[patch v4 0/2] Misc fixes in XFS realtime

[patch v4 0/2] Misc fixes in XFS realtime

[Nirjhar Roy (IBM)]

This patchset has 2 fixes in some XFS realtime code. Details are
in the commit messages.

[v3] -> v4

1.Patch 1/2 -> Replaced the ASSERT with an XFS_IS_CORRUPT
2.Patch 2/2 -> Removed an extra line between tags


[v2] -> [v3]

1. Patch 1/2 -> Changed ASSERT(sum >= 0); to ASSERT(0);
   (as discussed in [3]) and removed RB from Darrick 
   since the code was slightly changed after the RB was given.
2. Patch 2/2 -> Added RB from Carlos.


[v1] --> [v2]

1. Added RB from Darrick in patch 1/2.
2. Added Cc, Fixes tag and RB from Darrck in patch 2/2.

[3] - https://lore.kernel.org/all/20260202185348.GI7712@frogsfrogsfrogs/
[v3]- https://lore.kernel.org/all/cover.1770121544.git.nirjhar.roy.lists@gmail.com/
[v2]- https://lore.kernel.org/all/cover.1769625536.git.nirjhar.roy.lists@gmail.com/
[v1]- https://lore.kernel.org/all/cover.1769613182.git.nirjhar.roy.lists@gmail.com/

Nirjhar Roy (IBM) (2):
  xfs: Replace ASSERT with XFS_IS_CORRUPT in xfs_rtcopy_summary()
  xfs: Fix in xfs_rtalloc_query_range()

 fs/xfs/libxfs/xfs_rtbitmap.c | 2 +-
 fs/xfs/xfs_rtalloc.c         | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

-- 
2.43.5

[patch v4 1/2] xfs: Replace ASSERT with XFS_IS_CORRUPT in xfs_rtcopy_summary()

[Nirjhar Roy (IBM)]

Replace ASSERT(sum > 0) with an XFS_IS_CORRUPT() and place it just
after the call to xfs_rtget_summary() so that we don't end up using
an illegal value of sum.

Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
---
 fs/xfs/xfs_rtalloc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index a12ffed12391..3035e4a7e817 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -112,6 +112,10 @@ xfs_rtcopy_summary(
 			error = xfs_rtget_summary(oargs, log, bbno, &sum);
 			if (error)
 				goto out;
+			if (XFS_IS_CORRUPT(oargs->mp, sum < 0)) {
+				error = -EFSCORRUPTED;
+				goto out;
+			}
 			if (sum == 0)
 				continue;
 			error = xfs_rtmodify_summary(oargs, log, bbno, -sum);
@@ -120,7 +124,6 @@ xfs_rtcopy_summary(
 			error = xfs_rtmodify_summary(nargs, log, bbno, sum);
 			if (error)
 				goto out;
-			ASSERT(sum > 0);
 		}
 	}
 	error = 0;
-- 
2.43.5

[patch v4 2/2] xfs: Fix in xfs_rtalloc_query_range()

[Nirjhar Roy (IBM)]

xfs_rtalloc_query_range() should not return 0 by doing a NOP when
start == end i.e, when the rtgroup size is 1. This causes incorrect
calculation of free rtextents i.e, the count is reduced by 1 since
the last rtgroup's rtextent count is not taken and hence xfs_scrub
throws false summary counter report (from xchk_fscounters()).

A simple way to reproduce the above bug:

$ mkfs.xfs -f -m metadir=1 \
	-r rtdev=/dev/loop2,extsize=4096,rgcount=4,size=1G \
	-d size=1G /dev/loop1
meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=1
         =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
         =                       exchange=1   metadir=1
data     =                       bsize=4096   blocks=262144, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
log      =internal log           bsize=4096   blocks=16384, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
         =                       rgcount=4    rgsize=65536 extents
         =                       zoned=0      start=0 reserved=0
Discarding blocks...Done.
Discarding blocks...Done.
$ mount -o rtdev=/dev/loop2 /dev/loop1 /mnt1/scratch
$ xfs_growfs -R $(( 65536 * 4 + 1 ))  /mnt1/scratch
meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=1
         =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
         =                       exchange=1   metadir=1
data     =                       bsize=4096   blocks=262144, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
log      =internal log           bsize=4096   blocks=16384, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
         =                       rgcount=4    rgsize=65536 extents
         =                       zoned=0      start=0 reserved=0
calling xfsctl with in.newblocks = 262145
realtime blocks changed from 262144 to 262145
$ xfs_scrub -n   -v /mnt1/scratch
Phase 1: Find filesystem geometry.
/mnt1/scratch: using 2 threads to scrub.
Phase 2: Check internal metadata.
Corruption: rtgroup 4 realtime summary: Repairs are required.
Phase 3: Scan all inodes.
Phase 5: Check directory tree.
Info: /mnt1/scratch: Filesystem has errors, skipping connectivity checks.
Phase 7: Check summary counters.
Corruption: filesystem summary counters: Repairs are required.
125.0MiB data used;  8.0KiB realtime data used;  15 inodes used.
64.3MiB data found; 4.0KiB realtime data found; 18 inodes found.
18 inodes counted; 18 inodes checked.
Phase 8: Trim filesystem storage.
/mnt1/scratch: corruptions found: 2
/mnt1/scratch: Re-run xfs_scrub without -n.

