Re: [PATCH v1 10/34] qemuDomainAttachDeviceMknodRecursive: Isolate bind mounted devices condition

When attaching a device into a domain, the corresponding /dev node might need to be created in the domain's namespace. For some types of files we call mknod(), for symlinks we call symlink(), but for others - which exist in the host namespace - we need to so called 'bind mount' them (which is a way of passing a file/directory between mount namespaces). There is this condition in qemuDomainAttachDeviceMknodRecursive() which decides whether a bind mount will be used, move it into a separate function so that it can be reused later. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_domain_namespace.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_domain_namespace.c b/src/qemu/qemu_domain_namespace.c index 40c4fb36cb..0c40118938 100644 --- a/src/qemu/qemu_domain_namespace.c +++ b/src/qemu/qemu_domain_namespace.c @@ -1253,6 +1253,17 @@ qemuDomainAttachDeviceMknodHelper(pid_t pid G_GNUC_UNUSED, } +static bool +qemuDomainMknodItemIsBindMounted(mode_t st_mode)

+{ + /* A block device S_ISBLK() or a chardev S_ISCHR() is intentionally not + * handled. We want to mknod() it instead of passing in through bind + * mounting. */ + return S_ISREG(st_mode) || S_ISFIFO(st_mode) || + S_ISSOCK(st_mode) || S_ISDIR(st_mode); +} + + static int qemuDomainAttachDeviceMknodRecursive(virQEMUDriverPtr driver, virDomainObjPtr vm, @@ -1267,7 +1278,6 @@ qemuDomainAttachDeviceMknodRecursive(virQEMUDriverPtr driver, g_autofree char *target = NULL; bool isLink; bool isReg; - bool isDir; if (!ttl) { virReportSystemError(ELOOP, @@ -1289,10 +1299,9 @@ qemuDomainAttachDeviceMknodRecursive(virQEMUDriverPtr driver, } isLink = S_ISLNK(data.sb.st_mode); - isReg = S_ISREG(data.sb.st_mode) || S_ISFIFO(data.sb.st_mode) || S_ISSOCK(data.sb.st_mode); - isDir = S_ISDIR(data.sb.st_mode); + isReg = qemuDomainMknodItemIsBindMounted(data.sb.st_mode);

- if ((isReg || isDir) && STRPREFIX(file, QEMU_DEVPREFIX)) { + if (isReg && STRPREFIX(file, QEMU_DEVPREFIX)) { cfg = virQEMUDriverGetConfig(driver); if (!(target = qemuDomainGetPreservedMountPath(cfg, vm, file)))