X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fmount%2Fnfsumount.c;fp=utils%2Fmount%2Fnfsumount.c;h=02d40ff9d2bcb32457f1414b073cbec16cb4f0b9;hp=b1927de92f156186b3099385ad383c3bfe2b2fad;hb=dc08c702a6c7f824f317af561f491635ee898a71;hpb=17962b82afb68ca8e6b0d3f432d36c6c7c4980ea

diff --git a/utils/mount/nfsumount.c b/utils/mount/nfsumount.c
index b1927de..02d40ff 100644
--- a/utils/mount/nfsumount.c
+++ b/utils/mount/nfsumount.c
@@ -38,6 +38,9 @@
 #include "parse_opt.h"
 #include "parse_dev.h"
 
+#define MOUNTSFILE	"/proc/mounts"
+#define LINELEN		(4096)
+
 #if !defined(MNT_FORCE)
 /* dare not try to include <linux/mount.h> -- lots of errors */
 #define MNT_FORCE 1
@@ -242,6 +245,91 @@ static int nfs_umount23(const char *devname, char *string)
 	return result;
 }
 
+/*
+ * Detect NFSv4 mounts.
+ *
+ * Consult /proc/mounts to determine if the mount point
+ * is an NFSv4 mount.  The kernel is authoritative about
+ * what type of mount this is.
+ *
+ * Returns 1 if "mc" is an NFSv4 mount, zero if not, and
+ * -1 if some error occurred.
+ */
+static int nfs_umount_is_vers4(const struct mntentchn *mc)
+{
+	char buffer[LINELEN], *next;
+	int retval;
+	FILE *f;
+
+	if ((f = fopen(MOUNTSFILE, "r")) == NULL) {
+		fprintf(stderr, "%s: %s\n",
+			MOUNTSFILE, strerror(errno));
+		return -1;
+	}
+
+	retval = -1;
+	while (fgets(buffer, sizeof(buffer), f) != NULL) {
+		char *device, *mntdir, *type, *flags;
+		struct mount_options *options;
+		char *line = buffer;
+
+		next = strchr(line, '\n');
+		if (next != NULL)
+			*next = '\0';
+
+		device = strtok(line, " \t");
+		if (device == NULL)
+			continue;
+		mntdir = strtok(NULL, " \t");
+		if (mntdir == NULL)
+			continue;
+		if (strcmp(device, mc->m.mnt_fsname) != 0 &&
+		    strcmp(mntdir, mc->m.mnt_dir) != 0)
+			continue;
+
+		type = strtok(NULL, " \t");
+		if (type == NULL)
+			continue;
+		if (strcmp(type, "nfs4") == 0)
+			goto out_nfs4;
+
+		flags = strtok(NULL, " \t");
+		if (flags == NULL)
+			continue;
+		options = po_split(flags);
+		if (options != NULL) {
+			unsigned long version;
+			int rc;
+
+			rc = nfs_nfs_version(options, &version);
+			po_destroy(options);
+			if (rc && version == 4)
+				goto out_nfs4;
+		}
+
+		goto out_nfs;
+	}
+	if (retval == -1)
+		fprintf(stderr, "%s was not found in %s\n",
+			mc->m.mnt_dir, MOUNTSFILE);
+
+out:
+	fclose(f);
+	return retval;
+
+out_nfs4:
+	if (verbose)
+		fprintf(stderr, "NFSv4 mount point detected\n");
+	retval = 1;
+	goto out;
+
+out_nfs:
+	if (verbose)
+		fprintf(stderr, "Legacy NFS mount point detected\n");
+	retval = 0;
+	goto out;
+}
+
 static struct option umount_longopts[] =
 {
   { "force", 0, 0, 'f' },
@@ -365,13 +453,22 @@ int nfsumount(int argc, char *argv[])
 
 	ret = EX_SUCCESS;
 	if (mc) {
-		if (!lazy && strcmp(mc->m.mnt_type, "nfs4") != 0)
-			/* We ignore the error from nfs_umount23.
-			 * If the actual umount succeeds (in del_mtab),
-			 * we don't want to signal an error, as that
-			 * could cause /sbin/mount to retry!
-			 */
-			nfs_umount23(mc->m.mnt_fsname, mc->m.mnt_opts);
+		if (!lazy) {
+			switch (nfs_umount_is_vers4(mc)) {
+			case 0:
+				/* We ignore the error from nfs_umount23.
+				 * If the actual umount succeeds (in del_mtab),
+				 * we don't want to signal an error, as that
+				 * could cause /sbin/mount to retry!
+				 */
+				nfs_umount23(mc->m.mnt_fsname, mc->m.mnt_opts);
+				break;
+			case 1:
+				break;
+			default:
+				return EX_FAIL;
+			}
+		}
 		ret = del_mtab(mc->m.mnt_fsname, mc->m.mnt_dir);
 	} else if (*spec != '/') {
 		if (!lazy)