Cc: <stable@vger.kernel.org> # v6.13
Fixes: e3088ae2dcae3c ("xfs: move RT bitmap and summary information to the rtgroup")
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
---
 fs/xfs/libxfs/xfs_rtbitmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index 618061d898d4..8f552129ffcc 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -1170,7 +1170,7 @@ xfs_rtalloc_query_range(
 
 	if (start > end)
 		return -EINVAL;
-	if (start == end || start >= rtg->rtg_extents)
+	if (start >= rtg->rtg_extents)
 		return 0;
 
 	end = min(end, rtg->rtg_extents - 1);
-- 
2.43.5

Re: [patch v4 1/2] xfs: Replace ASSERT with XFS_IS_CORRUPT in xfs_rtcopy_summary()

[Darrick J. Wong]

On Wed, Feb 04, 2026 at 08:36:26PM +0530, Nirjhar Roy (IBM) wrote:
> Replace ASSERT(sum > 0) with an XFS_IS_CORRUPT() and place it just
> after the call to xfs_rtget_summary() so that we don't end up using
> an illegal value of sum.
> 
> Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>

Looks good to me now, thanks for your persistence!
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_rtalloc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index a12ffed12391..3035e4a7e817 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -112,6 +112,10 @@ xfs_rtcopy_summary(
>  			error = xfs_rtget_summary(oargs, log, bbno, &sum);
>  			if (error)
>  				goto out;
> +			if (XFS_IS_CORRUPT(oargs->mp, sum < 0)) {
> +				error = -EFSCORRUPTED;
> +				goto out;
> +			}
>  			if (sum == 0)
>  				continue;
>  			error = xfs_rtmodify_summary(oargs, log, bbno, -sum);
> @@ -120,7 +124,6 @@ xfs_rtcopy_summary(
>  			error = xfs_rtmodify_summary(nargs, log, bbno, sum);
>  			if (error)
>  				goto out;
> -			ASSERT(sum > 0);
>  		}
>  	}
>  	error = 0;
> -- 
> 2.43.5
> 
> 

Re: [patch v4 1/2] xfs: Replace ASSERT with XFS_IS_CORRUPT in xfs_rtcopy_summary()

[Nirjhar Roy (IBM)]

On 2/5/26 21:51, Darrick J. Wong wrote:
> On Wed, Feb 04, 2026 at 08:36:26PM +0530, Nirjhar Roy (IBM) wrote:
>> Replace ASSERT(sum > 0) with an XFS_IS_CORRUPT() and place it just
>> after the call to xfs_rtget_summary() so that we don't end up using
>> an illegal value of sum.
>>
>> Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
> Looks good to me now, thanks for your persistence!
> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

Thank you for your review comments.

--NR

>
> --D
>
>> ---
>>   fs/xfs/xfs_rtalloc.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
>> index a12ffed12391..3035e4a7e817 100644
>> --- a/fs/xfs/xfs_rtalloc.c
>> +++ b/fs/xfs/xfs_rtalloc.c
>> @@ -112,6 +112,10 @@ xfs_rtcopy_summary(
>>   			error = xfs_rtget_summary(oargs, log, bbno, &sum);
>>   			if (error)
>>   				goto out;
>> +			if (XFS_IS_CORRUPT(oargs->mp, sum < 0)) {
>> +				error = -EFSCORRUPTED;
>> +				goto out;
>> +			}
>>   			if (sum == 0)
>>   				continue;
>>   			error = xfs_rtmodify_summary(oargs, log, bbno, -sum);
>> @@ -120,7 +124,6 @@ xfs_rtcopy_summary(
>>   			error = xfs_rtmodify_summary(nargs, log, bbno, sum);
>>   			if (error)
>>   				goto out;
>> -			ASSERT(sum > 0);
>>   		}
>>   	}
>>   	error = 0;
>> -- 
>> 2.43.5
>>
>>
-- 
Nirjhar Roy
Linux Kernel Developer
IBM, Bangalore

