From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: report a bug that panic when grow size for external bitmap Date: Thu, 31 Aug 2017 13:30:31 +1000 Message-ID: <87efrsfm7c.fsf@notabene.neil.brown.name> References: <87y3q3gq8g.fsf@notabene.neil.brown.name> <6eaf97d4-bd8c-e33c-a9c7-37d0fe2086ce@suse.com> <87mv6jgj8z.fsf@notabene.neil.brown.name> <87k21mhcqw.fsf@notabene.neil.brown.name> <73429dce-a22d-149e-656a-13af228c093f@suse.com> <87r2vsfuom.fsf@notabene.neil.brown.name> <2d737c2f-69f4-672f-2b7c-4a279f70c3c3@suse.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: <2d737c2f-69f4-672f-2b7c-4a279f70c3c3@suse.com> Sender: linux-raid-owner@vger.kernel.org To: Zhilong Liu Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Thu, Aug 31 2017, Zhilong Liu wrote: > On 08/31/2017 08:27 AM, NeilBrown wrote: >> On Wed, Aug 30 2017, Zhilong Liu wrote: >> >>> On 08/29/2017 06:47 PM, NeilBrown wrote: >>>> Thanks. I see what I missed. Please try this patch instead. >>> Hi, Neil; >>> I have tested the following patch, I still got the call-trace aft= er >>> I built with it. >>> If you need other infos, I would append. >> >> Thanks for testing. >> I looked more completely and I think it is easiest just to disable the >> functionality rather than try to fix it. >> Resizing the file in the kernel is extra complexity that I don't >> want to get in to. >> We could adjust the bitmap chunk size so that the file doesn't >> need to grow, but it started getting more complicated than I really >> wanted to deal with. >> If there is anyone actually using file-backed bitmaps who wants to >> be able to resize the array without removing the bitmap first, then >> we can look at the problem again. For now I've sent a patch which >> just returns an error instead of crashing when someone tries to resize >> an array with a file-backed bitmap. > > Hi, Neil; > Shall update the "SIZE CHANGES" under "GROW MODE" of man-page for > resize like following after kernel patch merged? Good idea, but it isn't just "--grow --size". It is anything that changes the size of the array, which includes changing the number of devices in a RAID5 etc. So a more general statement would be better. NeilBrown > > Thanks, > -Zhilong > > diff --git a/mdadm.8.in b/mdadm.8.in > index e0747fb..f0fd1fc 100644 > --- a/mdadm.8.in > +++ b/mdadm.8.in > @@ -2758,6 +2758,11 @@ Also the size of an array cannot be changed while= =20 > it has an active > bitmap. If an array has a bitmap, it must be removed before the size > can be changed. Once the change is complete a new bitmap can be created. > > +.PP > +Note: > +.B "--grow --size" > +is not yet supported for external file bitmap. > + > .SS RAID\-DEVICES CHANGES > > A RAID1 array can work with any number of devices from 1 upwards > >> Thanks, >> NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAlmngtkACgkQOeye3VZi gbmuUQ/9Fi91g2TuhW94+TfRvhlobyG2fbukG9fW4PLp2NNa5kEOz+V01uOtPXJg yyC1yCGRdUH2usGAshSOO/i0qxD5K0v2xBOY1GAt5ZvkaJXXV5qU515kxquG6ZDx dfPao+65NiUkgiRlva4DJz1x/YaEYqNhQfBy2sjPyGJiP6ujzcIa82Pj56TAAtzO kRQv3dvbr+KL3HJHcuPaT3CB4c3zfKG038V22g8GScSYrOQpsThvwhjkwAQ03mJ5 oF325Zk9g7qtouSKIUs0fQmLVMzv0ff3F4qI21ZBmv/ifofZOwzw3N1AELlj0Ih2 d/g1jGR+MqLY/8gMA558tpfJY7wl9KKviOffwrj8LeZK+E7q55GJJbtQvpOgVttK LBQH+zDHQG3QKxUlYBzdUx4eBfWPF7Sl8xDxGY0OGiuoEBFvrn3k7C37GefXRBiU Er0fUpOpPOdb02c1UnJOi+/cD3BJj82hLnS7WFfAE7acJUqHXbAxcwNRIYAikRht 1AipXyWyV+axE5KWT0xW46Ban0Vp+NPGYvIAO32bMVm7Zq6zFd/CUK3G34hDTWM2 nHG3bX0p5XaZTyy3tzAvotakv74dZCMMUbp8c1XiInLqZxlurI1baYef9EEQtJqf DtPrSpYVSDklSPrMIuk1DArPxSF6519aBODnO/ieTB30TsCjLGY= =TyWJ -----END PGP SIGNATURE----- --=-=-=--