mirror of
https://github.com/samba-team/samba.git
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67e7e14e62
This is in preparation of making us survive base-delaywrite with async I/O activated Signed-off-by: Jeremy Allison <jra@samba.org>
1058 lines
26 KiB
C
1058 lines
26 KiB
C
/*
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Unix SMB/Netbios implementation.
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Version 1.9.
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read/write to a files_struct
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Copyright (C) Andrew Tridgell 1992-1998
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Copyright (C) Jeremy Allison 2000-2002. - write cache.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "includes.h"
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#include "printing.h"
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#include "smbd/smbd.h"
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#include "smbd/globals.h"
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#include "smbprofile.h"
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struct write_cache {
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off_t file_size;
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off_t offset;
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size_t alloc_size;
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size_t data_size;
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char *data;
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};
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static bool setup_write_cache(files_struct *, off_t);
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/****************************************************************************
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Read from write cache if we can.
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****************************************************************************/
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static bool read_from_write_cache(files_struct *fsp,char *data,off_t pos,size_t n)
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{
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struct write_cache *wcp = fsp->wcp;
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if(!wcp) {
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return False;
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}
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if( n > wcp->data_size || pos < wcp->offset || pos + n > wcp->offset + wcp->data_size) {
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return False;
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}
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memcpy(data, wcp->data + (pos - wcp->offset), n);
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DO_PROFILE_INC(writecache_read_hits);
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return True;
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}
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/****************************************************************************
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Read from a file.
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****************************************************************************/
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ssize_t read_file(files_struct *fsp,char *data,off_t pos,size_t n)
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{
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ssize_t ret = 0;
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/* you can't read from print files */
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if (fsp->print_file) {
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errno = EBADF;
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return -1;
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}
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/*
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* Serve from write cache if we can.
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*/
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if(read_from_write_cache(fsp, data, pos, n)) {
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fsp->fh->pos = pos + n;
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fsp->fh->position_information = fsp->fh->pos;
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return n;
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}
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flush_write_cache(fsp, READ_FLUSH);
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fsp->fh->pos = pos;
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if (n > 0) {
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ret = SMB_VFS_PREAD(fsp,data,n,pos);
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if (ret == -1) {
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return -1;
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}
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}
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DEBUG(10,("read_file (%s): pos = %.0f, size = %lu, returned %lu\n",
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fsp_str_dbg(fsp), (double)pos, (unsigned long)n, (long)ret));
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fsp->fh->pos += ret;
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fsp->fh->position_information = fsp->fh->pos;
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return(ret);
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}
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/****************************************************************************
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*Really* write to a file.
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****************************************************************************/
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static ssize_t real_write_file(struct smb_request *req,
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files_struct *fsp,
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const char *data,
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off_t pos,
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size_t n)
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{
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ssize_t ret;
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if (pos == -1) {
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ret = vfs_write_data(req, fsp, data, n);
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} else {
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fsp->fh->pos = pos;
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if (pos && lp_strict_allocate(SNUM(fsp->conn) &&
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!fsp->is_sparse)) {
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if (vfs_fill_sparse(fsp, pos) == -1) {
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return -1;
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}
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}
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ret = vfs_pwrite_data(req, fsp, data, n, pos);
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}
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DEBUG(10,("real_write_file (%s): pos = %.0f, size = %lu, returned %ld\n",
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fsp_str_dbg(fsp), (double)pos, (unsigned long)n, (long)ret));
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if (ret != -1) {
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fsp->fh->pos += ret;
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/* Yes - this is correct - writes don't update this. JRA. */
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/* Found by Samba4 tests. */
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#if 0
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fsp->position_information = fsp->pos;
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#endif
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}
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return ret;
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}
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/****************************************************************************
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File size cache change.
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Updates size on disk but doesn't flush the cache.
