[PATCH 3/3] xfs: only log freed extents for the current RTG in zoned growfs

[PATCH 3/3] xfs: only log freed extents for the current RTG in zoned growfs

[Christoph Hellwig]

Otherwise a power fail or crash during growfs could lead to an
elevated sb_rblocks counter.

Note that the step function is much simpler compared to the classic RT
allocator, as zoned RT sections must be allocated to zone and thus
realtime group boundaries, and also because the rtextsize is fixed to a
single FSB.

Fixes: 01b71e64bb87 ("xfs: support growfs on zoned file systems")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_rtalloc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index fd07c1a18615..728f444fbc30 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -890,8 +890,7 @@ xfs_growfs_rt_sb_fields(
 
 static int
 xfs_growfs_rt_zoned(
-	struct xfs_rtgroup	*rtg,
-	xfs_rfsblock_t		nrblocks)
+	struct xfs_rtgroup	*rtg)
 {
 	struct xfs_mount	*mp = rtg_mount(rtg);
 	struct xfs_mount	*nmp;
@@ -903,7 +902,8 @@ xfs_growfs_rt_zoned(
 	 * Calculate new sb and mount fields for this round.  Also ensure the
 	 * rtg_extents value is uptodate as the rtbitmap code relies on it.
 	 */
-	nmp = xfs_growfs_rt_alloc_fake_mount(mp, nrblocks,
+	nmp = xfs_growfs_rt_alloc_fake_mount(mp,
+			mp->m_sb.sb_rgextents * (rtg_rgno(rtg) + 1),
 			mp->m_sb.sb_rextsize);
 	if (!nmp)
 		return -ENOMEM;
@@ -1219,7 +1219,7 @@ xfs_growfs_rtg(
 	}
 
 	if (xfs_has_zoned(mp)) {
-		error = xfs_growfs_rt_zoned(rtg, nrblocks);
+		error = xfs_growfs_rt_zoned(rtg);
 		goto out_rele;
 	}
 
-- 
2.53.0

Re: [PATCH 3/3] xfs: only log freed extents for the current RTG in zoned growfs

[Darrick J. Wong]

On Tue, Jun 09, 2026 at 09:56:43AM +0200, Christoph Hellwig wrote:
> Otherwise a power fail or crash during growfs could lead to an
> elevated sb_rblocks counter.
> 
> Note that the step function is much simpler compared to the classic RT
> allocator, as zoned RT sections must be allocated to zone and thus
> realtime group boundaries, and also because the rtextsize is fixed to a
> single FSB.
> 
> Fixes: 01b71e64bb87 ("xfs: support growfs on zoned file systems")
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_rtalloc.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index fd07c1a18615..728f444fbc30 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -890,8 +890,7 @@ xfs_growfs_rt_sb_fields(
>  
>  static int
>  xfs_growfs_rt_zoned(
> -	struct xfs_rtgroup	*rtg,
> -	xfs_rfsblock_t		nrblocks)
> +	struct xfs_rtgroup	*rtg)
>  {
>  	struct xfs_mount	*mp = rtg_mount(rtg);
>  	struct xfs_mount	*nmp;
> @@ -903,7 +902,8 @@ xfs_growfs_rt_zoned(
>  	 * Calculate new sb and mount fields for this round.  Also ensure the
>  	 * rtg_extents value is uptodate as the rtbitmap code relies on it.
>  	 */
> -	nmp = xfs_growfs_rt_alloc_fake_mount(mp, nrblocks,
> +	nmp = xfs_growfs_rt_alloc_fake_mount(mp,
> +			mp->m_sb.sb_rgextents * (rtg_rgno(rtg) + 1),

I wonder, do you have to be careful about the multiplication overflowing
here because rgextents and rgno are both 32-bit variables?

