From: Arvin Schnell <aschnell@suse.de>
Date: Wed, 12 Sep 2012 10:03:22 +0000 (+0200)
Subject: - added checks for btrfs subvolumes
X-Git-Tag: v0.1.3~97
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0509909a5e25d988bf0e6b604e9565b44bc0313c;p=thirdparty%2Fsnapper.git

- added checks for btrfs subvolumes
---

diff --git a/snapper/Filesystem.cc b/snapper/Filesystem.cc
index f6d054de..19d18ce0 100644
--- a/snapper/Filesystem.cc
+++ b/snapper/Filesystem.cc
@@ -72,7 +72,7 @@ namespace snapper
 {
 
     vector<string>
-    filter_mount_options(vector<string>& options)
+    filter_mount_options(const vector<string>& options)
     {
 	static const char* ign_opt[] = {
 	    "ro", "rw",
@@ -129,9 +129,9 @@ namespace snapper
 	}
 
 #ifdef UMOUNT_NOFOLLOW
-	int r2 = umount2(mount_point.c_str(), UMOUNT_NOFOLLOW);
+	int r2 = ::umount2(mount_point.c_str(), UMOUNT_NOFOLLOW);
 #else
-	int r2 = umount2(mount_point.c_str(), 0);
+	int r2 = ::umount2(mount_point.c_str(), 0);
 #endif
 	if (r2 != 0)
 	{
@@ -248,6 +248,27 @@ namespace snapper
     }
 
 
+    SDir
+    Btrfs::openSubvolumeDir() const
+    {
+	SDir subvolume_dir = Filesystem::openSubvolumeDir();
+
+	struct stat stat;
+	if (subvolume_dir.stat(&stat) != 0)
+	{
+	    throw IOErrorException();
+	}
+
+	if (!is_subvolume(stat))
+	{
+	    y2err("subvolume is not a btrfs snapshot");
+	    throw IOErrorException();
+	}
+
+	return subvolume_dir;
+    }
+
+
     SDir
     Btrfs::openInfosDir() const
     {
@@ -260,6 +281,12 @@ namespace snapper
 	    throw IOErrorException();
 	}
 
+	if (!is_subvolume(stat))
+	{
+	    y2err(".snapshots is not a btrfs snapshot");
+	    throw IOErrorException();
+	}
+
 	if (stat.st_uid != 0 || stat.st_gid != 0)
 	{
 	    y2err("owner/group of .snapshots wrong");
@@ -341,8 +368,7 @@ namespace snapper
 
 	    struct stat stat;
 	    int r = info_dir.stat("snapshot", &stat, AT_SYMLINK_NOFOLLOW);
-	    // check st_ino == 256 is copied from btrfsprogs
-	    return r == 0 && stat.st_ino == 256 && S_ISDIR(stat.st_mode);
+	    return r == 0 && is_subvolume(stat);
 	}
 	catch (const IOErrorException& e)
 	{
@@ -351,6 +377,14 @@ namespace snapper
     }
 
 
+    bool
+    Btrfs::is_subvolume(const struct stat& stat) const
+    {
+	// see btrfsprogs source code
+	return stat.st_ino == 256 && S_ISDIR(stat.st_mode);
+    }
+
+
     bool
     Btrfs::create_subvolume(int fddst, const string& name) const
     {
diff --git a/snapper/Filesystem.h b/snapper/Filesystem.h
index 3c4c3330..c1fb0fad 100644
--- a/snapper/Filesystem.h
+++ b/snapper/Filesystem.h
@@ -94,6 +94,7 @@ namespace snapper
 
 	virtual string snapshotDir(unsigned int num) const;
 
+	virtual SDir openSubvolumeDir() const;
 	virtual SDir openInfosDir() const;
 	virtual SDir openSnapshotDir(unsigned int num) const;
 
@@ -108,6 +109,8 @@ namespace snapper
 
     private:
 
+	bool is_subvolume(const struct stat& stat) const;
+
 	bool create_subvolume(int fddst, const string& name) const;
 	bool create_snapshot(int fd, int fddst, const string& name) const;
 	bool delete_subvolume(int fd, const string& name) const;