Re: [patch v4 1/2] xfs: Replace ASSERT with XFS_IS_CORRUPT in xfs_rtcopy_summary()

[Carlos Maiolino]

On Wed, Feb 04, 2026 at 08:36:26PM +0530, Nirjhar Roy (IBM) wrote:
> Replace ASSERT(sum > 0) with an XFS_IS_CORRUPT() and place it just
> after the call to xfs_rtget_summary() so that we don't end up using
> an illegal value of sum.
> 
> Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>

Looks good to me know. Thanks for addressing the ugly ASSERT :)

Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

> ---
>  fs/xfs/xfs_rtalloc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index a12ffed12391..3035e4a7e817 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -112,6 +112,10 @@ xfs_rtcopy_summary(
>  			error = xfs_rtget_summary(oargs, log, bbno, &sum);
>  			if (error)
>  				goto out;
> +			if (XFS_IS_CORRUPT(oargs->mp, sum < 0)) {
> +				error = -EFSCORRUPTED;
> +				goto out;
> +			}
>  			if (sum == 0)
>  				continue;
>  			error = xfs_rtmodify_summary(oargs, log, bbno, -sum);
> @@ -120,7 +124,6 @@ xfs_rtcopy_summary(
>  			error = xfs_rtmodify_summary(nargs, log, bbno, sum);
>  			if (error)
>  				goto out;
> -			ASSERT(sum > 0);
>  		}
>  	}
>  	error = 0;
> -- 
> 2.43.5
> 

Re: [patch v4 1/2] xfs: Replace ASSERT with XFS_IS_CORRUPT in xfs_rtcopy_summary()

[Nirjhar Roy (IBM)]

On 2/6/26 18:18, Carlos Maiolino wrote:
> On Wed, Feb 04, 2026 at 08:36:26PM +0530, Nirjhar Roy (IBM) wrote:
>> Replace ASSERT(sum > 0) with an XFS_IS_CORRUPT() and place it just
>> after the call to xfs_rtget_summary() so that we don't end up using
>> an illegal value of sum.
>>
>> Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
> Looks good to me know. Thanks for addressing the ugly ASSERT :)
>
> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

Thank you.

--NR

>
>> ---
>>   fs/xfs/xfs_rtalloc.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
>> index a12ffed12391..3035e4a7e817 100644
>> --- a/fs/xfs/xfs_rtalloc.c
>> +++ b/fs/xfs/xfs_rtalloc.c
>> @@ -112,6 +112,10 @@ xfs_rtcopy_summary(
>>   			error = xfs_rtget_summary(oargs, log, bbno, &sum);
>>   			if (error)
>>   				goto out;
>> +			if (XFS_IS_CORRUPT(oargs->mp, sum < 0)) {
>> +				error = -EFSCORRUPTED;
>> +				goto out;
>> +			}
>>   			if (sum == 0)
>>   				continue;
>>   			error = xfs_rtmodify_summary(oargs, log, bbno, -sum);
>> @@ -120,7 +124,6 @@ xfs_rtcopy_summary(
>>   			error = xfs_rtmodify_summary(nargs, log, bbno, sum);
>>   			if (error)
>>   				goto out;
>> -			ASSERT(sum > 0);
>>   		}
>>   	}
>>   	error = 0;
>> -- 
>> 2.43.5
>>
-- 
Nirjhar Roy
Linux Kernel Developer
IBM, Bangalore

Re: [patch v4 0/2] Misc fixes in XFS realtime

[Carlos Maiolino]

On Wed, 04 Feb 2026 20:36:25 +0530, Nirjhar Roy (IBM) wrote:
> This patchset has 2 fixes in some XFS realtime code. Details are
> in the commit messages.
> 
> [v3] -> v4
> 
> 1.Patch 1/2 -> Replaced the ASSERT with an XFS_IS_CORRUPT
> 2.Patch 2/2 -> Removed an extra line between tags
> 
> [...]

Applied to for-next, thanks!

