diff mbox series

[V8,08/19] xfs: Introduce XFS_SB_FEAT_INCOMPAT_NREXT64 and associated per-fs feature bit

Message ID 20220321051750.400056-9-chandan.babu@oracle.com (mailing list archive)
State Superseded
Headers show
Series xfs: Extend per-inode extent counters | expand

Commit Message

Chandan Babu R March 21, 2022, 5:17 a.m. UTC 
XFS_SB_FEAT_INCOMPAT_NREXT64 incompat feature bit will be set on filesystems
which support large per-inode extent counters. This commit defines the new
incompat feature bit and the corresponding per-fs feature bit (along with
inline functions to work on it).

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
---
 fs/xfs/libxfs/xfs_format.h | 1 +
 fs/xfs/libxfs/xfs_sb.c     | 3 +++
 fs/xfs/xfs_mount.h         | 2 ++
 3 files changed, 6 insertions(+)

Comments

Dave Chinner March 24, 2022, 9:37 p.m. UTC | #1 
On Mon, Mar 21, 2022 at 10:47:39AM +0530, Chandan Babu R wrote:
> XFS_SB_FEAT_INCOMPAT_NREXT64 incompat feature bit will be set on filesystems
> which support large per-inode extent counters. This commit defines the new
> incompat feature bit and the corresponding per-fs feature bit (along with
> inline functions to work on it).
> 
> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
> ---
>  fs/xfs/libxfs/xfs_format.h | 1 +
>  fs/xfs/libxfs/xfs_sb.c     | 3 +++
>  fs/xfs/xfs_mount.h         | 2 ++
>  3 files changed, 6 insertions(+)
> 
> diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
> index b5e9256d6d32..64ff0c310696 100644
> --- a/fs/xfs/libxfs/xfs_format.h
> +++ b/fs/xfs/libxfs/xfs_format.h
> @@ -372,6 +372,7 @@ xfs_sb_has_ro_compat_feature(
>  #define XFS_SB_FEAT_INCOMPAT_META_UUID	(1 << 2)	/* metadata UUID */
>  #define XFS_SB_FEAT_INCOMPAT_BIGTIME	(1 << 3)	/* large timestamps */
>  #define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4)	/* needs xfs_repair */
> +#define XFS_SB_FEAT_INCOMPAT_NREXT64	(1 << 5)	/* large extent counters */
>  #define XFS_SB_FEAT_INCOMPAT_ALL \
>  		(XFS_SB_FEAT_INCOMPAT_FTYPE|	\
>  		 XFS_SB_FEAT_INCOMPAT_SPINODES|	\
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index f4e84aa1d50a..bd632389ae92 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -124,6 +124,9 @@ xfs_sb_version_to_features(
>  		features |= XFS_FEAT_BIGTIME;
>  	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
>  		features |= XFS_FEAT_NEEDSREPAIR;
> +	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NREXT64)
> +		features |= XFS_FEAT_NREXT64;
> +

Shouldn't enabling the feature be the last patch in the series, once
all the infrastructure to support the feature is in place? i.e. if
someone does a bisect on a XFS_FEAT_NREXT64 enabled filesystem, they
can land in the middle of this series where the fs tries to use
XFS_FEAT_NREXT64 but the functionality is not complete.

