xfs: fix log recovery when unknown rocompat bits are set

[ Upstream commit 74ad4693b6473950e971b3dc525b5ee7570e05d0 ]

Log recovery has always run on read only mounts, even where the primary
superblock advertises unknown rocompat bits.  Due to a misunderstanding
between Eric and Darrick back in 2018, we accidentally changed the
superblock write verifier to shutdown the fs over that exact scenario.
As a result, the log cleaning that occurs at the end of the mounting
process fails if there are unknown rocompat bits set.

As we now allow writing of the superblock if there are unknown rocompat
bits set on a RO mount, we no longer want to turn off RO state to allow
log recovery to succeed on a RO mount.  Hence we also remove all the
(now unnecessary) RO state toggling from the log recovery path.

Fixes: 9e037cb7972f ("xfs: check for unknown v5 feature bits in superblock write verifier"
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Stable-dep-of: 652f03db897b ("xfs: remove unknown compat feature check in superblock write validation")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 26dd9ceb44b42b7ba14d001fc4e18a7d22b4b0be..f867da8128ca64686080242df093d164ad0914a8 100644 (file)
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -263,7 +263,8 @@ xfs_validate_sb_write(
                return -EFSCORRUPTED;
        }
 
-       if (xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
+       if (!xfs_is_readonly(mp) &&
+           xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
                xfs_alert(mp,
 "Corruption detected in superblock read-only compatible features (0x%x)!",
                        (sbp->sb_features_ro_compat &

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index eba295f666acc4ec870f22282e279f4de9cdddd9..be2f714d1553af06738b92a4fff4505cf8f69ab4 100644 (file)
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -707,15 +707,7 @@ xfs_log_mount(
         * just worked.
         */
        if (!xfs_has_norecovery(mp)) {
-               /*
-                * log recovery ignores readonly state and so we need to clear
-                * mount-based read only state so it can write to disk.
-                */
-               bool    readonly = test_and_clear_bit(XFS_OPSTATE_READONLY,
-                                               &mp->m_opstate);
                error = xlog_recover(log);
-               if (readonly)
-                       set_bit(XFS_OPSTATE_READONLY, &mp->m_opstate);
                if (error) {
                        xfs_warn(mp, "log mount/recovery failed: error %d",
                                error);
@@ -764,7 +756,6 @@ xfs_log_mount_finish(
        struct xfs_mount        *mp)
 {
        struct xlog             *log = mp->m_log;
-       bool                    readonly;
        int                     error = 0;
 
        if (xfs_has_norecovery(mp)) {
@@ -772,12 +763,6 @@ xfs_log_mount_finish(
                return 0;
        }
 
-       /*
-        * log recovery ignores readonly state and so we need to clear
-        * mount-based read only state so it can write to disk.
-        */
-       readonly = test_and_clear_bit(XFS_OPSTATE_READONLY, &mp->m_opstate);
-
        /*
         * During the second phase of log recovery, we need iget and
         * iput to behave like they do for an active filesystem.
@@ -828,8 +813,6 @@ xfs_log_mount_finish(
        xfs_buftarg_drain(mp->m_ddev_targp);
 
        clear_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);
-       if (readonly)
-               set_bit(XFS_OPSTATE_READONLY, &mp->m_opstate);
 
        /* Make sure the log is dead if we're returning failure. */
        ASSERT(!error || xlog_is_shutdown(log));