From 5e4d0eba1ccaf19f93222abdeda5a368be141785 Mon Sep 17 00:00:00 2001
From: Xin Yin <yinxin.x@bytedance.com>
Date: Tue, 21 Dec 2021 10:28:39 +0800
Subject: [PATCH] ext4: fix fast commit may miss tracking range for
 FALLOC_FL_ZERO_RANGE
Git-commit: 5e4d0eba1ccaf19f93222abdeda5a368be141785
Patch-mainline: v5.17-rc1
References: bsc#1202757

when call falloc with FALLOC_FL_ZERO_RANGE, to set an range to unwritten,
which has been already initialized. If the range is align to blocksize,
fast commit will not track range for this change.

Also track range for unwritten range in ext4_map_blocks().

Signed-off-by: Xin Yin <yinxin.x@bytedance.com>
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20211221022839.374606-1-yinxin.x@bytedance.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Acked-by: Jan Kara <jack@suse.cz>

---
 fs/ext4/extents.c | 2 --
 fs/ext4/inode.c   | 7 ++++---
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 38111ea18ae1..c3e76a5de661 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4647,8 +4647,6 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 	ret = ext4_mark_inode_dirty(handle, inode);
 	if (unlikely(ret))
 		goto out_handle;
-	ext4_fc_track_range(handle, inode, offset >> inode->i_sb->s_blocksize_bits,
-			(offset + len - 1) >> inode->i_sb->s_blocksize_bits);
 	/* Zero out partial block at the edges of the range */
 	ret = ext4_zero_partial_blocks(handle, inode, offset, len);
 	if (ret >= 0)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 82f555d26980..4895909de21b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -741,10 +741,11 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 			if (ret)
 				return ret;
 		}
-		ext4_fc_track_range(handle, inode, map->m_lblk,
-			    map->m_lblk + map->m_len - 1);
 	}
-
+	if (retval > 0 && (map->m_flags & EXT4_MAP_UNWRITTEN ||
+				map->m_flags & EXT4_MAP_MAPPED))
+		ext4_fc_track_range(handle, inode, map->m_lblk,
+					map->m_lblk + map->m_len - 1);
 	if (retval < 0)
 		ext_debug(inode, "failed with err %d\n", retval);
 	return retval;
-- 
2.35.3