diff mbox series

[3/6] block: open code __generic_file_write_iter for blkdev writes

Message ID 20230720140452.63817-4-hch@lst.de (mailing list archive)
State Superseded, archived
Headers show
Series [1/6] fs: remove emergency_thaw_bdev | expand

Commit Message

Christoph Hellwig July 20, 2023, 2:04 p.m. UTC
Open code __generic_file_write_iter to remove the indirect call into
->direct_IO and to prepare using the iomap based write code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/fops.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)

Comments

Johannes Thumshirn July 20, 2023, 2:14 p.m. UTC | #1
Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Hannes Reinecke July 20, 2023, 3:46 p.m. UTC | #2
On 7/20/23 16:04, Christoph Hellwig wrote:
> Open code __generic_file_write_iter to remove the indirect call into
> ->direct_IO and to prepare using the iomap based write code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/fops.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
>   1 file changed, 42 insertions(+), 2 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
Luis Chamberlain July 24, 2023, 8:05 p.m. UTC | #3
On Thu, Jul 20, 2023 at 04:04:49PM +0200, Christoph Hellwig wrote:
> Open code __generic_file_write_iter to remove the indirect call into
> ->direct_IO and to prepare using the iomap based write code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/fops.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 42 insertions(+), 2 deletions(-)
> 
> diff --git a/block/fops.c b/block/fops.c
> index a286bf3325c5d8..eb599a173ef02d 100644
> --- a/block/fops.c
> +++ b/block/fops.c
> @@ -533,6 +533,29 @@ static int blkdev_release(struct inode *inode, struct file *filp)
>  	return 0;
>  }
>  
> +static ssize_t
> +blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from)
> +{
> +	size_t count = iov_iter_count(from);
> +	ssize_t written;
> +
> +	written = kiocb_invalidate_pages(iocb, count);
> +	if (written) {
> +		if (written == -EBUSY)
> +			return 0;
> +		return written;
> +	}
> +
> +	written = blkdev_direct_IO(iocb, from);
> +	if (written > 0) {
> +		kiocb_invalidate_post_direct_write(iocb, count);
> +		iocb->ki_pos += written;
> +	}

I noted in the last series how this could be negative and then crash:

https://lkml.kernel.org/r/ZG6OTWckNlz+P+mo@bombadil.infradead.org

This can be fixed as follows:

diff --git a/block/fops.c b/block/fops.c
index eb599a173ef0..936ed207b5dc 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -536,9 +536,13 @@ static int blkdev_release(struct inode *inode, struct file *filp)
 static ssize_t
 blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from)
 {
+	struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host);
 	size_t count = iov_iter_count(from);
 	ssize_t written;
 
+	if (blkdev_dio_unaligned(bdev, iocb->ki_pos, from))
+                return -EINVAL;
+
 	written = kiocb_invalidate_pages(iocb, count);
 	if (written) {
 		if (written == -EBUSY)

With that:

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>

  Luis
diff mbox series

Patch

diff --git a/block/fops.c b/block/fops.c
index a286bf3325c5d8..eb599a173ef02d 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -533,6 +533,29 @@  static int blkdev_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+static ssize_t
+blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from)
+{
+	size_t count = iov_iter_count(from);
+	ssize_t written;
+
+	written = kiocb_invalidate_pages(iocb, count);
+	if (written) {
+		if (written == -EBUSY)
+			return 0;
+		return written;
+	}
+
+	written = blkdev_direct_IO(iocb, from);
+	if (written > 0) {
+		kiocb_invalidate_post_direct_write(iocb, count);
+		iocb->ki_pos += written;
+	}
+	if (written != -EIOCBQUEUED)
+		iov_iter_revert(from, count - written - iov_iter_count(from));
+	return written;
+}
+
 /*
  * Write data to the block device.  Only intended for the block device itself
  * and the raw driver which basically is a fake block device.
@@ -542,7 +565,8 @@  static int blkdev_release(struct inode *inode, struct file *filp)
  */
 static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
-	struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host);
+	struct file *file = iocb->ki_filp;
+	struct block_device *bdev = I_BDEV(file->f_mapping->host);
 	struct inode *bd_inode = bdev->bd_inode;
 	loff_t size = bdev_nr_bytes(bdev);
 	size_t shorted = 0;
@@ -569,7 +593,23 @@  static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		iov_iter_truncate(from, size);
 	}
 
-	ret = __generic_file_write_iter(iocb, from);
+	ret = file_remove_privs(file);
+	if (ret)
+		return ret;
+
+	ret = file_update_time(file);
+	if (ret)
+		return ret;
+
+	if (iocb->ki_flags & IOCB_DIRECT) {
+		ret = blkdev_direct_write(iocb, from);
+		if (ret >= 0 && iov_iter_count(from))
+			ret = direct_write_fallback(iocb, from, ret,
+					generic_perform_write(iocb, from));
+	} else {
+		ret = generic_perform_write(iocb, from);
+	}
+
 	if (ret > 0)
 		ret = generic_write_sync(iocb, ret);
 	iov_iter_reexpand(from, iov_iter_count(from) + shorted);