diff options
Diffstat (limited to 'drivers/md/dm-io.c')
| -rw-r--r-- | drivers/md/dm-io.c | 77 |
1 files changed, 42 insertions, 35 deletions
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index db404a0f7e2c..c09359db3a90 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -33,7 +33,6 @@ struct dm_io_client { struct io { unsigned long error_bits; atomic_t count; - struct completion *wait; struct dm_io_client *client; io_notify_fn callback; void *context; @@ -112,28 +111,27 @@ static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io, * 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->wait) - complete(io->wait); + 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) @@ -376,41 +374,51 @@ static void dispatch_io(int rw, unsigned int num_regions, 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)); - DECLARE_COMPLETION_ONSTACK(wait); + 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->wait = &wait; 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); - wait_for_completion_io(&wait); + 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, @@ -428,7 +436,6 @@ 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->wait = NULL; io->client = client; io->callback = fn; io->context = context; @@ -481,9 +488,9 @@ static int dp_init(struct dm_io_request *io_req, struct dpages *dp, * 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) |