When finding an export for an fsid, check submounts too.

When looking for the exportpoint to match a given fsid,
if an NFSEXP_CROSSMOUNT export is found, also check all filesystems
mounted below there.

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index 2f13f03ec9a61247228d3c4e347488c7393e3af5..fb2a8e7281c5832264e545ed18fe4f908ad1e856 100644 (file)
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -23,6 +23,7 @@
 #include <ctype.h>
 #include <pwd.h>
 #include <grp.h>
+#include <mntent.h>
 #include "misc.h"
 #include "nfslib.h"
 #include "exportfs.h"
@@ -215,7 +216,31 @@ int get_uuid(char *path, char *uuid, int uuidlen, char *u)
        }
        return 1;
 }
-       
+
+/* Iterate through /etc/mtab, finding mountpoints
+ * at or below a given path
+ */
+static char *next_mnt(void **v, char *p)
+{
+       FILE *f;
+       struct mntent *me;
+       int l = strlen(p);
+       if (*v == NULL) {
+               f = setmntent("/etc/mtab", "r");
+               *v = f;
+       } else
+               f = *v;
+       while ((me = getmntent(f)) != NULL &&
+              (strncmp(me->mnt_dir, p, l) != 0 ||
+               me->mnt_dir[l] != '/'))
+               ;
+       if (me == NULL) {
+               endmntent(f);
+               *v = NULL;
+               return NULL;
+       }
+       return me->mnt_dir;
+}
 
 void nfsd_fh(FILE *f)
 {
@@ -234,6 +259,7 @@ void nfsd_fh(FILE *f)
        unsigned int fsidnum=0;
        char fsid[32];
        struct exportent *found = NULL;
+       char *found_path = NULL;
        nfs_export *exp;
        int i;
        int dev_missing = 0;
@@ -328,9 +354,35 @@ void nfsd_fh(FILE *f)
 
        /* Now determine export point for this fsid/domain */
        for (i=0 ; i < MCL_MAXTYPES; i++) {
-               for (exp = exportlist[i]; exp; exp = exp->m_next) {
+               nfs_export *next_exp;
+               for (exp = exportlist[i]; exp; exp = next_exp) {
                        struct stat stb;
-                       char u[16];                     
+                       char u[16];
+                       char *path;
+
+                       if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
+                               static nfs_export *prev = NULL;
+                               static void *mnt = NULL;
+                               
+                               if (prev == exp) {
+                                       /* try a submount */
+                                       path = next_mnt(&mnt, exp->m_export.e_path);
+                                       if (!path) {
+                                               next_exp = exp->m_next;
+                                               prev = NULL;
+                                               continue;
+                                       }
+                                       next_exp = exp;
+                               } else {
+                                       prev = exp;
+                                       mnt = NULL;
+                                       path = exp->m_export.e_path;
+                                       next_exp = exp;
+                               }
+                       } else {
+                               path = exp->m_export.e_path;
+                               next_exp = exp->m_next;
+                       }
 
                        if (!client_member(dom, exp->m_client->m_hostname))
                                continue;
@@ -339,7 +391,7 @@ void nfsd_fh(FILE *f)
                                           exp->m_export.e_mountpoint:
                                           exp->m_export.e_path))
                                dev_missing ++;
-                       if (stat(exp->m_export.e_path, &stb) != 0)
+                       if (stat(path, &stb) != 0)
                                continue;
                        switch(fsidtype){
                        case FSID_DEV:
@@ -363,13 +415,13 @@ void nfsd_fh(FILE *f)
                                goto check_uuid;
                        case FSID_UUID8:
                        case FSID_UUID16:
-                               if (!is_mountpoint(exp->m_export.e_path))
+                               if (!is_mountpoint(path))
                                        continue;
                        check_uuid:
                                if (exp->m_export.e_uuid)
                                        get_uuid(NULL, exp->m_export.e_uuid,
                                                 uuidlen, u);
-                               else if (get_uuid(exp->m_export.e_path, NULL,
+                               else if (get_uuid(path, NULL,
                                                  uuidlen, u) == 0)
                                        continue;
 
@@ -378,12 +430,13 @@ void nfsd_fh(FILE *f)
                                break;
                        }
                        /* It's a match !! */
-                       if (!found)
+                       if (!found) {
                                found = &exp->m_export;
-                       else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
+                               found_path = strdup(path);
+                       } else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
                        {
                                xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
-                                    found->e_path, exp->m_export.e_path, dom);
+                                    found_path, path, dom);
                        }
                }
        }
@@ -408,7 +461,7 @@ void nfsd_fh(FILE *f)
        }
 
        if (found)
-               cache_export_ent(dom, found, found->e_path);
+               cache_export_ent(dom, found, found_path);
 
        qword_print(f, dom);
        qword_printint(f, fsidtype);