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****************************************************************************/
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static int wcp_file_size_change(files_struct *fsp)
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{
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int ret;
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struct write_cache *wcp = fsp->wcp;
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wcp->file_size = wcp->offset + wcp->data_size;
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ret = SMB_VFS_FTRUNCATE(fsp, wcp->file_size);
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if (ret == -1) {
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DEBUG(0,("wcp_file_size_change (%s): ftruncate of size %.0f "
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"error %s\n", fsp_str_dbg(fsp),
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(double)wcp->file_size, strerror(errno)));
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}
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return ret;
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}
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void update_write_time_handler(struct event_context *ctx,
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struct timed_event *te,
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struct timeval now,
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void *private_data)
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{
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files_struct *fsp = (files_struct *)private_data;
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DEBUG(5, ("Update write time on %s\n", fsp_str_dbg(fsp)));
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/* change the write time in the open file db. */
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(void)set_write_time(fsp->file_id, timespec_current());
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/* And notify. */
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notify_fname(fsp->conn, NOTIFY_ACTION_MODIFIED,
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FILE_NOTIFY_CHANGE_LAST_WRITE, fsp->fsp_name->base_name);
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/* Remove the timed event handler. */
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TALLOC_FREE(fsp->update_write_time_event);
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}
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/*********************************************************
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Schedule a write time update for WRITE_TIME_UPDATE_USEC_DELAY
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in the future.
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*********************************************************/
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void trigger_write_time_update(struct files_struct *fsp)
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{
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int delay;
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if (fsp->posix_open) {
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/* Don't use delayed writes on POSIX files. */
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return;
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}
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if (fsp->write_time_forced) {
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/* No point - "sticky" write times
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* in effect.
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*/
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return;
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}
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/* We need to remember someone did a write
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* and update to current time on close. */
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fsp->update_write_time_on_close = true;
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if (fsp->update_write_time_triggered) {
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/*
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* We only update the write time after 2 seconds
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* on the first normal write. After that
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* no other writes affect this until close.
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*/
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return;
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}
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fsp->update_write_time_triggered = true;
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delay = lp_parm_int(SNUM(fsp->conn),
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"smbd", "writetimeupdatedelay",
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WRITE_TIME_UPDATE_USEC_DELAY);
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DEBUG(5, ("Update write time %d usec later on %s\n",
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delay, fsp_str_dbg(fsp)));
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/* trigger the update 2 seconds later */
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fsp->update_write_time_event =
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tevent_add_timer(fsp->conn->sconn->ev_ctx, NULL,
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timeval_current_ofs_usec(delay),
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update_write_time_handler, fsp);
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}
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void trigger_write_time_update_immediate(struct files_struct *fsp)
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{
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struct smb_file_time ft;
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if (fsp->posix_open) {
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/* Don't use delayed writes on POSIX files. */
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return;
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}
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if (fsp->write_time_forced) {
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/*
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* No point - "sticky" write times
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* in effect.
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*/
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return;
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}
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TALLOC_FREE(fsp->update_write_time_event);
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DEBUG(5, ("Update write time immediate on %s\n",
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fsp_str_dbg(fsp)));
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/* After an immediate update, reset the trigger. */
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fsp->update_write_time_triggered = true;
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fsp->update_write_time_on_close = false;
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ZERO_STRUCT(ft);
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ft.mtime = timespec_current();
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/* Update the time in the open file db. */
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(void)set_write_time(fsp->file_id, ft.mtime);
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/* Now set on disk - takes care of notify. */
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(void)smb_set_file_time(fsp->conn, fsp, fsp->fsp_name, &ft, false);
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}
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void mark_file_modified(files_struct *fsp)
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{
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int dosmode;
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if (fsp->modified) {
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return;
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}
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fsp->modified = true;
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if (SMB_VFS_FSTAT(fsp, &fsp->fsp_name->st) != 0) {
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return;
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}
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trigger_write_time_update(fsp);
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if (fsp->posix_open) {
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return;
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}
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if (!(lp_store_dos_attributes(SNUM(fsp->conn)) ||
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MAP_ARCHIVE(fsp->conn))) {
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return;
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}
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dosmode = dos_mode(fsp->conn, fsp->fsp_name);
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if (IS_DOS_ARCHIVE(dosmode)) {
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return;
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}
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file_set_dosmode(fsp->conn, fsp->fsp_name,
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dosmode | FILE_ATTRIBUTE_ARCHIVE, NULL, false);
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}
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/****************************************************************************
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Write to a file.
