struct bio *bio;
bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0;
bool is_read = (iov_iter_rw(iter) == READ), is_sync;
- bool nowait = (iocb->ki_flags & IOCB_NOWAIT) != 0;
loff_t pos = iocb->ki_pos;
blk_qc_t qc = BLK_QC_T_NONE;
- gfp_t gfp;
- ssize_t ret;
+ int ret = 0;
if ((pos | iov_iter_alignment(iter)) &
(bdev_logical_block_size(bdev) - 1))
return -EINVAL;
- if (nowait)
- gfp = GFP_NOWAIT;
- else
- gfp = GFP_KERNEL;
-
- bio = bio_alloc_bioset(gfp, nr_pages, &blkdev_dio_pool);
- if (!bio)
- return -EAGAIN;
+ bio = bio_alloc_bioset(GFP_KERNEL, nr_pages, &blkdev_dio_pool);
dio = container_of(bio, struct blkdev_dio, bio);
dio->is_sync = is_sync = is_sync_kiocb(iocb);
if (!is_poll)
blk_start_plug(&plug);
- ret = 0;
for (;;) {
- int err;
-
bio_set_dev(bio, bdev);
bio->bi_iter.bi_sector = pos >> 9;
bio->bi_write_hint = iocb->ki_hint;
bio->bi_end_io = blkdev_bio_end_io;
bio->bi_ioprio = iocb->ki_ioprio;
- err = bio_iov_iter_get_pages(bio, iter);
- if (unlikely(err)) {
- if (!ret)
- ret = err;
+ ret = bio_iov_iter_get_pages(bio, iter);
+ if (unlikely(ret)) {
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
break;
task_io_account_write(bio->bi_iter.bi_size);
}
- /*
- * Tell underlying layer to not block for resource shortage.
- * And if we would have blocked, return error inline instead
- * of through the bio->bi_end_io() callback.
- */
- if (nowait)
- bio->bi_opf |= (REQ_NOWAIT | REQ_NOWAIT_INLINE);
-
dio->size += bio->bi_iter.bi_size;
pos += bio->bi_iter.bi_size;
}
qc = submit_bio(bio);
- if (qc == BLK_QC_T_EAGAIN) {
- if (!ret)
- ret = -EAGAIN;
- goto error;
- }
if (polled)
WRITE_ONCE(iocb->ki_cookie, qc);
atomic_inc(&dio->ref);
}
- qc = submit_bio(bio);
- if (qc == BLK_QC_T_EAGAIN) {
- if (!ret)
- ret = -EAGAIN;
- goto error;
- }
- ret += bio->bi_iter.bi_size;
-
- bio = bio_alloc(gfp, nr_pages);
- if (!bio) {
- if (!ret)
- ret = -EAGAIN;
- goto error;
- }
+ submit_bio(bio);
+ bio = bio_alloc(GFP_KERNEL, nr_pages);
}
if (!is_poll)
}
__set_current_state(TASK_RUNNING);
-out:
if (!ret)
ret = blk_status_to_errno(dio->bio.bi_status);
+ if (likely(!ret))
+ ret = dio->size;
bio_put(&dio->bio);
return ret;
-error:
- if (!is_poll)
- blk_finish_plug(&plug);
- goto out;
}
static ssize_t
* Pointer to the block device containing @bdev on success, ERR_PTR()
* value on failure.
*/
-static struct block_device *bd_start_claiming(struct block_device *bdev,
- void *holder)
+struct block_device *bd_start_claiming(struct block_device *bdev, void *holder)
{
struct gendisk *disk;
struct block_device *whole;
return ERR_PTR(err);
}
}
+EXPORT_SYMBOL(bd_start_claiming);
+
+static void bd_clear_claiming(struct block_device *whole, void *holder)
+{
+ lockdep_assert_held(&bdev_lock);
+ /* tell others that we're done */
+ BUG_ON(whole->bd_claiming != holder);
+ whole->bd_claiming = NULL;
+ wake_up_bit(&whole->bd_claiming, 0);
+}
+
+/**
+ * bd_finish_claiming - finish claiming of a block device
+ * @bdev: block device of interest
+ * @whole: whole block device (returned from bd_start_claiming())
+ * @holder: holder that has claimed @bdev
+ *
+ * Finish exclusive open of a block device. Mark the device as exlusively
+ * open by the holder and wake up all waiters for exclusive open to finish.
+ */
+void bd_finish_claiming(struct block_device *bdev, struct block_device *whole,
+ void *holder)
+{
+ spin_lock(&bdev_lock);
+ BUG_ON(!bd_may_claim(bdev, whole, holder));
+ /*
+ * Note that for a whole device bd_holders will be incremented twice,
+ * and bd_holder will be set to bd_may_claim before being set to holder
+ */
+ whole->bd_holders++;
+ whole->bd_holder = bd_may_claim;
+ bdev->bd_holders++;
+ bdev->bd_holder = holder;
+ bd_clear_claiming(whole, holder);
+ spin_unlock(&bdev_lock);
+}
+EXPORT_SYMBOL(bd_finish_claiming);
+
+/**
+ * bd_abort_claiming - abort claiming of a block device
+ * @bdev: block device of interest
+ * @whole: whole block device (returned from bd_start_claiming())
+ * @holder: holder that has claimed @bdev
+ *
+ * Abort claiming of a block device when the exclusive open failed. This can be
+ * also used when exclusive open is not actually desired and we just needed
+ * to block other exclusive openers for a while.
+ */
+void bd_abort_claiming(struct block_device *bdev, struct block_device *whole,
+ void *holder)
+{
+ spin_lock(&bdev_lock);
+ bd_clear_claiming(whole, holder);
+ spin_unlock(&bdev_lock);
+}
+EXPORT_SYMBOL(bd_abort_claiming);
#ifdef CONFIG_SYSFS
struct bd_holder_disk {
/* finish claiming */
mutex_lock(&bdev->bd_mutex);
- spin_lock(&bdev_lock);
-
- if (!res) {
- BUG_ON(!bd_may_claim(bdev, whole, holder));
- /*
- * Note that for a whole device bd_holders
- * will be incremented twice, and bd_holder
- * will be set to bd_may_claim before being
- * set to holder
- */
- whole->bd_holders++;
- whole->bd_holder = bd_may_claim;
- bdev->bd_holders++;
- bdev->bd_holder = holder;
- }
-
- /* tell others that we're done */
- BUG_ON(whole->bd_claiming != holder);
- whole->bd_claiming = NULL;
- wake_up_bit(&whole->bd_claiming, 0);
-
- spin_unlock(&bdev_lock);
-
+ if (!res)
+ bd_finish_claiming(bdev, whole, holder);
+ else
+ bd_abort_claiming(bdev, whole, holder);
/*
* Block event polling for write claims if requested. Any
* write holder makes the write_holder state stick until
projects / linux-2.6-block.git / blobdiff