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/*
Unix SMB/Netbios implementation.
Version 1.9.
read/write to a files_struct
Copyright (C) Andrew Tridgell 1992-1998
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"
extern int DEBUGLEVEL;
/****************************************************************************
seek a file. Try to avoid the seek if possible
****************************************************************************/
SMB_OFF_T seek_file(files_struct *fsp,SMB_OFF_T pos)
{
SMB_OFF_T offset = 0;
SMB_OFF_T seek_ret;
if (fsp->print_file && lp_postscript(fsp->conn->service))
offset = 3;
seek_ret = sys_lseek(fsp->fd_ptr->fd,pos+offset,SEEK_SET);
/*
* We want to maintain the fiction that we can seek
* on a fifo for file system purposes. This allows
* people to set up UNIX fifo's that feed data to Windows
* applications. JRA.
*/
if((seek_ret == -1) && (errno == ESPIPE)) {
seek_ret = pos+offset;
errno = 0;
}
if((seek_ret == -1) || (seek_ret != pos+offset)) {
DEBUG(0,("seek_file: sys_lseek failed. Error was %s\n", strerror(errno) ));
fsp->pos = -1;
return -1;
}
fsp->pos = seek_ret - offset;
DEBUG(10,("seek_file: requested pos = %.0f, new pos = %.0f\n",
(double)(pos+offset), (double)fsp->pos ));
return(fsp->pos);
}
/****************************************************************************
read from a file
****************************************************************************/
ssize_t read_file(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
{
ssize_t ret=0,readret;
#if USE_READ_PREDICTION
if (!fsp->can_write) {
ret = read_predict(fsp->fd_ptr->fd,pos,data,NULL,n);
data += ret;
n -= ret;
pos += ret;
}
#endif
#if WITH_MMAP
if (fsp->mmap_ptr) {
SMB_OFF_T num = (fsp->mmap_size > pos) ? (fsp->mmap_size - pos) : 0;
num = MIN(n,num);
if (num > 0) {
memcpy(data,fsp->mmap_ptr+pos,num);
data += num;
pos += num;
n -= num;
ret += num;
}
}
#endif
if (seek_file(fsp,pos) == -1) {
DEBUG(3,("read_file: Failed to seek to %.0f\n",(double)pos));
return(ret);
}
if (n > 0) {
readret = read(fsp->fd_ptr->fd,data,n);
if (readret > 0) ret += readret;
}
return(ret);
}
/****************************************************************************
write to a file
****************************************************************************/
ssize_t write_file(files_struct *fsp, char *data, SMB_OFF_T pos, size_t n)
{
if (!fsp->can_write) {
errno = EPERM;
return(0);
}
if (!fsp->modified) {
SMB_STRUCT_STAT st;
fsp->modified = True;
if (sys_fstat(fsp->fd_ptr->fd,&st) == 0) {
int dosmode = dos_mode(fsp->conn,fsp->fsp_name,&st);
if (MAP_ARCHIVE(fsp->conn) && !IS_DOS_ARCHIVE(dosmode)) {
file_chmod(fsp->conn,fsp->fsp_name,dosmode | aARCH,&st);
}
}
}
/*
* If this file is level II oplocked then we need
* to grab the shared memory lock and inform all
* other files with a level II lock that they need
* to flush their read caches. We keep the lock over
* the shared memory area whilst doing this.
*/
if (LEVEL_II_OPLOCK_TYPE(fsp->oplock_type)) {
SMB_DEV_T dev = fsp->fd_ptr->dev;
SMB_INO_T inode = fsp->fd_ptr->inode;
share_mode_entry *share_list = NULL;
pid_t pid = getpid();
int token = -1;
int num_share_modes = 0;
int i;
if (lock_share_entry(fsp->conn, dev, inode, &token) == False) {
DEBUG(0,("write_file: failed to lock share mode entry for file %s.\n", fsp->fsp_name ));
}
num_share_modes = get_share_modes(fsp->conn, token, dev, inode, &share_list);
for(i = 0; i < num_share_modes; i++) {
share_mode_entry *share_entry = &share_list[i];
/*
* As there could have been multiple writes waiting at the lock_share_entry
* gate we may not be the first to enter. Hence the state of the op_types
* in the share mode entries may be partly NO_OPLOCK and partly LEVEL_II
* oplock. It will do no harm to re-send break messages to those smbd's
* that are still waiting their turn to remove their LEVEL_II state, and
* also no harm to ignore existing NO_OPLOCK states. JRA.
*/
if (share_entry->op_type == NO_OPLOCK)
continue;
/* Paranoia .... */
if (EXLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
DEBUG(0,("write_file: PANIC. share mode entry %d is an exlusive oplock !\n", i ));
abort();
}
/*
* Check if this is a file we have open (including the
* file we've been called to do write_file on. If so
* then break it directly without releasing the lock.
*/
if (pid == share_entry->pid) {
files_struct *new_fsp = file_find_dit(dev, inode, &share_entry->time);
/* Paranoia check... */
if(new_fsp == NULL) {
DEBUG(0,("write_file: PANIC. share mode entry %d is not a local file !\n", i ));
abort();
}
oplock_break_level2(new_fsp, True, token);
} else {
/*
* This is a remote file and so we send an asynchronous
* message.
*/
request_oplock_break(share_entry, dev, inode);
}
}
free((char *)share_list);
unlock_share_entry(fsp->conn, dev, inode, token);
}
/* Paranoia check... */
if (LEVEL_II_OPLOCK_TYPE(fsp->oplock_type)) {
DEBUG(0,("write_file: PANIC. File %s still has a level II oplock.\n", fsp->fsp_name));
abort();
}
if ((pos != -1) && (seek_file(fsp,pos) == -1))
return -1;
return(write_data(fsp->fd_ptr->fd,data,n));
}
/*******************************************************************
sync a file
********************************************************************/
void sync_file(connection_struct *conn, files_struct *fsp)
{
#ifdef HAVE_FSYNC
if(lp_strict_sync(SNUM(conn)) && fsp->fd_ptr != NULL)
fsync(fsp->fd_ptr->fd);
#endif
}
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