diff mbox series

[06/26] loop: also use the default block size from an underlying block device

Message ID 20240611051929.513387-7-hch@lst.de (mailing list archive)
State Superseded, archived
Delegated to: Benjamin Marzinski
Headers show
Series [01/26] sd: fix sd_is_zoned | expand

Commit Message

Christoph Hellwig June 11, 2024, 5:19 a.m. UTC
Fix the code in loop_reconfigure_limits to pick a default block size for
O_DIRECT file descriptors to also work when the loop device sits on top
of a block device and not just on a regular file on a block device based
file system.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/loop.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Damien Le Moal June 11, 2024, 5:58 a.m. UTC | #1
On 6/11/24 2:19 PM, Christoph Hellwig wrote:
> Fix the code in loop_reconfigure_limits to pick a default block size for
> O_DIRECT file descriptors to also work when the loop device sits on top
> of a block device and not just on a regular file on a block device based
> file system.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/block/loop.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index 4f6d8514d19bd6..d7cf6bbbfb1b86 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -988,10 +988,16 @@ static int loop_reconfigure_limits(struct loop_device *lo, unsigned short bsize)
>  {
>  	struct file *file = lo->lo_backing_file;
>  	struct inode *inode = file->f_mapping->host;
> +	struct block_device *backing_bdev = NULL;
>  	struct queue_limits lim;
>  
> +	if (S_ISBLK(inode->i_mode))
> +		backing_bdev = I_BDEV(inode);
> +	else if (inode->i_sb->s_bdev)
> +		backing_bdev = inode->i_sb->s_bdev;
> +

Why not move this hunk inside the below "if" ? (backing_dev declaration can go
there too).

>  	if (!bsize)
> -		bsize = loop_default_blocksize(lo, inode->i_sb->s_bdev);
> +		bsize = loop_default_blocksize(lo, backing_bdev);
>  
>  	lim = queue_limits_start_update(lo->lo_queue);
>  	lim.logical_block_size = bsize;
Christoph Hellwig June 11, 2024, 5:59 a.m. UTC | #2
On Tue, Jun 11, 2024 at 02:58:56PM +0900, Damien Le Moal wrote:
> > +	if (S_ISBLK(inode->i_mode))
> > +		backing_bdev = I_BDEV(inode);
> > +	else if (inode->i_sb->s_bdev)
> > +		backing_bdev = inode->i_sb->s_bdev;
> > +
> 
> Why not move this hunk inside the below "if" ? (backing_dev declaration can go
> there too).

Because another use will pop up a bit later :)
Hannes Reinecke June 11, 2024, 8:17 a.m. UTC | #3
On 6/11/24 07:19, Christoph Hellwig wrote:
> Fix the code in loop_reconfigure_limits to pick a default block size for
> O_DIRECT file descriptors to also work when the loop device sits on top
> of a block device and not just on a regular file on a block device based
> file system.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   drivers/block/loop.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
Bart Van Assche June 11, 2024, 7:28 p.m. UTC | #4
On 6/10/24 10:19 PM, Christoph Hellwig wrote:
> Fix the code in loop_reconfigure_limits to pick a default block size for
> O_DIRECT file descriptors to also work when the loop device sits on top
> of a block device and not just on a regular file on a block device based
> file system.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
diff mbox series

Patch

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 4f6d8514d19bd6..d7cf6bbbfb1b86 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -988,10 +988,16 @@  static int loop_reconfigure_limits(struct loop_device *lo, unsigned short bsize)
 {
 	struct file *file = lo->lo_backing_file;
 	struct inode *inode = file->f_mapping->host;
+	struct block_device *backing_bdev = NULL;
 	struct queue_limits lim;
 
+	if (S_ISBLK(inode->i_mode))
+		backing_bdev = I_BDEV(inode);
+	else if (inode->i_sb->s_bdev)
+		backing_bdev = inode->i_sb->s_bdev;
+
 	if (!bsize)
-		bsize = loop_default_blocksize(lo, inode->i_sb->s_bdev);
+		bsize = loop_default_blocksize(lo, backing_bdev);
 
 	lim = queue_limits_start_update(lo->lo_queue);
 	lim.logical_block_size = bsize;