Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
 "Ext4 bug fixes.

  We also reserved code points for encryption and read-only images (for
  which the implementation is mostly just the reserved code point for a
  read-only feature :-)"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix indirect punch hole corruption
  ext4: ignore journal checksum on remount; don't fail
  ext4: remove duplicate remount check for JOURNAL_CHECKSUM change
  ext4: fix mmap data corruption in nodelalloc mode when blocksize < pagesize
  ext4: support read-only images
  ext4: change to use setup_timer() instead of init_timer()
  ext4: reserve codepoints used by the ext4 encryption feature
  jbd2: complain about descriptor block checksum errors

1 files changed, 13 insertions, 18 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1adac6868e6f..e061e66c8280 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2779,6 +2779,12 @@ static int ext4_feature_set_ok(struct super_block *sb, int readonly)
         if (readonly)
                 return 1;
 
+        if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_READONLY)) {
+                ext4_msg(sb, KERN_INFO, "filesystem is read-only");
+                sb->s_flags |= MS_RDONLY;
+                return 1;
+        }
+
         /* Check that feature set is OK for a read-write mount */
         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
@@ -3936,9 +3942,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
         spin_lock_init(&sbi->s_next_gen_lock);
 
-        init_timer(&sbi->s_err_report);
-        sbi->s_err_report.function = print_daily_error_info;
-        sbi->s_err_report.data = (unsigned long) sb;
+        setup_timer(&sbi->s_err_report, print_daily_error_info,
+                (unsigned long) sb);
 
         /* Register extent status tree shrinker */
         if (ext4_es_register_shrinker(sbi))
@@ -4866,9 +4871,6 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
 
-        /*
-         * Allow the "check" option to be passed as a remount option.
-         */
         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
                 err = -EINVAL;
                 goto restore_opts;
@@ -4877,17 +4879,8 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
             test_opt(sb, JOURNAL_CHECKSUM)) {
                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
-                         "during remount not supported");
-                err = -EINVAL;
-                goto restore_opts;
-        }
-
-        if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
-            test_opt(sb, JOURNAL_CHECKSUM)) {
-                ext4_msg(sb, KERN_ERR, "changing journal_checksum "
-                         "during remount not supported");
-                err = -EINVAL;
-                goto restore_opts;
+                         "during remount not supported; ignoring");
+                sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
         }
 
         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
@@ -4963,7 +4956,9 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
                                 ext4_mark_recovery_complete(sb, es);
                 } else {
                         /* Make sure we can mount this feature set readwrite */
-                        if (!ext4_feature_set_ok(sb, 0)) {
+                        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+                                        EXT4_FEATURE_RO_COMPAT_READONLY) ||
+                            !ext4_feature_set_ok(sb, 0)) {
                                 err = -EROFS;
                                 goto restore_opts;
                         }