#include <linux/device-mapper.h>
#include <linux/bio.h>
+#include <linux/completion.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/sched.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 io {
unsigned long error_bits;
atomic_t count;
- struct task_struct *sleeper;
struct dm_io_client *client;
io_notify_fn callback;
void *context;
struct dm_io_client *dm_io_client_create(void)
{
struct dm_io_client *client;
+ unsigned min_ios = dm_get_reserved_bio_based_ios();
client = kmalloc(sizeof(*client), GFP_KERNEL);
if (!client)
return ERR_PTR(-ENOMEM);
- client->pool = mempool_create_slab_pool(MIN_IOS, _dm_io_cache);
+ client->pool = mempool_create_slab_pool(min_ios, _dm_io_cache);
if (!client->pool)
goto bad;
- client->bios = bioset_create(MIN_BIOS, 0);
+ client->bios = bioset_create(min_ios, 0);
if (!client->bios)
goto bad;
return client;
bad:
- if (client->pool)
- mempool_destroy(client->pool);
+ mempool_destroy(client->pool);
kfree(client);
return ERR_PTR(-ENOMEM);
}
* 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)
+static void complete_io(struct io *io)
{
- if (error)
- set_bit(region, &io->error_bits);
+ unsigned long error_bits = io->error_bits;
+ io_notify_fn fn = io->callback;
+ void *context = io->context;
- 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->vma_invalidate_size)
+ invalidate_kernel_vmap_range(io->vma_invalidate_address,
+ io->vma_invalidate_size);
- if (io->sleeper)
- wake_up_process(io->sleeper);
+ mempool_free(io, io->client->pool);
+ fn(error_bits, context);
+}
- else {
- unsigned long r = io->error_bits;
- io_notify_fn fn = io->callback;
- void *context = io->context;
+static void dec_count(struct io *io, unsigned int region, int error)
+{
+ if (error)
+ set_bit(region, &io->error_bits);
- mempool_free(io, io->client->pool);
- fn(r, context);
- }
- }
+ if (atomic_dec_and_test(&io->count))
+ complete_io(io);
}
-static void endio(struct bio *bio, int error)
+static void endio(struct bio *bio)
{
struct io *io;
unsigned region;
+ int error;
- if (error && bio_data_dir(bio) == READ)
+ if (bio->bi_error && bio_data_dir(bio) == READ)
zero_fill_bio(bio);
/*
*/
retrieve_io_and_region_from_bio(bio, &io, ®ion);
+ error = bio->bi_error;
bio_put(bio);
dec_count(io, region, error);
/*
* Functions for getting the pages from a bvec.
*/
-static void bvec_get_page(struct dpages *dp,
- struct page **p, unsigned long *len, unsigned *offset)
+static void bio_get_page(struct dpages *dp, struct page **p,
+ unsigned long *len, unsigned *offset)
{
- struct bio_vec *bvec = (struct bio_vec *) dp->context_ptr;
+ struct bio_vec *bvec = dp->context_ptr;
*p = bvec->bv_page;
- *len = bvec->bv_len;
- *offset = bvec->bv_offset;
+ *len = bvec->bv_len - dp->context_u;
+ *offset = bvec->bv_offset + dp->context_u;
}
-static void bvec_next_page(struct dpages *dp)
+static void bio_next_page(struct dpages *dp)
{
- struct bio_vec *bvec = (struct bio_vec *) dp->context_ptr;
+ struct bio_vec *bvec = dp->context_ptr;
dp->context_ptr = bvec + 1;
+ dp->context_u = 0;
}
-static void bvec_dp_init(struct dpages *dp, struct bio_vec *bvec)
+static void bio_dp_init(struct dpages *dp, struct bio *bio)
{
- dp->get_page = bvec_get_page;
- dp->next_page = bvec_next_page;
- dp->context_ptr = bvec;
+ dp->get_page = bio_get_page;
+ dp->next_page = bio_next_page;
+ dp->context_ptr = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
+ dp->context_u = bio->bi_iter.bi_bvec_done;
}
/*
struct request_queue *q = bdev_get_queue(where->bdev);
unsigned short logical_block_size = queue_logical_block_size(q);
sector_t num_sectors;
+ unsigned int uninitialized_var(special_cmd_max_sectors);
+
+ /*
+ * Reject unsupported discard and write same requests.
+ */
+ if (rw & REQ_DISCARD)
+ special_cmd_max_sectors = q->limits.max_discard_sectors;
+ else if (rw & REQ_WRITE_SAME)
+ special_cmd_max_sectors = q->limits.max_write_same_sectors;
+ if ((rw & (REQ_DISCARD | REQ_WRITE_SAME)) && special_cmd_max_sectors == 0) {
+ dec_count(io, region, -EOPNOTSUPP);
+ return;
+ }
/*
* where->count may be zero if rw holds a flush and we need to
if ((rw & REQ_DISCARD) || (rw & REQ_WRITE_SAME))
num_bvecs = 1;
else
- num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev),
+ num_bvecs = min_t(int, BIO_MAX_PAGES,
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_iter.bi_sector = where->sector + (where->count - remaining);
bio->bi_bdev = where->bdev;
bio->bi_end_io = endio;
store_io_and_region_in_bio(bio, io, region);
if (rw & REQ_DISCARD) {
- num_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
- bio->bi_size = num_sectors << SECTOR_SHIFT;
+ num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining);
+ bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT;
remaining -= num_sectors;
} else if (rw & REQ_WRITE_SAME) {
/*
*/
dp->get_page(dp, &page, &len, &offset);
bio_add_page(bio, page, logical_block_size, offset);
- num_sectors = min_t(sector_t, q->limits.max_write_same_sectors, remaining);
- bio->bi_size = num_sectors << SECTOR_SHIFT;
+ num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining);
+ bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT;
offset = 0;
remaining -= num_sectors;
dec_count(io, 0, 0);
}
+struct sync_io {
+ unsigned long error_bits;
+ struct completion wait;
+};
+
+static void sync_io_complete(unsigned long error, void *context)
+{
+ struct sync_io *sio = context;
+
+ sio->error_bits = error;
+ complete(&sio->wait);
+}
+
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));
+ struct io *io;
+ struct sync_io sio;
if (num_regions > 1 && (rw & RW_MASK) != WRITE) {
WARN_ON(1);
return -EIO;
}
+ init_completion(&sio.wait);
+
+ io = mempool_alloc(client->pool, GFP_NOIO);
io->error_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
- io->sleeper = current;
io->client = client;
+ io->callback = sync_io_complete;
+ io->context = &sio;
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);
+ wait_for_completion_io(&sio.wait);
if (error_bits)
- *error_bits = io->error_bits;
+ *error_bits = sio.error_bits;
- return io->error_bits ? -EIO : 0;
+ return sio.error_bits ? -EIO : 0;
}
static int async_io(struct dm_io_client *client, unsigned int num_regions,
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;
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);
+ case DM_IO_BIO:
+ bio_dp_init(dp, io_req->mem.ptr.bio);
break;
case DM_IO_VMA:
* 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.
+ * 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)