[PATCH 04/14] btrfs: use vfs_utimes to update file timestamps

Christoph Hellwig
2025-11-14T06:27:18Z

Btrfs updates the device node timestamps for block device special files
when it stop using the device.

Commit 8f96a5bfa150 ("btrfs: update the bdev time directly when closing")
switch that update from the correct layering to directly call the
low-level helper on the bdev inode. This is wrong and got fixed in
commit 54fde91f52f5 ("btrfs: update device path inode time instead of
bd_inode") by updating the file system inode instead of the bdev inode,
but this kept the incorrect bypassing of the VFS interfaces and file
system ->update_times method. Fix this by using the propet vfs_utimes
interface.

Fixes: 8f96a5bfa150 ("btrfs: update the bdev time directly when closing")
Fixes: 54fde91f52f5 ("btrfs: update device path inode time instead of bd_inode")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/btrfs/volumes.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 2bec544d8ba3..259e8b0496df 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2002,14 +2002,11 @@ static int btrfs_add_dev_item(struct btrfs_trans_handle *trans,
static void update_dev_time(const char *device_path)
{
struct path path;
- int ret;

- ret = kern_path(device_path, LOOKUP_FOLLOW, &path);
- if (ret)
- return;
-
- inode_update_time(d_inode(path.dentry), S_MTIME | S_CTIME | S_VERSION);
- path_put(&path);
+ if (!kern_path(device_path, LOOKUP_FOLLOW, &path)) {
+ vfs_utimes(&path, NULL);
+ path_put(&path);
+ }
}

static int btrfs_rm_dev_item(struct btrfs_trans_handle *trans,
--
2.47.3