[1/2] xfs: Replace ASSERT with XFS_IS_CORRUPT in xfs_rtcopy_summary()
      commit: ce95c72c7f95b820ca124e4a2b0d2b84224d6971
[2/2] xfs: Fix in xfs_rtalloc_query_range()
      commit: 60cb35d383aa5d185685e301e27346b51bf48026

Best regards,
-- 
Carlos Maiolino <cem@kernel.org>

Re: [patch v4 0/2] Misc fixes in XFS realtime

[Nirjhar Roy (IBM)]

On 2/16/26 22:12, Carlos Maiolino wrote:
> On Wed, 04 Feb 2026 20:36:25 +0530, Nirjhar Roy (IBM) wrote:
>> This patchset has 2 fixes in some XFS realtime code. Details are
>> in the commit messages.
>>
>> [v3] -> v4
>>
>> 1.Patch 1/2 -> Replaced the ASSERT with an XFS_IS_CORRUPT
>> 2.Patch 2/2 -> Removed an extra line between tags

Thank you.

--NR

>>
>> [...]
> Applied to for-next, thanks!
>
> [1/2] xfs: Replace ASSERT with XFS_IS_CORRUPT in xfs_rtcopy_summary()
>        commit: ce95c72c7f95b820ca124e4a2b0d2b84224d6971
> [2/2] xfs: Fix in xfs_rtalloc_query_range()
>        commit: 60cb35d383aa5d185685e301e27346b51bf48026
>
> Best regards,

-- 
Nirjhar Roy
Linux Kernel Developer
IBM, Bangalore

Re: [patch v4 2/2] xfs: Fix in xfs_rtalloc_query_range()

[Carlos Maiolino]

On Wed, Feb 04, 2026 at 08:36:27PM +0530, Nirjhar Roy (IBM) wrote:
> xfs_rtalloc_query_range() should not return 0 by doing a NOP when
> start == end i.e, when the rtgroup size is 1. This causes incorrect
> calculation of free rtextents i.e, the count is reduced by 1 since
> the last rtgroup's rtextent count is not taken and hence xfs_scrub
> throws false summary counter report (from xchk_fscounters()).

This causes a regression in xfstests's generic/475 running on a RT
device.

I'm dropping this patch until I have time to investigate what's wrong.

> 
> A simple way to reproduce the above bug:
> 
> $ mkfs.xfs -f -m metadir=1 \
> 	-r rtdev=/dev/loop2,extsize=4096,rgcount=4,size=1G \
> 	-d size=1G /dev/loop1
> meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
>          =                       sectsz=512   attr=2, projid32bit=1
>          =                       crc=1        finobt=1, sparse=1, rmapbt=1
>          =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
>          =                       exchange=1   metadir=1
> data     =                       bsize=4096   blocks=262144, imaxpct=25
>          =                       sunit=0      swidth=0 blks
> naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
> log      =internal log           bsize=4096   blocks=16384, version=2
>          =                       sectsz=512   sunit=0 blks, lazy-count=1
> realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
>          =                       rgcount=4    rgsize=65536 extents
>          =                       zoned=0      start=0 reserved=0
> Discarding blocks...Done.
> Discarding blocks...Done.
> $ mount -o rtdev=/dev/loop2 /dev/loop1 /mnt1/scratch
> $ xfs_growfs -R $(( 65536 * 4 + 1 ))  /mnt1/scratch
> meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
>          =                       sectsz=512   attr=2, projid32bit=1
>          =                       crc=1        finobt=1, sparse=1, rmapbt=1
>          =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
>          =                       exchange=1   metadir=1
> data     =                       bsize=4096   blocks=262144, imaxpct=25
>          =                       sunit=0      swidth=0 blks
> naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
> log      =internal log           bsize=4096   blocks=16384, version=2
>          =                       sectsz=512   sunit=0 blks, lazy-count=1
> realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
>          =                       rgcount=4    rgsize=65536 extents
>          =                       zoned=0      start=0 reserved=0
> calling xfsctl with in.newblocks = 262145
> realtime blocks changed from 262144 to 262145
> $ xfs_scrub -n   -v /mnt1/scratch
> Phase 1: Find filesystem geometry.
> /mnt1/scratch: using 2 threads to scrub.
> Phase 2: Check internal metadata.
> Corruption: rtgroup 4 realtime summary: Repairs are required.
> Phase 3: Scan all inodes.
> Phase 5: Check directory tree.
> Info: /mnt1/scratch: Filesystem has errors, skipping connectivity checks.
> Phase 7: Check summary counters.
> Corruption: filesystem summary counters: Repairs are required.
> 125.0MiB data used;  8.0KiB realtime data used;  15 inodes used.
> 64.3MiB data found; 4.0KiB realtime data found; 18 inodes found.
> 18 inodes counted; 18 inodes checked.
> Phase 8: Trim filesystem storage.
> /mnt1/scratch: corruptions found: 2
> /mnt1/scratch: Re-run xfs_scrub without -n.
> 
> Cc: <stable@vger.kernel.org> # v6.13
> Fixes: e3088ae2dcae3c ("xfs: move RT bitmap and summary information to the rtgroup")
> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
> Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
> ---
>  fs/xfs/libxfs/xfs_rtbitmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
> index 618061d898d4..8f552129ffcc 100644
> --- a/fs/xfs/libxfs/xfs_rtbitmap.c
> +++ b/fs/xfs/libxfs/xfs_rtbitmap.c
> @@ -1170,7 +1170,7 @@ xfs_rtalloc_query_range(
>  
>  	if (start > end)
>  		return -EINVAL;
> -	if (start == end || start >= rtg->rtg_extents)
> +	if (start >= rtg->rtg_extents)
>  		return 0;
>  
>  	end = min(end, rtg->rtg_extents - 1);
> -- 
> 2.43.5
> 
> 

