MAX_REGIONS))); - -static struct kmem_cache *_dm_io_cache; - -/* - * Create a client with mempool and bioset. - */ -struct dm_io_client *dm_io_client_create(void) -{ - struct dm_io_client *client; - - client = kmalloc(sizeof(*client), GFP_KERNEL); - if (!client) - return ERR_PTR(-ENOMEM); - - client->pool = mempool_create_slab_pool(MIN_IOS, _dm_io_cache); - if (!client->pool) - goto bad; - - client->bios = bioset_create(MIN_BIOS, 0); - 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); - -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. - * To avoid a memory allocation to store just 5 or 6 bits, we - * ensure the 'struct io' pointer is aligned so enough low bits are - * always zero and then combine it with the region number directly in - * bi_private. - *---------------------------------------------------------------*/ -static void store_io_and_region_in_bio(struct bio *bio, struct io *io, - unsigned region) -{ - if (unlikely(!IS_ALIGNED((unsigned long)io, DM_IO_MAX_REGIONS))) { - DMCRIT("Unaligned struct io pointer %p", io); - BUG(); - } - - bio->bi_private = (void *)((unsigned long)io | region); -} - -static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io, - unsigned *region) -{ - unsigned long val = (unsigned long)bio->bi_private; - - *io = (void *)(val & -(unsigned long)DM_IO_MAX_REGIONS); - *region = val & (DM_IO_MAX_REGIONS - 1); -} - -/*----------------------------------------------------------------- - * We need an io object to keep track of the number of bios that - * have been dispatched for a particular io. - *---------------------------------------------------------------*/ -static void dec_count(struct io *io, unsigned int region, int error) -{ - if (error) - set_bit(region, &io->error_bits); - - if (atomic_dec_and_test(&io->count)) { - if (io->vma_invalidate_size) - invalidate_kernel_vmap_range(io->vma_invalidate_address, - io->vma_invalidate_size); - - if (io->sleeper) - wake_up_process(io->sleeper); - - else { - unsigned long r = io->error_bits; - io_notify_fn fn = io->callback; - void *context = io->context; - - mempool_free(io, io->client->pool); - fn(r, context); - } - } -} - -static void endio(struct bio *bio, int error) -{ - struct io *io; - unsigned region; - - if (error && bio_data_dir(bio) == READ) - zero_fill_bio(bio); - - /* - * The bio destructor in bio_put() may use the io object. - */ - retrieve_io_and_region_from_bio(bio, &io, ®ion); - - bio_put(bio); - - dec_count(io, region, error); -} - -/*----------------------------------------------------------------- - * These little objects provide an abstraction for getting a new - * destination page for io. - *---------------------------------------------------------------*/ -struct dpages { - void (*get_page)(struct dpages *dp, - struct page **p, unsigned long *len, unsigned *offset); - void (*next_page)(struct dpages *dp); - - unsigned context_u; - void *context_ptr; - - void *vma_invalidate_address; - unsigned long vma_invalidate_size; -}; - -/* - * Functions for getting the pages from a list. - */ -static void list_get_page(struct dpages *dp, - struct page **p, unsigned long *len, unsigned *offset) -{ - unsigned o = dp->context_u; - struct page_list *pl = (struct page_list *) dp->context_ptr; - - *p = pl->page; - *len = PAGE_SIZE - o; - *offset = o; -} - -static void list_next_page(struct dpages *dp) -{ - struct page_list *pl = (struct page_list *) dp->context_ptr; - dp->context_ptr = pl->next; - dp->context_u = 0; -} - -static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned offset) -{ - dp->get_page = list_get_page; - dp->next_page = list_next_page; - dp->context_u = offset; - dp->context_ptr = pl; -} - -/* - * Functions for getting the pages from a bvec. - */ -static void bvec_get_page(struct dpages *dp, - struct page **p, unsigned long *len, unsigned *offset) -{ - struct bio_vec *bvec = (struct bio_vec *) dp->context_ptr; - *p = bvec->bv_page; - *len = bvec->bv_len; - *offset = bvec->bv_offset; -} - -static void bvec_next_page(struct dpages *dp) -{ - struct bio_vec *bvec = (struct bio_vec *) dp->context_ptr; - dp->context_ptr = bvec + 1; -} - -static void bvec_dp_init(struct dpages *dp, struct bio_vec *bvec) -{ - dp->get_page = bvec_get_page; - dp->next_page = bvec_next_page; - 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) -{ - *p = vmalloc_to_page(dp->context_ptr); - *offset = dp->context_u; - *len = PAGE_SIZE - dp->context_u; -} - -static void vm_next_page(struct dpages *dp) -{ - dp->context_ptr += PAGE_SIZE - dp->context_u; - dp->context_u = 0; -} - -static void vm_dp_init(struct dpages *dp, void *data) -{ - dp->get_page = vm_get_page; - dp->next_page = vm_next_page; - dp->context_u = ((unsigned long) data) & (PAGE_SIZE - 1); - dp->context_ptr = data; -} - -static void dm_bio_destructor(struct bio *bio) -{ - unsigned region; - struct io *io; - - retrieve_io_and_region_from_bio(bio, &io, ®ion); - - bio_free(bio, io->client->bios); -} - -/* - * 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. - *---------------------------------------------------------------*/ -static void