Re: [libvirt] [PATCH 3/3] qemuDomainGetPreservedMounts: Fix suffixes for corner cases

https://bugzilla.redhat.com/show_bug.cgi?id=1431112 Imagine a FS mounted on /dev/blah/blah2. Our process of creating suffix for temporary location where all the mounted filesystems are moved is very simplistic. We want: /var/run/libvirt/qemu/$domName.$suffix\ were $suffix is just the mount point path stripped of the "/dev/" preffix. For instance:

/var/run/libvirt/qemu/fedora.mqueue for /dev/mqueue /var/run/libvirt/qemu/fedora.pts for /dev/pts and so on. Now if we plug /dev/blah/blah2 into the example we see some misbehaviour: /var/run/libvirt/qemu/fedora.blah/blah2 Well, misbehaviour if /dev/blah/blah2 is a file, because in that case we call virFileTouch() instead of virFileMakePath().

Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_domain.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index accf05a6f..547c9fbfb 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -7570,7 +7570,9 @@ qemuDomainGetPreservedMounts(virQEMUDriverConfigPtr cfg, goto error; for (i = 0; i < nmounts; i++) { + char *tmp; const char *suffix = mounts[i] + strlen(DEVPREFIX); + size_t off; if (STREQ(mounts[i], "/dev")) suffix = "dev"; @@ -7578,6 +7580,20 @@ qemuDomainGetPreservedMounts(virQEMUDriverConfigPtr cfg, if (virAsprintf(&paths[i], "%s/%s.%s", cfg->stateDir, vm->def->name, suffix) < 0) goto error; + + /* Now consider that mounts[i] is "/dev/blah/blah2". + * @suffix then points to "blah/blah2". However, caller + * expects all the @paths to be the same depth. The + * caller doesn't always do `mkdir -p` but sometimes bare + * `touch`. Therefore fix all the suffixes. */ + off = strlen(paths[i]) - strlen(suffix); + + tmp = paths[i] + off; + while (*tmp) { + if (*tmp == '/') + *tmp = '.'; + tmp++; + } } if (devPath)