/* * 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" struct readahead_data { SMB_OFF_T off_bound; SMB_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, SMB_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(fromfsp->fh->fd, offset, (size_t)rhd->len); DEBUG(10,("readahead_sendfile: readahead on fd %u, offset %llu, len %u returned %d\n", (unsigned int)fromfsp->fh->fd, (unsigned long long)offset, (unsigned int)rhd->len, err )); #elif defined(HAVE_POSIX_FADVISE) int err = posix_fadvise(fromfsp->fh->fd, 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)fromfsp->fh->fd, (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, SMB_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->fh->fd, offset, (size_t)rhd->len); DEBUG(10,("readahead_pread: readahead on fd %u, offset %llu, len %u returned %d\n", (unsigned int)fsp->fh->fd, (unsigned long long)offset, (unsigned int)rhd->len, err )); #elif defined(HAVE_POSIX_FADVISE) int err = posix_fadvise(fsp->fh->fd, 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->fh->fd, (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 = readahead_sendfile, .pread = readahead_pread, .connect_fn = readahead_connect }; /******************************************************************* Module initialization boilerplate. *******************************************************************/ NTSTATUS vfs_readahead_init(void); NTSTATUS vfs_readahead_init(void) { return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "readahead", &vfs_readahead_fns); }