source: trunk/server/source4/ntvfs/posix/pvfs_write.c

/* 
   Unix SMB/CIFS implementation.

   POSIX NTVFS backend - write

   Copyright (C) Andrew Tridgell 2004

   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 "vfs_posix.h"
#include "librpc/gen_ndr/security.h"
#include "lib/events/events.h"

static void pvfs_write_time_update_handler(struct tevent_context *ev,
                                           struct tevent_timer *te,
                                           struct timeval tv,
                                           void *private_data)
{
        struct pvfs_file_handle *h = talloc_get_type(private_data,
                                     struct pvfs_file_handle);
        struct odb_lock *lck;
        NTSTATUS status;
        NTTIME write_time;

        lck = odb_lock(h, h->pvfs->odb_context, &h->odb_locking_key);
        if (lck == NULL) {
                DEBUG(0,("Unable to lock opendb for write time update\n"));
                return;
        }

        write_time = timeval_to_nttime(&tv);

        status = odb_set_write_time(lck, write_time, false);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0,("Unable to update write time: %s\n",
                        nt_errstr(status)));
                return;
        }

        talloc_free(lck);

        h->write_time.update_event = NULL;
}

static void pvfs_trigger_write_time_update(struct pvfs_file_handle *h)
{
        struct pvfs_state *pvfs = h->pvfs;
        struct timeval tv;

        if (h->write_time.update_triggered) {
                return;
        }

        tv = timeval_current_ofs(0, pvfs->writetime_delay);

        h->write_time.update_triggered = true;
        h->write_time.update_on_close = true;
        h->write_time.update_event = event_add_timed(pvfs->ntvfs->ctx->event_ctx,
                                                     h, tv,
                                                     pvfs_write_time_update_handler,
                                                     h);
        if (!h->write_time.update_event) {
                DEBUG(0,("Failed event_add_timed\n"));
        }
}

/*
  write to a file
*/
NTSTATUS pvfs_write(struct ntvfs_module_context *ntvfs,
                    struct ntvfs_request *req, union smb_write *wr)
{
        struct pvfs_state *pvfs = talloc_get_type(ntvfs->private_data,
                                  struct pvfs_state);
        ssize_t ret;
        struct pvfs_file *f;
        NTSTATUS status;

        if (wr->generic.level != RAW_WRITE_WRITEX) {
                return ntvfs_map_write(ntvfs, req, wr);
        }

        f = pvfs_find_fd(pvfs, req, wr->writex.in.file.ntvfs);
        if (!f) {
                return NT_STATUS_INVALID_HANDLE;
        }

        if (f->handle->fd == -1) {
                return NT_STATUS_INVALID_DEVICE_REQUEST;
        }

        if (!(f->access_mask & (SEC_FILE_WRITE_DATA | SEC_FILE_APPEND_DATA))) {
                return NT_STATUS_ACCESS_DENIED;
        }

        status = pvfs_check_lock(pvfs, f, req->smbpid, 
                                 wr->writex.in.offset,
                                 wr->writex.in.count,
                                 WRITE_LOCK);
        NT_STATUS_NOT_OK_RETURN(status);

        status = pvfs_break_level2_oplocks(f);
        NT_STATUS_NOT_OK_RETURN(status);

        pvfs_trigger_write_time_update(f->handle);

        if (f->handle->name->stream_name) {
                ret = pvfs_stream_write(pvfs,
                                        f->handle,
                                        wr->writex.in.data, 
                                        wr->writex.in.count,
                                        wr->writex.in.offset);
        } else {
#if HAVE_LINUX_AIO
                /* possibly try an aio write */
                if ((req->async_states->state & NTVFS_ASYNC_STATE_MAY_ASYNC) &&
                    (pvfs->flags & PVFS_FLAG_LINUX_AIO)) {
                        status = pvfs_aio_pwrite(req, wr, f);
                        if (NT_STATUS_IS_OK(status)) {
                                return NT_STATUS_OK;
                        }
                }
#endif
                ret = pwrite(f->handle->fd, 
                             wr->writex.in.data, 
                             wr->writex.in.count,
                             wr->writex.in.offset);
        }
        if (ret == -1) {
                if (errno == EFBIG) {
                        return NT_STATUS_INVALID_PARAMETER;
                }
                return pvfs_map_errno(pvfs, errno);
        }

        f->handle->seek_offset = wr->writex.in.offset + ret;
        
        wr->writex.out.nwritten = ret;
        wr->writex.out.remaining = 0; /* should fill this in? */

        return NT_STATUS_OK;
}