Cheers,

Dave.
Darrick J. Wong March 24, 2022, 9:40 p.m. UTC | #2 
On Fri, Mar 25, 2022 at 08:37:19AM +1100, Dave Chinner wrote:
> On Mon, Mar 21, 2022 at 10:47:39AM +0530, Chandan Babu R wrote:
> > XFS_SB_FEAT_INCOMPAT_NREXT64 incompat feature bit will be set on filesystems
> > which support large per-inode extent counters. This commit defines the new
> > incompat feature bit and the corresponding per-fs feature bit (along with
> > inline functions to work on it).
> > 
> > Reviewed-by: Darrick J. Wong <djwong@kernel.org>
> > Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
> > ---
> >  fs/xfs/libxfs/xfs_format.h | 1 +
> >  fs/xfs/libxfs/xfs_sb.c     | 3 +++
> >  fs/xfs/xfs_mount.h         | 2 ++
> >  3 files changed, 6 insertions(+)
> > 
> > diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
> > index b5e9256d6d32..64ff0c310696 100644
> > --- a/fs/xfs/libxfs/xfs_format.h
> > +++ b/fs/xfs/libxfs/xfs_format.h
> > @@ -372,6 +372,7 @@ xfs_sb_has_ro_compat_feature(
> >  #define XFS_SB_FEAT_INCOMPAT_META_UUID	(1 << 2)	/* metadata UUID */
> >  #define XFS_SB_FEAT_INCOMPAT_BIGTIME	(1 << 3)	/* large timestamps */
> >  #define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4)	/* needs xfs_repair */
> > +#define XFS_SB_FEAT_INCOMPAT_NREXT64	(1 << 5)	/* large extent counters */
> >  #define XFS_SB_FEAT_INCOMPAT_ALL \
> >  		(XFS_SB_FEAT_INCOMPAT_FTYPE|	\
> >  		 XFS_SB_FEAT_INCOMPAT_SPINODES|	\
> > diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> > index f4e84aa1d50a..bd632389ae92 100644
> > --- a/fs/xfs/libxfs/xfs_sb.c
> > +++ b/fs/xfs/libxfs/xfs_sb.c
> > @@ -124,6 +124,9 @@ xfs_sb_version_to_features(
> >  		features |= XFS_FEAT_BIGTIME;
> >  	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
> >  		features |= XFS_FEAT_NEEDSREPAIR;
> > +	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NREXT64)
> > +		features |= XFS_FEAT_NREXT64;
> > +
> 
> Shouldn't enabling the feature be the last patch in the series, once
> all the infrastructure to support the feature is in place? i.e. if
> someone does a bisect on a XFS_FEAT_NREXT64 enabled filesystem, they
> can land in the middle of this series where the fs tries to use
> XFS_FEAT_NREXT64 but the functionality is not complete.

The last patch of the series does exactly that, by adding NREXT64 to
XFS_SB_FEAT_INCOMPAT_ALL.

--D

> 
> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> david@fromorbit.com
Chandan Babu R March 25, 2022, 6:01 a.m. UTC | #3 
On 25 Mar 2022 at 03:10, Darrick J. Wong wrote:
> On Fri, Mar 25, 2022 at 08:37:19AM +1100, Dave Chinner wrote:
>> On Mon, Mar 21, 2022 at 10:47:39AM +0530, Chandan Babu R wrote:
>> > XFS_SB_FEAT_INCOMPAT_NREXT64 incompat feature bit will be set on filesystems
>> > which support large per-inode extent counters. This commit defines the new
>> > incompat feature bit and the corresponding per-fs feature bit (along with
>> > inline functions to work on it).
>> > 
>> > Reviewed-by: Darrick J. Wong <djwong@kernel.org>
>> > Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
>> > ---
>> >  fs/xfs/libxfs/xfs_format.h | 1 +
>> >  fs/xfs/libxfs/xfs_sb.c     | 3 +++
>> >  fs/xfs/xfs_mount.h         | 2 ++
>> >  3 files changed, 6 insertions(+)
>> > 
>> > diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
>> > index b5e9256d6d32..64ff0c310696 100644
>> > --- a/fs/xfs/libxfs/xfs_format.h
>> > +++ b/fs/xfs/libxfs/xfs_format.h
>> > @@ -372,6 +372,7 @@ xfs_sb_has_ro_compat_feature(
>> >  #define XFS_SB_FEAT_INCOMPAT_META_UUID	(1 << 2)	/* metadata UUID */
>> >  #define XFS_SB_FEAT_INCOMPAT_BIGTIME	(1 << 3)	/* large timestamps */
>> >  #define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4)	/* needs xfs_repair */
>> > +#define XFS_SB_FEAT_INCOMPAT_NREXT64	(1 << 5)	/* large extent counters */
>> >  #define XFS_SB_FEAT_INCOMPAT_ALL \
>> >  		(XFS_SB_FEAT_INCOMPAT_FTYPE|	\
>> >  		 XFS_SB_FEAT_INCOMPAT_SPINODES|	\
>> > diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
>> > index f4e84aa1d50a..bd632389ae92 100644
>> > --- a/fs/xfs/libxfs/xfs_sb.c
>> > +++ b/fs/xfs/libxfs/xfs_sb.c
>> > @@ -124,6 +124,9 @@ xfs_sb_version_to_features(
>> >  		features |= XFS_FEAT_BIGTIME;
>> >  	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
>> >  		features |= XFS_FEAT_NEEDSREPAIR;
>> > +	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NREXT64)
>> > +		features |= XFS_FEAT_NREXT64;
>> > +
>> 
>> Shouldn't enabling the feature be the last patch in the series, once
>> all the infrastructure to support the feature is in place? i.e. if
>> someone does a bisect on a XFS_FEAT_NREXT64 enabled filesystem, they
>> can land in the middle of this series where the fs tries to use
>> XFS_FEAT_NREXT64 but the functionality is not complete.
>
> The last patch of the series does exactly that, by adding NREXT64 to
> XFS_SB_FEAT_INCOMPAT_ALL.
>

