----- 原始邮件 ----- > 发件人: "Steve Dickson" <SteveD@xxxxxxxxxx> > 收件人: "Jianhong Yin" <jiyin@xxxxxxxxxx> > 抄送: "尹剑虹" <yin-jianhong@xxxxxxx>, linux-nfs@xxxxxxxxxxxxxxx > 发送时间: 星期一, 2018年 10 月 22日 下午 10:10:57 > 主题: Re: [PATCH] [nfs-utils] fix issue: mount -osharecache failure but return 'true' > > > > On 10/21/18 11:14 PM, Jianhong Yin wrote: > > > > ----- 原始邮件 ----- > >> 发件人: "Jianhong Yin" <jiyin@xxxxxxxxxx> > >> 收件人: "Steve Dickson" <SteveD@xxxxxxxxxx> > >> 抄送: "尹剑虹" <yin-jianhong@xxxxxxx>, linux-nfs@xxxxxxxxxxxxxxx > >> 发送时间: 星期一, 2018年 10 月 22日 上午 10:56:31 > >> 主题: Re: [PATCH] [nfs-utils] fix issue: mount -osharecache failure but > >> return 'true' > >> > >> > >> ----- 原始邮件 ----- > >>> 发件人: "Steve Dickson" <SteveD@xxxxxxxxxx> > >>> 收件人: "尹剑虹" <yin-jianhong@xxxxxxx> > >>> 抄送: jiyin@xxxxxxxxxx, linux-nfs@xxxxxxxxxxxxxxx > >>> 发送时间: 星期六, 2018年 10 月 20日 下午 10:35:48 > >>> 主题: Re: [PATCH] [nfs-utils] fix issue: mount -osharecache failure but > >>> return 'true' > >>> > >>> Hello, > >>> > >>> On 10/19/18 11:31 PM, 尹剑虹 wrote: > >>>> > >>>> Hi Steved > >>>> > >>>> The scenario is: these two mountings use different "context=" and > >>>> sharecache option, in this case mount(2) return fail with EBUSY. > >>> Fair enough.... I did miss the different contexts... > >>> > >>> But we already have a routine that check mount points > >>> is_mountpoint() used my mountd. I would rather use that. > > > > Hi Sir > > > > I reviewed function is_mountpoint(), seems it just check if the > > mountpoint is a root-fs， > > our goal is check if special dev has been mounted on specail path. > No. It check to see if the directory above the path (aka /..) > is on the same device (or filesystem) as path is. When the > device numbers are the same, both paths are on the same filesystem. > When they are not the same, the paths are on different filesystems I know.. ah sorry I used wrong word root-fs(not top rootfs, just means mountpoint). What I want to say is: Two(or more) devices could be mounted on same mountpoint on Linux, only check "mi->node" is a mountpoint is not enough we have to check if "mi->node" is a mountpoint *and* mounted on "mi->spec" Jianhong > steved. > > > > > WDYT? > > > >> Got it, good to know. > >> > >>> > >>> I'll resend the patch... > >>> > >>> Thanks!! > >>> > >>> steved. > >>> > >>>> > >>>> Jianhong > >>>> > >>>> > >>>> > >>>> 尹剑虹 > >>>> 邮箱：yin-jianhong@xxxxxxx > >>>> > >>>> <https://maas.mail.163.com/dashi-web-extend/html/proSignature.html?iconUrl=https%3A%2F%2Fmail-online.nosdn.127.net%2Fqiyelogo%2FdefaultAvatar.png&name=%E5%B0%B9%E5%89%91%E8%99%B9&uid=yin-jianhong%40163.com&ftlId=1&items=%5B%22%E9%82%AE%E7%AE%B1%EF%BC%9Ayin-jianhong%40163.com%22%5D> > >>>> > >>>> 签名由 网易邮箱大师 <https://mail.163.com/dashi/dlpro.html?from=mail88> 定制 > >>>> > >>>> On 10/20/2018 01:36, Steve Dickson <mailto:SteveD@xxxxxxxxxx> > >>>> wrote: > >>>> > >>>> > >>>> On 10/19/18 4:03 AM, jiyin@xxxxxxxxxx wrote: > >>>> > From: "Jianhong.Yin" <yin-jianhong@xxxxxxx> > >>>> > > >>>> > see: