2 * Copyright (c) Jeremy Allison 2007.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 #include "system/filesys.h"
20 #include "smbd/smbd.h"
22 struct readahead_data {
29 * This module copes with Vista AIO read requests on Linux
30 * by detecting the initial 0x80000 boundary reads and causing
31 * the buffer cache to be filled in advance.
34 /*******************************************************************
35 sendfile wrapper that does readahead/posix_fadvise.
36 *******************************************************************/
38 static ssize_t readahead_sendfile(struct vfs_handle_struct *handle,
40 files_struct *fromfsp,
41 const DATA_BLOB *header,
45 struct readahead_data *rhd = (struct readahead_data *)handle->data;
47 if ( offset % rhd->off_bound == 0) {
48 #if defined(HAVE_LINUX_READAHEAD)
49 int err = readahead(fromfsp->fh->fd, offset, (size_t)rhd->len);
50 DEBUG(10,("readahead_sendfile: readahead on fd %u, offset %llu, len %u returned %d\n",
51 (unsigned int)fromfsp->fh->fd,
52 (unsigned long long)offset,
53 (unsigned int)rhd->len,
55 #elif defined(HAVE_POSIX_FADVISE)
56 int err = posix_fadvise(fromfsp->fh->fd, offset, (off_t)rhd->len, POSIX_FADV_WILLNEED);
57 DEBUG(10,("readahead_sendfile: posix_fadvise on fd %u, offset %llu, len %u returned %d\n",
58 (unsigned int)fromfsp->fh->fd,
59 (unsigned long long)offset,
60 (unsigned int)rhd->len,
64 DEBUG(0,("readahead_sendfile: no readahead on this platform\n"));
69 return SMB_VFS_NEXT_SENDFILE(handle,
77 /*******************************************************************
78 pread wrapper that does readahead/posix_fadvise.
79 *******************************************************************/
81 static ssize_t readahead_pread(vfs_handle_struct *handle,
87 struct readahead_data *rhd = (struct readahead_data *)handle->data;
89 if ( offset % rhd->off_bound == 0) {
90 #if defined(HAVE_LINUX_READAHEAD)
91 int err = readahead(fsp->fh->fd, offset, (size_t)rhd->len);
92 DEBUG(10,("readahead_pread: readahead on fd %u, offset %llu, len %u returned %d\n",
93 (unsigned int)fsp->fh->fd,
94 (unsigned long long)offset,
95 (unsigned int)rhd->len,
97 #elif defined(HAVE_POSIX_FADVISE)
98 int err = posix_fadvise(fsp->fh->fd, offset, (off_t)rhd->len, POSIX_FADV_WILLNEED);
99 DEBUG(10,("readahead_pread: posix_fadvise on fd %u, offset %llu, len %u returned %d\n",
100 (unsigned int)fsp->fh->fd,
101 (unsigned long long)offset,
102 (unsigned int)rhd->len,
106 DEBUG(0,("readahead_pread: no readahead on this platform\n"));
111 return SMB_VFS_NEXT_PREAD(handle, fsp, data, count, offset);
114 /*******************************************************************
115 Directly called from main smbd when freeing handle.
116 *******************************************************************/
118 static void free_readahead_data(void **pptr)
123 /*******************************************************************
124 Allocate the handle specific data so we don't call the expensive
125 conv_str_size function for each sendfile/pread.
126 *******************************************************************/
128 static int readahead_connect(struct vfs_handle_struct *handle,
132 struct readahead_data *rhd;
133 int ret = SMB_VFS_NEXT_CONNECT(handle, service, user);
138 rhd = SMB_MALLOC_P(struct readahead_data);
140 SMB_VFS_NEXT_DISCONNECT(handle);
141 DEBUG(0,("readahead_connect: out of memory\n"));
147 rhd->off_bound = conv_str_size(lp_parm_const_string(SNUM(handle->conn),
151 if (rhd->off_bound == 0) {
152 rhd->off_bound = 0x80000;
154 rhd->len = conv_str_size(lp_parm_const_string(SNUM(handle->conn),
159 rhd->len = rhd->off_bound;
162 handle->data = (void *)rhd;
163 handle->free_data = free_readahead_data;
167 static struct vfs_fn_pointers vfs_readahead_fns = {
168 .sendfile = readahead_sendfile,
169 .pread = readahead_pread,
170 .connect_fn = readahead_connect
173 /*******************************************************************
174 Module initialization boilerplate.
175 *******************************************************************/
177 NTSTATUS vfs_readahead_init(void);
178 NTSTATUS vfs_readahead_init(void)
180 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "readahead",