Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
"Some miscellaneous ext4 fixes for 4.18; one fix is for a regression
introduced in 4.18-rc4.

Sorry for the late-breaking pull. I was originally going to wait for
the next merge window, but Eric Whitney found a regression introduced
in 4.18-rc4, so I decided to push out the regression plus the other
fixes now. (The other commits have been baking in linux-next since
early July)"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix check to prevent initializing reserved inodes
ext4: check for allocation block validity with block group locked
ext4: fix inline data updates with checksums enabled
ext4: clear mmp sequence number when remounting read-only
ext4: fix false negatives *and* false positives in ext4_check_descriptors()

fs/ext4/balloc.c

···
 		return -EFSCORRUPTED;
 
 	ext4_lock_group(sb, block_group);
+	if (buffer_verified(bh))
+		goto verified;
 	if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
 			desc, bh))) {
 		ext4_unlock_group(sb, block_group);
···
 		return -EFSCORRUPTED;
 	}
 	set_buffer_verified(bh);
+verified:
 	ext4_unlock_group(sb, block_group);
 	return 0;
 }

fs/ext4/ialloc.c

···
 		return -EFSCORRUPTED;
 
 	ext4_lock_group(sb, block_group);
+	if (buffer_verified(bh))
+		goto verified;
 	blk = ext4_inode_bitmap(sb, desc);
 	if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
 					   EXT4_INODES_PER_GROUP(sb) / 8)) {
···
 		return -EFSBADCRC;
 	}
 	set_buffer_verified(bh);
+verified:
 	ext4_unlock_group(sb, block_group);
 	return 0;
 }
···
 			    ext4_itable_unused_count(sb, gdp)),
 			    sbi->s_inodes_per_block);
 
-	if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) {
+	if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group) ||
+	    ((group == 0) && ((EXT4_INODES_PER_GROUP(sb) -
+			       ext4_itable_unused_count(sb, gdp)) <
+			      EXT4_FIRST_INO(sb)))) {
 		ext4_error(sb, "Something is wrong with group %u: "
 			   "used itable blocks: %d; "
 			   "itable unused count: %u",

fs/ext4/inline.c

···
 		goto convert;
 	}
 
+	ret = ext4_journal_get_write_access(handle, iloc.bh);
+	if (ret)
+		goto out;
+
 	flags |= AOP_FLAG_NOFS;
 
 	page = grab_cache_page_write_begin(mapping, 0, flags);
···
 out_up_read:
 	up_read(&EXT4_I(inode)->xattr_sem);
 out:
-	if (handle)
+	if (handle && (ret != 1))
 		ext4_journal_stop(handle);
 	brelse(iloc.bh);
 	return ret;
···
 
 	ext4_write_unlock_xattr(inode, &no_expand);
 	brelse(iloc.bh);
+	mark_inode_dirty(inode);
 out:
 	return copied;
 }
···
 		goto out;
 	}
 
-
 	page = grab_cache_page_write_begin(mapping, 0, flags);
 	if (!page) {
 		ret = -ENOMEM;
···
 		if (ret < 0)
 			goto out_release_page;
 	}
+	ret = ext4_journal_get_write_access(handle, iloc.bh);
+	if (ret)
+		goto out_release_page;
 
 	up_read(&EXT4_I(inode)->xattr_sem);
 	*pagep = page;
···
 				  unsigned len, unsigned copied,
 				  struct page *page)
 {
-	int i_size_changed = 0;
 	int ret;
 
 	ret = ext4_write_inline_data_end(inode, pos, len, copied, page);
···
 	 * But it's important to update i_size while still holding page lock:
 	 * page writeout could otherwise come in and zero beyond i_size.
 	 */
-	if (pos+copied > inode->i_size) {
+	if (pos+copied > inode->i_size)
 		i_size_write(inode, pos+copied);
-		i_size_changed = 1;
-	}
 	unlock_page(page);
 	put_page(page);
 
