On Sun, Feb 28, 2021 at 08:57:20AM -0500, Drew DeVault wrote: > On Sat Feb 27, 2021 at 11:03 PM EST, Matthew Wilcox wrote: > > > 1. Program A creates a directory > > > 2. Program A is pre-empted > > > 3. Program B deletes the directory > > > 4. Program A creates a file in that directory > > > 5. RIP > > > > umm ... program B deletes the directory. program A opens it in order to > > use openat(). program A gets ENOENT and exits, confused. that's the > > race you're removing here -- and it seems fairly insignificant to me. > > Yes, that is the race being eliminated here. Instead of this, program A > has an fd which holds a reference to the directory, so it just works. A > race is a race. It's an oversight in the API. Step 4 still fails either way, because you can't create a file in an unlinked directory, even if you hold a reference to that directory. What's the behavior change at step 4 that you're hoping for? --b.