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****************************************************************************/
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ssize_t write_file(struct smb_request *req,
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files_struct *fsp,
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const char *data,
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off_t pos,
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size_t n)
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{
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struct write_cache *wcp = fsp->wcp;
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ssize_t total_written = 0;
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int write_path = -1;
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if (fsp->print_file) {
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uint32_t t;
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int ret;
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ret = print_spool_write(fsp, data, n, pos, &t);
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if (ret) {
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errno = ret;
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return -1;
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}
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return t;
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}
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if (!fsp->can_write) {
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errno = EPERM;
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return -1;
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}
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/*
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* If this is the first write and we have an exclusive oplock
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* then setup the write cache.
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*/
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if (!fsp->modified &&
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EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) &&
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(wcp == NULL)) {
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setup_write_cache(fsp, fsp->fsp_name->st.st_ex_size);
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wcp = fsp->wcp;
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}
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mark_file_modified(fsp);
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#ifdef WITH_PROFILE
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DO_PROFILE_INC(writecache_total_writes);
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if (!fsp->oplock_type) {
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DO_PROFILE_INC(writecache_non_oplock_writes);
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}
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#endif
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/*
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* If this file is level II oplocked then we need
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* to grab the shared memory lock and inform all
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* other files with a level II lock that they need
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* to flush their read caches. We keep the lock over
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* the shared memory area whilst doing this.
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*/
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/* This should actually be improved to span the write. */
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contend_level2_oplocks_begin(fsp, LEVEL2_CONTEND_WRITE);
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contend_level2_oplocks_end(fsp, LEVEL2_CONTEND_WRITE);
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#ifdef WITH_PROFILE
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if (profile_p && profile_p->writecache_total_writes % 500 == 0) {
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DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u total=%u \
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nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n",
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profile_p->writecache_init_writes,
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profile_p->writecache_abutted_writes,
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profile_p->writecache_total_writes,
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profile_p->writecache_non_oplock_writes,
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profile_p->writecache_allocated_write_caches,
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profile_p->writecache_num_write_caches,
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profile_p->writecache_direct_writes,
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profile_p->writecache_num_perfect_writes,
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profile_p->writecache_read_hits ));
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DEBUG(3,("WRITECACHE: Flushes SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
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profile_p->writecache_flushed_writes[SEEK_FLUSH],
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profile_p->writecache_flushed_writes[READ_FLUSH],
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profile_p->writecache_flushed_writes[WRITE_FLUSH],
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profile_p->writecache_flushed_writes[READRAW_FLUSH],
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profile_p->writecache_flushed_writes[OPLOCK_RELEASE_FLUSH],
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profile_p->writecache_flushed_writes[CLOSE_FLUSH],
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profile_p->writecache_flushed_writes[SYNC_FLUSH] ));
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}
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#endif
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if (wcp && req->unread_bytes) {
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/* If we're using receivefile don't
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* deal with a write cache.
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*/
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flush_write_cache(fsp, WRITE_FLUSH);
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delete_write_cache(fsp);
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wcp = NULL;
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}
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if(!wcp) {
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DO_PROFILE_INC(writecache_direct_writes);
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total_written = real_write_file(req, fsp, data, pos, n);
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return total_written;
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}
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DEBUG(9,("write_file (%s)(fd=%d pos=%.0f size=%u) wcp->offset=%.0f "
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"wcp->data_size=%u\n", fsp_str_dbg(fsp), fsp->fh->fd,
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(double)pos, (unsigned int)n, (double)wcp->offset,
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(unsigned int)wcp->data_size));
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fsp->fh->pos = pos + n;
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if ((n == 1) && (data[0] == '\0') && (pos > wcp->file_size)) {
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int ret;
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/*
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* This is a 1-byte write of a 0 beyond the EOF and
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* thus implicitly also beyond the current active
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* write cache, the typical file-extending (and
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* allocating, but we're using the write cache here)
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* write done by Windows. We just have to ftruncate
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* the file and rely on posix semantics to return
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* zeros for non-written file data that is within the
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* file length.