Re: [patch v4 2/2] xfs: Fix in xfs_rtalloc_query_range()

[Nirjhar Roy (IBM)]

On 2/25/26 16:10, Carlos Maiolino wrote:
> On Wed, Feb 04, 2026 at 08:36:27PM +0530, Nirjhar Roy (IBM) wrote:
>> xfs_rtalloc_query_range() should not return 0 by doing a NOP when
>> start == end i.e, when the rtgroup size is 1. This causes incorrect
>> calculation of free rtextents i.e, the count is reduced by 1 since
>> the last rtgroup's rtextent count is not taken and hence xfs_scrub
>> throws false summary counter report (from xchk_fscounters()).
> This causes a regression in xfstests's generic/475 running on a RT
> device.
>
> I'm dropping this patch until I have time to investigate what's wrong.


I just took a quick glance at generic/475 - It does something related to 
recovery. I am not sure how this fix is affecting this test. Maybe this 
fix is triggering some other bug which needs to be fixed. Can you please 
share the error logs and the local.config you used?

--NR

>
>> A simple way to reproduce the above bug:
>>
>> $ mkfs.xfs -f -m metadir=1 \
>> 	-r rtdev=/dev/loop2,extsize=4096,rgcount=4,size=1G \
>> 	-d size=1G /dev/loop1
>> meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
>>           =                       sectsz=512   attr=2, projid32bit=1
>>           =                       crc=1        finobt=1, sparse=1, rmapbt=1
>>           =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
>>           =                       exchange=1   metadir=1
>> data     =                       bsize=4096   blocks=262144, imaxpct=25
>>           =                       sunit=0      swidth=0 blks
>> naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
>> log      =internal log           bsize=4096   blocks=16384, version=2
>>           =                       sectsz=512   sunit=0 blks, lazy-count=1
>> realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
>>           =                       rgcount=4    rgsize=65536 extents
>>           =                       zoned=0      start=0 reserved=0
>> Discarding blocks...Done.
>> Discarding blocks...Done.
>> $ mount -o rtdev=/dev/loop2 /dev/loop1 /mnt1/scratch
>> $ xfs_growfs -R $(( 65536 * 4 + 1 ))  /mnt1/scratch
>> meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
>>           =                       sectsz=512   attr=2, projid32bit=1
>>           =                       crc=1        finobt=1, sparse=1, rmapbt=1
>>           =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
>>           =                       exchange=1   metadir=1
>> data     =                       bsize=4096   blocks=262144, imaxpct=25
>>           =                       sunit=0      swidth=0 blks
>> naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
>> log      =internal log           bsize=4096   blocks=16384, version=2
>>           =                       sectsz=512   sunit=0 blks, lazy-count=1
>> realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
>>           =                       rgcount=4    rgsize=65536 extents
>>           =                       zoned=0      start=0 reserved=0
>> calling xfsctl with in.newblocks = 262145
>> realtime blocks changed from 262144 to 262145
>> $ xfs_scrub -n   -v /mnt1/scratch
>> Phase 1: Find filesystem geometry.
>> /mnt1/scratch: using 2 threads to scrub.
>> Phase 2: Check internal metadata.
>> Corruption: rtgroup 4 realtime summary: Repairs are required.
>> Phase 3: Scan all inodes.
>> Phase 5: Check directory tree.
>> Info: /mnt1/scratch: Filesystem has errors, skipping connectivity checks.
>> Phase 7: Check summary counters.
>> Corruption: filesystem summary counters: Repairs are required.
>> 125.0MiB data used;  8.0KiB realtime data used;  15 inodes used.
>> 64.3MiB data found; 4.0KiB realtime data found; 18 inodes found.
>> 18 inodes counted; 18 inodes checked.
>> Phase 8: Trim filesystem storage.
>> /mnt1/scratch: corruptions found: 2
>> /mnt1/scratch: Re-run xfs_scrub without -n.
>>
>> Cc: <stable@vger.kernel.org> # v6.13
>> Fixes: e3088ae2dcae3c ("xfs: move RT bitmap and summary information to the rtgroup")
>> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
>> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
>> Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
>> ---
>>   fs/xfs/libxfs/xfs_rtbitmap.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
>> index 618061d898d4..8f552129ffcc 100644
>> --- a/fs/xfs/libxfs/xfs_rtbitmap.c
>> +++ b/fs/xfs/libxfs/xfs_rtbitmap.c
>> @@ -1170,7 +1170,7 @@ xfs_rtalloc_query_range(
>>   
>>   	if (start > end)
>>   		return -EINVAL;
>> -	if (start == end || start >= rtg->rtg_extents)
>> +	if (start >= rtg->rtg_extents)
>>   		return 0;
>>   
>>   	end = min(end, rtg->rtg_extents - 1);
>> -- 
>> 2.43.5
>>
>>
-- 
Nirjhar Roy
Linux Kernel Developer
IBM, Bangalore

