Re: [PATCH v3 05/19] VFS: introduce d_alloc_noblock()
Al Viro <[email protected]>
| Newsgroups | org.kernel.vger.linux-unionfs,org.kernel.vger.linux-efi,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-nfs |
|---|---|
| Message-ID | <20260428022245.GU3518998@ZenIV> |
On Mon, Apr 27, 2026 at 02:01:23PM +1000, NeilBrown wrote: > From: NeilBrown <[email protected]> > > Several filesystems use the results of readdir to prime the dcache. > These filesystems use d_alloc_parallel() which can block if there is a > concurrent lookup. Blocking in that case is pointless as the lookup > will add info to the dcache and there is no value in the readdir waiting > to see if it should add the info too. ... except that there is - large part of the reasons for that in the original user (procfs) is that we want getdents() + open() + fstat() + compare ->st_ino from fstat() with ->d_ino from getdents() to work, even if you race with lookup from another process coming in the middle of your getdents(). What are your plans in that area?