On Mon, Feb 17, 2025 at 04:30:02PM +1100, NeilBrown wrote: > Here is a second attempt at this change. Guided by Al I have handled > other file systems which don't return a hashed positive dentry on success. > > It is not always possible to provide a reliable answer. One example is > that cifs might find, after successfully creating a directory, that the > name now leads to a non-directory (due to a race with another client). > So callers of vfs_mkdir() need to cope with successful mkdir but no > usable dentry. There is nothing they can do to recover and must > continue gracefully. This failre mode is detected by the returned > dentry being unhashed. > > ORIGINAL DESCRIPTION - updated to reflect changes. > > This is a small set of patches which are needed before we can make the > locking on directory operations more fine grained. I think they are > useful even if we don't go that direction. > > Some callers of vfs_mkdir() need to operate on the resulting directory > but cannot be guaranteed that the dentry will be hashed and positive on > success - another dentry might have been used. > > This patch changes ->mkdir to return a dentry, changes several Thanks for doing that. > filesystems to return the correct dentry, and changes vfs_mkdir() to > return that dentry, only performing a lookup as a last resort. > > I have not Cc: the developers of all the individual filesystems NFS. I > or kernel-test-robot have build-tested all the changes. If anyone sees > this on fs-devel and wants to provide a pre-emptive ack I will collect > those and avoid further posting for those fs. Once I'll merge this into async.dir it'll show up in fs-next which means it'll get additional xfstest testing.
