On Fri, Feb 14, 2025 at 04:16:40PM +1100, NeilBrown wrote: > 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 operation 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 NFS in particular > to return the correct dentry (I believe it is the only filesystem to > possibly not use the given dentry), and changes vfs_mkdir() to return > that dentry, removing the look that a few callers currently need. > > I have not Cc: the developers of all the individual filesystems - only > NFS. I have build-tested all the changes except hostfs. I can email > them explicitly if/when this is otherwise acceptable. 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. 1) please, don't sprinkle the PTR_ERR_OR_ZERO() shite all over the place. Almost always the same thing can be done without it and it ends up being cleaner. Seriously. 2) I suspect that having method instances return NULL for "just use the argument" would would be harder to fuck up; basically, the same as for ->lookup() instances. I'll try to tweak it and see what falls out... 3) I'm pretty sure that NFS is *not* the only filesystem that returns unhashed negative in some success cases; will need to go over the instances to verify that, though.
