fs: lift the FMODE_NOCMTIME check into file_update_time_flags

FMODE_NOCMTIME used to be just a hack for the legacy XFS handle-based
"invisible I/O", but commit e5e9b24ab8fa ("nfsd: freeze c/mtime updates
with outstanding WRITE_ATTRS delegation") started using it from
generic callers.

I'm not sure other file systems are actually read for this in general,
so the above commit should get a closer look, but for it to make any
sense, file_update_time needs to respect the flag.

Lift the check from file_modified_flags to file_update_time so that
users of file_update_time inherit the behavior and so that all the
checks are done in one place.

Fixes: e5e9b24ab8fa ("nfsd: freeze c/mtime updates with outstanding WRITE_ATTRS delegation")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20251120064859.2911749-3-hch@lst.de
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/inode.c b/fs/inode.c
index 4884ffa931e7bc3f96a2a1091f33b8f31f279594..24dab63844dbefeb0be1970a4e2b15419649f694 100644 (file)
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2320,6 +2320,8 @@ static int file_update_time_flags(struct file *file, unsigned int flags)
        /* First try to exhaust all avenues to not sync */
        if (IS_NOCMTIME(inode))
                return 0;
+       if (unlikely(file->f_mode & FMODE_NOCMTIME))
+               return 0;
 
        now = current_time(inode);
 
@@ -2391,8 +2393,6 @@ static int file_modified_flags(struct file *file, int flags)
        ret = file_remove_privs_flags(file, flags);
        if (ret)
                return ret;
-       if (unlikely(file->f_mode & FMODE_NOCMTIME))
-               return 0;
        return file_update_time_flags(file, flags);
 }