[PATCH 4.14 24/27] ext4: use ext4_write_inode() when fsyncing w/o a journal

From: Greg Kroah-Hartman
Date: Tue Jan 15 2019 - 11:40:47 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Theodore Ts'o <tytso@xxxxxxx>

commit ad211f3e94b314a910d4af03178a0b52a7d1ee0a upstream.

In no-journal mode, we previously used __generic_file_fsync() in
no-journal mode. This triggers a lockdep warning, and in addition,
it's not safe to depend on the inode writeback mechanism in the case
ext4. We can solve both problems by calling ext4_write_inode()
directly.

Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Cc: stable@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/ext4/fsync.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -116,8 +116,16 @@ int ext4_sync_file(struct file *file, lo
goto out;
}

+ ret = file_write_and_wait_range(file, start, end);
+ if (ret)
+ return ret;
+
if (!journal) {
- ret = __generic_file_fsync(file, start, end, datasync);
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL
+ };
+
+ ret = ext4_write_inode(inode, &wbc);
if (!ret)
ret = ext4_sync_parent(inode);
if (test_opt(inode->i_sb, BARRIER))
@@ -125,9 +133,6 @@ int ext4_sync_file(struct file *file, lo
goto out;
}

- ret = file_write_and_wait_range(file, start, end);
- if (ret)
- return ret;
/*
* data=writeback,ordered:
* The caller's filemap_fdatawrite()/wait will sync the data.