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samba-mirror/source3/modules/vfs_prealloc.c
Christof Schmitt 618af83d1b vfs_prealloc: Remove call to gpfs_prealloc
Calling gpfs_prealloc changes the actual size of the file, and this
should not be done implicitly. Also this code does not compile due to
the missing dependency to the gpfs library. The best way solution here
is probably removing the call to gpfs_prealloc. The vfs_gpfs module
already implements the call to gpfs_prelloc when this can be done
safely.

Signed-off-by: Christof Schmitt <cs@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Wed Feb 11 02:03:09 CET 2015 on sn-devel-104
2015-02-11 02:03:08 +01:00

222 lines
5.4 KiB
C

/*
* XFS preallocation support module.
*
* Copyright (c) James Peach 2006
*
* 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"
#include "system/filesys.h"
#include "smbd/smbd.h"
/* Extent preallocation module.
*
* The purpose of this module is to preallocate space on the filesystem when
* we have a good idea of how large files are supposed to be. This lets writes
* proceed without having to allocate new extents and results in better file
* layouts on disk.
*
* Currently only implemented for XFS. This module is based on an original idea
* and implementation by Sebastian Brings.
*
* Tunables.
*
* prealloc: <ext> Number of bytes to preallocate for a file with
* the matching extension.
* prealloc:debug Debug level at which to emit messages.
*
* Example.
*
* prealloc:mpeg = 500M # Preallocate *.mpeg to 500 MiB.
*/
#ifdef HAVE_XFS_LIBXFS_H
#include <xfs/libxfs.h>
#define lock_type xfs_flock64_t
#else
#define lock_type struct flock64
#endif
#define MODULE "prealloc"
static int module_debug;
static int preallocate_space(int fd, off_t size)
{
int err;
lock_type fl = {0};
if (size <= 0) {
return 0;
}
fl.l_whence = SEEK_SET;
fl.l_start = 0;
fl.l_len = size;
/* IMPORTANT: We use RESVSP because we want the extents to be
* allocated, but we don't want the allocation to show up in
* st_size or persist after the close(2).
*/
#if defined(XFS_IOC_RESVSP64)
/* On Linux this comes in via libxfs.h. */
err = xfsctl(NULL, fd, XFS_IOC_RESVSP64, &fl);
#elif defined(F_RESVSP64)
/* On IRIX, this comes from fcntl.h. */
err = fcntl(fd, F_RESVSP64, &fl);
#else
err = -1;
errno = ENOSYS;
#endif
if (err) {
DEBUG(module_debug,
("%s: preallocate failed on fd=%d size=%lld: %s\n",
MODULE, fd, (long long)size, strerror(errno)));
}
return err;
}
static int prealloc_connect(
struct vfs_handle_struct * handle,
const char * service,
const char * user)
{
int ret = SMB_VFS_NEXT_CONNECT(handle, service, user);
if (ret < 0) {
return ret;
}
module_debug = lp_parm_int(SNUM(handle->conn),
MODULE, "debug", 100);
return 0;
}
static int prealloc_open(vfs_handle_struct* handle,
struct smb_filename *smb_fname,
files_struct * fsp,
int flags,
mode_t mode)
{
int fd;
off_t size = 0;
const char * dot;
char fext[10];
if (!(flags & (O_CREAT|O_TRUNC))) {
/* Caller is not intending to rewrite the file. Let's not mess
* with the allocation in this case.
*/
goto normal_open;
}
*fext = '\0';
dot = strrchr(smb_fname->base_name, '.');
if (dot && *++dot) {
if (strlen(dot) < sizeof(fext)) {
strncpy(fext, dot, sizeof(fext));
if (!strnorm(fext, CASE_LOWER)) {
goto normal_open;
}
}
}
if (*fext == '\0') {
goto normal_open;
}
/* Syntax for specifying preallocation size is:
* MODULE: <extension> = <size>
* where
* <extension> is the file extension in lower case
* <size> is a size like 10, 10K, 10M
*/
size = conv_str_size(lp_parm_const_string(SNUM(handle->conn), MODULE,
fext, NULL));
if (size <= 0) {
/* No need to preallocate this file. */
goto normal_open;
}
fd = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
if (fd < 0) {
return fd;
}
/* Prellocate only if the file is being created or replaced. Note that
* Samba won't ever pass down O_TRUNC, which is why we have to handle
* truncate calls specially.
*/
if ((flags & O_CREAT) || (flags & O_TRUNC)) {
off_t * psize;
psize = VFS_ADD_FSP_EXTENSION(handle, fsp, off_t, NULL);
if (psize == NULL || *psize == -1) {
return fd;
}
DEBUG(module_debug,
("%s: preallocating %s (fd=%d) to %lld bytes\n",
MODULE, smb_fname_str_dbg(smb_fname), fd,
(long long)size));
*psize = size;
if (preallocate_space(fd, *psize) < 0) {
VFS_REMOVE_FSP_EXTENSION(handle, fsp);
}
}
return fd;
normal_open:
/* We are not creating or replacing a file. Skip the
* preallocation.
*/
DEBUG(module_debug, ("%s: skipping preallocation for %s\n",
MODULE, smb_fname_str_dbg(smb_fname)));
return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
}
static int prealloc_ftruncate(vfs_handle_struct * handle,
files_struct * fsp,
off_t offset)
{
off_t *psize;
int ret = SMB_VFS_NEXT_FTRUNCATE(handle, fsp, offset);
/* Maintain the allocated space even in the face of truncates. */
if ((psize = VFS_FETCH_FSP_EXTENSION(handle, fsp))) {
preallocate_space(fsp->fh->fd, *psize);
}
return ret;
}
static struct vfs_fn_pointers prealloc_fns = {
.open_fn = prealloc_open,
.ftruncate_fn = prealloc_ftruncate,
.connect_fn = prealloc_connect,
};
NTSTATUS vfs_prealloc_init(void);
NTSTATUS vfs_prealloc_init(void)
{
return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
MODULE, &prealloc_fns);
}