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*
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* We can not use wcp_file_size_change here because we
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* might have an existing write cache, and
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* wcp_file_size_change assumes a change to just the
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* end of the current write cache.
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*/
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wcp->file_size = pos + 1;
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ret = SMB_VFS_FTRUNCATE(fsp, wcp->file_size);
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if (ret == -1) {
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DEBUG(0,("wcp_file_size_change (%s): ftruncate of size %.0f"
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"error %s\n", fsp_str_dbg(fsp),
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(double)wcp->file_size, strerror(errno)));
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return -1;
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}
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return 1;
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}
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/*
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* If we have active cache and it isn't contiguous then we flush.
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* NOTE: There is a small problem with running out of disk ....
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*/
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if (wcp->data_size) {
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bool cache_flush_needed = False;
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if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) {
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/* ASCII art.... JRA.
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+--------------+-----
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| Cached data | Rest of allocated cache buffer....
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+--------------+-----
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+-------------------+
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| Data to write |
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+-------------------+
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*/
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/*
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* Start of write overlaps or abutts the existing data.
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*/
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size_t data_used = MIN((wcp->alloc_size - (pos - wcp->offset)), n);
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memcpy(wcp->data + (pos - wcp->offset), data, data_used);
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/*
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* Update the current buffer size with the new data.
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*/
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if(pos + data_used > wcp->offset + wcp->data_size) {
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wcp->data_size = pos + data_used - wcp->offset;
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}
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/*
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* Update the file size if changed.
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*/
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if (wcp->offset + wcp->data_size > wcp->file_size) {
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if (wcp_file_size_change(fsp) == -1) {
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return -1;
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}
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}
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/*
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* If we used all the data then
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* return here.
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*/
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if(n == data_used) {
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return n;
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} else {
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cache_flush_needed = True;
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}
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/*
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* Move the start of data forward by the amount used,
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* cut down the amount left by the same amount.
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*/
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data += data_used;
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pos += data_used;
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n -= data_used;
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DO_PROFILE_INC(writecache_abutted_writes);
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total_written = data_used;
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write_path = 1;
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} else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
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(pos + n <= wcp->offset + wcp->alloc_size)) {
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|
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/* ASCII art.... JRA.
|
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|
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+---------------+
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| Cache buffer |
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+---------------+
|
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+-------------------+
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| Data to write |
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+-------------------+
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*/
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/*
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* End of write overlaps the existing data.
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*/
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size_t data_used = pos + n - wcp->offset;
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|
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memcpy(wcp->data, data + n - data_used, data_used);
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/*
|
|
* Update the current buffer size with the new data.
|
|
*/
|
|
|
|
if(pos + n > wcp->offset + wcp->data_size) {
|
|
wcp->data_size = pos + n - wcp->offset;
|
|
}
|
|
|
|
/*
|
|
* Update the file size if changed.
|
|
*/
|
|
|
|
if (wcp->offset + wcp->data_size > wcp->file_size) {
|
|
if (wcp_file_size_change(fsp) == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We don't need to move the start of data, but we
|
|
* cut down the amount left by the amount used.
|
|
*/
|
|
|
|
n -= data_used;
|
|
|
|
/*
|
|
* We cannot have used all the data here.
|
|
*/
|
|
|
|
cache_flush_needed = True;
|
|
|
|
DO_PROFILE_INC(writecache_abutted_writes);
|
|
total_written = data_used;
|
|
|
|
write_path = 2;
|
|
|
|
} else if ( (pos >= wcp->file_size) &&
|
|
(wcp->offset + wcp->data_size == wcp->file_size) &&
|
|
(pos > wcp->offset + wcp->data_size) &&
|
|
(pos < wcp->offset + wcp->alloc_size) ) {
|
|
|
|
/* ASCII art.... JRA.
