Messages in this thread | | | Date | Tue, 11 Dec 2018 10:45:53 -0800 | From | Matthew Wilcox <> | Subject | Re: [PATCH] aio: Convert ioctx_table to XArray |
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On Tue, Dec 11, 2018 at 11:41:55AM -0700, Jens Axboe wrote: > On Wed, Nov 28, 2018 at 11:35 AM Matthew Wilcox <willy@infradead.org> wrote: > > > > rcu_read_lock(); > > - table = rcu_dereference(mm->ioctx_table); > > - > > - if (!table || id >= table->nr) > > - goto out; > > - > > - ctx = rcu_dereference(table->table[id]); > > + ctx = xa_load(&mm->ioctx, id); > > if (ctx && ctx->user_id == ctx_id) { > > if (percpu_ref_tryget_live(&ctx->users)) > > ret = ctx; > > } > > Question on this part - do we need that RCU read lock around this now? I > don't think we do.
I think we need the rcu read lock here to prevent ctx from being freed under us by free_ioctx().
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