do_region(int rw, unsigned region, struct dm_io_region *where, - struct dpages *dp, struct io *io) -{ - struct bio *bio; - struct page *page; - unsigned long len; - unsigned offset; - unsigned num_bvecs; - sector_t remaining = where->count; - struct request_queue *q = bdev_get_queue(where->bdev); - sector_t discard_sectors; - - /* - * where->count may be zero if rw holds a flush and we need to - * send a zero-sized flush. - */ - do { - /* - * Allocate a suitably sized-bio. - */ - if (rw & REQ_DISCARD) - num_bvecs = 1; - else - num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev), - dm_sector_div_up(remaining, (PAGE_SIZE >> SECTOR_SHIFT))); - - 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; - bio->bi_destructor = dm_bio_destructor; - store_io_and_region_in_bio(bio, io, region); - - if (rw & REQ_DISCARD) { - discard_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining); - bio->bi_size = discard_sectors << SECTOR_SHIFT; - remaining -= discard_sectors; - } else while (remaining) { - /* - * Try and add as many pages as possible. - */ - dp->get_page(dp, &page, &len, &offset); - len = min(len, to_bytes(remaining)); - if (!bio_add_page(bio, page, len, offset)) - break; - - offset = 0; - remaining -= to_sector(len); - dp->next_page(dp); - } - - atomic_inc(&io->count); - submit_bio(rw, bio); - } while (remaining); -} - -static void dispatch_io(int rw, unsigned int num_regions, - struct dm_io_region *where, struct dpages *dp, - struct io *io, int sync) -{ - int i; - struct dpages old_pages = *dp; - - BUG_ON(num_regions > DM_IO_MAX_REGIONS); - - if (sync) - rw |= REQ_SYNC; - - /* - * For multiple regions we need to be careful to rewind - * the dp object for each call to do_region. - */ - for (i = 0; i < num_regions; i++) { - *dp = old_pages; - if (where[i].count || (rw & REQ_FLUSH)) - do_region(rw, i, where + i, dp, io); - } - - /* - * 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(struct dm_io_client *client, unsigned int num_regions, - struct dm_io_region *where, int rw, struct dpages *dp, - unsigned long *error_bits) -{ - /* - * gcc <= 4.3 can't do the alignment for stack variables, so we must - * align it on our own. - * volatile prevents the optimizer from removing or reusing - * "io_" field from the stack frame (allowed in ANSI C). - */ - volatile char io_[sizeof(struct io) + __alignof__(struct io) - 1]; - struct io *io = (struct io *)PTR_ALIGN(&io_, __alignof__(struct io)); - - if (num_regions > 1 && (rw & RW_MASK) != WRITE) { - WARN_ON(1); - return -EIO; - } - - io->error_bits = 0; - atomic_set(&io->count, 1); /* see dispatch_io() */ - io->sleeper = current; - io->client = client; - - io->vma_invalidate_address = dp->vma_invalidate_address; - io->vma_invalidate_size = dp->vma_invalidate_size; - - dispatch_io(rw, num_regions, where, dp, io, 1); - - while (1) { - set_current_state(TASK_UNINTERRUPTIBLE); - - if (!atomic_read(&io->count)) - break; - - io_schedule(); - } - set_current_state(TASK_RUNNING); - - if (error_bits) - *error_bits = io->error_bits; - - return io->error_bits ? -EIO : 0; -} - -static int async_io(struct dm_io_client *client, unsigned int num_regions, - struct dm_io_region *where, int rw, struct dpages *dp, - io_notify_fn fn, void *context) -{ - struct io *io; - - if (num_regions > 1 && (rw & RW_MASK) != WRITE) { - WARN_ON(1); - fn(1, context); - return -EIO; - } - - io = mempool_alloc(client->pool, GFP_NOIO); - io->error_bits = 0; - atomic_set(&io->count, 1); /* see dispatch_io() */ - io->sleeper = NULL; - io->client = client; - io->callback = fn; - io->context = context; - - io->vma_invalidate_address = dp->vma_invalidate_address; - io->vma_invalidate_size = dp->vma_invalidate_size; - - dispatch_io(rw, num_regions, where, dp, io, 0); - return 0; -} - -static int dp_init(struct dm_io_request *io_req, struct dpages *dp, - unsigned long size) -{ - /* Set up dpages based on memory type */ - - dp->vma_invalidate_address = NULL; - dp->vma_invalidate_size = 0; - - 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: - flush_kernel_vmap_range(io_req->mem.ptr.vma, size); - if ((io_req->bi_rw & RW_MASK) == READ) { - dp->vma_invalidate_address = io_req->mem.ptr.vma; - dp->vma_invalidate_size = size; - } - 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. - * - * If the IO is asynchronous (i.e. it has notify.fn), you must either unplug - * the queue with blk_unplug() some time later or set REQ_SYNC in -io_req->bi_rw. If you fail to do one of these, the IO will be submitted to - * the disk after q->unplug_delay, which defaults to 3ms in blk-settings.c. - */ -int dm_io(struct dm_io_request *io_req, unsigned num_regions, - struct dm_io_region *where, unsigned long *sync_error_bits) -{ - int r; - struct dpages dp; - - r = dp_init(io_req, &dp, (unsigned long)where->count << SECTOR_SHIFT); - 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); - -int __init dm_io_init(void) -{ - _dm_io_cache = KMEM_CACHE(io, 0); - if (!_dm_io_cache) - return -ENOMEM; - - return 0; -} - -void dm_io_exit(void) -{ - kmem_cache_destroy(_dm_io_cache); - _dm_io_cache = NULL; -} |