|
|
|
|
End of file ---->|
|
|
|
|
+---------------+---------------+
|
|
| Cached data | Cache buffer |
|
|
+---------------+---------------+
|
|
|
|
+-------------------+
|
|
| Data to write |
|
|
+-------------------+
|
|
|
|
*/
|
|
|
|
/*
|
|
* Non-contiguous write part of which fits within
|
|
* the cache buffer and is extending the file
|
|
* and the cache contents reflect the current
|
|
* data up to the current end of the file.
|
|
*/
|
|
|
|
size_t data_used;
|
|
|
|
if(pos + n <= wcp->offset + wcp->alloc_size) {
|
|
data_used = n;
|
|
} else {
|
|
data_used = wcp->offset + wcp->alloc_size - pos;
|
|
}
|
|
|
|
/*
|
|
* Fill in the non-continuous area with zeros.
|
|
*/
|
|
|
|
memset(wcp->data + wcp->data_size, '\0',
|
|
pos - (wcp->offset + wcp->data_size) );
|
|
|
|
memcpy(wcp->data + (pos - wcp->offset), data, data_used);
|
|
|
|
/*
|
|
* Update the current buffer size with the new data.
|
|
*/
|
|
|
|
if(pos + data_used > wcp->offset + wcp->data_size) {
|
|
wcp->data_size = pos + data_used - wcp->offset;
|
|
}
|
|
|
|
/*
|
|
* Update the file size if changed.
|
|
*/
|
|
|
|
if (wcp->offset + wcp->data_size > wcp->file_size) {
|
|
if (wcp_file_size_change(fsp) == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we used all the data then
|
|
* return here.
|
|
*/
|
|
|
|
if(n == data_used) {
|
|
return n;
|
|
} else {
|
|
cache_flush_needed = True;
|
|
}
|
|
|
|
/*
|
|
* Move the start of data forward by the amount used,
|
|
* cut down the amount left by the same amount.
|
|
*/
|
|
|
|
data += data_used;
|
|
pos += data_used;
|
|
n -= data_used;
|
|
|
|
DO_PROFILE_INC(writecache_abutted_writes);
|
|
total_written = data_used;
|
|
|
|
write_path = 3;
|
|
|
|
} else if ( (pos >= wcp->file_size) &&
|
|
(n == 1) &&
|
|
(wcp->file_size == wcp->offset + wcp->data_size) &&
|
|
(pos < wcp->file_size + wcp->alloc_size)) {
|
|
|
|
/*
|
|
|
|
End of file ---->|
|
|
|
|
+---------------+---------------+
|
|
| Cached data | Cache buffer |
|
|
+---------------+---------------+
|
|
|
|
|<------- allocated size ---------------->|
|
|
|
|
+--------+
|
|
| 1 Byte |
|
|
+--------+
|
|
|
|
MS-Office seems to do this a lot to determine if there's enough
|
|
space on the filesystem to write a new file.
|
|
|
|
Change to :
|
|
|
|
End of file ---->|
|
|
+-----------------------+--------+
|
|
| Zeroed Cached data | 1 Byte |
|
|
+-----------------------+--------+
|
|
*/
|
|
|
|
flush_write_cache(fsp, WRITE_FLUSH);
|
|
wcp->offset = wcp->file_size;
|
|
wcp->data_size = pos - wcp->file_size + 1;
|
|
memset(wcp->data, '\0', wcp->data_size);
|
|
memcpy(wcp->data + wcp->data_size-1, data, 1);
|
|
|
|
/*
|
|
* Update the file size if changed.
|
|
*/
|
|
|
|
if (wcp->offset + wcp->data_size > wcp->file_size) {
|
|
if (wcp_file_size_change(fsp) == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
return n;
|
|
|
|
} else {
|
|
|
|
/* ASCII art..... JRA.
