[PATCH] xfs: Fix per-inode DAX flag inheritance

[PATCH] xfs: Fix per-inode DAX flag inheritance

[Lukas Czerner]

According to the commit that implemented per-inode DAX flag:
commit 58f88ca2df72 ("xfs: introduce per-inode DAX enablement")
the flag is supposed to act as "inherit flag".

Currently this only works in the situations where parent directory
already has a flag in di_flags set, otherwise inheritance does not
work. This is because setting the XFS_DIFLAG2_DAX flag is done in a
wrong branch designated for di_flags, not di_flags2.

Fix this by moving the code to branch designated for setting di_flags2,
which does test for flags in di_flags2.

Fixes: 58f88ca2df72 ("xfs: introduce per-inode DAX enablement")
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
---
 fs/xfs/xfs_inode.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index ceef77c..ff48f00 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -874,7 +874,6 @@ xfs_ialloc(
 	case S_IFREG:
 	case S_IFDIR:
 		if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
-			uint64_t	di_flags2 = 0;
 			uint		di_flags = 0;
 
 			if (S_ISDIR(mode)) {
@@ -911,20 +910,23 @@ xfs_ialloc(
 				di_flags |= XFS_DIFLAG_NODEFRAG;
 			if (pip->i_d.di_flags & XFS_DIFLAG_FILESTREAM)
 				di_flags |= XFS_DIFLAG_FILESTREAM;
-			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
-				di_flags2 |= XFS_DIFLAG2_DAX;
 
 			ip->i_d.di_flags |= di_flags;
-			ip->i_d.di_flags2 |= di_flags2;
 		}
 		if (pip &&
 		    (pip->i_d.di_flags2 & XFS_DIFLAG2_ANY) &&
 		    pip->i_d.di_version == 3 &&
 		    ip->i_d.di_version == 3) {
+			uint64_t	di_flags2 = 0;
+
 			if (pip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) {
-				ip->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
+				di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
 				ip->i_d.di_cowextsize = pip->i_d.di_cowextsize;
 			}
+			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
+				di_flags2 |= XFS_DIFLAG2_DAX;
+
+			ip->i_d.di_flags2 |= di_flags2;
 		}
 		/* FALLTHROUGH */
 	case S_IFLNK:
-- 
2.7.5

Re: [PATCH] xfs: Fix per-inode DAX flag inheritance

[Darrick J. Wong]

On Thu, Aug 03, 2017 at 04:37:18PM +0200, Lukas Czerner wrote:
> According to the commit that implemented per-inode DAX flag:
> commit 58f88ca2df72 ("xfs: introduce per-inode DAX enablement")
> the flag is supposed to act as "inherit flag".
> 
> Currently this only works in the situations where parent directory
> already has a flag in di_flags set, otherwise inheritance does not
> work. This is because setting the XFS_DIFLAG2_DAX flag is done in a
> wrong branch designated for di_flags, not di_flags2.
> 
> Fix this by moving the code to branch designated for setting di_flags2,
> which does test for flags in di_flags2.
> 
> Fixes: 58f88ca2df72 ("xfs: introduce per-inode DAX enablement")
> Signed-off-by: Lukas Czerner <lczerner@redhat.com>

Looks good,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

> ---
>  fs/xfs/xfs_inode.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index ceef77c..ff48f00 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -874,7 +874,6 @@ xfs_ialloc(
>  	case S_IFREG:
>  	case S_IFDIR:
>  		if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
> -			uint64_t	di_flags2 = 0;
>  			uint		di_flags = 0;
>  
>  			if (S_ISDIR(mode)) {
> @@ -911,20 +910,23 @@ xfs_ialloc(
>  				di_flags |= XFS_DIFLAG_NODEFRAG;
>  			if (pip->i_d.di_flags & XFS_DIFLAG_FILESTREAM)
>  				di_flags |= XFS_DIFLAG_FILESTREAM;
> -			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
> -				di_flags2 |= XFS_DIFLAG2_DAX;
>  
>  			ip->i_d.di_flags |= di_flags;
> -			ip->i_d.di_flags2 |= di_flags2;
>  		}
>  		if (pip &&
>  		    (pip->i_d.di_flags2 & XFS_DIFLAG2_ANY) &&
>  		    pip->i_d.di_version == 3 &&
>  		    ip->i_d.di_version == 3) {
> +			uint64_t	di_flags2 = 0;
> +
>  			if (pip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) {
> -				ip->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
> +				di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
>  				ip->i_d.di_cowextsize = pip->i_d.di_cowextsize;
>  			}
> +			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
> +				di_flags2 |= XFS_DIFLAG2_DAX;
> +
> +			ip->i_d.di_flags2 |= di_flags2;
>  		}
>  		/* FALLTHROUGH */
>  	case S_IFLNK:
> -- 
> 2.7.5
> 
> --
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