Re: [patch v4 2/2] xfs: Fix in xfs_rtalloc_query_range()

[Carlos Maiolino]

On Wed, Feb 25, 2026 at 04:58:26PM +0530, Nirjhar Roy (IBM) wrote:
> 
> On 2/25/26 16:10, Carlos Maiolino wrote:
> > On Wed, Feb 04, 2026 at 08:36:27PM +0530, Nirjhar Roy (IBM) wrote:
> > > xfs_rtalloc_query_range() should not return 0 by doing a NOP when
> > > start == end i.e, when the rtgroup size is 1. This causes incorrect
> > > calculation of free rtextents i.e, the count is reduced by 1 since
> > > the last rtgroup's rtextent count is not taken and hence xfs_scrub
> > > throws false summary counter report (from xchk_fscounters()).
> > This causes a regression in xfstests's generic/475 running on a RT
> > device.
> > 
> > I'm dropping this patch until I have time to investigate what's wrong.
> 
> 
> I just took a quick glance at generic/475 - It does something related to
> recovery. I am not sure how this fix is affecting this test. Maybe this fix
> is triggering some other bug which needs to be fixed. Can you please share
> the error logs and the local.config you used?

I will get the info and let you know, I don't have access to my test
system right now to get the details.

What config did you use? I'll give it a try later tonight and see if I
spot any differences.


