From: Darrick J. Wong <djwong@kernel.org>
Date: Fri, 17 Feb 2023 23:45:51 +0000 (-0800)
Subject: xfs: restore old agirotor behavior
X-Git-Tag: libxfs-sync-6.3_2023-04-05~5
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=cd1faa10b9c99de893e9738323810fc978941648;p=xfsprogs-dev.git

xfs: restore old agirotor behavior

Source kernel commit: 127c6534882090d848652a723b436eaef90fce53

Prior to the removal of xfs_ialloc_next_ag, we would increment the agi
rotor and return the *old* value.  atomic_inc_return returns the new
value, which causes mkfs to allocate the root directory in AG 1.  Put
back the old behavior (at least for mkfs) by subtracting 1 here.

Fixes: 20a5eab49d35 ("xfs: convert xfs_ialloc_next_ag() to an atomic")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---

diff --git a/libxfs/xfs_ialloc.c b/libxfs/xfs_ialloc.c
index 791880a3..50ffa820 100644
--- a/libxfs/xfs_ialloc.c
+++ b/libxfs/xfs_ialloc.c
@@ -1724,7 +1724,8 @@ xfs_dialloc(
 	 * an AG has enough space for file creation.
 	 */
 	if (S_ISDIR(mode))
-		start_agno = atomic_inc_return(&mp->m_agirotor) % mp->m_maxagi;
+		start_agno = (atomic_inc_return(&mp->m_agirotor) - 1) %
+				mp->m_maxagi;
 	else {
 		start_agno = XFS_INO_TO_AGNO(mp, parent);
 		if (start_agno >= mp->m_maxagi)