[PATCH] xfs: fix rtalloc rotoring when delalloc is in use

[PATCH] xfs: fix rtalloc rotoring when delalloc is in use

[Christoph Hellwig]

If we're trying to allocate real space for a delalloc reservation at
offset 0, we should use the rotor to spread files across the rt volume.

Switch the rtalloc to use the XFS_ALLOC_INITIAL_USER_DATA flag that
is set for any write at startoff to make it match the behavior for
the main data device.

Based on a patch from Darrick J. Wong.

Fixes: 6a94b1acda7e ("xfs: reinstate delalloc for RT inodes (if sb_rextsize == 1)")
Repored-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_rtalloc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 5a7ddfed1bb855..0c3e96c621a672 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -12,6 +12,7 @@
 #include "xfs_bit.h"
 #include "xfs_mount.h"
 #include "xfs_inode.h"
+#include "xfs_alloc.h"
 #include "xfs_bmap.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_bmap_util.h"
@@ -1382,7 +1383,7 @@ xfs_bmap_rtalloc(
 		start = 0;
 	} else if (xfs_bmap_adjacent(ap)) {
 		start = xfs_rtb_to_rtx(mp, ap->blkno);
-	} else if (ap->eof && ap->offset == 0) {
+	} else if (ap->datatype & XFS_ALLOC_INITIAL_USER_DATA) {
 		/*
 		 * If it's an allocation to an empty file at offset 0, pick an
 		 * extent that will space things out in the rt area.
-- 
2.43.0

Re: [PATCH] xfs: fix rtalloc rotoring when delalloc is in use

[Darrick J. Wong]

On Mon, Jul 08, 2024 at 02:02:57PM +0200, Christoph Hellwig wrote:
> If we're trying to allocate real space for a delalloc reservation at
> offset 0, we should use the rotor to spread files across the rt volume.
> 
> Switch the rtalloc to use the XFS_ALLOC_INITIAL_USER_DATA flag that
> is set for any write at startoff to make it match the behavior for
> the main data device.
> 
> Based on a patch from Darrick J. Wong.
> 
> Fixes: 6a94b1acda7e ("xfs: reinstate delalloc for RT inodes (if sb_rextsize == 1)")
> Repored-by: Darrick J. Wong <djwong@kernel.org>

  Reported-by:

> Signed-off-by: Christoph Hellwig <hch@lst.de>

With that fixed,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_rtalloc.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index 5a7ddfed1bb855..0c3e96c621a672 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -12,6 +12,7 @@
>  #include "xfs_bit.h"
>  #include "xfs_mount.h"
>  #include "xfs_inode.h"
> +#include "xfs_alloc.h"
>  #include "xfs_bmap.h"
>  #include "xfs_bmap_btree.h"
>  #include "xfs_bmap_util.h"
> @@ -1382,7 +1383,7 @@ xfs_bmap_rtalloc(
>  		start = 0;
>  	} else if (xfs_bmap_adjacent(ap)) {
>  		start = xfs_rtb_to_rtx(mp, ap->blkno);
> -	} else if (ap->eof && ap->offset == 0) {
> +	} else if (ap->datatype & XFS_ALLOC_INITIAL_USER_DATA) {
>  		/*
>  		 * If it's an allocation to an empty file at offset 0, pick an
>  		 * extent that will space things out in the rt area.
> -- 
> 2.43.0
> 
>