> 
> --NR
> 
> > 
> > > A simple way to reproduce the above bug:
> > > 
> > > $ mkfs.xfs -f -m metadir=1 \
> > > 	-r rtdev=/dev/loop2,extsize=4096,rgcount=4,size=1G \
> > > 	-d size=1G /dev/loop1
> > > meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
> > >           =                       sectsz=512   attr=2, projid32bit=1
> > >           =                       crc=1        finobt=1, sparse=1, rmapbt=1
> > >           =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
> > >           =                       exchange=1   metadir=1
> > > data     =                       bsize=4096   blocks=262144, imaxpct=25
> > >           =                       sunit=0      swidth=0 blks
> > > naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
> > > log      =internal log           bsize=4096   blocks=16384, version=2
> > >           =                       sectsz=512   sunit=0 blks, lazy-count=1
> > > realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
> > >           =                       rgcount=4    rgsize=65536 extents
> > >           =                       zoned=0      start=0 reserved=0
> > > Discarding blocks...Done.
> > > Discarding blocks...Done.
> > > $ mount -o rtdev=/dev/loop2 /dev/loop1 /mnt1/scratch
> > > $ xfs_growfs -R $(( 65536 * 4 + 1 ))  /mnt1/scratch
> > > meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
> > >           =                       sectsz=512   attr=2, projid32bit=1
> > >           =                       crc=1        finobt=1, sparse=1, rmapbt=1
> > >           =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
> > >           =                       exchange=1   metadir=1
> > > data     =                       bsize=4096   blocks=262144, imaxpct=25
> > >           =                       sunit=0      swidth=0 blks
> > > naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
> > > log      =internal log           bsize=4096   blocks=16384, version=2
> > >           =                       sectsz=512   sunit=0 blks, lazy-count=1
> > > realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
> > >           =                       rgcount=4    rgsize=65536 extents
> > >           =                       zoned=0      start=0 reserved=0
> > > calling xfsctl with in.newblocks = 262145
> > > realtime blocks changed from 262144 to 262145
> > > $ xfs_scrub -n   -v /mnt1/scratch
> > > Phase 1: Find filesystem geometry.
> > > /mnt1/scratch: using 2 threads to scrub.
> > > Phase 2: Check internal metadata.
> > > Corruption: rtgroup 4 realtime summary: Repairs are required.
> > > Phase 3: Scan all inodes.
> > > Phase 5: Check directory tree.
> > > Info: /mnt1/scratch: Filesystem has errors, skipping connectivity checks.
> > > Phase 7: Check summary counters.
> > > Corruption: filesystem summary counters: Repairs are required.
> > > 125.0MiB data used;  8.0KiB realtime data used;  15 inodes used.
> > > 64.3MiB data found; 4.0KiB realtime data found; 18 inodes found.
> > > 18 inodes counted; 18 inodes checked.
> > > Phase 8: Trim filesystem storage.
> > > /mnt1/scratch: corruptions found: 2
> > > /mnt1/scratch: Re-run xfs_scrub without -n.
> > > 
> > > Cc: <stable@vger.kernel.org> # v6.13
> > > Fixes: e3088ae2dcae3c ("xfs: move RT bitmap and summary information to the rtgroup")
> > > Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
> > > Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
> > > Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
> > > ---
> > >   fs/xfs/libxfs/xfs_rtbitmap.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
> > > index 618061d898d4..8f552129ffcc 100644
> > > --- a/fs/xfs/libxfs/xfs_rtbitmap.c
> > > +++ b/fs/xfs/libxfs/xfs_rtbitmap.c
> > > @@ -1170,7 +1170,7 @@ xfs_rtalloc_query_range(
> > >   	if (start > end)
> > >   		return -EINVAL;
> > > -	if (start == end || start >= rtg->rtg_extents)
> > > +	if (start >= rtg->rtg_extents)
> > >   		return 0;
> > >   	end = min(end, rtg->rtg_extents - 1);
> > > -- 
> > > 2.43.5
> > > 
> > > 
> -- 
> Nirjhar Roy
> Linux Kernel Developer
> IBM, Bangalore
> 

Re: [patch v4 2/2] xfs: Fix in xfs_rtalloc_query_range()

[Nirjhar Roy (IBM)]

On 2/25/26 17:49, Carlos Maiolino wrote:
> On Wed, Feb 25, 2026 at 04:58:26PM +0530, Nirjhar Roy (IBM) wrote:
>> On 2/25/26 16:10, Carlos Maiolino wrote:
>>> On Wed, Feb 04, 2026 at 08:36:27PM +0530, Nirjhar Roy (IBM) wrote:
>>>> xfs_rtalloc_query_range() should not return 0 by doing a NOP when
>>>> start == end i.e, when the rtgroup size is 1. This causes incorrect
>>>> calculation of free rtextents i.e, the count is reduced by 1 since
>>>> the last rtgroup's rtextent count is not taken and hence xfs_scrub
>>>> throws false summary counter report (from xchk_fscounters()).
>>> This causes a regression in xfstests's generic/475 running on a RT
>>> device.
>>>
>>> I'm dropping this patch until I have time to investigate what's wrong.
>>
>> I just took a quick glance at generic/475 - It does something related to
>> recovery. I am not sure how this fix is affecting this test. Maybe this fix
>> is triggering some other bug which needs to be fixed. Can you please share
>> the error logs and the local.config you used?
> I will get the info and let you know, I don't have access to my test
> system right now to get the details.


Okay sure, thank you.

>
> What config did you use? I'll give it a try later tonight and see if I
> spot any differences.


I haven't run it yet. But I usually use the following configuration

[xfs_4k]
export TEST_DEV=/dev/loop0
export TEST_DIR=/mnt1/test
export SCRATCH_DEV=/dev/loop1
export SCRATCH_MNT=/mnt1/scratch
export SCRATCH_RTDEV=/dev/loop2
export USE_EXTERNAL=yes

Most of the options are the default ones and/or used by the test script 
itself.

