On Wed, Jun 12, 2024 at 08:43:42AM -0700, Darrick J. Wong wrote: > On Wed, Jun 12, 2024 at 07:55:31AM +0100, John Garry wrote: > > On 12/06/2024 03:10, Long Li wrote: > > > On Mon, Apr 29, 2024 at 05:47:33PM +0000, John Garry wrote: > > > > From: "Darrick J. Wong"<djwong@xxxxxxxxxx> > > > > > > > > Add a new inode flag to require that all file data extent mappings must > > > > be aligned (both the file offset range and the allocated space itself) > > > > to the extent size hint. Having a separate COW extent size hint is no > > > > longer allowed. > > > > > > > > The goal here is to enable sysadmins and users to mandate that all space > > > > mappings in a file must have a startoff/blockcount that are aligned to > > > > (say) a 2MB alignment and that the startblock/blockcount will follow the > > > > same alignment. > > > > > > > > jpg: Enforce extsize is a power-of-2 and aligned with afgsize + stripe > > > > alignment for forcealign > > > > Signed-off-by: "Darrick J. Wong"<djwong@xxxxxxxxxx> > > > > Co-developed-by: John Garry<john.g.garry@xxxxxxxxxx> > > > > Signed-off-by: John Garry<john.g.garry@xxxxxxxxxx> > > > > --- > > > > fs/xfs/libxfs/xfs_format.h | 6 ++++- > > > > fs/xfs/libxfs/xfs_inode_buf.c | 50 +++++++++++++++++++++++++++++++++++ > > > > fs/xfs/libxfs/xfs_inode_buf.h | 3 +++ > > > > fs/xfs/libxfs/xfs_sb.c | 2 ++ > > > > fs/xfs/xfs_inode.c | 12 +++++++++ > > > > fs/xfs/xfs_inode.h | 2 +- > > > > fs/xfs/xfs_ioctl.c | 34 +++++++++++++++++++++++- > > > > fs/xfs/xfs_mount.h | 2 ++ > > > > fs/xfs/xfs_super.c | 4 +++ > > > > include/uapi/linux/fs.h | 2 ++ > > > > 10 files changed, 114 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h > > > > index 2b2f9050fbfb..4dd295b047f8 100644 > > > > --- a/fs/xfs/libxfs/xfs_format.h > > > > +++ b/fs/xfs/libxfs/xfs_format.h > > > > @@ -353,6 +353,7 @@ xfs_sb_has_compat_feature( > > > > #define XFS_SB_FEAT_RO_COMPAT_RMAPBT (1 << 1) /* reverse map btree */ > > > > #define XFS_SB_FEAT_RO_COMPAT_REFLINK (1 << 2) /* reflinked files */ > > > > #define XFS_SB_FEAT_RO_COMPAT_INOBTCNT (1 << 3) /* inobt block counts */ > > > > +#define XFS_SB_FEAT_RO_COMPAT_FORCEALIGN (1 << 30) /* aligned file data extents */ > > > Hi, John > > > > > > You know I've been using and testing your atomic writes patch series recently, > > > and I'm particularly interested in the changes to the on-disk format. I noticed > > > that XFS_SB_FEAT_RO_COMPAT_FORCEALIGN uses bit 30 instead of bit 4, which would > > > be the next available bit in sequence. > > > > > > I'm wondering if using bit 30 is just a temporary solution to avoid conflicts, > > > and if the plan is to eventually use bits sequentially, for example, using bit 4? > > > I'm looking forward to your explanation. > > > > I really don't know. I'm looking through the history and it has been like > > that this the start of my source control records. > > > > Maybe it was a copy-and-paste error from XFS_FEAT_FORCEALIGN, whose value > > has changed since. > > > > Anyway, I'll ask a bit more internally, and I'll look to change to (1 << 4) > > if ok. > > I tend to use upper bits for ondisk features that are still under > development so that (a) there won't be collisions with other features > getting merged and (b) after the feature I'm working on gets merged, any > old fs images in my zoo will no longer mount. > I get it, thank you very much for your response.
