2 * XFS preallocation support module.
4 * Copyright (c) James Peach 2006
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
21 #include "system/filesys.h"
22 #include "smbd/smbd.h"
24 /* Extent preallocation module.
26 * The purpose of this module is to preallocate space on the filesystem when
27 * we have a good idea of how large files are supposed to be. This lets writes
28 * proceed without having to allocate new extents and results in better file
31 * Currently only implemented for XFS. This module is based on an original idea
32 * and implementation by Sebastian Brings.
36 * prealloc: <ext> Number of bytes to preallocate for a file with
37 * the matching extension.
38 * prealloc:debug Debug level at which to emit messages.
42 * prealloc:mpeg = 500M # Preallocate *.mpeg to 500 MiB.
45 #ifdef HAVE_XFS_LIBXFS_H
46 #include <xfs/libxfs.h>
47 #define lock_type xfs_flock64_t
49 #define lock_type struct flock64
56 #define MODULE "prealloc"
57 static int module_debug;
59 static int preallocate_space(int fd, off_t size)
69 fl.l_whence = SEEK_SET;
73 /* IMPORTANT: We use RESVSP because we want the extents to be
74 * allocated, but we don't want the allocation to show up in
75 * st_size or persist after the close(2).
78 #if defined(XFS_IOC_RESVSP64)
79 /* On Linux this comes in via libxfs.h. */
80 err = xfsctl(NULL, fd, XFS_IOC_RESVSP64, &fl);
81 #elif defined(F_RESVSP64)
82 /* On IRIX, this comes from fcntl.h. */
83 err = fcntl(fd, F_RESVSP64, &fl);
88 #else /* GPFS uses completely different interface */
89 err = gpfs_prealloc(fd, (gpfs_off64_t)0, (gpfs_off64_t)size);
94 ("%s: preallocate failed on fd=%d size=%lld: %s\n",
95 MODULE, fd, (long long)size, strerror(errno)));
101 static int prealloc_connect(
102 struct vfs_handle_struct * handle,
103 const char * service,
106 int ret = SMB_VFS_NEXT_CONNECT(handle, service, user);
112 module_debug = lp_parm_int(SNUM(handle->conn),
113 MODULE, "debug", 100);
118 static int prealloc_open(vfs_handle_struct* handle,
119 struct smb_filename *smb_fname,
130 if (!(flags & (O_CREAT|O_TRUNC))) {
131 /* Caller is not intending to rewrite the file. Let's not mess
132 * with the allocation in this case.
138 dot = strrchr(smb_fname->base_name, '.');
140 if (strlen(dot) < sizeof(fext)) {
141 strncpy(fext, dot, sizeof(fext));
142 if (!strnorm(fext, CASE_LOWER)) {
152 /* Syntax for specifying preallocation size is:
153 * MODULE: <extension> = <size>
155 * <extension> is the file extension in lower case
156 * <size> is a size like 10, 10K, 10M
158 size = conv_str_size(lp_parm_const_string(SNUM(handle->conn), MODULE,
161 /* No need to preallocate this file. */
165 fd = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
170 /* Prellocate only if the file is being created or replaced. Note that
171 * Samba won't ever pass down O_TRUNC, which is why we have to handle
172 * truncate calls specially.
174 if ((flags & O_CREAT) || (flags & O_TRUNC)) {
177 psize = VFS_ADD_FSP_EXTENSION(handle, fsp, off_t, NULL);
178 if (psize == NULL || *psize == -1) {
183 ("%s: preallocating %s (fd=%d) to %lld bytes\n",
184 MODULE, smb_fname_str_dbg(smb_fname), fd,
188 if (preallocate_space(fd, *psize) < 0) {
189 VFS_REMOVE_FSP_EXTENSION(handle, fsp);
196 /* We are not creating or replacing a file. Skip the
199 DEBUG(module_debug, ("%s: skipping preallocation for %s\n",
200 MODULE, smb_fname_str_dbg(smb_fname)));
201 return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
204 static int prealloc_ftruncate(vfs_handle_struct * handle,
209 int ret = SMB_VFS_NEXT_FTRUNCATE(handle, fsp, offset);
211 /* Maintain the allocated space even in the face of truncates. */
212 if ((psize = VFS_FETCH_FSP_EXTENSION(handle, fsp))) {
213 preallocate_space(fsp->fh->fd, *psize);
219 static struct vfs_fn_pointers prealloc_fns = {
220 .open_fn = prealloc_open,
221 .ftruncate_fn = prealloc_ftruncate,
222 .connect_fn = prealloc_connect,
225 NTSTATUS vfs_prealloc_init(void);
226 NTSTATUS vfs_prealloc_init(void)
228 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
229 MODULE, &prealloc_fns);