--D

>  			mp->m_sb.sb_rextsize);
>  	if (!nmp)
>  		return -ENOMEM;
> @@ -1219,7 +1219,7 @@ xfs_growfs_rtg(
>  	}
>  
>  	if (xfs_has_zoned(mp)) {
> -		error = xfs_growfs_rt_zoned(rtg, nrblocks);
> +		error = xfs_growfs_rt_zoned(rtg);
>  		goto out_rele;
>  	}
>  
> -- 
> 2.53.0
> 
> 

Re: [PATCH 3/3] xfs: only log freed extents for the current RTG in zoned growfs

[Damien Le Moal]

On 2026/06/09 15:56, Christoph Hellwig wrote:
> Otherwise a power fail or crash during growfs could lead to an
> elevated sb_rblocks counter.
> 
> Note that the step function is much simpler compared to the classic RT
> allocator, as zoned RT sections must be allocated to zone and thus

s/zone/zones

> realtime group boundaries, and also because the rtextsize is fixed to a
> single FSB.
> 
> Fixes: 01b71e64bb87 ("xfs: support growfs on zoned file systems")
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_rtalloc.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index fd07c1a18615..728f444fbc30 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -890,8 +890,7 @@ xfs_growfs_rt_sb_fields(
>  
>  static int
>  xfs_growfs_rt_zoned(
> -	struct xfs_rtgroup	*rtg,
> -	xfs_rfsblock_t		nrblocks)
> +	struct xfs_rtgroup	*rtg)
>  {
>  	struct xfs_mount	*mp = rtg_mount(rtg);
>  	struct xfs_mount	*nmp;
> @@ -903,7 +902,8 @@ xfs_growfs_rt_zoned(
>  	 * Calculate new sb and mount fields for this round.  Also ensure the
>  	 * rtg_extents value is uptodate as the rtbitmap code relies on it.
>  	 */
> -	nmp = xfs_growfs_rt_alloc_fake_mount(mp, nrblocks,
> +	nmp = xfs_growfs_rt_alloc_fake_mount(mp,
> +			mp->m_sb.sb_rgextents * (rtg_rgno(rtg) + 1),
>  			mp->m_sb.sb_rextsize);
>  	if (!nmp)
>  		return -ENOMEM;
> @@ -1219,7 +1219,7 @@ xfs_growfs_rtg(
>  	}
>  
>  	if (xfs_has_zoned(mp)) {
> -		error = xfs_growfs_rt_zoned(rtg, nrblocks);
> +		error = xfs_growfs_rt_zoned(rtg);
>  		goto out_rele;
>  	}
>  


-- 
Damien Le Moal
Western Digital Research

zoned growfs fix v2

[Christoph Hellwig]

Hi all,

this series fixes growfs on zoned file systems, which so far has been
completely broken.  A test to verify it properly will be sent out as
well.

Changes since v1:
 - rename xfs_add_free_zone to xfs_zone_mark_free
 - use xfs_rtgs_to_rfsbs to avoid overflows
 - improve a commit message
 - add a comment explaining the zoned growfs space accounting logic

Diffstat:
 xfs_rtalloc.c    |   16 ++++++++++++----
 xfs_zone_alloc.c |   11 +++++++++--
 xfs_zone_alloc.h |    1 +
 xfs_zone_gc.c    |    4 +---
 4 files changed, 23 insertions(+), 9 deletions(-)

[PATCH 1/3] xfs: factor out a xfs_zone_mark_free helper

[Christoph Hellwig]

Add a helper for adding a zone to the free pool in preparation of adding
another caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
---
 fs/xfs/xfs_zone_alloc.c | 11 +++++++++--
 fs/xfs/xfs_zone_alloc.h |  1 +
 fs/xfs/xfs_zone_gc.c    |  4 +---
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/xfs_zone_alloc.c b/fs/xfs/xfs_zone_alloc.c
index 5e297b75a85f..08d8b34f467e 100644
--- a/fs/xfs/xfs_zone_alloc.c
+++ b/fs/xfs/xfs_zone_alloc.c
@@ -944,6 +944,14 @@ xfs_zone_rgbno_is_valid(
 			rtg_rgno(rtg), XFS_RTG_FREE);
 }
 
