Re: [libvirt] [PATCH 2/3] qemuDomainGetPreservedMounts: Prune nested mount points

On 06/12/2017 11:57 AM, Michal Privoznik wrote: > https://bugzilla.redhat.com/show_bug.cgi?id=1431112 > > There can be nested mount points. For instance /dev/shm/blah can > be a mount point and /dev/shm too. It doesn't make much sense to > return the former path because callers preserve the latter (and > with that the former too). Therefore prune nested mount points. > > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; > --- > src/qemu/qemu_domain.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c > index 23b92606e..accf05a6f 100644 > --- a/src/qemu/qemu_domain.c > +++ b/src/qemu/qemu_domain.c > @@ -7533,7 +7533,7 @@ qemuDomainGetPreservedMounts(virQEMUDriverConfigPtr cfg, > size_t *ndevPath) > { > char **paths = NULL, **mounts = NULL; > - size_t i, nmounts; > + size_t i, j, nmounts; > > if (virFileGetMountSubtree(PROC_MOUNTS, "/dev", > &mounts, &nmounts) < 0) > @@ -7545,6 +7545,27 @@ qemuDomainGetPreservedMounts(virQEMUDriverConfigPtr cfg, > return 0; > } > > + /* There can be nested mount points. For instance > + * /dev/shm/blah can be a mount point and /dev/shm too. It > + * doesn't make much sense to return the former path because > + * caller preserves the latter (and with that the former > + * too). Therefore prune nested mount points. > + * NB mounts[0] is "/dev". Should we start the outer loop > + * from the beginning of the array all we'd be left with is > + * just the first element. Think about it. > + */ > + for (i = 1; i < nmounts; i++) { > + for (j = i + 1; j < nmounts;) { > + if (STRPREFIX(mounts[j], mounts[i])) { > + VIR_DEBUG("Dropping path %s because of %s", mounts[j], mounts[i]); > + VIR_DELETE_ELEMENT(mounts, j, nmounts); > + } else { > + j++; > + } Ewww I prefer a : j = i + 1; while (j < nmounts) { if () ... else j++; }