While adding shared direct IO write locks to fuse Miklos noticed that file_remove_privs() needs an exclusive lock. I then noticed that btrfs actually has the same issue as I had in my patch, it was calling into that function with a shared lock. This series adds a new exported function file_needs_remove_privs(), which used by the follow up btrfs patch and will be used by the DIO code path in fuse as well. If that function returns any mask the shared lock needs to be dropped and replaced by the exclusive variant. Note: Compilation tested only. v2: Already check for IS_NOSEC in btrfs_direct_write before the first lock is taken. Slight modification to make the code easier to read (boolean pointer is passed to btrfs_write_check, instead of flags). Cc: Miklos Szeredi <miklos@xxxxxxxxxx> Cc: Dharmendra Singh <dsingh@xxxxxxx> Cc: Josef Bacik <josef@xxxxxxxxxxxxxx> Cc: linux-btrfs@xxxxxxxxxxxxxxx Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Christian Brauner <brauner@xxxxxxxxxx> Cc: linux-fsdevel@xxxxxxxxxxxxxxx Bernd Schubert (2): fs: Add and export file_needs_remove_privs btrfs: file_remove_privs needs an exclusive lock fs/btrfs/file.c | 37 +++++++++++++++++++++++++++++-------- fs/inode.c | 8 ++++++++ include/linux/fs.h | 1 + 3 files changed, 38 insertions(+), 8 deletions(-) -- 2.39.2
