From: Asias He <asias@xxxxxxxxxx>
Use generic_file_read_iter for read_iter. Add blkdev_write_iter which is
based on blkdev_aio_write for write_iter.
Signed-off-by: Asias He <asias@xxxxxxxxxx>
Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx>
---
fs/block_dev.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index ba3ed89..1a3aef9 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1593,6 +1593,21 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
return blkdev_ioctl(bdev, mode, cmd, arg);
}
+static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *iter,
+ loff_t pos)
+{
+ ssize_t ret;
+ struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host);
+
+ percpu_down_read(&bdev->bd_block_size_semaphore);
+
+ ret = generic_file_read_iter(iocb, iter, pos);
+
+ percpu_up_read(&bdev->bd_block_size_semaphore);
+
+ return ret;
+}
+
ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
@@ -1609,6 +1624,25 @@ ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
}
EXPORT_SYMBOL_GPL(blkdev_aio_read);
+ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
+{
+ struct file *file = iocb->ki_filp;
+ ssize_t ret;
+
+ BUG_ON(iocb->ki_pos != pos);
+
+ ret = __generic_file_write_iter(iocb, iter, &pos);
+ if (ret > 0 || ret == -EIOCBQUEUED) {
+ ssize_t err;
+
+ err = generic_write_sync(file, pos, ret);
+ if (err < 0 && ret > 0)
+ ret = err;
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blkdev_write_iter);
+
/*
* Write data to the block device. Only intended for the block device itself
* and the raw driver which basically is a fake block device.
@@ -1693,6 +1727,8 @@ const struct file_operations def_blk_fops = {
.write = do_sync_write,
.aio_read = blkdev_aio_read,
.aio_write = blkdev_aio_write,
+ .read_iter = blkdev_read_iter,
+ .write_iter = blkdev_write_iter,
.mmap = blkdev_mmap,
.fsync = blkdev_fsync,
.unlocked_ioctl = block_ioctl,
--
1.7.12.3
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