Make sure errno is correctly used

encfs/DirNode.cpp

@@ -185,8 +185,9 @@ bool RenameOp::apply() {
 
       // rename on disk..
       if (::rename(last->oldCName.c_str(), last->newCName.c_str()) == -1) {
+        int eno = errno;
         RLOG(WARNING) << "Error renaming " << last->oldCName << ": "
-                      << strerror(errno);
+                      << strerror(eno);
         dn->renameNode(last->newPName.c_str(), last->oldPName.c_str(), false);
         return false;
       }
@@ -355,7 +356,8 @@ DirTraverse DirNode::openDir(const char *plaintextPath) {
 
   DIR *dir = ::opendir(cyName.c_str());
   if (dir == NULL) {
-    VLOG(1) << "opendir error " << strerror(errno);
+    int eno = errno;
+    VLOG(1) << "opendir error " << strerror(eno);
     return DirTraverse(shared_ptr<DIR>(), 0, std::shared_ptr<NameIO>());
   } else {
     std::shared_ptr<DIR> dp(dir, DirDeleter());
@@ -569,8 +571,7 @@ int DirNode::rename(const char *fromPlaintext, const char *toPlaintext) {
   }
 
   if (res != 0) {
-    VLOG(1) << "rename failed: " << strerror(errno);
-    res = -errno;
+    VLOG(1) << "rename failed: " << strerror(-res);
   }
 
   return res;
@@ -692,7 +693,7 @@ int DirNode::unlink(const char *plaintextName) {
     res = ::unlink(fullName.c_str());
     if (res == -1) {
       res = -errno;
-      VLOG(1) << "unlink error: " << strerror(errno);
+      VLOG(1) << "unlink error: " << strerror(-res);
     }
   }
 

encfs/FileNode.cpp

@@ -140,14 +140,16 @@ int FileNode::mknod(mode_t mode, dev_t rdev, uid_t uid, gid_t gid) {
   if (uid != 0) {
     olduid = setfsuid(uid);
     if (olduid == -1) {
-      RLOG(DEBUG) << "setfsuid error: " << strerror(errno);
+      int eno = errno;
+      RLOG(DEBUG) << "setfsuid error: " << strerror(eno);
       return -EPERM;
     }
   }
   if (gid != 0) {
     oldgid = setfsgid(gid);
     if (oldgid == -1) {
-      RLOG(DEBUG) << "setfsgid error: " << strerror(errno);
+      int eno = errno;
+      RLOG(DEBUG) << "setfsgid error: " << strerror(eno);
       return -EPERM;
     }
   }
@@ -165,15 +167,15 @@ int FileNode::mknod(mode_t mode, dev_t rdev, uid_t uid, gid_t gid) {
   else
     res = ::mknod(_cname.c_str(), mode, rdev);
 
-  if (olduid >= 0) setfsuid(olduid);
-  if (oldgid >= 0) setfsgid(oldgid);
-
   if (res == -1) {
     int eno = errno;
     VLOG(1) << "mknod error: " << strerror(eno);
     res = -eno;
   }
 
+  if (olduid >= 0) setfsuid(olduid);
+  if (oldgid >= 0) setfsgid(oldgid);
+
   return res;
 }
 

encfs/RawFileIO.cpp

@@ -92,13 +92,11 @@ static int open_readonly_workaround(const char *path, int flags) {
   memset(&stbuf, 0, sizeof(struct stat));
   if (lstat(path, &stbuf) != -1) {
     // make sure user has read/write permission..
-    chmod(path, stbuf.st_mode | 0600);
+    if (chmod(path, stbuf.st_mode | 0600) != -1) {
       fd = ::open(path, flags);
       chmod(path, stbuf.st_mode);
-  } else {
-    RLOG(INFO) << "can't stat file " << path;
     }
-
+  }
   return fd;
 }
 
@@ -131,10 +129,11 @@ int RawFileIO::open(int flags) {
 #endif
 
     int newFd = ::open(name.c_str(), finalFlags);
+    int eno = errno;
 
     VLOG(1) << "open file with flags " << finalFlags << ", result = " << newFd;
 
-    if ((newFd == -1) && (errno == EACCES)) {
+    if ((newFd == -1) && (eno == EACCES)) {
       VLOG(1) << "using readonly workaround for open";
       newFd = open_readonly_workaround(name.c_str(), finalFlags);
     }
@@ -152,7 +151,7 @@ int RawFileIO::open(int flags) {
       result = fd = newFd;
     } else {
       result = -errno;
-      RLOG(DEBUG) << "::open error: " << strerror(errno);
+      RLOG(DEBUG) << "::open error: " << strerror(-result);
     }
   }
 
@@ -185,8 +184,9 @@ off_t RawFileIO::getSize() const {
       const_cast<RawFileIO *>(this)->knownSize = true;
       return fileSize;
     } else {
-      RLOG(ERROR) << "getSize on " << name << " failed: " << strerror(errno);
-      return -1;
+      int eno = errno;
+      RLOG(ERROR) << "getSize on " << name << " failed: " << strerror(eno);
+      return -eno;
     }
   } else {
     return fileSize;
@@ -199,8 +199,9 @@ ssize_t RawFileIO::read(const IORequest &req) const {
   ssize_t readSize = pread(fd, req.data, req.dataLen, req.offset);
 
   if (readSize < 0) {
+    readSize = -errno;
     RLOG(WARNING) << "read failed at offset " << req.offset << " for "
-                  << req.dataLen << " bytes: " << strerror(errno);
+                  << req.dataLen << " bytes: " << strerror(-readSize);
   }
 
   return readSize;
@@ -254,9 +255,6 @@ int RawFileIO::truncate(off_t size) {
 
   if (fd >= 0 && canWrite) {
     res = ::ftruncate(fd, size);
-#if !defined(__FreeBSD__) && !defined(__APPLE__)
-    ::fdatasync(fd);
-#endif
   } else
     res = ::truncate(name.c_str(), size);
 
@@ -272,6 +270,12 @@ int RawFileIO::truncate(off_t size) {
     knownSize = true;
   }
 
+#if !defined(__FreeBSD__) && !defined(__APPLE__)
+  if (fd >= 0 && canWrite) {
+    ::fdatasync(fd);
+  }
+#endif
+
   return res;
 }
 

encfs/encfs.h

@@ -41,7 +41,8 @@ static __inline int setfsuid(uid_t uid) {
   uid_t olduid = geteuid();
 
   if (seteuid(uid) != 0) {
-    VLOG(1) << "seteuid error: " << errno;
+    int eno = errno;
+    VLOG(1) << "seteuid error: " << strerror(eno);
   }
 
   return olduid;
@@ -51,7 +52,8 @@ static __inline int setfsgid(gid_t gid) {
   gid_t oldgid = getegid();
 
   if (setegid(gid) != 0) {
-    VLOG(1) << "setfsgid error: " << errno;
+    int eno = errno;
+    VLOG(1) << "setfsgid error: " << strerror(eno);
   }
 
   return oldgid;

encfs/main.cpp

@@ -504,9 +504,10 @@ void *encfs_init(fuse_conn_info *conn) {
 
     int res = pthread_create(&ctx->monitorThread, 0, idleMonitor, (void *)ctx);
     if (res != 0) {
+      int eno = errno;
       RLOG(ERROR) << "error starting idle monitor thread, "
                      "res = "
-                  << res << ", errno = " << errno;
+                  << res << ", " << strerror(eno);
     }
   }