rocfile: Untangle rocFileIo(...) and Fallback backend tests.

rocfile/src/backend/fallback.cpp

@@ -50,19 +50,24 @@ ssize_t
 Fallback::io(IoType io_type, shared_ptr<IFile> file, shared_ptr<IBuffer> buffer, size_t size,
              hoff_t file_offset, hoff_t buffer_offset, size_t chunk_size)
 {
+    size_t buflen{buffer->getLength()};
+
     size = min(size, rocFile::MAX_RW_COUNT);
 
-    if ((buffer_offset < 0) || (buffer->getLength() <= static_cast<size_t>(buffer_offset)) ||
-        (buffer->getLength() - static_cast<size_t>(buffer_offset) < size)) {
-        throw std::invalid_argument("bad buffer offset");
+    if (file_offset < 0) {
+        throw std::invalid_argument("Negative file offset");
     }
 
-    if (file_offset < 0) {
-        throw std::invalid_argument("negative file offset");
+    if (buffer_offset < 0) {
+        throw std::invalid_argument("Negative buffer offset");
     }
 
-    if (size == 0) {
-        return 0;
+    if (buflen <= static_cast<size_t>(buffer_offset)) {
+        throw std::invalid_argument("Buffer offset larger than buffer length");
+    }
+
+    if (buflen - static_cast<size_t>(buffer_offset) < size) {
+        throw std::invalid_argument("IO could overflow buffer");
     }
 
     auto ptr     = Context<Sys>::get()->mmap(nullptr, chunk_size, PROT_READ | PROT_WRITE,
@@ -71,7 +76,7 @@ Fallback::io(IoType io_type, shared_ptr<IFile> file, shared_ptr<IBuffer> buffer,
     unique_ptr<void, decltype(deleter)> bounce_buffer{ptr, deleter};
 
     ssize_t total_io_bytes = 0;
-    while (static_cast<size_t>(total_io_bytes) < size) {
+    do {
         auto    count                  = min(chunk_size, size - static_cast<size_t>(total_io_bytes));
         auto    offset                 = file_offset + total_io_bytes;
         ssize_t io_bytes               = 0;
@@ -108,7 +113,7 @@ Fallback::io(IoType io_type, shared_ptr<IFile> file, shared_ptr<IBuffer> buffer,
         if (io_bytes == 0) {
             break;
         }
-    }
+    } while (static_cast<size_t>(total_io_bytes) < size);
 
     return total_io_bytes;
 }

rocfile/src/backend/fastpath.cpp

@@ -130,9 +130,6 @@ Fastpath::score(shared_ptr<IFile> file, shared_ptr<IBuffer> buffer, size_t size,
 
     accept_io &= buffer->getType() == hipMemoryTypeDevice;
 
-    accept_io &= 0 <= file_offset;
-    accept_io &= 0 <= buffer_offset;
-
 #if defined(STATX_DIOALIGN)
     const struct statx &stx{file->getStatx()};
     accept_io &= !!(stx.stx_mask & STATX_DIOALIGN);
@@ -156,9 +153,26 @@ Fastpath::io(IoType type, shared_ptr<IFile> file, shared_ptr<IBuffer> buffer, si
     void *devptr{reinterpret_cast<void *>(reinterpret_cast<intptr_t>(buffer->getBuffer()) + buffer_offset)};
     hipAmdFileHandle_t handle{};
     size_t             nbytes{};
+    size_t             buflen{buffer->getLength()};
 
     handle.fd = file->getFd();
 
+    if (file_offset < 0) {
+        throw std::invalid_argument("Negative file offset");
+    }
+
+    if (buffer_offset < 0) {
+        throw std::invalid_argument("Negative buffer offset");
+    }
+
+    if (buflen <= static_cast<size_t>(buffer_offset)) {
+        throw std::invalid_argument("Invalid buffer offset");
+    }
+
+    if (buflen - static_cast<size_t>(buffer_offset) < size) {
+        throw std::invalid_argument("IO could overflow buffer");
+    }
+
     switch (type) {
         case IoType::Read:
             nbytes = Context<Hip>::get()->hipAmdFileRead(handle, devptr, size, file_offset);

rocfile/src/rocfile-private.h

@@ -8,10 +8,13 @@
 #include "hipfile-types.h"
 #include "rocfile.h"
 
+#include <memory>
 #include <sys/types.h>
+#include <vector>
 
 namespace rocFile {
 enum class IoType;
+struct Backend;
 }
 
 // NOTE: This is an internal API that we don't document, even though it's
@@ -24,4 +27,5 @@ ROCFILE_API
 void rocFileEnsureDriverInitPrivate();
 
 ssize_t rocFileIo(rocFile::IoType type, rocFileHandle_t fh, const void *buffer_base, size_t size,
-                  hoff_t file_offset, hoff_t buffer_offset);
+                  hoff_t file_offset, hoff_t buffer_offset,
+                  const std::vector<std::shared_ptr<rocFile::Backend>> &backends);

rocfile/src/rocfile.cpp

@@ -24,6 +24,7 @@
 #include <system_error>
 
 using namespace rocFile;
+using namespace std;
 
 const char *
 rocFileOpStatusError(rocFileOpError_t status)
@@ -224,14 +225,20 @@ catch (...) {
     return handle_exception();
 }
 
-ssize_t
-rocFileIo(IoType type, rocFileHandle_t fh, const void *buffer_base, size_t size, hoff_t file_offset,
-          hoff_t buffer_offset)
-try {
+/// @brief Get the cached list of backends obtained from DriverState
+static const vector<shared_ptr<Backend>> &
+getCachedBackends()
+{
     HIPFILE_WARN_NO_EXIT_DTOR_OFF
     static const auto backends{Context<DriverState>::get()->getBackends()};
     HIPFILE_WARN_NO_EXIT_DTOR_ON
+    return backends;
+}
 
+ssize_t
+rocFileIo(IoType type, rocFileHandle_t fh, const void *buffer_base, size_t size, hoff_t file_offset,
+          hoff_t buffer_offset, const vector<shared_ptr<Backend>> &backends)
+try {
     auto [file, buffer] = Context<DriverState>::get()->getFileAndBuffer(fh, buffer_base, size, 0);
     int                      score{-1};
     std::shared_ptr<Backend> backend{};
@@ -288,14 +295,14 @@ catch (...) {
 ssize_t
 rocFileRead(rocFileHandle_t fh, void *buffer_base, size_t size, hoff_t file_offset, hoff_t buffer_offset)
 {
-    return rocFileIo(IoType::Read, fh, buffer_base, size, file_offset, buffer_offset);
+    return rocFileIo(IoType::Read, fh, buffer_base, size, file_offset, buffer_offset, getCachedBackends());
 }
 
 ssize_t
 rocFileWrite(rocFileHandle_t fh, const void *buffer_base, size_t size, hoff_t file_offset,
              hoff_t buffer_offset)
 {
-    return rocFileIo(IoType::Write, fh, buffer_base, size, file_offset, buffer_offset);
+    return rocFileIo(IoType::Write, fh, buffer_base, size, file_offset, buffer_offset, getCachedBackends());
 }
 
 rocFileError_t

rocfile/test/CMakeLists.txt

@@ -21,8 +21,8 @@ set(TEST_SOURCE_FILES
     driver.cpp
     handle.cpp
     hip.cpp
+    fallback.cpp
     fastpath.cpp
-    io.cpp
     misc.cpp
     mountinfo.cpp
     rocfile.cpp