tmp

velox/common/caching/SsdFile.cpp

@@ -492,6 +492,41 @@ bool SsdFile::write(
         << ", size: " << iovecs.size() << ", offset: " << offset
         << ", error code: " << errno
         << ", error string: " << folly::errnoStr(errno);
+    // 1. The file descriptor fd is not valid.
+    // 2. The array of buffers iov is null or has a null pointer in it.
+    // 3. The number of buffers iovcnt is less than 1 or greater than UIO_MAXIOV.
+    // 4. The offset offset is negative or greater than the size of the file.
+    auto fd = writeDataFile_->fd();
+    VELOX_SSD_CACHE_LOG(ERROR) << " fd " << fd;
+    int flags = fcntl(fd, F_GETFD);
+    VELOX_SSD_CACHE_LOG(ERROR) << "fd flags: " << flags << " err: " << folly::errnoStr(errno);
+    VELOX_SSD_CACHE_LOG(ERROR) << " iovecs ";
+    for (const auto &iovec :iovecs) {
+      VELOX_SSD_CACHE_LOG(ERROR) << "iov_base: " << iovec.iov_base << " iov_len " << iovec.iov_len;
+      ssize_t n = writev(fd, &iovec, 1);
+      if (n == -1) {
+        VELOX_SSD_CACHE_LOG(ERROR) << "[writev] n:"  << n << " -> "<< folly::errnoStr(errno);
+
+        ssize_t bytes_written;
+        char buf0[] = "short string\n";
+        char buf1[] = "This is a longer string\n";
+        char buf2[] = "This is the longest string in this example\n";
+        struct iovec iov[3];
+        iov[0].iov_base = buf0;
+        iov[0].iov_len = strlen(buf0);
+        iov[1].iov_base = buf1;
+        iov[1].iov_len = strlen(buf1);
+        iov[2].iov_base = buf2;
+        iov[2].iov_len = strlen(buf2);
+        int iovcnt = sizeof(iov) / sizeof(struct iovec);
+
+        bytes_written = writev(fd, iov, iovcnt);
+        VELOX_SSD_CACHE_LOG(ERROR) << "[writev] bytes_written:"  << bytes_written << " -> "<< folly::errnoStr(errno);;
+        exit(1);
+      }
+    }
+    VELOX_SSD_CACHE_LOG(ERROR) << " iovcnt " <<  iovecs.size();
+    VELOX_SSD_CACHE_LOG(ERROR) << " offset " <<  offset;
     ++stats_.writeSsdErrors;
     return false;
   }

velox/common/file/File.h

@@ -191,6 +191,10 @@ class WriteFile {
   /// be needed to get the exact size written, and this should be able to be
   /// called after the file close.
   virtual uint64_t size() const = 0;
+
+  virtual int32_t fd() {
+    VELOX_NYI("{} is not implemented", __FUNCTION__);
+  }
 };
 
 // We currently do a simple implementation for the in-memory files
@@ -349,6 +353,11 @@ class LocalWriteFile final : public WriteFile {
     return size_;
   }
 
+  int32_t fd() {
+    return fd_;
+  }
+
+
  private:
   // File descriptor.
   int32_t fd_{-1};