During a remount of a cifs filesystem, the mtab file is not properly updated, which
leads to a doubled entry of the same filesystem in the /etc/mtab file. This patch
adds a new function del_mtab() which is called before the add_mtab() in case the fs
is being remounted.
The del_mtab() function will delete from the mtab, the old entry from the filesystem which
is being remounted, and then, calls add_mtab() to add an updated entry to the mtab file.
Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
---
mount.cifs.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 81 insertions(+), 0 deletions(-)
diff --git a/mount.cifs.c b/mount.cifs.c
index 147f7fc..6535b40 100644
--- a/mount.cifs.c
+++ b/mount.cifs.c
@@ -161,6 +161,7 @@
#define OPT_BKUPUID 30
#define OPT_BKUPGID 31
+#define MNT_TMP_PATH "/tmp/mtab.tmp"
/* struct for holding parsed mount info for use by privleged process */
struct parsed_mount_info {
@@ -1624,6 +1625,81 @@ add_mtab_exit:
return rc;
}
+static int
+del_mtab(char *devname, char *mountpoint)
+{
+ int fd, tmprc, rc = 0;
+ FILE *mnttmp, *mntmtab;
+ struct mntent *mountent;
+ struct stat statbuf;
+
+ rc = lock_mtab();
+ if(rc) {
+ fprintf(stderr, "del_mtab: cannot lock mtab");
+ rc = EX_FILEIO;
+ goto del_mtab_exit;
+ }
+
+ mntmtab = setmntent(MOUNTED, "r");
+ if (!mntmtab) {
+ fprintf(stderr, "del_mtab: could not update mount table\n");
+ rc = EX_FILEIO;
+ goto del_mtab_exit;
+ }
+
+ mnttmp = setmntent(MNT_TMP_PATH, "w");
+ if (!mnttmp) {
+ fprintf(stderr, "del_mtab: could not update mount table\n");
+ endmntent(mntmtab);
+ rc = EX_FILEIO;
+ goto del_mtab_exit;
+ }
+
+ fd = fileno(mntmtab);
+ if (fd < 0) {
+ fprintf(stderr, "mntent does not appear to be valid\n");
+ endmntent(mntmtab);
+ endmntent(mnttmp);
+ rc = EX_FILEIO;
+ goto del_mtab_exit;
+ }
+
+ while((mountent = getmntent(mntmtab)) != NULL){
+ if(!strcmp(mountent->mnt_dir,mountpoint))
+ continue;
+ rc = addmntent(mnttmp, mountent);
+ if (rc) {
+ fprintf(stderr, "unable to add mount entry to mtab\n");
+ ftruncate(fd, statbuf.st_size);
+ rc = EX_FILEIO;
+ break;
+ }
+ }
+
+ rc = fstat(fd, &statbuf);
+ if (rc != 0) {
+ fprintf(stderr, "unable to fstat open mtab\n");
+ endmntent(mntmtab);
+ endmntent(mnttmp);
+ rc = EX_FILEIO;
+ goto del_mtab_exit;
+ }
+
+ tmprc = my_endmntent(mntmtab, statbuf.st_size);
+ if (tmprc) {
+ fprintf(stderr, "error %d detected on close of mtab\n", tmprc);
+ rc = EX_FILEIO;
+ }
+ endmntent(mnttmp);
+
+ rename(MNT_TMP_PATH, MOUNTED);
+ unlink(MNT_TMP_PATH);
+
+del_mtab_exit:
+ unlock_mtab();
+ return rc;
+}
+
/* have the child drop root privileges */
static int
drop_child_privs(void)
@@ -2021,6 +2097,11 @@ mount_retry:
}
do_mtab:
+ if(parsed_info->flags & MS_REMOUNT){
+ rc = del_mtab(orig_dev, mountpoint);
+ if(rc)
+ goto mount_exit;
+ }
if (!parsed_info->nomtab && !mtab_unusable())
rc = add_mtab(orig_dev, mountpoint, parsed_info->flags, fstype);
--
1.7.6.4
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