From: Christoph Hellwig <hch@lst.de>
Date: Mon, 14 Apr 2025 05:35:48 +0000 (+0200)
Subject: xfs: reduce metafile reservations
X-Git-Tag: v6.15.0~40
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=433f46a5b7d3f6fad28518044486bbdd4b46aad9;p=thirdparty%2Fxfsprogs-dev.git

xfs: reduce metafile reservations

Source kernel commit: 272e20bb24dc895375ccc18a82596a7259b5a652

There is no point in reserving more space than actually available
on the data device for the worst case scenario that is unlikely to
happen.  Reserve at most 1/4th of the data device blocks, which is
still a heuristic.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/libxfs/xfs_metafile.c b/libxfs/xfs_metafile.c
index 1216a0e5..6ded87d0 100644
--- a/libxfs/xfs_metafile.c
+++ b/libxfs/xfs_metafile.c
@@ -258,6 +258,7 @@ xfs_metafile_resv_init(
 	struct xfs_rtgroup	*rtg = NULL;
 	xfs_filblks_t		used = 0, target = 0;
 	xfs_filblks_t		hidden_space;
+	xfs_rfsblock_t		dblocks_avail = mp->m_sb.sb_dblocks / 4;
 	int			error = 0;
 
 	if (!xfs_has_metadir(mp))
@@ -295,6 +296,8 @@ xfs_metafile_resv_init(
 	 */
 	if (used > target)
 		target = used;
+	else if (target > dblocks_avail)
+		target = dblocks_avail;
 	hidden_space = target - used;
 
 	error = xfs_dec_fdblocks(mp, hidden_space, true);