+void
+xfs_zone_mark_free(
+	struct xfs_rtgroup	*rtg)
+{
+	xfs_group_set_mark(rtg_group(rtg), XFS_RTG_FREE);
+	atomic_inc(&rtg_mount(rtg)->m_zone_info->zi_nr_free_zones);
+}
+
 static void
 xfs_free_open_zones(
 	struct xfs_zone_info	*zi)
@@ -1082,8 +1090,7 @@ xfs_init_zone(
 
 	if (write_pointer == 0) {
 		/* zone is empty */
-		atomic_inc(&zi->zi_nr_free_zones);
-		xfs_group_set_mark(rtg_group(rtg), XFS_RTG_FREE);
+		xfs_zone_mark_free(rtg);
 		iz->available += rtg_blocks(rtg);
 	} else if (write_pointer < rtg_blocks(rtg)) {
 		/* zone is open */
diff --git a/fs/xfs/xfs_zone_alloc.h b/fs/xfs/xfs_zone_alloc.h
index 8b2ef98c81ef..abf8358bb266 100644
--- a/fs/xfs/xfs_zone_alloc.h
+++ b/fs/xfs/xfs_zone_alloc.h
@@ -42,6 +42,7 @@ void xfs_zoned_wake_all(struct xfs_mount *mp);
 bool xfs_zone_rgbno_is_valid(struct xfs_rtgroup *rtg, xfs_rgnumber_t rgbno);
 void xfs_mark_rtg_boundary(struct iomap_ioend *ioend);
 
+void xfs_zone_mark_free(struct xfs_rtgroup *rtg);
 uint64_t xfs_zoned_default_resblks(struct xfs_mount *mp,
 		enum xfs_free_counter ctr);
 void xfs_zoned_show_stats(struct seq_file *m, struct xfs_mount *mp);
diff --git a/fs/xfs/xfs_zone_gc.c b/fs/xfs/xfs_zone_gc.c
index f03211e4354a..f76a09130852 100644
--- a/fs/xfs/xfs_zone_gc.c
+++ b/fs/xfs/xfs_zone_gc.c
@@ -924,9 +924,7 @@ xfs_zone_gc_finish_reset(
 		goto out;
 	}
 
-	xfs_group_set_mark(rtg_group(rtg), XFS_RTG_FREE);
-	atomic_inc(&zi->zi_nr_free_zones);
-
+	xfs_zone_mark_free(rtg);
 	xfs_zoned_add_available(mp, rtg_blocks(rtg));
 
 	wake_up_all(&zi->zi_zone_wait);
-- 
2.53.0

[PATCH 2/3] xfs: add newly added RTGs to the free pool in growfs

[Christoph Hellwig]

When growing a zoned RT section, the newly added RTGs also need to be
tagged as free in the radix tree and add to the nr_free_zones counters.
Call xfs_add_free_zone to do that, otherwise using up the newly added
space will wait for free zones forever.

Fixes: 01b71e64bb87 ("xfs: support growfs on zoned file systems")
Cc: <stable@vger.kernel.org> # v6.15
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_rtalloc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 153f3c378f9f..debbcefdf07f 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -933,6 +933,14 @@ xfs_growfs_rt_zoned(
 	mp->m_features |= XFS_FEAT_REALTIME;
 	xfs_rtrmapbt_compute_maxlevels(mp);
 	xfs_rtrefcountbt_compute_maxlevels(mp);
+
+	/*
+	 * Finally add the newly added zone to the freelist and add the space
+	 * to the available counter.  The order is important here: only add
+	 * the available space after the zones, as available space guarantees
+	 * that zones to back it are available.
+	 */
+	xfs_zone_mark_free(rtg);
 	xfs_zoned_add_available(mp, freed_rtx);
 out_free:
 	kfree(nmp);
-- 
2.53.0

[PATCH 3/3] xfs: only log freed extents for the current RTG in zoned growfs

[Christoph Hellwig]

Otherwise a power fail or crash during growfs could lead to an
elevated sb_rblocks counter.

Note that the step function is much simpler compared to the classic RT
allocator as zoned RT sections must be aligned to real time group
boundaries.

Fixes: 01b71e64bb87 ("xfs: support growfs on zoned file systems")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_rtalloc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index debbcefdf07f..7a3f97686989 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -890,8 +890,7 @@ xfs_growfs_rt_sb_fields(
 
