From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: [PATCH 3/4] raid5-cache: handle flush request for journal hotadd Date: Wed, 06 Jan 2016 12:12:05 +1100 Message-ID: <87d1tfy0ii.fsf@notabene.neil.brown.name> References: <7b8a15be93941a393a5a08232659fef9ead4610b.1452028077.git.shli@fb.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: <7b8a15be93941a393a5a08232659fef9ead4610b.1452028077.git.shli@fb.com> 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: > When we hotadd journal for array which isn't created with journal, the > array might be running write requests. Such writes aren't protected by > journal yet, so we can't skip disk flush. There is no easy way to know > when all such writes are finished, but the time should be enough after > reclaim runs once. There is an easy way to know when such writes are finished. Call mddev_suspend(mddev). This is used for the more intrusive reconfiguration such as initiating a reshape. I think it would be perfectly appropriate to call mddev_suspend() attach the journal call mddev_resume() Thanks, NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJWjGnlAAoJEDnsnt1WYoG5oC8P/1lxVsysOUQCqkLcSNrl7pW4 EGi36kb4wjfHEm/2sFXQaCGMyGIabdsjGQDz8MrQ8ZTqui4UxySp5f1gKJL+oD56 YTY4rbTfUSrBRxwonkFqBxRB0gSAw5q8lAM294gBUfDYpZr1u+17egTsQbadafip oPClqIthbkdEorR5ugP+84k5j1tRkDEbfaKPVwIR7QNfNjP7Yi5S/V8+s6+ChlTZ +kyNpM8Amfcwgi4XuTa8nC9LYFOPB0uC1VsCssk6jqjLivNm608jYCmYORD6L9kD 4rQRndQW9lvdSkvDvNZxrmv2XXDzAhepjA9Dlze8WLos51dEjsA+RQfUnF0X2LkJ xASRpP5M+2PFmTXxorNTgNVTbhJmWfSLFrk2PCdHu7DFdi6t3bBx6RjcD5dc9+Kk JdKIQN0I03hyP3Neikm22vfuEpQYcLr5k9vVh1NRr4qoQGbYgv+EyRyGXxBTlwjh kjsVzmCldpw6pLrE5Be8Jb8z1sfBeTxEcOuvoFtvm0AccPnlsnEzJIlgXlIHx1R9 wF9oGtxuUTtgrPnEbdQPLctnOD73tgOsA6cn4rllqC9U+of2dE+enIo04OaS4yTO WWetIN3iJevFdmBVyBlXA4KBWBH6Iex/t6Q81v/x6u1mRYxvcOA4K0SusjQI51c3 knR5WSRVeJhA0B1agBRt =Flf3 -----END PGP SIGNATURE----- --=-=-=--