From 67d2cecbbe82e380509664ba8fd1e019e0aa724d Mon Sep 17 00:00:00 2001 From: Gerald Carter Date: Mon, 9 Apr 2007 17:08:02 +0000 Subject: r22141: add forgotten vfs_readahead file --- source/modules/vfs_readahead.c | 188 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 188 insertions(+) create mode 100644 source/modules/vfs_readahead.c diff --git a/source/modules/vfs_readahead.c b/source/modules/vfs_readahead.c new file mode 100644 index 00000000000..550562d03d0 --- /dev/null +++ b/source/modules/vfs_readahead.c @@ -0,0 +1,188 @@ +/* + * 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 2 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, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include "includes.h" + +#if !defined(HAVE_LINUX_READAHEAD) && !defined(HAVE_POSIX_FADVISE) +static BOOL didmsg; +#endif + +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 *fsp, + int fromfd, + 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(fromfd, offset, (size_t)rhd->len); + DEBUG(10,("readahead_sendfile: readahead on fd %u, offset %llu, len %u returned %d\n", + (unsigned int)fromfd, + (unsigned long long)offset, + (unsigned int)rhd->len, + err )); +#elif defined(HAVE_POSIX_FADVISE) + int err = posix_fadvise(fromfd, 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)fromfd, + (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, + fsp, + fromfd, + header, + offset, + count); +} + +/******************************************************************* + pread wrapper that does readahead/posix_fadvise. +*******************************************************************/ + +static ssize_t readahead_pread(vfs_handle_struct *handle, + files_struct *fsp, + int fd, + 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(fd, offset, (size_t)rhd->len); + DEBUG(10,("readahead_pread: readahead on fd %u, offset %llu, len %u returned %d\n", + (unsigned int)fd, + (unsigned long long)offset, + (unsigned int)rhd->len, + err )); +#elif defined(HAVE_POSIX_FADVISE) + int err = posix_fadvise(fromfd, 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)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, fd, 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 = SMB_MALLOC_P(struct readahead_data); + if (!rhd) { + 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; +} + +/******************************************************************* + Functions we're replacing. + We don't replace read as it isn't used from smbd to read file + data. +*******************************************************************/ + +static vfs_op_tuple readahead_ops [] = +{ + {SMB_VFS_OP(readahead_sendfile), SMB_VFS_OP_SENDFILE, SMB_VFS_LAYER_TRANSPARENT}, + {SMB_VFS_OP(readahead_pread), SMB_VFS_OP_PREAD, SMB_VFS_LAYER_TRANSPARENT}, + {SMB_VFS_OP(readahead_connect), SMB_VFS_OP_CONNECT, SMB_VFS_LAYER_TRANSPARENT}, + {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP} +}; + +/******************************************************************* + Module initialization boilerplate. +*******************************************************************/ + +NTSTATUS vfs_readahead_init(void); +NTSTATUS vfs_readahead_init(void) +{ + return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "readahead", readahead_ops); +} -- cgit