rocfile: Use statx to get direct io alignment and size requirements

rocfile/src/backend/fastpath.cpp

@@ -13,16 +13,23 @@
 #include <cstdint>
 #include <fcntl.h>
 #include <hip/hip_runtime_api.h>
+#include <linux/stat.h>
 #include <stdexcept>
 
 using namespace rocFile;
 using namespace std;
 
 /* The fastpath backend is used when:
  *  - The file has been opened with the O_DIRECT flag
- *  - file_offset is 4KiB aligned
- *  - buffer_offset is 4KiB aligned
- *  - size is a multiple of 4KiB
+ *  - if statx contains direct io information
+ *      - statx indicates the file descriptor supports direct IO (see statx (2))
+ *      - file_offset is a multiple of stx_dio_offset_align (see statx (2))
+ *      - buffer_offset is a multiple of stx_dio_mem_align (see statx (2))
+ *      - size is a multiple of stx_dio_offset_align (see statx (2))
+ *  - if statx does not contain direct io information
+ *      - file_offset is a multiple of 4096
+ *      - buffer_offset is a multiple of 4096
+ *      - size is a multiple of 4096
  *  - The buffer type is hipMemoryTypeDevice
  *
  * When using the fastpath the IO flows through the following
@@ -126,9 +133,18 @@ Fastpath::score(shared_ptr<IFile> file, shared_ptr<IBuffer> buffer, size_t size,
     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);
+    accept_io &= stx.stx_dio_offset_align && stx.stx_dio_mem_align;
+    accept_io &= !(size & (stx.stx_dio_offset_align - 1));
+    accept_io &= !(file_offset & (stx.stx_dio_offset_align - 1));
+    accept_io &= !(buffer_offset & (stx.stx_dio_mem_align - 1));
+#else
     accept_io &= !(size & 0xFFF);
     accept_io &= !(file_offset & 0xFFF);
     accept_io &= !(buffer_offset & 0xFFF);
+#endif
 
     return accept_io ? 100 : -1;
 }

rocfile/src/file.cpp

@@ -13,6 +13,7 @@
 #include <fcntl.h>
 #include <iterator>
 #include <utility>
+#include <sys/sysmacros.h>
 #include <vector>
 
 using std::optional;
@@ -23,8 +24,16 @@ using std::vector;
 namespace rocFile {
 
 UnregisteredFile::UnregisteredFile(int fd)
-    : m_fd(fd), m_stat{Context<Sys>::get()->fstat(fd)}, m_flags{Context<Sys>::get()->fcntl(fd, F_GETFL, 0)},
-      m_mountinfo{Context<LibMountHelper>::get()->getMountInfo(m_stat.st_dev)}
+    : m_fd(fd), m_stx{Context<Sys>::get()->statx(fd, "", AT_EMPTY_PATH,
+#if defined(STATX_DIOALIGN)
+                                                 STATX_TYPE | STATX_MODE | STATX_DIOALIGN
+#else
+                                                 STATX_TYPE | STATX_MODE
+#endif
+                                                 )},
+      m_flags{Context<Sys>::get()->fcntl(fd, F_GETFL, 0)},
+      m_mountinfo{
+          Context<LibMountHelper>::get()->getMountInfo(makedev(m_stx.stx_dev_major, m_stx.stx_dev_minor))}
 {
 }
 
@@ -34,10 +43,10 @@ UnregisteredFile::getFd() const noexcept
     return m_fd;
 }
 
-struct stat
-UnregisteredFile::getStat() const noexcept
+struct statx
+UnregisteredFile::getStatx() const noexcept
 {
-    return m_stat;
+    return m_stx;
 }
 
 int
@@ -59,8 +68,7 @@ IFile::getHandle() const
 }
 
 File::File(const UnregisteredFile &uf)
-    : fd{uf.getFd()}, device{uf.getStat().st_dev}, mode{uf.getStat().st_mode}, status_flags{uf.getFlags()},
-      mountinfo{uf.getMountInfo()}
+    : fd{uf.getFd()}, stx{uf.getStatx()}, status_flags{uf.getFlags()}, mountinfo{uf.getMountInfo()}
 {
 }
 
@@ -70,16 +78,10 @@ File::getFd() const
     return fd;
 }
 
-dev_t
-File::getDevice() const
-{
-    return device;
-}
-
-mode_t
-File::getMode() const
+const struct statx &
+File::getStatx() const noexcept
 {
-    return mode;
+    return stx;
 }
 
 int

rocfile/src/file.h

@@ -8,11 +8,10 @@
 #include "rocfile.h"
 #include "mountinfo.h"
 
