From d9a85a8d82d002371eb2fdbd2c74cfdf491d394d Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Wed, 1 May 2024 11:41:12 -0700 Subject: [PATCH] xfs: short circuit xfs_growfs_data_private() if delta is zero [ Upstream commit 84712492e6dab803bf595fb8494d11098b74a652 ] Although xfs_growfs_data() doesn't call xfs_growfs_data_private() if in->newblocks == mp->m_sb.sb_dblocks, xfs_growfs_data_private() further massages the new block count so that we don't i.e. try to create a too-small new AG. This may lead to a delta of "0" in xfs_growfs_data_private(), so we end up in the shrink case and emit the EXPERIMENTAL warning even if we're not changing anything at all. Fix this by returning straightaway if the block delta is zero. (nb: in older kernels, the result of entering the shrink case with delta == 0 may actually let an -ENOSPC escape to userspace, which is confusing for users.) Fixes: fb2fc1720185 ("xfs: support shrinking unused space in the last AG") Signed-off-by: Eric Sandeen Reviewed-by: "Darrick J. Wong" Signed-off-by: Chandan Babu R Signed-off-by: Leah Rumancik Acked-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman --- fs/xfs/xfs_fsops.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index 13851c0d640b..332da0d7b85c 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -129,6 +129,10 @@ xfs_growfs_data_private( if (delta < 0 && nagcount < 2) return -EINVAL; + /* No work to do */ + if (delta == 0) + return 0; + oagcount = mp->m_sb.sb_agcount; /* allocate the new per-ag structures */ if (nagcount > oagcount) {