|
|
|
|
Case 1).
|
|
|
|
+---------------+---------------+
|
|
| Cached data | Cache buffer |
|
|
+---------------+---------------+
|
|
|
|
+-------------------+
|
|
| Data to write |
|
|
+-------------------+
|
|
|
|
Case 2).
|
|
|
|
+---------------+---------------+
|
|
| Cached data | Cache buffer |
|
|
+---------------+---------------+
|
|
|
|
+-------------------+
|
|
| Data to write |
|
|
+-------------------+
|
|
|
|
Case 3).
|
|
|
|
+---------------+---------------+
|
|
| Cached data | Cache buffer |
|
|
+---------------+---------------+
|
|
|
|
+-----------------------------------------------------+
|
|
| Data to write |
|
|
+-----------------------------------------------------+
|
|
|
|
*/
|
|
|
|
/*
|
|
* Write is bigger than buffer, or there is no overlap on the
|
|
* low or high ends.
|
|
*/
|
|
|
|
DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
|
|
len = %u\n",fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
|
|
|
|
/*
|
|
* If write would fit in the cache, and is larger than
|
|
* the data already in the cache, flush the cache and
|
|
* preferentially copy the data new data into it. Otherwise
|
|
* just write the data directly.
|
|
*/
|
|
|
|
if ( n <= wcp->alloc_size && n > wcp->data_size) {
|
|
cache_flush_needed = True;
|
|
} else {
|
|
ssize_t ret = real_write_file(NULL,fsp, data, pos, n);
|
|
|
|
/*
|
|
* If the write overlaps the entire cache, then
|
|
* discard the current contents of the cache.
|
|
* Fix from Rasmus Borup Hansen rbh@math.ku.dk.
|
|
*/
|
|
|
|
if ((pos <= wcp->offset) &&
|
|
(pos + n >= wcp->offset + wcp->data_size) ) {
|
|
DEBUG(9,("write_file: discarding overwritten write \
|
|
cache: fd = %d, off=%.0f, size=%u\n", fsp->fh->fd, (double)wcp->offset, (unsigned int)wcp->data_size ));
|
|
wcp->data_size = 0;
|
|
}
|
|
|
|
DO_PROFILE_INC(writecache_direct_writes);
|
|
if (ret == -1) {
|
|
return ret;
|
|
}
|
|
|
|
if (pos + ret > wcp->file_size) {
|
|
wcp->file_size = pos + ret;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
write_path = 4;
|
|
|
|
}
|
|
|
|
if (cache_flush_needed) {
|
|
DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
|
|
n = %u, wcp->offset=%.0f, wcp->data_size=%u\n",
|
|
write_path, fsp->fh->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
|
|
(double)wcp->offset, (unsigned int)wcp->data_size ));
|
|
|
|
flush_write_cache(fsp, WRITE_FLUSH);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If the write request is bigger than the cache
|
|
* size, write it all out.
|
|
*/
|
|
|
|
if (n > wcp->alloc_size ) {
|
|
ssize_t ret = real_write_file(NULL,fsp, data, pos, n);
|
|
if (ret == -1) {
|
|
return -1;
|
|
}
|
|
|
|
if (pos + ret > wcp->file_size) {
|
|
wcp->file_size = pos + n;
|
|
}
|
|
|
|
DO_PROFILE_INC(writecache_direct_writes);
|
|
return total_written + n;
|
|
}
|
|
|
|
/*
|
|
* If there's any data left, cache it.
|
|
*/
|
|
|
|
if (n) {
|
|
#ifdef WITH_PROFILE
|
|
if (wcp->data_size) {
|
|
DO_PROFILE_INC(writecache_abutted_writes);
|
|
} else {
|
|
DO_PROFILE_INC(writecache_init_writes);
|
|
}
|
|
#endif
|
|
|
|
if ((wcp->data_size == 0)
|
|
&& (pos > wcp->file_size)
|
|
&& (pos + n <= wcp->file_size + wcp->alloc_size)) {
|
|
/*
|
|
* This is a write completely beyond the
|
|
* current EOF, but within reach of the write
|
|
* cache. We expect fill-up writes pretty
|
|
* soon, so it does not make sense to start
|
|
* the write cache at the current
|
|
* offset. These fill-up writes would trigger
|
|
* separate pwrites or even unnecessary cache
|
|
* flushes because they overlap if this is a
|
|
* one-byte allocating write.
