On 2015-05-19 10:29 AM, Theodore Ts'o wrote: > On Mon, May 18, 2015 at 10:36:41PM -0700, Jaegeuk Kim wrote: >> Previoulsy, fi->i_crypt_info was not covered by any lock, resulting in >> memory leak. >> >> This patch adds a rwsem to avoid leaking objects on i_crypt_info. >> >> Signed-off-by: Jaegeuk Kim <[email protected]> > > I'm not sure we need an rwsem to fix this issue. In terms of > serializing the creation and deletion of the structure, it should be > possible to use an cmpxchg() on the pointer itself. (e.g., if we lose > the race on the creation side, we just release our structure and use > the one that the winner allocated). > > If we do end up needing to serialize access to the tfm in the > i_crypt_info object for datapath reads/writes, then we might need a > mutex, but I think that should be it, no? > > - Ted > > ------------------------------------------------------------------------------ > One dashboard for servers and applications across Physical-Virtual-Cloud > Widest out-of-the-box monitoring support with 50+ applications > Performance metrics, stats and reports that give you Actionable Insights > Deep dive visibility with transaction tracing using APM Insight. > http://ad.doubleclick.net/ddm/clk/290420510;117567292;y > _______________________________________________ > Linux-f2fs-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > I have to agree with Ted here, as mutual exclusion locking is ideal for the scenario here of a reader vs writer exclusion. My only concern is that can there be many readers to one writer here as if so reader/writer spin locks may be better. Nick
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