2018-06-19 08:57:26

by Benjamin Coddington

Subject: [PATCH] nfsd: don't advertise a SCSI layout for an unsupported request_queue

Commit 30181faae37f ("nfsd: Check queue type before submitting a SCSI
request") did the work of ensuring that we don't send SCSI requests to a
request queue that won't support them, but that check is in the
GETDEVICEINFO path. Let's not set the SCSI layout in fs_layout_type in the
first place, and then we'll have less clients sending GETDEVICEINFO for
non-SCSI request queues and less unnecessary WARN_ONs.

While we're in here, remove some outdated comments that refer to
"overwriting" layout seletion because commit 8a4c3926889e ("nfsd: allow
nfsd to advertise multiple layout types") changed things to no longer
overwrite the layout type.

Signed-off-by: Benjamin Coddington <[email protected]>
---
fs/nfsd/nfs4layouts.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
index 7d888369f85a..0ba7d3150213 100644
--- a/fs/nfsd/nfs4layouts.c
+++ b/fs/nfsd/nfs4layouts.c
@@ -133,27 +133,20 @@ void nfsd4_setup_layout_type(struct svc_export *exp)
if (!(exp->ex_flags & NFSEXP_PNFS))
return;

- /*
- * If flex file is configured, use it by default. Otherwise
- * check if the file system supports exporting a block-like layout.
- * If the block device supports reservations prefer the SCSI layout,
- * otherwise advertise the block layout.
- */
#ifdef CONFIG_NFSD_FLEXFILELAYOUT
exp->ex_layout_types |= 1 << LAYOUT_FLEX_FILES;
#endif
#ifdef CONFIG_NFSD_BLOCKLAYOUT
- /* overwrite flex file layout selection if needed */
if (sb->s_export_op->get_uuid &&
sb->s_export_op->map_blocks &&
sb->s_export_op->commit_blocks)
exp->ex_layout_types |= 1 << LAYOUT_BLOCK_VOLUME;
#endif
#ifdef CONFIG_NFSD_SCSILAYOUT
- /* overwrite block layout selection if needed */
if (sb->s_export_op->map_blocks &&
sb->s_export_op->commit_blocks &&
- sb->s_bdev && sb->s_bdev->bd_disk->fops->pr_ops)
+ sb->s_bdev && sb->s_bdev->bd_disk->fops->pr_ops &&
+ blk_queue_scsi_passthrough(sb->s_bdev->bd_disk->queue))
exp->ex_layout_types |= 1 << LAYOUT_SCSI;
#endif
}
--
2.14.3

2018-06-19 13:55:53

by J. Bruce Fields

Subject: Re: [PATCH] nfsd: don't advertise a SCSI layout for an unsupported request_queue

Thanks, applying.--b.

On Tue, Jun 19, 2018 at 04:57:24AM -0400, Benjamin Coddington wrote:
> Commit 30181faae37f ("nfsd: Check queue type before submitting a SCSI
> request") did the work of ensuring that we don't send SCSI requests to a
> request queue that won't support them, but that check is in the
> GETDEVICEINFO path. Let's not set the SCSI layout in fs_layout_type in the
> first place, and then we'll have less clients sending GETDEVICEINFO for
> non-SCSI request queues and less unnecessary WARN_ONs.
>
> While we're in here, remove some outdated comments that refer to
> "overwriting" layout seletion because commit 8a4c3926889e ("nfsd: allow
> nfsd to advertise multiple layout types") changed things to no longer
> overwrite the layout type.
>
> Signed-off-by: Benjamin Coddington <[email protected]>
> ---
> fs/nfsd/nfs4layouts.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
> index 7d888369f85a..0ba7d3150213 100644
> --- a/fs/nfsd/nfs4layouts.c
> +++ b/fs/nfsd/nfs4layouts.c
> @@ -133,27 +133,20 @@ void nfsd4_setup_layout_type(struct svc_export *exp)
> if (!(exp->ex_flags & NFSEXP_PNFS))
> return;
>
> - /*
> - * If flex file is configured, use it by default. Otherwise
> - * check if the file system supports exporting a block-like layout.
> - * If the block device supports reservations prefer the SCSI layout,
> - * otherwise advertise the block layout.
> - */
> #ifdef CONFIG_NFSD_FLEXFILELAYOUT
> exp->ex_layout_types |= 1 << LAYOUT_FLEX_FILES;
> #endif
> #ifdef CONFIG_NFSD_BLOCKLAYOUT
> - /* overwrite flex file layout selection if needed */
> if (sb->s_export_op->get_uuid &&
> sb->s_export_op->map_blocks &&
> sb->s_export_op->commit_blocks)
> exp->ex_layout_types |= 1 << LAYOUT_BLOCK_VOLUME;
> #endif
> #ifdef CONFIG_NFSD_SCSILAYOUT
> - /* overwrite block layout selection if needed */
> if (sb->s_export_op->map_blocks &&
> sb->s_export_op->commit_blocks &&
> - sb->s_bdev && sb->s_bdev->bd_disk->fops->pr_ops)
> + sb->s_bdev && sb->s_bdev->bd_disk->fops->pr_ops &&
> + blk_queue_scsi_passthrough(sb->s_bdev->bd_disk->queue))
> exp->ex_layout_types |= 1 << LAYOUT_SCSI;
> #endif
> }
> --
> 2.14.3

2018-06-19 14:11:07

by Christoph Hellwig

Subject: Re: [PATCH] nfsd: don't advertise a SCSI layout for an unsupported request_queue

On Tue, Jun 19, 2018 at 04:57:24AM -0400, Benjamin Coddington wrote:
> Commit 30181faae37f ("nfsd: Check queue type before submitting a SCSI
> request") did the work of ensuring that we don't send SCSI requests to a
> request queue that won't support them, but that check is in the
> GETDEVICEINFO path. Let's not set the SCSI layout in fs_layout_type in the
> first place, and then we'll have less clients sending GETDEVICEINFO for
> non-SCSI request queues and less unnecessary WARN_ONs.
>
> While we're in here, remove some outdated comments that refer to
> "overwriting" layout seletion because commit 8a4c3926889e ("nfsd: allow
> nfsd to advertise multiple layout types") changed things to no longer
> overwrite the layout type.
>
> Signed-off-by: Benjamin Coddington <[email protected]>

Looks good,

Reviewed-by: Christoph Hellwig <[email protected]>