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.
Thanks,
John