+#include <linux/stat.h>
 #include <memory>
 #include <optional>
 #include <stdexcept>
-#include <sys/stat.h>
-#include <sys/types.h>
 #include <unordered_map>
 
 namespace rocFile {
@@ -51,8 +50,8 @@ class UnregisteredFile {
     /// @return Returns the file descriptor
     int getFd() const noexcept;
 
-    /// @return Returns the information provided by fstat (2)
-    struct stat getStat() const noexcept;
+    /// @return Returns the information provided by statx (2)
+    struct statx getStatx() const noexcept;
 
     /// @return Returns the flags provided by fcntl (2)
     int getFlags() const noexcept;
@@ -64,8 +63,8 @@ class UnregisteredFile {
     /// @brief The file descriptor
     int m_fd;
 
-    /// @brief Information provided by fstat (2)
-    struct stat m_stat;
+    /// @brief Information provided by statx (2)
+    struct statx m_stx;
 
     /// @brief Flags provided by fcntl(2)
     int m_flags;
@@ -82,11 +81,10 @@ class IFile {
     /// @return The handle for this file
     virtual rocFileHandle_t getHandle() const;
 
-    virtual int                      getFd() const          = 0;
-    virtual dev_t                    getDevice() const      = 0;
-    virtual mode_t                   getMode() const        = 0;
-    virtual int                      getStatusFlags() const = 0;
-    virtual std::optional<MountInfo> getMountInfo() const   = 0;
+    virtual int                      getFd() const             = 0;
+    virtual const struct statx      &getStatx() const noexcept = 0;
+    virtual int                      getStatusFlags() const    = 0;
+    virtual std::optional<MountInfo> getMountInfo() const      = 0;
 };
 
 class File : public IFile {
@@ -103,8 +101,7 @@ class File : public IFile {
     File &operator=(File &&) = delete;
 
     virtual int                      getFd() const override;
-    virtual dev_t                    getDevice() const override;
-    virtual mode_t                   getMode() const override;
+    virtual const struct statx      &getStatx() const noexcept override;
     virtual int                      getStatusFlags() const override;
     virtual std::optional<MountInfo> getMountInfo() const override;
 
@@ -116,15 +113,8 @@ class File : public IFile {
     /// @brief The file descriptor
     int fd;
 
-    /// @brief The ID of the device containing file
-    ///
-    /// Used to lookup mount information. See fstat(2), inode(7), and proc_pid_mountinfo(5)
-    dev_t device;
-
-    /// @brief The file type and mode
-    ///
-    /// Specifies the file type (regular file, block device, ...) and mode. See fstat(2) and inode(7)
-    mode_t mode;
+    /// @brief File status information obtained from statx (2)
+    struct statx stx;
 
     /// @brief The file's status flags. See fcntl(2)
     ///

rocfile/src/sys.cpp

@@ -5,6 +5,7 @@
 
 #include "sys.h"
 
+#include <bits/statx-generic.h>
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <syslog.h>
@@ -69,4 +70,12 @@ Sys::fcntl(int fd, int op, uintptr_t arg) const
     return throwOn<Sys::RuntimeError>(-1, ::fcntl(fd, op, arg));
 }
 
+struct statx
+Sys::statx(int dirfd, const char *pathname, int flags, unsigned int mask) const
+{
+    struct statx statxbuf;
+    throwOn<Sys::RuntimeError>(-1, ::statx(dirfd, pathname, flags, mask, &statxbuf));
+    return statxbuf;
+}
+
 }

rocfile/src/sys.h

@@ -8,8 +8,8 @@
 #include <cerrno>
 #include <cstddef>
 #include <cstdint>
+#include <linux/stat.h>
 #include <stdexcept>
-
 #include <sys/stat.h>
 #include <sys/types.h>
 
@@ -33,7 +33,8 @@ struct Sys {
 
     virtual void syslog(int priority, const char *msg) const;
 
-    virtual struct stat fstat(int fd) const;
+    virtual struct stat  fstat(int fd) const;
+    virtual struct statx statx(int dirfd, const char *pathname, int flags, unsigned int mask) const;
 
     virtual int fcntl(int fd, int op, uintptr_t arg) const;
 

rocfile/test/driver.cpp

@@ -105,7 +105,7 @@ TEST_F(RocFileDriverAdmin, HandleRegisterBadFD)
     descr.handle.fd = -1;
     descr.type      = rocFileHandleTypeOpaqueFD;
 
-    EXPECT_CALL(msys, fstat).WillOnce(Throw(Sys::RuntimeError(EBADF)));
+    EXPECT_CALL(msys, statx).WillOnce(Throw(Sys::RuntimeError(EBADF)));
 
     ASSERT_EQ(rocFileUseCount(), 0);
     ASSERT_NE(rocFileHandleRegister(&handle, &descr), ROCFILE_SUCCESS);