[PATCH AUTOSEL 5.10 9/9] ext4: enable the lazy init thread when remounting read/write

[Sasha Levin]

From: Theodore Ts'o <tytso@xxxxxxx>

[ Upstream commit eb1f822c76beeaa76ab8b6737ab9dc9f9798408c ]

In commit a44be64bbecb ("ext4: don't clear SB_RDONLY when remounting
r/w until quota is re-enabled") we defer clearing tyhe SB_RDONLY flag
in struct super.  However, we didn't defer when we checked sb_rdonly()
to determine the lazy itable init thread should be enabled, with the
next result that the lazy inode table initialization would not be
properly started.  This can cause generic/231 to fail in ext4's
nojournal mode.

Fix this by moving when we decide to start or stop the lazy itable
init thread to after we clear the SB_RDONLY flag when we are
remounting the file system read/write.

Fixes a44be64bbecb ("ext4: don't clear SB_RDONLY when remounting r/w until...")

Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Link: https://lore.kernel.org/r/20230527035729.1001605-1-tytso@xxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/ext4/super.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d89750e90bc4b..f72896384dbc9 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -6005,18 +6005,6 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 		}
 	}
 
-	/*
-	 * Reinitialize lazy itable initialization thread based on
-	 * current settings
-	 */
-	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
-		ext4_unregister_li_request(sb);
-	else {
-		ext4_group_t first_not_zeroed;
-		first_not_zeroed = ext4_has_uninit_itable(sb);
-		ext4_register_li_request(sb, first_not_zeroed);
-	}
-
 	/*
 	 * Handle creation of system zone data early because it can fail.
 	 * Releasing of existing data is done when we are sure remount will
@@ -6054,6 +6042,18 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 	if (enable_rw)
 		sb->s_flags &= ~SB_RDONLY;
 
+	/*
+	 * Reinitialize lazy itable initialization thread based on
+	 * current settings
+	 */
+	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
+		ext4_unregister_li_request(sb);
+	else {
+		ext4_group_t first_not_zeroed;
+		first_not_zeroed = ext4_has_uninit_itable(sb);
+		ext4_register_li_request(sb, first_not_zeroed);
+	}
+
 	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
 		ext4_stop_mmpd(sbi);
 
-- 
2.39.2