On 8/19/2014 4:04 PM, Bryan Drewery wrote: > Author: bdrewery > Date: Tue Aug 19 21:04:31 2014 > New Revision: 270183 > URL: http://svnweb.freebsd.org/changeset/base/270183 > > Log: > Avoid showing stale errors when nmount(2) fails. > > Sometimes nmount(2) will fail without setting errmsg. The previous (ignored) > error would then be shown as the reason for the failed call if the next > nmount(2) also fails without [ENOENT,ENOTSUP]. > > An example is when there is a tmpfs mounted with -o size. vfs_filteropt() > adds > 'size' as an error in errmsg due to 'size' not being in tmpfs_updateopts. > Then > tmpfs_mount returns [ENOTSUP] from nmount(2), which is then ignored. The > next > call may race with an unmount causing an invalid [EINVAL] that then does > log an > error, with the tmpfs errmsg. > > The race itself is a separate issue to fix as it is expected to have an > [ENOENT] returned instead.
The actual race causing the EINVAL is here with a proposed patch: http://lists.freebsd.org/pipermail/freebsd-fs/2013-August/018008.html I have not spent time analyzing/testing it yet. > > In this example the mount being shown is actually nullfs, not tmpfs that the > error is from. > > mountd[740]: can't delete exports for > /poudriere/data/.m/exp-head-commit-test-devel/04/.npkg: Invalid argument > mount option <size> is unknown > > It should only show: > > mountd[740]: can't delete exports for > /poudriere/data/.m/exp-head-commit-test-devel/04/.npkg: Invalid argument > > MFC after: 2 weeks > > Modified: > head/usr.sbin/mountd/mountd.c > > Modified: head/usr.sbin/mountd/mountd.c > ============================================================================== > --- head/usr.sbin/mountd/mountd.c Tue Aug 19 20:53:28 2014 > (r270182) > +++ head/usr.sbin/mountd/mountd.c Tue Aug 19 21:04:31 2014 > (r270183) > @@ -1744,6 +1744,7 @@ get_exportlist(void) > iov[3].iov_len = strlen(fsp->f_mntonname) + 1; > iov[5].iov_base = fsp->f_mntfromname; > iov[5].iov_len = strlen(fsp->f_mntfromname) + 1; > + errmsg[0] = '\0'; > > if (nmount(iov, iovlen, fsp->f_flags) < 0 && > errno != ENOENT && errno != ENOTSUP) { > @@ -2501,6 +2502,7 @@ do_mount(struct exportlist *ep, struct g > iov[3].iov_len = strlen(fsb->f_mntonname) + 1; > iov[5].iov_base = fsb->f_mntfromname; /* "from" */ > iov[5].iov_len = strlen(fsb->f_mntfromname) + 1; > + errmsg[0] = '\0'; > > while (nmount(iov, iovlen, fsb->f_flags) < 0) { > if (cp) > -- Regards, Bryan Drewery
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