--NR

>
>
>> --NR
>>
>>>> A simple way to reproduce the above bug:
>>>>
>>>> $ mkfs.xfs -f -m metadir=1 \
>>>> 	-r rtdev=/dev/loop2,extsize=4096,rgcount=4,size=1G \
>>>> 	-d size=1G /dev/loop1
>>>> meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
>>>>            =                       sectsz=512   attr=2, projid32bit=1
>>>>            =                       crc=1        finobt=1, sparse=1, rmapbt=1
>>>>            =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
>>>>            =                       exchange=1   metadir=1
>>>> data     =                       bsize=4096   blocks=262144, imaxpct=25
>>>>            =                       sunit=0      swidth=0 blks
>>>> naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
>>>> log      =internal log           bsize=4096   blocks=16384, version=2
>>>>            =                       sectsz=512   sunit=0 blks, lazy-count=1
>>>> realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
>>>>            =                       rgcount=4    rgsize=65536 extents
>>>>            =                       zoned=0      start=0 reserved=0
>>>> Discarding blocks...Done.
>>>> Discarding blocks...Done.
>>>> $ mount -o rtdev=/dev/loop2 /dev/loop1 /mnt1/scratch
>>>> $ xfs_growfs -R $(( 65536 * 4 + 1 ))  /mnt1/scratch
>>>> meta-data=/dev/loop1             isize=512    agcount=4, agsize=65536 blks
>>>>            =                       sectsz=512   attr=2, projid32bit=1
>>>>            =                       crc=1        finobt=1, sparse=1, rmapbt=1
>>>>            =                       reflink=0    bigtime=1 inobtcount=1 nrext64=1
>>>>            =                       exchange=1   metadir=1
>>>> data     =                       bsize=4096   blocks=262144, imaxpct=25
>>>>            =                       sunit=0      swidth=0 blks
>>>> naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
>>>> log      =internal log           bsize=4096   blocks=16384, version=2
>>>>            =                       sectsz=512   sunit=0 blks, lazy-count=1
>>>> realtime =/dev/loop2             extsz=4096   blocks=262144, rtextents=262144
>>>>            =                       rgcount=4    rgsize=65536 extents
>>>>            =                       zoned=0      start=0 reserved=0
>>>> calling xfsctl with in.newblocks = 262145
>>>> realtime blocks changed from 262144 to 262145
>>>> $ xfs_scrub -n   -v /mnt1/scratch
>>>> Phase 1: Find filesystem geometry.
>>>> /mnt1/scratch: using 2 threads to scrub.
>>>> Phase 2: Check internal metadata.
>>>> Corruption: rtgroup 4 realtime summary: Repairs are required.
>>>> Phase 3: Scan all inodes.
>>>> Phase 5: Check directory tree.
>>>> Info: /mnt1/scratch: Filesystem has errors, skipping connectivity checks.
>>>> Phase 7: Check summary counters.
>>>> Corruption: filesystem summary counters: Repairs are required.
>>>> 125.0MiB data used;  8.0KiB realtime data used;  15 inodes used.
>>>> 64.3MiB data found; 4.0KiB realtime data found; 18 inodes found.
>>>> 18 inodes counted; 18 inodes checked.
>>>> Phase 8: Trim filesystem storage.
>>>> /mnt1/scratch: corruptions found: 2
>>>> /mnt1/scratch: Re-run xfs_scrub without -n.
>>>>
>>>> Cc: <stable@vger.kernel.org> # v6.13
>>>> Fixes: e3088ae2dcae3c ("xfs: move RT bitmap and summary information to the rtgroup")
>>>> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
>>>> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
>>>> Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
>>>> ---
>>>>    fs/xfs/libxfs/xfs_rtbitmap.c | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
>>>> index 618061d898d4..8f552129ffcc 100644
>>>> --- a/fs/xfs/libxfs/xfs_rtbitmap.c
>>>> +++ b/fs/xfs/libxfs/xfs_rtbitmap.c
>>>> @@ -1170,7 +1170,7 @@ xfs_rtalloc_query_range(
>>>>    	if (start > end)
>>>>    		return -EINVAL;
>>>> -	if (start == end || start >= rtg->rtg_extents)
>>>> +	if (start >= rtg->rtg_extents)
>>>>    		return 0;
>>>>    	end = min(end, rtg->rtg_extents - 1);
>>>> -- 
>>>> 2.43.5
>>>>
>>>>
>> -- 
>> Nirjhar Roy
>> Linux Kernel Developer
>> IBM, Bangalore
>>
-- 
Nirjhar Roy
Linux Kernel Developer
IBM, Bangalore