On Tue, May 19, 2015 at 10:35:30AM -0400, nick wrote: > > > 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 <jaegeuk@xxxxxxxxxx> > > > > 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 > > > 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 What I'm saying is writer vs writer actually. > is that can there be many readers to one writer here as if so reader/writer > spin locks may be better. I could write another patch using a rwlock by removing needless down_write for f2fs_free_encryption_info. Thanks, > Nick -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