···
 	 * ordering of page lock and transaction start for journaling
 	 * filesystems.
 	 */
-	if (i_size_changed)
-		mark_inode_dirty(inode);
+	mark_inode_dirty(inode);
 
 	return copied;
 }

fs/ext4/inode.c

···
 	loff_t old_size = inode->i_size;
 	int ret = 0, ret2;
 	int i_size_changed = 0;
+	int inline_data = ext4_has_inline_data(inode);
 
 	trace_ext4_write_end(inode, pos, len, copied);
-	if (ext4_has_inline_data(inode)) {
+	if (inline_data) {
 		ret = ext4_write_inline_data_end(inode, pos, len,
 						 copied, page);
 		if (ret < 0) {
···
 	 * ordering of page lock and transaction start for journaling
 	 * filesystems.
 	 */
-	if (i_size_changed)
+	if (i_size_changed || inline_data)
 		ext4_mark_inode_dirty(handle, inode);
 
 	if (pos + len > inode->i_size && ext4_can_truncate(inode))
···
 	int partial = 0;
 	unsigned from, to;
 	int size_changed = 0;
+	int inline_data = ext4_has_inline_data(inode);
 
 	trace_ext4_journalled_write_end(inode, pos, len, copied);
 	from = pos & (PAGE_SIZE - 1);
···
 
 	BUG_ON(!ext4_handle_valid(handle));
 
-	if (ext4_has_inline_data(inode)) {
+	if (inline_data) {
 		ret = ext4_write_inline_data_end(inode, pos, len,
 						 copied, page);
 		if (ret < 0) {
···
 	if (old_size < pos)
 		pagecache_isize_extended(inode, old_size, pos);
 
-	if (size_changed) {
+	if (size_changed || inline_data) {
 		ret2 = ext4_mark_inode_dirty(handle, inode);
 		if (!ret)
 			ret = ret2;
···
 	}
 
 	if (inline_data) {
-		BUFFER_TRACE(inode_bh, "get write access");
-		ret = ext4_journal_get_write_access(handle, inode_bh);
-
-		err = ext4_handle_dirty_metadata(handle, inode, inode_bh);
-
+		ret = ext4_mark_inode_dirty(handle, inode);
 	} else {
 		ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
 					     do_journal_get_write_access);

fs/ext4/mmp.c

···
 			goto exit_thread;
 		}
 
-		if (sb_rdonly(sb)) {
-			ext4_warning(sb, "kmmpd being stopped since filesystem "
-				     "has been remounted as readonly.");
-			goto exit_thread;
-		}
+		if (sb_rdonly(sb))
+			break;
 
 		diff = jiffies - last_update_time;
 		if (diff < mmp_update_interval * HZ)

fs/ext4/super.c

···
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
 	ext4_fsblk_t last_block;
-	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0) + 1;
+	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
 	ext4_fsblk_t block_bitmap;
 	ext4_fsblk_t inode_bitmap;
 	ext4_fsblk_t inode_table;
···
 		if (!gdp)
 			continue;
 
-		if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))
-			continue;
-		if (group != 0)
+		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
 			break;
-		ext4_error(sb, "Inode table for bg 0 marked as "
-			   "needing zeroing");
-		if (sb_rdonly(sb))
-			return ngroups;
 	}
 
 	return group;
···
 			goto failed_mount2;
 		}
 	}
+	sbi->s_gdb_count = db_count;
 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
 		ret = -EFSCORRUPTED;
 		goto failed_mount2;
 	}
-
-	sbi->s_gdb_count = db_count;
 
 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
 
···
 
 			if (sbi->s_journal)
 				ext4_mark_recovery_complete(sb, es);
+			if (sbi->s_mmp_tsk)
+				kthread_stop(sbi->s_mmp_tsk);
 		} else {
 			/* Make sure we can mount this feature set readwrite */
 			if (ext4_has_feature_readonly(sb) ||