From 34389616a963480b20ea7f997533380ae3946fba Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 11 Sep 2023 08:39:09 -0700 Subject: xfs: require a relatively recent V5 filesystem for LARP mode While reviewing the FIEXCHANGE code in XFS, I realized that the function that enables logged xattrs doesn't actually check that the superblock has a LOG_INCOMPAT feature bit field. Add a check to refuse the operation if we don't have a V5 filesystem... ...but on second though, let's require either reflink or rmap so that we only have to deal with LARP mode on relatively /modern/ kernel. 4.14 is about as far back as I feel like going. Seeing as LARP is a debugging-only option anyway, this isn't likely to affect any real users. Fixes: d9c61ccb3b09 ("xfs: move xfs_attr_use_log_assist out of xfs_log.c") Really-Fixes: f3f36c893f26 ("xfs: Add xfs_attr_set_deferred and xfs_attr_remove_deferred") Signed-off-by: Darrick J. Wong Reviewed-by: Bill O'Donnell --- fs/xfs/xfs_xattr.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'fs/xfs') diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c index 43e5c219aaed..a3975f325f4e 100644 --- a/fs/xfs/xfs_xattr.c +++ b/fs/xfs/xfs_xattr.c @@ -46,6 +46,17 @@ xfs_attr_grab_log_assist( if (xfs_sb_version_haslogxattrs(&mp->m_sb)) return 0; + /* + * Check if the filesystem featureset is new enough to set this log + * incompat feature bit. Strictly speaking, the minimum requirement is + * a V5 filesystem for the superblock field, but we'll require rmap + * or reflink to avoid having to deal with really old kernels. + */ + if (!xfs_has_reflink(mp) && !xfs_has_rmapbt(mp)) { + error = -EOPNOTSUPP; + goto drop_incompat; + } + /* Enable log-assisted xattrs. */ error = xfs_add_incompat_log_feature(mp, XFS_SB_FEAT_INCOMPAT_LOG_XATTRS); -- cgit v1.2.3