Imported reiserfsprogs-3.6.20

libutil/mntent.c

@@ -0,0 +1,164 @@
+/*
+ * Copyright 1996-2004 by Hans Reiser, licensing governed by 
+ * reiserfsprogs/README
+ */
+
+/* Lookup the @file in the @mntfile. @file is mntent.mnt_fsname if @fsname 
+   is set; mntent.mnt_dir otherwise. Return the mnt entry from the @mntfile.
+   
+   Warning: if the root fs is mounted RO, the content of /etc/mtab may be 
+   not correct. */
+
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include "misc/types.h"
+#include "util/device.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/vfs.h>
+#include <mntent.h>
+#include <assert.h>
+#include <stdio.h>
+
+static struct mntent *util_mntent_lookup(char *mntfile, 
+					 char *file, 
+					 int path) 
+{
+	struct mntent *mnt;
+	int name_match = 0;
+	struct stat st;
+	dev_t rdev = 0;
+	dev_t dev = 0;
+	ino_t ino = 0;
+	char *name;
+	FILE *fp;
+	
+	assert(mntfile != NULL);
+	assert(file != NULL);
+
+	if (stat(file, &st) == 0) {
+		/* Devices is stated. */
+		if (S_ISBLK(st.st_mode)) {
+			rdev = st.st_rdev;
+		} else {
+			dev = st.st_dev;
+			ino = st.st_ino;
+		}
+	}
+
+	if ((fp = setmntent(mntfile, "r")) == NULL)
+		return INVAL_PTR;
+
+	while ((mnt = getmntent(fp)) != NULL) {
+		/* Check if names match. */
+		name = path ? mnt->mnt_dir : mnt->mnt_fsname;
+		
+		if (strcmp(file, name) == 0)
+			name_match = 1;
+
+		if (stat(name, &st))
+			continue;
+		
+		/* If names do not match, check if stats match. */
+		if (!name_match) {
+			if (rdev && S_ISBLK(st.st_mode)) {
+				if (rdev != st.st_rdev)
+					continue;
+			} else if (dev && !S_ISBLK(st.st_mode)) {
+				if (dev != st.st_dev ||
+				    ino != st.st_ino)
+					continue;
+			} else {
+				continue;
+			}
+		}
+
+		/* If not path and not block device do not check anything more. */
+		if (!path && !rdev) 
+			break;
+
+		if (path) {
+			/* Either names or stats match. Make sure the st_dev of 
+			   the path is same as @mnt_fsname device rdev. */
+			if (stat(mnt->mnt_fsname, &st) == 0 && 
+			    dev == st.st_rdev)
+				break;
+		} else {
+			/* Either names or stats match. Make sure the st_dev of 
+			   the mount entry is same as the given device rdev. */
+			if (stat(mnt->mnt_dir, &st) == 0 && 
+			    rdev == st.st_dev)
+				break;
+		}
+	}
+
+	endmntent (fp);
+        return mnt;
+}
+
+struct mntent *util_mntent(char *device) {
+	int proc = 0, path = 0, root = 0;
+	
+	struct mntent *mnt;
+	struct statfs stfs;
+
+	assert(device != NULL);
+	
+	/* Check if the root. */
+	if (util_root_mounted(device) == 1)
+		root = 1;
+	
+#ifdef __linux__
+	/* Check if /proc is procfs. */
+	if (statfs("/proc", &stfs) == 0 && stfs.f_type == 0x9fa0) {
+		proc = 1;
+		
+		if (root) {
+			/* Lookup the "/" entry in /proc/mounts. Special 
+			   case as root entry can present as:
+				rootfs / rootfs rw 0 0
+			   Look up the mount point in this case. */
+			mnt = util_mntent_lookup("/proc/mounts", "/", 1);
+		} else {
+			/* Lookup the @device /proc/mounts */
+			mnt = util_mntent_lookup("/proc/mounts", device, 0);
+		}
+		
+		if (mnt == INVAL_PTR) 
+			proc = 0;
+		else if (mnt)
+			return mnt;
+	}
+#endif /* __linux__ */
+
+#if defined(MOUNTED) || defined(_PATH_MOUNTED)
+
+#ifndef MOUNTED
+    #define MOUNTED _PATH_MOUNTED
+#endif
+	/* Check in MOUNTED (/etc/mtab) if RW. */
+	if (!util_file_ro(MOUNTED)) {
+		path = 1;
+
+		if (root) {
+			mnt = util_mntent_lookup(MOUNTED, "/", 1);
+		} else {
+			mnt = util_mntent_lookup(MOUNTED, device, 0);
+		}
+
+		if (mnt == INVAL_PTR) 
+			path = 0;
+		else if (mnt)
+			return mnt;
+	}
+#endif /* defined(MOUNTED) || defined(_PATH_MOUNTED) */
+	
+	/* If has not been checked in neither /proc/mounts nor /etc/mtab (or 
+	   errors have occured), return INVAL_PTR, NULL otherwise. */
+	return (!proc && !path) ? INVAL_PTR : NULL;
+}
+