diff options
Diffstat (limited to 'source3/modules')
| -rw-r--r-- | source3/modules/vfs_readahead.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/source3/modules/vfs_readahead.c b/source3/modules/vfs_readahead.c new file mode 100644 index 0000000000..5b08f004c4 --- /dev/null +++ b/source3/modules/vfs_readahead.c @@ -0,0 +1,117 @@ +/* + * 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 + +/* + * 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. + */ + +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) +{ + unsigned long off_bound = lp_parm_ulong(SNUM(handle->conn), "readahead", "offset", 0x80000); + if ( offset % off_bound == 0) { + unsigned long len = lp_parm_ulong(SNUM(handle->conn), "readahead", "length", off_bound); +#if defined(HAVE_LINUX_READAHEAD) + int err = readahead(fromfd, offset, (size_t)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)len, + err )); +#elif defined(HAVE_POSIX_FADVISE) + int err = posix_fadvise(fromfd, offset, (off_t)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)len, + err )); +#else + if (!didmsg) { + DEBUG(0,("readahead_sendfile: no readahead on this platform\n")); + didmsg = True; + } +#endif + } + return SMB_VFS_NEXT_SENDFILE(handle, + tofd, + fsp, + fromfd, + header, + offset, + count); +} + +static ssize_t readahead_pread(vfs_handle_struct *handle, + files_struct *fsp, + int fd, + void *data, + size_t count, + SMB_OFF_T offset) +{ + unsigned long off_bound = lp_parm_ulong(SNUM(handle->conn), "readahead", "offset", 0x80000); + if ( offset % off_bound == 0) { + unsigned long len = lp_parm_ulong(SNUM(handle->conn), "readahead", "length", off_bound); +#if defined(HAVE_LINUX_READAHEAD) + int err = readahead(fd, offset, (size_t)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)len, + err )); +#elif defined(HAVE_POSIX_FADVISE) + int err = posix_fadvise(fromfd, offset, (off_t)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)len, + (err )); +#else + if (!didmsg) { + DEBUG(0,("readahead_pread: no readahead on this platform\n")); + didmsg = True; + } +#endif + } + return SMB_VFS_NEXT_PREAD(handle, fsp, fd, data, count, offset); +} + +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(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP} +}; + +NTSTATUS vfs_readahead_init(void); +NTSTATUS vfs_readahead_init(void) +{ + return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "readahead", readahead_ops); +} |