2019-04-23 08:10:03

by Pankaj Gupta

Subject: [PATCH v6 6/6] xfs: disable map_sync for async flush

Dont support 'MAP_SYNC' with non-DAX files and DAX files
with asynchronous dax_device. Virtio pmem provides
asynchronous host page cache flush mechanism. We don't
support 'MAP_SYNC' with virtio pmem and xfs.

Signed-off-by: Pankaj Gupta <[email protected]>
---
fs/xfs/xfs_file.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 1f2e2845eb76..0e59be018511 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1196,11 +1196,13 @@ xfs_file_mmap(
struct file *filp,
struct vm_area_struct *vma)
{
- /*
- * We don't support synchronous mappings for non-DAX files. At least
- * until someone comes with a sensible use case.
+ struct dax_device *dax_dev = xfs_find_daxdev_for_inode
+ (file_inode(filp));
+
+ /* We don't support synchronous mappings for non-DAX files and
+ * for DAX files if underneath dax_device is not synchronous.
*/
- if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
+ if (!daxdev_mapping_supported(vma, dax_dev))
return -EOPNOTSUPP;

file_accessed(filp);
--
2.20.1

2019-04-23 22:04:10

by Dave Chinner

Subject: Re: [PATCH v6 6/6] xfs: disable map_sync for async flush

On Tue, Apr 23, 2019 at 01:36:12PM +0530, Pankaj Gupta wrote:
> Dont support 'MAP_SYNC' with non-DAX files and DAX files
> with asynchronous dax_device. Virtio pmem provides
> asynchronous host page cache flush mechanism. We don't
> support 'MAP_SYNC' with virtio pmem and xfs.
>
> Signed-off-by: Pankaj Gupta <[email protected]>
> ---
> fs/xfs/xfs_file.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 1f2e2845eb76..0e59be018511 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1196,11 +1196,13 @@ xfs_file_mmap(
> struct file *filp,
> struct vm_area_struct *vma)
> {
> - /*
> - * We don't support synchronous mappings for non-DAX files. At least
> - * until someone comes with a sensible use case.
> + struct dax_device *dax_dev = xfs_find_daxdev_for_inode
> + (file_inode(filp));
> +
> + /* We don't support synchronous mappings for non-DAX files and
> + * for DAX files if underneath dax_device is not synchronous.
> */

/*
* This is the correct multi-line comment format. Please
* update the patch to maintain the existing comment format.
*/

Cheers,

Dave.
--
Dave Chinner
[email protected]

2019-04-23 22:14:08

by Darrick J. Wong

Subject: Re: [PATCH v6 6/6] xfs: disable map_sync for async flush

On Wed, Apr 24, 2019 at 08:02:17AM +1000, Dave Chinner wrote:
> On Tue, Apr 23, 2019 at 01:36:12PM +0530, Pankaj Gupta wrote:
> > Dont support 'MAP_SYNC' with non-DAX files and DAX files
> > with asynchronous dax_device. Virtio pmem provides
> > asynchronous host page cache flush mechanism. We don't
> > support 'MAP_SYNC' with virtio pmem and xfs.
> >
> > Signed-off-by: Pankaj Gupta <[email protected]>
> > ---
> > fs/xfs/xfs_file.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> > index 1f2e2845eb76..0e59be018511 100644
> > --- a/fs/xfs/xfs_file.c
> > +++ b/fs/xfs/xfs_file.c
> > @@ -1196,11 +1196,13 @@ xfs_file_mmap(
> > struct file *filp,
> > struct vm_area_struct *vma)
> > {
> > - /*
> > - * We don't support synchronous mappings for non-DAX files. At least
> > - * until someone comes with a sensible use case.
> > + struct dax_device *dax_dev = xfs_find_daxdev_for_inode
> > + (file_inode(filp));

tab separation here ^^^ ^^^^ and cut
down the indent
while you're at
it, please:

struct dax_device *dax_dev;

dax_dev = xfs_find_daxdev_for_inode(file_inode(filp));
if (!dax_is_frobbed(dax))
return -EMEWANTCOOKIE;

--D

> > +
> > + /* We don't support synchronous mappings for non-DAX files and
> > + * for DAX files if underneath dax_device is not synchronous.
> > */
>
> /*
> * This is the correct multi-line comment format. Please
> * update the patch to maintain the existing comment format.
> */
>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> [email protected]

2019-04-24 04:56:57

by Pankaj Gupta

Subject: Re: [PATCH v6 6/6] xfs: disable map_sync for async flush

>
> On Tue, Apr 23, 2019 at 01:36:12PM +0530, Pankaj Gupta wrote:
> > Dont support 'MAP_SYNC' with non-DAX files and DAX files
> > with asynchronous dax_device. Virtio pmem provides
> > asynchronous host page cache flush mechanism. We don't
> > support 'MAP_SYNC' with virtio pmem and xfs.
> >
> > Signed-off-by: Pankaj Gupta <[email protected]>
> > ---
> > fs/xfs/xfs_file.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> > index 1f2e2845eb76..0e59be018511 100644
> > --- a/fs/xfs/xfs_file.c
> > +++ b/fs/xfs/xfs_file.c
> > @@ -1196,11 +1196,13 @@ xfs_file_mmap(
> > struct file *filp,
> > struct vm_area_struct *vma)
> > {
> > - /*
> > - * We don't support synchronous mappings for non-DAX files. At least
> > - * until someone comes with a sensible use case.
> > + struct dax_device *dax_dev = xfs_find_daxdev_for_inode
> > + (file_inode(filp));
> > +
> > + /* We don't support synchronous mappings for non-DAX files and
> > + * for DAX files if underneath dax_device is not synchronous.
> > */
>
> /*
> * This is the correct multi-line comment format. Please
> * update the patch to maintain the existing comment format.
> */

Sure. Will correct this for both xfs & ext4.

Thanks,
Pankaj

>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> [email protected]
>