 static int
 xfs_growfs_rt_zoned(
-	struct xfs_rtgroup	*rtg,
-	xfs_rfsblock_t		nrblocks)
+	struct xfs_rtgroup	*rtg)
 {
 	struct xfs_mount	*mp = rtg_mount(rtg);
 	struct xfs_mount	*nmp;
@@ -903,7 +902,8 @@ xfs_growfs_rt_zoned(
 	 * Calculate new sb and mount fields for this round.  Also ensure the
 	 * rtg_extents value is uptodate as the rtbitmap code relies on it.
 	 */
-	nmp = xfs_growfs_rt_alloc_fake_mount(mp, nrblocks,
+	nmp = xfs_growfs_rt_alloc_fake_mount(mp,
+			xfs_rtgs_to_rfsbs(mp, rtg_rgno(rtg) + 1),
 			mp->m_sb.sb_rextsize);
 	if (!nmp)
 		return -ENOMEM;
@@ -1226,7 +1226,7 @@ xfs_growfs_rtg(
 	}
 
 	if (xfs_has_zoned(mp)) {
-		error = xfs_growfs_rt_zoned(rtg, nrblocks);
+		error = xfs_growfs_rt_zoned(rtg);
 		goto out_rele;
 	}
 
-- 
2.53.0

Re: [PATCH 3/3] xfs: only log freed extents for the current RTG in zoned growfs

[Darrick J. Wong]

On Wed, Jun 10, 2026 at 07:07:21AM +0200, Christoph Hellwig wrote:
> Otherwise a power fail or crash during growfs could lead to an
> elevated sb_rblocks counter.
> 
> Note that the step function is much simpler compared to the classic RT
> allocator as zoned RT sections must be aligned to real time group
> boundaries.
> 
> Fixes: 01b71e64bb87 ("xfs: support growfs on zoned file systems")
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_rtalloc.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index debbcefdf07f..7a3f97686989 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -890,8 +890,7 @@ xfs_growfs_rt_sb_fields(
>  
>  static int
>  xfs_growfs_rt_zoned(
> -	struct xfs_rtgroup	*rtg,
> -	xfs_rfsblock_t		nrblocks)
> +	struct xfs_rtgroup	*rtg)
>  {
>  	struct xfs_mount	*mp = rtg_mount(rtg);
>  	struct xfs_mount	*nmp;
> @@ -903,7 +902,8 @@ xfs_growfs_rt_zoned(
>  	 * Calculate new sb and mount fields for this round.  Also ensure the
>  	 * rtg_extents value is uptodate as the rtbitmap code relies on it.
>  	 */
> -	nmp = xfs_growfs_rt_alloc_fake_mount(mp, nrblocks,
> +	nmp = xfs_growfs_rt_alloc_fake_mount(mp,
> +			xfs_rtgs_to_rfsbs(mp, rtg_rgno(rtg) + 1),

Heh, I forgot we had a helper for this!

Cc: <stable@vger.kernel.org> # v6.15
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

>  			mp->m_sb.sb_rextsize);
>  	if (!nmp)
>  		return -ENOMEM;
> @@ -1226,7 +1226,7 @@ xfs_growfs_rtg(
>  	}
>  
>  	if (xfs_has_zoned(mp)) {
> -		error = xfs_growfs_rt_zoned(rtg, nrblocks);
> +		error = xfs_growfs_rt_zoned(rtg);
>  		goto out_rele;
>  	}
>  
> -- 
> 2.53.0
> 
> 

Re: [PATCH 3/3] xfs: only log freed extents for the current RTG in zoned growfs

[Christoph Hellwig]

On Tue, Jun 09, 2026 at 10:12:18PM -0700, Darrick J. Wong wrote:
> > -	nmp = xfs_growfs_rt_alloc_fake_mount(mp, nrblocks,
> > +	nmp = xfs_growfs_rt_alloc_fake_mount(mp,
> > +			xfs_rtgs_to_rfsbs(mp, rtg_rgno(rtg) + 1),
> 
> Heh, I forgot we had a helper for this!

Yeah, if only the person who added it would remember to consistently use
it..

Re: [PATCH 3/3] xfs: only log freed extents for the current RTG in zoned growfs

[Damien Le Moal]

On 2026/06/10 13:07, Christoph Hellwig wrote:
> Otherwise a power fail or crash during growfs could lead to an
> elevated sb_rblocks counter.
> 
> Note that the step function is much simpler compared to the classic RT
> allocator as zoned RT sections must be aligned to real time group
> boundaries.
> 
> Fixes: 01b71e64bb87 ("xfs: support growfs on zoned file systems")
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

-- 
Damien Le Moal
Western Digital Research