Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 186 insertions, 0 deletions

diff --git a/source3/modules/vfs_readahead.c b/source3/modules/vfs_readahead.c
new file mode 100644
index 0000000..bb31b57
--- /dev/null
+++ b/source3/modules/vfs_readahead.c
@@ -0,0 +1,186 @@
+/*
+ * Copyright (c) Jeremy Allison 2007.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "includes.h"
+#include "system/filesys.h"
+#include "smbd/smbd.h"
+
+#if defined(HAVE_LINUX_READAHEAD) && ! defined(HAVE_READAHEAD_DECL)
+ssize_t readahead(int fd, off_t offset, size_t count);
+#endif
+
+struct readahead_data {
+	off_t off_bound;
+	off_t len;
+	bool didmsg;
+};
+
+/* 
+ * This module copes with Vista AIO read requests on Linux
+ * by detecting the initial 0x80000 boundary reads and causing
+ * the buffer cache to be filled in advance.
+ */
+
+/*******************************************************************
+ sendfile wrapper that does readahead/posix_fadvise.
+*******************************************************************/
+
+static ssize_t readahead_sendfile(struct vfs_handle_struct *handle,
+					int tofd,
+					files_struct *fromfsp,
+					const DATA_BLOB *header,
+					off_t offset,
+					size_t count)
+{
+	struct readahead_data *rhd = (struct readahead_data *)handle->data;
+
+	if ( offset % rhd->off_bound == 0) {
+#if defined(HAVE_LINUX_READAHEAD)
+		int err = readahead(fsp_get_io_fd(fromfsp), offset, (size_t)rhd->len);
+		DEBUG(10,("readahead_sendfile: readahead on fd %u, offset %llu, len %u returned %d\n",
+			(unsigned int)fsp_get_io_fd(fromfsp),
+			(unsigned long long)offset,
+			(unsigned int)rhd->len,
+		        err ));
+#elif defined(HAVE_POSIX_FADVISE)
+		int err = posix_fadvise(fsp_get_io_fd(fromfsp), offset, (off_t)rhd->len, POSIX_FADV_WILLNEED);
+		DEBUG(10,("readahead_sendfile: posix_fadvise on fd %u, offset %llu, len %u returned %d\n",
+			(unsigned int)fsp_get_io_fd(fromfsp),
+			(unsigned long long)offset,
+			(unsigned int)rhd->len,
+			err ));
+#else
+		if (!rhd->didmsg) {
+			DEBUG(0,("readahead_sendfile: no readahead on this platform\n"));
+			rhd->didmsg = True;
+		}
+#endif
+	}
+	return SMB_VFS_NEXT_SENDFILE(handle,
+					tofd,
+					fromfsp,
+					header,
+					offset,
+					count);
+}
+
+/*******************************************************************
+ pread wrapper that does readahead/posix_fadvise.
+*******************************************************************/
+
+static ssize_t readahead_pread(vfs_handle_struct *handle,
+				files_struct *fsp,
+				void *data,
+				size_t count,
+				off_t offset)
+{
+	struct readahead_data *rhd = (struct readahead_data *)handle->data;
+
+	if ( offset % rhd->off_bound == 0) {
+#if defined(HAVE_LINUX_READAHEAD)
+		int err = readahead(fsp_get_io_fd(fsp), offset, (size_t)rhd->len);
+		DEBUG(10,("readahead_pread: readahead on fd %u, offset %llu, len %u returned %d\n",
+			(unsigned int)fsp_get_io_fd(fsp),
+			(unsigned long long)offset,
+			(unsigned int)rhd->len,
+			err ));
+#elif defined(HAVE_POSIX_FADVISE)
+		int err = posix_fadvise(fsp_get_io_fd(fsp), offset, (off_t)rhd->len, POSIX_FADV_WILLNEED);
+		DEBUG(10,("readahead_pread: posix_fadvise on fd %u, offset %llu, len %u returned %d\n",
+			(unsigned int)fsp_get_io_fd(fsp),
+			(unsigned long long)offset,
+			(unsigned int)rhd->len,
+			err ));
+#else
+		if (!rhd->didmsg) {
+			DEBUG(0,("readahead_pread: no readahead on this platform\n"));
+			rhd->didmsg = True;
+		}
+#endif
+        }
+        return SMB_VFS_NEXT_PREAD(handle, fsp, data, count, offset);
+}
+
+/*******************************************************************
+ Directly called from main smbd when freeing handle.
+*******************************************************************/
+
+static void free_readahead_data(void **pptr)
+{
+	SAFE_FREE(*pptr);
+}
+
+/*******************************************************************
+ Allocate the handle specific data so we don't call the expensive
+ conv_str_size function for each sendfile/pread.
+*******************************************************************/
+
+static int readahead_connect(struct vfs_handle_struct *handle,
+				const char *service,
+				const char *user)
+{
+	struct readahead_data *rhd;
+	int ret = SMB_VFS_NEXT_CONNECT(handle, service, user);
+
+	if (ret < 0) {
+		return ret;
+	}
+	rhd = SMB_MALLOC_P(struct readahead_data);
+	if (!rhd) {
+		SMB_VFS_NEXT_DISCONNECT(handle);
+		DEBUG(0,("readahead_connect: out of memory\n"));
+		return -1;
+	}
+	ZERO_STRUCTP(rhd);
+
+	rhd->didmsg = False;
+	rhd->off_bound = conv_str_size(lp_parm_const_string(SNUM(handle->conn),
+						"readahead",
+						"offset",
+						NULL));
+	if (rhd->off_bound == 0) {
+		rhd->off_bound = 0x80000;
+	}
+	rhd->len = conv_str_size(lp_parm_const_string(SNUM(handle->conn),
+						"readahead",
+						"length",
+						NULL));
+	if (rhd->len == 0) {
+		rhd->len = rhd->off_bound;
+	}
+
+	handle->data = (void *)rhd;
+	handle->free_data = free_readahead_data;
+	return 0;
+}
+
+static struct vfs_fn_pointers vfs_readahead_fns = {
+	.sendfile_fn = readahead_sendfile,
+	.pread_fn = readahead_pread,
+	.connect_fn = readahead_connect
+};
+
+/*******************************************************************
+ Module initialization boilerplate.
+*******************************************************************/
+
+static_decl_vfs;
+NTSTATUS vfs_readahead_init(TALLOC_CTX *ctx)
+{
+	return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "readahead",
+				&vfs_readahead_fns);
+}