From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: [PATCH 1/4] raid5-cache: use rcu api to access r5conf->log Date: Wed, 06 Jan 2016 12:04:11 +1100 Message-ID: <87fuyby0vo.fsf@notabene.neil.brown.name> References: Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Shaohua Li , linux-raid@vger.kernel.org Cc: Kernel-team@fb.com, songliubraving@fb.com List-Id: linux-raid.ids --=-=-= Content-Type: text/plain On Wed, Jan 06 2016, Shaohua Li wrote: > If we add journal disk to an array which isn't created with journal, IO > might be running in the array. We must be careful about the log checks > to make sure log is fully initialized, which is the job of > rcu_dereference(). Don't need rcu read lock protection here, as > hotremove only happens when there is no write requests. Very sensible, especially as conf->log is set using rcu_assign_ptr(). Applied, thanks NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJWjGgLAAoJEDnsnt1WYoG5FOYP/AmLfb45fUAvCD9yVzAm1bnI vg1adQVuLn6MLZ+NMW61d2auyXHIxtz7gyQRbIUUvWnYcgJ5gLEOEMCYHNn5z8qF fzM+kjX73LhTbtCRNmo4m+bBwMmFUgoGb0Hn88Y+ii/YUi/LJ9aQMBoUzmL+vj86 1YaOOmvAGrO2tdHfMRxypQrQCMjV5CEb7fpIzUFKyJBM2TCY6J6Z01mDyI/VM8/S w/dMKOuKdmqiZge6aEAod7XhmCNGpJsB2nIW6ssAzD1eOH9UFDpO2BQGIwCy+bfo WEuWeLl4j4Y6dunL/ZYOhWHk9v5/yee5MmurVcf7QBG1ZU3r7FiGpOM/7R/PgFm/ iAADj5OY6wGvEwuh2kl+tm0CI96iPXPWA19mT1Pi3eL5nh0CjeHiViZmQaZm2GVR 5B45GLQpSrtDiPEYFDPgfd484A4LkDMOXCdSX8j9c1mdWmMkMfnLC1dfR8t+uCfA qOSpke77mqfCPeX6srALmVQU8lxL2WI8f2lt1G55IUVAkUcYjW+TSevs1NbQMout g08GHDFVT68S7OiRKO9m5vnCsD8iwWaxYPCqltJCiFn4FEb74gPhPOh18o+2/JqO Lpb9PgaX7n8EFM0Ts6IcTBHH0SkG4D9XX9uKjX1kXfgXQqsaBfwurq5B0uTfhLz9 HaCH6UIJ1GLHqOS3oTE6 =AQQM -----END PGP SIGNATURE----- --=-=-=--