https://bugzilla.redhat.com/show_bug.cgi?id=1629705 > >>>> > mount.nfs4 -o > >>>> > context=system_u:object_r:user_home_dir_t:s0,sharecache > >>>> > $serv:$expdir $nfsmp > >>>> > mount.nfs4 -o > >>>> > context=system_u:object_r:xferlog_t:s0,sharecache > >>>> > $serv:$expdir $nfsmp2 > >>>> > ^^^ here mount fail, but return true. it confuse user! > >>>> Why should it fail? Two different mounts are being used and > >>>> using > >>>> -o sharecache > >>>> which is the default the way... > >>>> > >>>> steved. > >>>> > > >>>> > according: > >>>> > https://patchwork.kernel.org/patch/10602607/#22234047 > >>>> > add function is_mounted_already() > >>>> > - if (errno == EBUSY) > >>>> > + if (errno == EBUSY && is_mounted_already(mi->spec, > >>>> > mi->node)) > >>>> > return EX_SUCCESS; > >>>> > > >>>> > Signed-off-by: Jianhong Yin <yin-jianhong@xxxxxxx> > >>>> > --- > >>>> > utils/mount/stropts.c | 31 ++++++++++++++++++++++++------- > >>>> > 1 file changed, 24 insertions(+), 7 deletions(-) > >>>> > > >>>> > diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c > >>>> > index 4d2e37e..4be7e61 100644 > >>>> > --- a/utils/mount/stropts.c > >>>> > +++ b/utils/mount/stropts.c > >>>> > @@ -48,6 +48,7 @@ > >>>> > #include "version.h" > >>>> > #include "parse_dev.h" > >>>> > #include "conffile.h" > >>>> > +#include <mntent.h> > >>>> > > >>>> > #ifndef NFS_PROGRAM > >>>> > #define NFS_PROGRAM (100003) > >>>> > @@ -1056,6 +1057,27 @@ static int nfs_is_permanent_error(int > >>>> > error) > >>>> > } > >>>> > } > >>>> > > >>>> > +static int is_mounted_already(const char *fsname, const char > >>>> > *dir) > >>>> > +{ > >>>> > + struct mntent *ent; > >>>> > + FILE *fp; > >>>> > + int ret = 0; > >>>> > + > >>>> > + fp = setmntent("/proc/mounts", "r"); > >>>> > + if (fp == NULL) { > >>>> > + perror("[unlikely] setmntent(3) fail"); > >>>> > + exit(1); > >>>> > + } > >>>> > + while (NULL != (ent = getmntent(fp))) { > >>>> > + if (!strcmp(ent->mnt_fsname, fsname) && > >>>> > !strcmp(ent->mnt_dir, dir)) { > >>>> > + ret = 1; > >>>> > + break; > >>>> > + } > >>>> > + } > >>>> > + endmntent(fp); > >>>> > + return ret; > >>>> > +} > >>>> > + > >>>> > /* > >>>> > * Handle "foreground" NFS mounts. > >>>> > * > >>>> > @@ -1078,13 +1100,8 @@ static int nfsmount_fg(struct > >>>> > nfsmount_info *mi) > >>>> > if (nfs_try_mount(mi)) > >>>> > return EX_SUCCESS; > >>>> > > >>>> > - if (errno == EBUSY) > >>>> > - /* The only cause of EBUSY is if exactly the > >>>> > desired > >>>> > - * filesystem is already mounted. That can > >>>> > arguably > >>>> > - * be seen as success. "mount -a" tries to > >>>> > optimise > >>>> > - * out this case but sometimes fails. Help it > >>>> > out > >>>> > - * by pretending everything is rosy > >>>> > - */ > >>>> > + /* if EBUSY is caused by re-mount, ignore the error > >>>> > */ > >>>> > + if (errno == EBUSY && is_mounted_already(mi->spec, > >>>> > mi->node)) > >>>> > return EX_SUCCESS; > >>>> > > >>>> > if (nfs_is_permanent_error(errno)) > >>>> > > >>>> > >>> > >> >