|
|
*/
|
|
wcp->offset = wcp->file_size;
|
|
wcp->data_size = pos - wcp->file_size;
|
|
memset(wcp->data, 0, wcp->data_size);
|
|
}
|
|
|
|
memcpy(wcp->data+wcp->data_size, data, n);
|
|
if (wcp->data_size == 0) {
|
|
wcp->offset = pos;
|
|
DO_PROFILE_INC(writecache_num_write_caches);
|
|
}
|
|
wcp->data_size += n;
|
|
|
|
/*
|
|
* Update the file size if changed.
|
|
*/
|
|
|
|
if (wcp->offset + wcp->data_size > wcp->file_size) {
|
|
if (wcp_file_size_change(fsp) == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
DEBUG(9,("wcp->offset = %.0f wcp->data_size = %u cache return %u\n",
|
|
(double)wcp->offset, (unsigned int)wcp->data_size, (unsigned int)n));
|
|
|
|
total_written += n;
|
|
return total_written; /* .... that's a write :) */
|
|
}
|
|
|
|
return total_written;
|
|
}
|
|
|
|
/****************************************************************************
|
|
Delete the write cache structure.
|
|
****************************************************************************/
|
|
|
|
void delete_write_cache(files_struct *fsp)
|
|
{
|
|
struct write_cache *wcp;
|
|
|
|
if(!fsp) {
|
|
return;
|
|
}
|
|
|
|
if(!(wcp = fsp->wcp)) {
|
|
return;
|
|
}
|
|
|
|
DO_PROFILE_DEC(writecache_allocated_write_caches);
|
|
allocated_write_caches--;
|
|
|
|
SMB_ASSERT(wcp->data_size == 0);
|
|
|
|
SAFE_FREE(wcp->data);
|
|
SAFE_FREE(fsp->wcp);
|
|
|
|
DEBUG(10,("delete_write_cache: File %s deleted write cache\n",
|
|
fsp_str_dbg(fsp)));
|
|
}
|
|
|
|
/****************************************************************************
|
|
Setup the write cache structure.
|
|
****************************************************************************/
|
|
|
|
static bool setup_write_cache(files_struct *fsp, off_t file_size)
|
|
{
|
|
ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
|
|
struct write_cache *wcp;
|
|
|
|
if (allocated_write_caches >= MAX_WRITE_CACHES) {
|
|
return False;
|
|
}
|
|
|
|
if(alloc_size == 0 || fsp->wcp) {
|
|
return False;
|
|
}
|
|
|
|
if((wcp = SMB_MALLOC_P(struct write_cache)) == NULL) {
|
|
DEBUG(0,("setup_write_cache: malloc fail.\n"));
|
|
return False;
|
|
}
|
|
|
|
wcp->file_size = file_size;
|
|
wcp->offset = 0;
|
|
wcp->alloc_size = alloc_size;
|
|
wcp->data_size = 0;
|
|
if((wcp->data = (char *)SMB_MALLOC(wcp->alloc_size)) == NULL) {
|
|
DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
|
|
(unsigned int)wcp->alloc_size ));
|
|
SAFE_FREE(wcp);
|
|
return False;
|
|
}
|
|
|
|
memset(wcp->data, '\0', wcp->alloc_size );
|
|
|
|
fsp->wcp = wcp;
|
|
DO_PROFILE_INC(writecache_allocated_write_caches);
|
|
allocated_write_caches++;
|
|
|
|
DEBUG(10,("setup_write_cache: File %s allocated write cache size %lu\n",
|
|
fsp_str_dbg(fsp), (unsigned long)wcp->alloc_size));
|
|
|
|
return True;
|
|
}
|
|
|
|
/****************************************************************************
|
|
Cope with a size change.
