libmount: add fstab/mtab/mountinfo lookup routines

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 149 insertions, 0 deletions

diff --git a/shlibs/mount/src/fs.c b/shlibs/mount/src/fs.c
index 0e12052d5..01c2d0277 100644
--- a/shlibs/mount/src/fs.c
+++ b/shlibs/mount/src/fs.c
@@ -11,6 +11,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <ctype.h>
+#include <errno.h>
 #include <blkid/blkid.h>
 
 #include "nls.h"
@@ -415,6 +416,154 @@ int mnt_fs_get_option(mnt_fs *fs, const char *name,
 }
 
 
+/**
+ * mnt_fs_match_target:
+ * @fs: filesystem
+ * @target: mountpoint path
+ * @cache: tags/paths cache or NULL
+ *
+ * Possible are three attempts:
+ *	1) compare @target with @fs->target
+ *	2) realpath(@target) with @fs->target
+ *	3) realpath(@target) with realpath(@fs->target).
+ *
+ * The 2nd and 3rd attempts are not performed when @cache is NULL.
+ *
+ * Returns 1 if @fs target is equal to @target else 0.
+ */
+int mnt_fs_match_target(mnt_fs *fs, const char *target, mnt_cache *cache)
+{
+	int rc = 0;
+
+	if (!fs || !target || !fs->target)
+		return 0;
+
+	/* 1) native paths */
+	rc = !strcmp(target, fs->target);
+
+	if (!rc && cache) {
+		/* 2) - canonicalized and non-canonicalized */
+		char *cn = mnt_resolve_path(target, cache);
+		rc = (cn && strcmp(cn, fs->target) == 0);
+
+		/* 3) - canonicalized and canonicalized */
+		if (!rc && cn) {
+			char *tcn = mnt_resolve_path(fs->target, cache);
+			rc = (tcn && strcmp(cn, tcn) == 0);
+		}
+	}
+
+	return rc;
+}
+
+/**
+ * mnt_fs_match_source:
+ * @fs: filesystem
+ * @source: tag or path (device or so)
+ * @cache: tags/paths cache or NULL
+ *
+ * Possible are four attempts:
+ *	1) compare @source with @fs->source
+ *	2) compare realpath(@source) with @fs->source
+ *	3) compare realpath(@source) with realpath(@fs->source)
+ *	4) compare realpath(@source) with evaluated tag from @fs->source
+ *
+ * The 2nd, 3rd and 4th attempts are not performed when @cache is NULL. The
+ * 2nd and 3rd attempts are not performed if @fs->source is tag.
+ *
+ * Returns 1 if @fs source is equal to @source else 0.
+ */
+int mnt_fs_match_source(mnt_fs *fs, const char *source, mnt_cache *cache)
+{
+	int rc = 0;
+	char *cn;
+	const char *src, *t, *v;
+
+	if (!fs || !source || !fs->source)
+		return 0;
+
+	/* 1) native paths/tags */
+	rc = !strcmp(source, fs->source);
+	if (rc || !cache)
+		return rc;
+
+	if (fs->flags & (MNT_FS_NET | MNT_FS_PSEUDO))
+		return 0;
+
+	cn = mnt_resolve_spec(source, cache);
+	if (!cn)
+		return 0;
+
+	/* 2) canonicalized and native */
+	src = mnt_fs_get_srcpath(fs);
+	if (src)
+		rc = !strcmp(cn, src);
+
+	/* 3) canonicalized and canonicalized */
+	if (src && !rc) {
+		src = mnt_resolve_path(src, cache);
+		rc = !strcmp(cn, src);
+	}
+	if (src && !rc)
+		/* fs->source is path and does not match with @source */
+		return 0;
+
+	if (mnt_fs_get_tag(fs, &t, &v))
+		return 0;
+
+	/* read @source's tags to the cache */
+	if (mnt_cache_read_tags(cache, cn) < 1) {
+		if (errno == EACCES) {
+			/* we don't have permissions to read TAGs from
+			 * @source, but can translate @fs tag to devname.
+			 *
+			 * (because libblkid uses udev symlinks and this is
+			 * accessible for non-root uses)
+			 */
+			char *x = mnt_resolve_tag(t, v, cache);
+			if (x && !strcmp(x, cn))
+				return 1;
+		}
+		return 0;
+	}
+
+	/* 4) has the @source a tag that matches with tag from @fs ? */
+	if (!mnt_cache_device_has_tag(cache, cn, t, v))
+		return 0;
+
+	return 1;
+}
+
+/**
+ * mnt_fs_match_fstype:
+ * @fs: filesystem
+ * @types: filesystem name or comma delimited list of filesystems
+ *
+ * For more details see mnt_match_fstype().
+ *
+ * Returns 1 if @fs type is matching to @types else 0. The function returns
+ * 0 when types is NULL.
+ */
+int mnt_fs_match_fstype(mnt_fs *fs, const char *types)
+{
+	return mnt_match_fstype(fs->fstype, types);
+}
+
+/**
+ * mnt_fs_match_options:
+ * @fs: filesystem
+ * @options: comma delimited list of options (and nooptions)
+ *
+ * For more details see mnt_match_options().
+ *
+ * Returns 1 if @fs type is matching to @options else 0. The function returns
+ * 0 when types is NULL.
+ */
+int mnt_fs_match_options(mnt_fs *fs, const char *options)
+{
+	return mnt_match_options(fs->optstr, options);
+}
+
 /* Unfortunately the classical Unix /etc/mtab and /etc/fstab
    do not handle directory names containing spaces.
    Here we mangle them, replacing a space by \040.