From: Akihiro Sagawa <sagawa.aki@gmail.com>
Subject: [PATCH 1/4] server: Implement access pattern hints for file data.
Message-Id: <20191212223839.105D.375B48EC@gmail.com>
Date: Thu, 12 Dec 2019 22:39:35 +0900

Signed-off-by: Akihiro Sagawa <sagawa.aki@gmail.com>
---
 configure               |  1 +
 configure.ac            |  1 +
 dlls/ntdll/tests/file.c |  2 ++
 include/config.h.in     |  3 +++
 server/fd.c             | 19 +++++++++++++++++++
 5 files changed, 26 insertions(+)

diff --git a/configure b/configure
index a5c504b..cb34665 100755
--- a/configure
+++ b/configure
@@ -17710,6 +17710,7 @@ for ac_func in \
 	pipe2 \
 	poll \
 	port_create \
+	posix_fadvise \
 	prctl \
 	pread \
 	proc_pidinfo \
diff --git a/configure.ac b/configure.ac
index 13f9718..47c1dc0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2161,6 +2161,7 @@ AC_CHECK_FUNCS(\
 	pipe2 \
 	poll \
 	port_create \
+	posix_fadvise \
 	prctl \
 	pread \
 	proc_pidinfo \
diff --git a/dlls/ntdll/tests/file.c b/dlls/ntdll/tests/file.c
index 539ce44..1d42058 100644
--- a/dlls/ntdll/tests/file.c
+++ b/dlls/ntdll/tests/file.c
@@ -3744,6 +3744,8 @@ static void test_file_mode(void)
         { &file_name, FILE_SYNCHRONOUS_IO_ALERT, FILE_SYNCHRONOUS_IO_ALERT },
         { &file_name, FILE_NO_INTERMEDIATE_BUFFERING, FILE_NO_INTERMEDIATE_BUFFERING },
         { &file_name, FILE_SYNCHRONOUS_IO_NONALERT | FILE_NON_DIRECTORY_FILE, FILE_SYNCHRONOUS_IO_NONALERT },
+        { &file_name, FILE_RANDOM_ACCESS | FILE_SEQUENTIAL_ONLY, FILE_SEQUENTIAL_ONLY },
+        { &file_name, FILE_SEQUENTIAL_ONLY, FILE_SEQUENTIAL_ONLY },
         { &file_name, FILE_DELETE_ON_CLOSE, 0 },
         { &file_name, FILE_RANDOM_ACCESS | FILE_NO_COMPRESSION, 0 },
         { &pipe_dev_name, 0, 0 },
diff --git a/include/config.h.in b/include/config.h.in
index 63396e9..3550b52 100644
--- a/include/config.h.in
+++ b/include/config.h.in
@@ -707,6 +707,9 @@
 /* Define to 1 if you have the <port.h> header file. */
 #undef HAVE_PORT_H
 
+/* Define to 1 if you have the `posix_fadvise' function. */
+#undef HAVE_POSIX_FADVISE
+
 /* Define to 1 if you have the `powl' function. */
 #undef HAVE_POWL
 
diff --git a/server/fd.c b/server/fd.c
index 5d80e21..dd0e662 100644
--- a/server/fd.c
+++ b/server/fd.c
@@ -1756,6 +1756,9 @@ struct fd *open_fd( struct fd *root, const char *name, int flags, mode_t *mode,
     struct fd *fd;
     int root_fd = -1;
     int rw_mode;
+#ifdef HAVE_POSIX_FADVISE
+    int advice = POSIX_FADV_NORMAL;
+#endif
 
     if (((options & FILE_DELETE_ON_CLOSE) && !(access & DELETE)) ||
         ((options & FILE_DIRECTORY_FILE) && (flags & O_TRUNC)))
@@ -1894,6 +1897,22 @@ struct fd *open_fd( struct fd *root, const char *name, int flags, mode_t *mode,
         free( closed_fd );
         fd->cacheable = 1;
     }
+
+#ifdef HAVE_POSIX_FADVISE
+    /* hint file access patterns */
+    switch (options & (FILE_SEQUENTIAL_ONLY | FILE_RANDOM_ACCESS))
+    {
+    case FILE_SEQUENTIAL_ONLY:
+        advice = POSIX_FADV_SEQUENTIAL;
+        break;
+    case FILE_RANDOM_ACCESS:
+        advice = POSIX_FADV_RANDOM;
+        break;
+    }
+    if (advice != POSIX_FADV_NORMAL)
+        posix_fadvise(fd->unix_fd, 0, 0, advice);
+#endif
+
     if (root_fd != -1) fchdir( server_dir_fd ); /* go back to the server dir */
     return fd;