|
|
****************************************************************************/
|
|
|
|
void set_filelen_write_cache(files_struct *fsp, off_t file_size)
|
|
{
|
|
if(fsp->wcp) {
|
|
/* The cache *must* have been flushed before we do this. */
|
|
if (fsp->wcp->data_size != 0) {
|
|
char *msg;
|
|
if (asprintf(&msg, "set_filelen_write_cache: size change "
|
|
"on file %s with write cache size = %lu\n",
|
|
fsp->fsp_name->base_name,
|
|
(unsigned long)fsp->wcp->data_size) != -1) {
|
|
smb_panic(msg);
|
|
} else {
|
|
smb_panic("set_filelen_write_cache");
|
|
}
|
|
}
|
|
fsp->wcp->file_size = file_size;
|
|
}
|
|
}
|
|
|
|
/*******************************************************************
|
|
Flush a write cache struct to disk.
|
|
********************************************************************/
|
|
|
|
ssize_t flush_write_cache(files_struct *fsp, enum flush_reason_enum reason)
|
|
{
|
|
struct write_cache *wcp = fsp->wcp;
|
|
size_t data_size;
|
|
ssize_t ret;
|
|
|
|
if(!wcp || !wcp->data_size) {
|
|
return 0;
|
|
}
|
|
|
|
data_size = wcp->data_size;
|
|
wcp->data_size = 0;
|
|
|
|
DO_PROFILE_DEC_INC(writecache_num_write_caches,writecache_flushed_writes[reason]);
|
|
|
|
DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
|
|
fsp->fh->fd, (double)wcp->offset, (unsigned int)data_size));
|
|
|
|
#ifdef WITH_PROFILE
|
|
if(data_size == wcp->alloc_size) {
|
|
DO_PROFILE_INC(writecache_num_perfect_writes);
|
|
}
|
|
#endif
|
|
|
|
ret = real_write_file(NULL, fsp, wcp->data, wcp->offset, data_size);
|
|
|
|
/*
|
|
* Ensure file size if kept up to date if write extends file.
|
|
*/
|
|
|
|
if ((ret != -1) && (wcp->offset + ret > wcp->file_size)) {
|
|
wcp->file_size = wcp->offset + ret;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*******************************************************************
|
|
sync a file
|
|
********************************************************************/
|
|
|
|
NTSTATUS sync_file(connection_struct *conn, files_struct *fsp, bool write_through)
|
|
{
|
|
if (fsp->fh->fd == -1)
|
|
return NT_STATUS_INVALID_HANDLE;
|
|
|
|
if (lp_strict_sync(SNUM(conn)) &&
|
|
(lp_syncalways(SNUM(conn)) || write_through)) {
|
|
int ret = flush_write_cache(fsp, SYNC_FLUSH);
|
|
if (ret == -1) {
|
|
return map_nt_error_from_unix(errno);
|
|
}
|
|
ret = SMB_VFS_FSYNC(fsp);
|
|
if (ret == -1) {
|
|
return map_nt_error_from_unix(errno);
|
|
}
|
|
}
|
|
return NT_STATUS_OK;
|
|
}
|
|
|
|
/************************************************************
|
|
Perform a stat whether a valid fd or not.
|
|
************************************************************/
|
|
|
|
int fsp_stat(files_struct *fsp)
|
|
{
|
|
if (fsp->fh->fd == -1) {
|
|
if (fsp->posix_open) {
|
|
return SMB_VFS_LSTAT(fsp->conn, fsp->fsp_name);
|
|
} else {
|
|
return SMB_VFS_STAT(fsp->conn, fsp->fsp_name);
|
|
}
|
|
} else {
|
|
return SMB_VFS_FSTAT(fsp, &fsp->fsp_name->st);
|
|
}
|
|
}
|