If a bisection lands on the current patch, the "Unknown incompat feature"
check would cause the filesystem mount to fail. Hence, I think the code is
safe since it does not allow partially implemented NREXT64 feature to be
executed.
diff mbox series

Patch

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index b5e9256d6d32..64ff0c310696 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -372,6 +372,7 @@  xfs_sb_has_ro_compat_feature(
 #define XFS_SB_FEAT_INCOMPAT_META_UUID	(1 << 2)	/* metadata UUID */
 #define XFS_SB_FEAT_INCOMPAT_BIGTIME	(1 << 3)	/* large timestamps */
 #define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4)	/* needs xfs_repair */
+#define XFS_SB_FEAT_INCOMPAT_NREXT64	(1 << 5)	/* large extent counters */
 #define XFS_SB_FEAT_INCOMPAT_ALL \
 		(XFS_SB_FEAT_INCOMPAT_FTYPE|	\
 		 XFS_SB_FEAT_INCOMPAT_SPINODES|	\
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index f4e84aa1d50a..bd632389ae92 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -124,6 +124,9 @@  xfs_sb_version_to_features(
 		features |= XFS_FEAT_BIGTIME;
 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
 		features |= XFS_FEAT_NEEDSREPAIR;
+	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NREXT64)
+		features |= XFS_FEAT_NREXT64;
+
 	return features;
 }
 
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 00720a02e761..a008e8f983d8 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -276,6 +276,7 @@  typedef struct xfs_mount {
 #define XFS_FEAT_INOBTCNT	(1ULL << 23)	/* inobt block counts */
 #define XFS_FEAT_BIGTIME	(1ULL << 24)	/* large timestamps */
 #define XFS_FEAT_NEEDSREPAIR	(1ULL << 25)	/* needs xfs_repair */
+#define XFS_FEAT_NREXT64	(1ULL << 26)	/* large extent counters */
 
 /* Mount features */
 #define XFS_FEAT_NOATTR2	(1ULL << 48)	/* disable attr2 creation */
@@ -338,6 +339,7 @@  __XFS_HAS_FEAT(realtime, REALTIME)
 __XFS_HAS_FEAT(inobtcounts, INOBTCNT)
 __XFS_HAS_FEAT(bigtime, BIGTIME)
 __XFS_HAS_FEAT(needsrepair, NEEDSREPAIR)
+__XFS_HAS_FEAT(large_extent_counts, NREXT64)
 
 /*
  * Mount features