2 files changed, 17 insertions, 2 deletions

diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index fc938ebbddec..a8bc47f75fa0 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -98,8 +98,13 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 
         trace_ext4_sync_file_enter(file, datasync);
 
-        if (inode->i_sb->s_flags & MS_RDONLY)
+        if (inode->i_sb->s_flags & MS_RDONLY) {
+                /* Make sure that we read updated s_mount_flags value */
+                smp_rmb();
+                if (EXT4_SB(inode->i_sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
+                        ret = -EROFS;
                 goto out;
+        }
 
         if (!journal) {
                 ret = generic_file_fsync(file, start, end, datasync);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 0f77c2e4b888..eb52a7be1fc1 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -399,6 +399,11 @@ static void ext4_handle_error(struct super_block *sb)
         }
         if (test_opt(sb, ERRORS_RO)) {
                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
+                /*
+                 * Make sure updated value of ->s_mount_flags will be visible
+                 * before ->s_flags update
+                 */
+                smp_wmb();
                 sb->s_flags |= MS_RDONLY;
         }
         if (test_opt(sb, ERRORS_PANIC))
@@ -571,8 +576,13 @@ void __ext4_abort(struct super_block *sb, const char *function,
 
         if ((sb->s_flags & MS_RDONLY) == 0) {
                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
-                sb->s_flags |= MS_RDONLY;
                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
+                /*
+                 * Make sure updated value of ->s_mount_flags will be visible
+                 * before ->s_flags update
+                 */
+                smp_wmb();
+                sb->s_flags |= MS_RDONLY;
                 if (EXT4_SB(sb)->s_journal)
                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
                 save_error_info(sb, function, line);