export points with the "mountpoint" flag should not be exported
if they aren't mounted.
They shouldn't even appear in the pseudo-root filesystem.
So add an appropriate check to v4root_set().
This means that the v4root might need to be recomputed whenever a
filesystem is mounted or unmounted. So when there are export points
with the "mountpoint" flag, check for changes in the mount table.
This is done be measuring the size of /proc/mounts.
Signed-off-by: NeilBrown <neilb@xxxxxxxx>
---
support/include/v4root.h | 2 +-
utils/mountd/auth.c | 29 +++++++++++++++++++++++++++--
utils/mountd/v4root.c | 11 ++++++++++-
3 files changed, 38 insertions(+), 4 deletions(-)
diff --git a/support/include/v4root.h b/support/include/v4root.h
index 706c15c70d95..406fd4e43e5a 100644
--- a/support/include/v4root.h
+++ b/support/include/v4root.h
@@ -10,6 +10,6 @@
#define V4ROOT_H
extern int v4root_needed;
-extern void v4root_set(void);
+extern void v4root_set(int *mountpoints_checked);
#endif /* V4ROOT_H */
diff --git a/utils/mountd/auth.c b/utils/mountd/auth.c
index 0881d9a6edba..5bd7e6622307 100644
--- a/utils/mountd/auth.c
+++ b/utils/mountd/auth.c
@@ -77,6 +77,29 @@ check_useipaddr(void)
cache_flush(1);
}
+static int mountpoints_changed(void)
+{
+ static int last_size = 0;
+ int size;
+ int fd;
+ char buf[4096];
+ int n;
+
+ fd = open("/proc/mounts", O_RDONLY);
+ if (fd < 0)
+ /* ignore mountpoint changes if we cannot read /proc/mounts */
+ return 0;
+ size = 0;
+ while ((n = read(fd, buf, sizeof(buf))) > 0)
+ size += n;
+ if (n < 0)
+ return 0;
+ if (size == last_size)
+ return 0;
+ last_size = size;
+ return 1;
+}
+
unsigned int
auth_reload()
{
@@ -84,6 +107,7 @@ auth_reload()
static ino_t last_inode;
static int last_fd = -1;
static unsigned int counter;
+ static int mountpoints_checked = 0;
int fd;
if ((fd = open(_PATH_ETAB, O_RDONLY)) < 0) {
@@ -91,7 +115,8 @@ auth_reload()
} else if (fstat(fd, &stb) < 0) {
xlog(L_FATAL, "couldn't stat %s", _PATH_ETAB);
close(fd);
- } else if (last_fd != -1 && stb.st_ino == last_inode) {
+ } else if (last_fd != -1 && stb.st_ino == last_inode &&
+ (!mountpoints_checked || !mountpoints_changed())) {
/* We opened the etab file before, and its inode
* number hasn't changed since then.
*/
@@ -114,7 +139,7 @@ auth_reload()
memset(&my_client, 0, sizeof(my_client));
xtab_export_read();
check_useipaddr();
- v4root_set();
+ v4root_set(&mountpoints_checked);
++counter;
diff --git a/utils/mountd/v4root.c b/utils/mountd/v4root.c
index d52172592823..1a5778f9c7de 100644
--- a/utils/mountd/v4root.c
+++ b/utils/mountd/v4root.c
@@ -183,7 +183,7 @@ static int v4root_add_parents(nfs_export *exp)
* looking for components of the v4 mount.
*/
void
-v4root_set()
+v4root_set(int *mountpoints_checked)
{
nfs_export *exp;
int i;
@@ -193,6 +193,7 @@ v4root_set()
if (!v4root_support())
return;
+ *mountpoints_checked = 0;
for (i = 0; i < MCL_MAXTYPES; i++) {
for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
if (exp->m_export.e_flags & NFSEXP_V4ROOT)
@@ -202,6 +203,14 @@ v4root_set()
*/
continue;
+ if (exp->m_export.e_mountpoint) {
+ *mountpoints_checked = 1;
+ if (!is_mountpoint(exp->m_export.e_mountpoint[0]?
+ exp->m_export.e_mountpoint:
+ exp->m_export.e_path))
+ continue;
+ }
+
if (strcmp(exp->m_export.e_path, "/") == 0 &&
!(exp->m_export.e_flags & NFSEXP_FSID)) {
/* Force '/' to be exported as fsid == 0*/
--
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