From: nordaux <nordaux@gmail.com>
Date: Mon, 13 Feb 2012 03:44:20 +0000 (+0200)
Subject: mount.zfs: canonicalize mount point for mtab
X-Git-Tag: debian/0.7.9-2~364^2~1
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=33364b15d302abfb2945129994b9cf42e61dc302;p=mirror_zfs-debian.git

mount.zfs: canonicalize mount point for mtab

Canonicalize the mount point passed to the mount.zfs helper.
This way a clean path is always added to mtab which ensures
the umount can properly locate and remove the entry.

Test case:
$ mkdir /mnt/foo
$ mount -t zfs zpool/foo /mnt/../mnt/foo////
$ umount /mnt/foo
$ cat /etc/mtab | grep zpool/foo
zpool/foo /mnt/../mnt/foo//// zfs rw 0 0

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #573
---

diff --git a/cmd/mount_zfs/mount_zfs.c b/cmd/mount_zfs/mount_zfs.c
index 0a69d69d..6dd831d7 100644
--- a/cmd/mount_zfs/mount_zfs.c
+++ b/cmd/mount_zfs/mount_zfs.c
@@ -311,7 +311,8 @@ main(int argc, char **argv)
 	char mntopts[MNT_LINE_MAX] = { '\0' };
 	char badopt[MNT_LINE_MAX] = { '\0' };
 	char mtabopt[MNT_LINE_MAX] = { '\0' };
-	char *dataset, *mntpoint;
+	char mntpoint[PATH_MAX];
+	char *dataset;
 	unsigned long mntflags = 0, zfsflags = 0, remount = 0;
 	int sloppy = 0, fake = 0, verbose = 0, nomtab = 0, zfsutil = 0;
 	int error, c;
@@ -367,7 +368,13 @@ main(int argc, char **argv)
 	}
 
 	dataset = parse_dataset(argv[0]);
-	mntpoint = argv[1];
+
+	/* canonicalize the mount point */
+	if (realpath(argv[1], mntpoint) == NULL) {
+		(void) fprintf(stderr, gettext("filesystem '%s' cannot be "
+		    "mounted due to a canonicalization failure.\n"), dataset);
+		return (MOUNT_SYSERR);
+	}
 
 	/* validate mount options and set mntflags */
 	error = parse_options(mntopts, &mntflags, &zfsflags, sloppy,