From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Majchrzak Subject: Re: [PATCH] Monitor: don't assume mdadm parameter is a block device Date: Mon, 19 Jun 2017 11:16:58 +0200 Message-ID: <20170619091658.GA9305@proton.igk.intel.com> References: <1497621778-8967-1-git-send-email-tomasz.majchrzak@intel.com> <585FFF8D-0238-4AB3-AA77-4C3C00C3C55D@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <585FFF8D-0238-4AB3-AA77-4C3C00C3C55D@suse.com> Sender: linux-raid-owner@vger.kernel.org To: Zhilong Liu Cc: linux-raid@vger.kernel.org, jes.sorensen@gmail.com List-Id: linux-raid.ids On Sun, Jun 18, 2017 at 10:10:02PM +0800, Zhilong Liu wrote: > > > > 在 2017年6月16日，22:02，Tomasz Majchrzak 写道： > > > > If symlink (e.g. /dev/md/raid) is passed as a parameter to mdadm --wait, > > it fails as it's not able to find a corresponding entry in /proc/mdstat > > output. Get parameter file major:minor and look for block device name in > > sysfs. This commit is partial revert of commit 9e04ac1c43e6 > > ("mdadm/util: unify fstat checking blkdev into function"). > > > > Thanks very much for catching this. Just remind a typo in (commit title), correct fstat as stat. Will do. > > > Signed-off-by: Tomasz Majchrzak > > --- > > Monitor.c | 13 +++++++++++-- > > 1 file changed, 11 insertions(+), 2 deletions(-) > > > > v2: > > next Zhilong Liu commit id > > > > diff --git a/Monitor.c b/Monitor.c > > index bef2f1b..c9f24bd 100644 > > --- a/Monitor.c > > +++ b/Monitor.c > > @@ -982,12 +982,21 @@ static void link_containers_with_subarrays(struct state *list) > > int Wait(char *dev) > > { > > char devnm[32]; > > + dev_t rdev; > > + char *tmp; > > int rv = 1; > > int frozen_remaining = 3; > > > > - if (!stat_is_blkdev(dev, NULL)) > > + if (!stat_is_blkdev(dev, &rdev)) > > + return 2; > > + > > + tmp = devid2devnm(rdev); > > + if (!tmp) { > > + pr_err("Cannot get md device name.\n"); > > return 2; > > - strcpy(devnm, dev); > > + } > > + > > + strcpy(devnm, tmp); > > > > Quite agreed with the code here, just a small question, I may use > > strcpy(devnm, devid2devnm(rdev)); > directly since stat_is_blkdev() has returned the major/minor devid. I don't know "get md device name " would be failed in which scenario. > I'm asking this question since I haven't been familiar with all raids situations. :-) > > Thanks again, > Zhilong Well, there could be a race and RAID array might get stopped between two calls (stat_is_blkdev, devid2devnm) so corresponding sysfs entry would not exist. Also I don't think we should assume devid2devnm implementation won't change one day. I just did it safe way, otherwise static code analyzers would complain. Tomek