After commit 77573fa310d9 ("fs: Kill DCACHE_DONTCACHE dentry even if
DCACHE_REFERENCED is set"), changes to DAX policy will take effect
as soon as all references to this file are gone.
Update the documentation accordingly.
Signed-off-by: Hao Li <[email protected]>
---
Changes in v2:
* simplify sentences and fix style problems.
Documentation/filesystems/dax.txt | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt
index 8fdb78f3c6c9..e03c20564f3a 100644
--- a/Documentation/filesystems/dax.txt
+++ b/Documentation/filesystems/dax.txt
@@ -83,20 +83,9 @@ Summary
directories. This has runtime constraints and limitations that are
described in 6) below.
- 6. When changing the S_DAX policy via toggling the persistent FS_XFLAG_DAX flag,
- the change in behaviour for existing regular files may not occur
- immediately. If the change must take effect immediately, the administrator
- needs to:
-
- a) stop the application so there are no active references to the data set
- the policy change will affect
-
- b) evict the data set from kernel caches so it will be re-instantiated when
- the application is restarted. This can be achieved by:
-
- i. drop-caches
- ii. a filesystem unmount and mount cycle
- iii. a system reboot
+ 6. When changing the S_DAX policy via toggling the persistent FS_XFLAG_DAX
+ flag, the change to existing regular files won't take effect until the
+ files are closed by all processes.
Details
--
2.29.2
On Wed, Jan 06, 2021 at 09:50:00AM +0800, Hao Li wrote:
> After commit 77573fa310d9 ("fs: Kill DCACHE_DONTCACHE dentry even if
> DCACHE_REFERENCED is set"), changes to DAX policy will take effect
> as soon as all references to this file are gone.
>
> Update the documentation accordingly.
>
> Signed-off-by: Hao Li <[email protected]>
LGTM
Reviewed-by: Ira Weiny <[email protected]>
> ---
> Changes in v2:
> * simplify sentences and fix style problems.
>
> Documentation/filesystems/dax.txt | 17 +++--------------
> 1 file changed, 3 insertions(+), 14 deletions(-)
>
> diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt
> index 8fdb78f3c6c9..e03c20564f3a 100644
> --- a/Documentation/filesystems/dax.txt
> +++ b/Documentation/filesystems/dax.txt
> @@ -83,20 +83,9 @@ Summary
> directories. This has runtime constraints and limitations that are
> described in 6) below.
>
> - 6. When changing the S_DAX policy via toggling the persistent FS_XFLAG_DAX flag,
> - the change in behaviour for existing regular files may not occur
> - immediately. If the change must take effect immediately, the administrator
> - needs to:
> -
> - a) stop the application so there are no active references to the data set
> - the policy change will affect
> -
> - b) evict the data set from kernel caches so it will be re-instantiated when
> - the application is restarted. This can be achieved by:
> -
> - i. drop-caches
> - ii. a filesystem unmount and mount cycle
> - iii. a system reboot
> + 6. When changing the S_DAX policy via toggling the persistent FS_XFLAG_DAX
> + flag, the change to existing regular files won't take effect until the
> + files are closed by all processes.
>
>
> Details
> --
> 2.29.2
>
>
>
On Tue, 5 Jan 2021 21:45:41 -0800
Ira Weiny <[email protected]> wrote:
> On Wed, Jan 06, 2021 at 09:50:00AM +0800, Hao Li wrote:
> > After commit 77573fa310d9 ("fs: Kill DCACHE_DONTCACHE dentry even if
> > DCACHE_REFERENCED is set"), changes to DAX policy will take effect
> > as soon as all references to this file are gone.
> >
> > Update the documentation accordingly.
> >
> > Signed-off-by: Hao Li <[email protected]>
>
> LGTM
>
> Reviewed-by: Ira Weiny <[email protected]>
Applied, thanks.
jon